AF 447 Thread No. 12 [Archive] - Page 4

PJ2

9th Nov 2014, 14:51

Re, "and try to figure why one airline does this and one airline does that."

Now that's a question.

In a word, the manufacturer has no actual authority over what airlines do with their airplanes or how they fly them. The manufacturer writes what it considers the operating procedures for their product. Airlines are free, within a country's regulations, to change the procedures as they wish. They are of course accountable for such changes but the notion of "accountable" is often freely interpreted.

Most stick to "the book" and make small modifications. Some increase "guidance", and some simplifiy it. Line flying proves the procedures and it's why at an airline these things never stay the same...change is the only constant at most carriers, as learning from incidents and even accidents takes place.

Practically speaking however, an airline isn't free to radically alter the manufacturer's operating instructions, not, at least, without placing itself at risk should something occur. But some crazy things do emerge from airline folks who believe they know best...

Individual incidents and seeing how such incidents enable change is interesting enough and well understood within the industry but it's well worth finding some of the authors known for producing good work on flight safety to understand how the process works; for example, Charles Perrow, Sidney Dekker, Tony Kern, Robert Helmreich, Earl Weiner, the publications of the Flight Safety Foundation, the NTSB, (look up NTSB Docket). Such work has been used in the healthcare industry and also in medicine in recognizing that "human factors" aren't limited to only one industry which has risk associated with it.

At times, some modifications by one carrier might not make clear sense to another, or to many others. But the requirement to conform closely either to others or to the OEM SOPs doesn't exist even as the results may themselves be similar.

Such modifications are often positive, as many airlines have more experience operating a manufacturer's aircraft than the manufacturer does - the manufacturer must get the product certified according to standards already discussed here and elsewhere. The airlines must teach its pilots to operate the airplane safely and within the regulatory environment.

TurbineD;

Re, "Information was available to airbus pilots explaining UAS as resulting from pitot tube icing starting with the A-300-600:"

Absolutely correct.

I see now that even the QRH UAS memory item in the above drill to increase pitch to 5° when above FL100 is being questioned and instead indicating that no change in pitch and power should occur during the drill.

However, the "do nothing, maintain pitch and power" response by the crew was already in place in some flight crew training manuals and presentations which provided instructions on how to handle the procedure when the "safe conduct of the flight is not impacted", which it is not in stable, level flight at cruise altitude.

As you know I've maintained from the time we knew what transpired that the UAS drill was confusing and misleading if followed "precisely" - but thirty other crews knew what would happen to the airplane and it made no sense whatsoever to pitch the airplane up at all...just keep doing what it was doing prior to the failure of the pitot, and, as you point out, the airspeed information returns to normal, (as AF447's did, within about 50"). I subsequently found the Airbus presentation cited below which makes this clear.

First, from a number of FCTMs:

http://www.smugmug.com/photos/i-j7jzQD5/0/X2/i-j7jzQD5-X2.jpg ->>>>>> enlarged printing ->>>http://www.smugmug.com/photos/i-hvNcXRD/0/XL/i-hvNcXRD-XL.jpg

From an Airbus presentation in 2006 (http://home.base.be/fabrot31/airbusunreliablespeeds.pdf) on the UAS issue:

http://www.smugmug.com/photos/i-qKJxgsR/0/XL/i-qKJxgsR-XL.jpg->>>>>>>>>from the same document->>>>>>>http://www.smugmug.com/photos/i-cSg54hf/0/XL/i-cSg54hf-XL.jpg

DozyWannabe

11th Nov 2014, 17:14

SR111 is an interesting comparison with AF447.
SR111 went by the book whilst AF447 forgot the book yet both ended in tragedy.
Knowing what you can ignore is as almost as important as knowing what you need to pay attention to.
Hmm... I think while there's a general point to be made there, I'm not sure about the specifics.

As I understand it, the deal with SR111 was that "the book" was inadequate for purpose. Not in the same sense as AF447, where it appears AF were somewhat lackadaisical about passing Airbus's UAS addenda on to crews - but from the very beginning at MD. (emphasis mine) :

A review of several checklists showed a lack of emphasis on treating any amount of smoke in an aircraft as a serious fire threat. For example, neither the Swissair nor the McDonnell Douglas Smoke of Unknown Origin Checklist stipulated that preparations for a possible emergency landing should be considered immediately when smoke of unknown origin appears. Rather, on both versions, the reference to landing is the last action item on the checklist. Similarly, the Swissair guidance provided to flight crews was that the aircraft was to land at the nearest emergency airport if smoke of unknown origin was "persistent."

If I recall correctly, I think it did become something of a moot point because at the rate the fire propagated, even if they'd gone for a straight-in at Halifax when the smoke first appeared, they would not have had enough time to make it to the runway.

The crucial difference between SR111 and AF447 is that the former crew were faced with an aircraft which was going to depart controlled flight anyway - and quickly - due to the fire damage, whereas AF447's crew had an aircraft which - despite a transitory problem - was quite capable of staying in the air with little or no crew interference.

noske

14th Nov 2014, 08:38

If I recall correctly, I think it did become something of a moot point because at the rate the fire propagated, even if they'd gone for a straight-in at Halifax when the smoke first appeared, they would not have had enough time to make it to the runway.

A few years ago, there was a guest article in AeroSafetyWorld by a smoke/fire/fumes expert who tried several diversion scenarios in an MD-11 simulator. He more or less consistently achieved a safe landing at Halifax about 5 minutes before the time when the real aircraft struck the water. Or in other words, about the same time when their various systems started failing. Draw your own conclusions.

http://www.flightsafety.org/asw/oct09/asw_oct09_p16-17.pdf?dl=1
http://www.tsb.gc.ca/eng/rapports-reports/aviation/1998/a98h0003/01report/visual_library/images/appa_flightprofile.jpg

I hate fire.

gums

16th Nov 2014, 01:14

Do not know how this is getting on this thread.

One crew knew they had a problem and did their best ( up to/ me, I would have tried to land ASAP and screw the dumping then take chances skidding off other end of the runway.) Other crew could not comprehend that the jet would fail to protect them. At the end, one dude said they were trying to climb and the plane was not responding. Duh.......

Many of us on this forum have had bad things happen to our jets. The big lesson is to know as much as you can about the plane and do not do something stoopid. The poor folks on the Swiss jet did not appreciate how bad and how fast the electrical fire would proceed.

The one crash that touches my soul is the ValueJet prang. Sheesh. Control cables burning out, fumes in cockpit and pax cabin, and ....... Oh well.

PJ2

16th Nov 2014, 16:16

Hi gums;

The thread went this way because someone compared the AF447s crews' actions with SW111's.

Your post clarifies the difference between hindsight bias and understanding what actually went on in the cockpit of SW111.

I think it is important for some here to understand that the question itself, (Could they have made Halifax?), is natural enough and a good one to ask but that it is important to distinguish between the question and a creeping hindsight bias regarding the SW111 crew and their actions.

There really is no meaningful comparison between the two which can teach us something. But the opportunity to discuss why I think this is so can and does provide some lessons.

First, the Canadian TSB's Report into the Swissair 111 accident (http://www.tsb.gc.ca/eng/rapports-reports/aviation/1998/a98h0003/a98h0003.asp) is one of the finest investigative reports ever written. It sets a gold standard for how such reports should be done, and is well worth reading or re-reading.

Second, the Swissair crews' actions did not occur in a vacuum. There is a great deal of industry history behind the the actions the SW111 crew took. We can't even isolate the question without limiting ourselves to understanding the lessons that the accident ultimately had to teach the industry.

Some history...

From very early on (introduction of the jet transport in the late 50's), when smoke in the cockpit occurred, the drill was for "Smoke of Unknown Origin". After donning O2 masks etc., the "Smoke of Uknown Origin" drill for the DC8 and on other types was to troubleshoot, not land asap.

For the '8, we shut of one generator at a time to see if the smoke abated. The drill might take fifteen minutes. Then we'd do the air conditioning smoke drill if that didn't "work". Later, the drills were given a starting decision point regarding the "kind" of smoke...electrical or air conditioning, (essentially, was it arcing or oil sourced?...).

No crew ever thought to land the airplane first - or at least if they did and survived, it was certain that the first question asked would be, "Did you go through the smoke drill?". I know of at least one case where upon smelling smoke of unknown origin a crew did descend first and land. The company involved disciplined the captain for his actions - (gee, could it have had to do with embarrassing the company?). It turned out that the smoke was from one of the crewmember's cigarette butt that had dropped off and was smouldering on his seatbelt, (does anyone here remember when everyone smoked on board?!...even those in the "non-smoking" section?)...I can recall the cockpit blue with smoke while crossing the Atlantic - cigars, cigarettes, pipes. The nicotine stain was not only on many fingers, it was a long, brown streak along the fuselage behind the pressurization outlet door. Maintenance said many of the pressurization problems they had to deal with were with the sticking of these doors from the nicotine "goo" in the linkage...more history.

That was then and now is now. That needs to be understood by some, before coming to some conclusions. ;-)

Today, no crew in their "right minds" would hesitate to descend and land the airplane first. But that industry mentality only changed, and slowly, as a result of Swissair 111. The drill is to Land ASAP, while donning masks in the cockpit, (the masks are generally not deployed in the cabin), descending, and possibly troubleshooting on the way down.

You're absolutely right about "know the airplane", and that too has a history, and a sad one in my view. The value of "knowing", vice button-pushing automation has yet to be fully understood.

To return attention to AF447's crew and the thread topic, I think there is more in common between them and the crew of Colgan's Flight 3407 Q400 accident crew at Buffalo, N.Y. The First Officer was pretty new but, like all new pilots, hadn't been mentored into the profession but simply passed the checkrides and had the licenses. Mentoring is expensive, difficult to measure and therefore difficult to implement and sustain because the attitudes of airline managements at the time, partly driven by tremendous economic uncertainties and partly through ignorance, (no airline manager reads accident reports...it seems to be "against the religion"), considered the bare minimum qualification standards as acceptable. In both accidents, there are good reasons to say that this is not true.

Neither the F/O at Colgan nor the F/O's at Air France really "knew their stuff" and it wasn't entirely their fault. As I have written on the original threads, the Colgan F/O was "an innocent", earning US$16,000 a year, who's airline and who's captain in this case failed her in "bringing her along" in the profession. I don't think this is too broad a brush when it comes to adapting to the changes that have occurred to the profession since the early 70's. In many ways our knowledge of human factors is far better than then, but the citing of such factors in accident reports hasn't been able to change the industry.

The industry had shifted its attitudes towards pilots and pilot training and particularly the profession itself of which pilot associations were very slow to guard and sustain.

The pay and the status of "airline pilot" had plummeted (and is still there, where the industry put it), and people naturally respond to how they are treated. Sullenberger certainly understood the problem and said so to Congress (https://www.youtube.com/watch?v=8kePiiZ8_YA) soon after the Colgan accident, (but before AF447).

These days, how many, and how often do airline pilots hit the books in their free time? How many actually have the time to do so? How many regularly seek out and read accident reports? How many could carry on a discussion on basic aerodynamics, of high altitude flight, of the complexities of weather, of human factors and the realities of automation? How many are encouraged by "their elders" to do all this?

All this is in keeping with how a profession is defined - by expectations of self-governing behaviour, by a constant learning and by upholding standards in the face of those with different agendas and goals for your profession.

"Change is the only constant", is one way to assess how the commercial air transport industry treats flight crews; but the industry must also acknowledge that the principles of aviation, in terms of staying alive, do not change. I sense the industry has turned the corner on this but it has a long way to go, including attracting a steady stream of good candidates and teaching them well.

I think that is the historical lesson of AF447 and of Colgan. I think SW111's lessons are now well understood and already incorporated into the industry's and flight crews' collective mentality.

Sorry for the long post.

jcjeant

16th Nov 2014, 18:43

How many could carry on a discussion on basic aerodynamics, of high altitude flight, of the complexities of weather, of human factors and the realities of automation? How many are encouraged by "their elders" to do all this?Discussion like in another time

http://i.imgur.com/OUJcsjx.jpg

PJ2

16th Nov 2014, 18:52

WH;

Paying flight crews what any highly-skilled professional is paid does not make for "safer" operations.

What paying well does do however is attract those with the passion, the capacity, the talent, the discipline, and the resources to put into such a profession.

Our profession must compete with other professions which require similar capabilities from their new candidates and entrants. The medical and engineering professions are closely related to the profession of airline pilot in that they all have great capability to do real harm when not done well.

Although some may argue the case, the legal, education and dentistry professions require similar capabilities but do not have the same risks tightly-associated with poor work by the incapable or the incompetent.

I am by no means convinced that the MCP license and cadet programs are the answer. Though it may be effective on the surface, cookie-cutter thinking isn't a survival tool in aviation, it is a counter-liability tool first. Standards have degraded because most of the original problems associated with high-risk and high accident rates have been conquered. The naive thinking is that less skill is required thereby. Aviation is disproving that belief. After the dramatic drops in fatal accident rates and hull losses in the 50s, 60s and early 70s, the accident rate today remains steady though extremely low. The argument has been that if the percentage remains the same, then an increase in traffic is going to increase the number of fatal accidents and that isn't good enough.

Some companies are sufficiently enlightened to start flight crew remuneration back up to previous levels to attract a still-dwindling pool of suitable aircrew candidates. Others are going to have to settle for second-best and worse, unless the profession is made more attractive to those who would take their skills, talent and intelligence elsewhere.

gums

16th Nov 2014, 20:23

Ahhhh, I missed Galland by a few days when reporting in at Hill AFB in June of 1979 to join the first F-16 squadron in the world. He was touring with a Brit that had flown in the Battle of Britain. He signed our bar in the rec room and we used his quote for our official picture done by the Waki brothers - The Spirit of Attack. " Only the spirit of attack born in a brave heart will bring success to any fighter aircraft no matter how highly developed it may be."

see: Spirit of Attack (http://www.markwaki.com/pages/Spirit%20of%20Attack.htm)

As romantic as Galland's quote may sound, I am convinced that it applies to commercial pilots as well. We all became "system monitors and users" as the technology marched on, but the end game always depended upon our personal skill, knowledge, judgement and "hands". We few at the leading edge of technology in the military saw it sooner than the commercial folks. We adapted and we changed our instruction of new pilots. I was there as an IP from the WW2-like A-37 training squad to the A-7D and then the F-16. Helluva ride, gotta tellya.

I cried reading the reports of the ValueJet fire and the Swiss crash and the cargo fire in the sandbox. Then I recall my buddy's crash at Cali almost 20 years ago. The AF 447 debacle really hit a strong vibe, and I began to worry about the crews as much as the aircraft in some respects.

I am glad to see some changes in the emergency procedures and some emphasis upon the "boldface" that we military folks memorized. You know, "fire light", "engine stalls", "system "x" fails" and so on.

@PJ

One thing we learned early in the Viper was not to be a test pilot ( although we all "were" and discovered new and exciting things the engineers and such never imagined, heh heh). In other words, no trouble shooting, but get the jet on the ground ASAP. We had the first CVR and flight data recorders and such. So the folks on the ground could look at the data and fix things even if we punched out.

I am not disturbed so much about the pay scale for the newbies. I never thot the senior pilot pay should have been so high, but I have to look at the "responsibility" those folks have with a coupla hundred folks depending upon them ( and then we see Asiana, gasp).

PJ2

16th Nov 2014, 20:35

gums, re "senior" money, it tops out at around US$150,000 to $200,000 after about 25 years in. Bottom guys and gals are making between US$16k and $75k in the right seat, bit more in the left. An airline pilot may make around US$160k in the left seat of a B767/757 - (perhaps someone who knows for sure can chime it). You certainly can't raise a family on that kind of money at the lower end - it's not as though these pilots aren't already veterans, earning that kind of money. With student debt for the degree, the cost of licences and endorsements and putting the hours in, there's simply no return on the US$100,000+ investment to be qualified to land a first real job with a connector carrier. I believe it's slowly changing but the numbers make no sense whatsover to go through what it takes to become an airline pilot.

If you take a look at any CEO of a US$250m corporation and the liability that rests with one man in terms of potential losses, I think the salaries were commensurate and realistic. However, the prospects of good money and decent conditions are few and far between; and most carriers are working the ass off their crews, paying lip-service to fatigue risk management.

Today, pro hockey players, football players and basketball players each collect more in a couple of weeks work than almost all pilots make in a year. Brand new teachers and brand new nurses make more in their first year.

Not everyone can be a sports pro, but not everyone can fly either.

I'm not "negotiating for pilots" of course, I'm describing a phenomenon: It is what it is, and airlines will have to deal with the consequences of how they've treated the piloting profession. I'm retired. Thankfully, and I had a trememdous run and am watching things like AF447 happen needlessly.

Actually, it doesn't matter what any of us think because we were all told by senior managements at the time that we're worth what the "market" will pay. Well, that "market" is slowly starting to change in a few places because young people ain't coming into the profession any more, they're taking their skills and going into law, government, politics or becoming one o'those wealthy one-percenters who get multi-million dollar bonuses no matter if they fail or not. Nice gig; we all know what happens when an airline pilot "fails"...CEOs get bonuses, pilots get a funeral.

Bergerie1

19th Nov 2014, 14:27

PJ2
Once again I admire your posts, in particular No. 925 above. I have just been talking to an old flying colleague (Yes, I know we are both probably silly old farts) but it is most depressing to see what is happening in the profession today. You have hit the nail on the head! Thank you.

blind pew

21st Nov 2014, 07:45

PJ2
very good post and add two small snippets
Swissair had a cockpit fire out of MUN? a few years before SR111...they did a smart 180 and landed "blind" downwind having successfully sorted the problem out...which was incredibly obscure...short cct in the emergency power switch in the overhead panel...the skipper (a mate) walked around for the next couple of weeks wearing a bandage from the burn.
Whilst SR111 crew were "knocked" by other pilot groups having flown for BEA/BA(old BOAC) and SR I can honestly say the level of training and professionalism was way above my old employers. I flew 100 sectors on the DC9 with another copilot during my line training..far more than the combined total of my first two aircraft.
They also paid for their expertise.

Attended a presentation this week and over dinner was seated opposite a guy heavily involved in training ab initio pilots...relevant to the thread his first "flippant" comment was along the lines of "shag Fest" (447) (the crew were tired before they commenced their duty as highlighted on french TV).
His next peach was when he was CFI of a training organisation for a flag carrier a group of management and lawyers descended upon him and made huge cuts to the training program "because the authority doesn't require these subjects testing"..which he was forced to go along with;
and that FR reject over 50% of their applicants because their training hasn't been up to scratch.
An industry being forced to cut costs whilst the aviation authorities do nothing about training standards.

PJ2

21st Nov 2014, 16:19

Bergerie1;

Thank you for your response. How the present situation will resolve is anyone's guess but at present rates of intake for young pilots, something has to give...either growth, or the accident rate. A "cadet" system only works when there is a larger system in place, with a history, to teach newcomers the ropes. The alternative without any such apprenticing/mentoring, (unpopular terms these days, I know), is newbies in the cockpit who don't know what they don't know, re-learning old lessons anew with people in the back.

In some quarters, the conversation regarding these points has begun, and more broadly I sense a population fed up with the present disparity between those who have access to a multi-trillion dollar U.S. economy and the far more vast numbers who do not and who are shut out of the promise of a vibrant economy.

The sources of our own industry's present problems may be found in these larger matters, but I'll stay on-topic.

blind pew;

A couple of comments if I may. First, thank you for your comments.

We dwell in a technical milieu in which attitudes towards experience may be contrasted with the more technical notions surrounding "accreditation". In short, one is "qualified" if one has done "the training" and "has the licence", regardless of what one actually knows or what one can actually do both in terms of quantity of work and quality of work.

The latter two, (quality and quantity of work and knowledge), are assumed by those examining the formalities of training such as licences, diplomas, certificates, degrees and awards, all of which are supposed to represent "the back room" work done to achieve such formalities. It is an assumption which, like most assumptions, (and opinions!), requires constant re-evaluation and inspection, as well as an overarching stance of, "should we be doing this? - is this a good idea?" I think the 1500hr rule was a quick, sausage-making response for example.

In one way, this is the essence of SMS, and is also the very best reason why we need solid regulator oversight in what I think could be a very good system. However, the regulator itself must understand how things have changed.

A system based upon accreditation, documentation and audit processes works in high-risk industries so long as one is permitted and encouraged to hearken to experience, or "historical learning", or "brain trust", etc.

Your example of cuts to training programs illustrates the point beautifully, (and who hasn't seen such cuts in their own organization?).

The final arbiter of standards, the regulator, which may both set and enforce standards or merely enforce standards imposed by a country's government on their aviation system, will always bend to lobbied interests. For example, the long and sad story behind Fatigue Risk Management Systems for air carriers remains watered down with only a slight, concessionary bow towards the considerable science and industry, (flight crew) experience. Airlines must survive and in a heavily de-regulated industry, some have managed a respectable longevity, but not without the compromises you speak of, which can only come from a (heavily-lobbied) government regulator.

As we examine this, suddenly, there is another side of this argument which few have examined: Not only may standards be lowered, but in this new environment where accreditation, documentation and metrics of a system govern behaviours, (out of a fear of liability), we actually see reductions in a willingness to "go beyond" the standard not merely because it is more expensive (in the short term), but because such is not "accredited" in the regulations and therefore there is no way to quantify or measure quality of such initiatives.

In other words, if it is not recognized or governed in law, is there risk of liability by doing that which is not formally required?

Such a view seems ridiculous, doesn't it?....keep standards close to only what is required, for to go further may open one to risk of liability.

If we contrast this with the notion of "best practices", the counterargument when experience and history have less currency than documentation, etc., may be, "according to whom?"

I wouldn't say that the entire aviation system suffers thus, and as always such observations are made of a very complex system upon which thousands of books, articles and theses are done every year.

I've flown with pilots of the kind you describe - crusty, WWII guys, sharp airforce guys, sharp civilian guys who got their bones staying alive in the north, in the mountains or on the water. It can be done, and a fine pilot can be "made" starting out with only 250hrs of light-twin time with a keen, disciplined mind and a keen spirit. One took it on the chin if one wasn't "keen". I doubt if any cadet program teaches as well but the MCPL is where the industry has chosen to go.

One thing is for sure: The Profession of Airline Pilot has taken a beating, and unlike other professions save medicine & engineering, the outcomes have material consequences. I think there are a lot of guys and gals "out there" who know this and are quietly trying their best to retard the retreat. In a time when unions have all but been destroyed as the only agencies representing ordinary people and their interests, it is time for flight crew representatives to work even harder to retain authority over their profession to exercise their considerable understanding of what makes and keeps aviation safe.

I think this is the larger message of recent accidents, including the topic of this thread. While the technical aspects of the Air France accident are fascinating particularly for those who fly, or who flew the Airbus, the human factors story is far more relevant, but as yet has not, in my opinion, been examined widely enough.

_Phoenix_

22nd Nov 2014, 01:29

ok, now back to business
This crew can be blamed for this accident or lack of training at the same extent that a professional driver does not understand the significance of the red traffic light. Right?
...or, rather the traffic light indicated red-green erratically (stall warning on/off), without the presence of a traffic cop or any other backup(AOA indicator) and the car inexplicably accelerates while the brake pedal is pressed(THS at max NU)
Is that driver an idiot that died in intersection together with all passengers?
Unfortunately, this crew not only died physically. Also, it was killed their dignity of ordinary pilots.

Bergerie1

22nd Nov 2014, 06:35

Phoenix,
Unfortunately it is much more complex than that. This why I think that what PJ2 has to say is so important. Over the last 50 years or so flying has become very much safer because aircraft, their systems, their flying qualities, the operating environment, many human factors issues, safety management systems, etc, etc, have improved so much. But, at the same time, I think the professionalism of flying has deteriorated. I say 'I think' because I retired from flying nearly 20 years ago and am therefore getting more and more out of touch. But I strongly believe that what PJ2 has said in his posts here is highly relevant to the Air France accident and some of the others that have been mentioned on this thread. And when I say 'the professionalism of flying' I mean more than just the pilots themselves. I mean all the many factors surrounding the profession, in particular the quality and relevance of their training, the attitude of many airlines towards their pilots, the way they are now employed and the fact that automation is a two edged sword.

PJ2

22nd Nov 2014, 07:06

Phoenix;

What you think should have happened in the cockpit of AF447 and who should be blamed for what you are assuming went on, does not explain the accident.

RetiredF4

22nd Nov 2014, 07:08

I think that this change from piloting years ago to now can be overall expressed in simple terms. Years ago pilots had been trained to act as controller of the whole system, from planning stage to the time when leaving the airfield after work. Today pilots are trained to manage what's provided from other sources.

blind pew

22nd Nov 2014, 12:49

PJ2 re last part of your post 937.
Unfortunately I believe part of the human aspects are due to the double standards which I have witnessed throughout my career.
It started with "inaccurate" accident reports and continued with illegal operations, ignoring SOP and flying with blokes who shouldn't have passed their IR renewal.
When one witnesses one law for those with connections and one law for the rest the overall moral suffers.
I was impressed by a union rep who flew with an Air France management pilot in the 70s after a period of industrial action "Of course I didn't fly - I had to support my fellow pilots".
This was at a time where my management were lying to us as to the IRA bomb threat.
That after the 447 disaster the AF pilot's had to call a strike to get the Thales probes replaced shows how far the industry has lost it's direction.
SR ceased to exist because of management decisions - after Baltensweiler retired. We had many FM and other pilots stand up to the ridiculous policies...they either were sacked or resigned.
There were two "similar" near disasters in a previous employer...one was a long range night flight where the captain made what he thought was a good decision for the company and the other was a "short haul" flight whose captain's decision was based on his ego and his wallet. One was hung out to dry and the second has a gold plated pension.
Reading of other incidents which smack of a lack of professionalism and education leads to a conclusion that Air France isn't unique but perhaps unlucky.
The malaise is throughout the industry...authorities - manufacturers - schools and is driven by short term profit.
There are many whistleblowers who are largely ignored and there are ALWAYS several of their mates willing to sell their souls to replace them - most of them who otherwise wouldn't get promoted.
I had a friend training on the A380 who phoned me to complain that it was dangerous as he didn't have a safety pilot....it went quiet when I suggested he threatened to resign.
Unfortunately money is a necessity - morals aren't and while we have authorities beholding to politician and airline pressure with the media in the same circus ring it will be down to individuals and luck.

roulishollandais

22nd Nov 2014, 13:57

I'm not far from the point of vew of blind pew, as expressed here about european aviation..
But profit is not the motor of that disfonctioning. Ego and megalomania of a little kernel of de facto prescriptors are the actors of that sad story.

Our civil aviation is not a normal economical activity, but a strategic activity in the hands of people ready to kill father and mother to reach their target. We must not be estonished that innocent passengers die in crashes, billions are transfered in wrong places, and Justice is mute.

_Phoenix_

22nd Nov 2014, 15:36

Bergerie1 and PJ2,
20 years ago, pilots were the lords of the skies. They had a dreamlike profession, a proper social status and a nice paycheck. Then the automated systems and FBW were introduced for the idea to decrease the pilot loading, for increased safety and comfort, but mostly to minimize the fuel consumption and maximize the profits.
Basically in normal law, the FBW aircraft can be flown by grandma, the controls are used as mouse&keyboard that input the computers. We know well that in fact the computer flies the plane. Perhaps for this reason the pilot is seen more and more as a computer operator and his role in the cockpit is increasingly impaired. If we look at the other side of the double-edged sword, if the plane leaves the normal law, then you need the superman in the cockpit. Well, you can not have both of them in the same skin. I mean, we must understand that we have to bring grandma and superman to a common denominator. If the plane leaves the normal law, the pilot must be put in a unique law "back-up flight - direct law", back to stick and rudder. The aircraft must comply accordingly. I am referring mostly to the horizontal stabilizer function, if the pilot's command is nose down, then the aerodynamic vector of stabilizer-elevator combination must be up and not vice-versa. The operator must provide appropriate training for pilot, to fly the plane in the conventional way, at any stage of the flight or emergency situation.

gums

23rd Nov 2014, 19:09

@ Phoenix.....

Seem to be a current poster but maybe a long time lurker. Can't tell from user info ( sheesh, the intell folks can find us easy, so my bio and such is clearly exposed. Ditto for SPAM webcrawlers and so forth)

The AF 447 debacle brought forth a super discussion here about systems, piloting, corporate interests, crrew management, and more. Wish you would have been here since 2009 to see the thousands of posts and such. Also know your background.

I continue some philosophy and such while still addressing Phoenix.

Was fortunate to fly one of the first computer jets back in 1971 - the A-7D. I was a single seat dude from 1967 until I retired in 1984. We had to be able to fly the jet, but we also had to monitor and program and use all the computers because we didn't have a second troop to help on basic stuff. Those suckers really reduced workload once in the air, and they allowed navigation and weapon delivery options we had never seen. The HUD really helped with IFR approaches and seeing flight conditions ( attitude, flight path, speed, AoA, altitude very fast). The integrated inertial/doppler and projected map was a miracle. We also had super radar for ground map and such. All that aside, we still had to be able to fly the jet and fly it in bad weather, navigate if the computers failed, and so forth ( not going to get into refueling at night in a storm, diverting to another base, dealing with battle damage, and all those other things we dealt with).

So I take issue with the qoute by Phoenix:

Basically in normal law, the FBW aircraft can be flown by grandma, the controls are used as mouse&keyboard that input the computers. We know well that in fact the computer flies the plane. Perhaps for this reason the pilot is seen more and more as a computer operator and his role in the cockpit is increasingly impaired. If we look at the other side of the double-edged sword, if the plane leaves the normal law, then you need the superman in the cockpit. Well, you can not have both of them in the same skin.

I and thousands of other pilots in the military adapted to the computers and still maintained our "pilot" skills. This was primarily among the single seat folks, but the "crewed" jets also adapted.

In defense of the "heavy" pilots here, they cannot program all the computers and then sit back to watch/monitor. It is true than many portions of the mission can use the autopilot and such, but the critical phases require good pilots.

My problem with the industry is the emphasis upon automation versus the basic skills to fly a plane.

The FBW laws are not the problem for the most part. What I have seen is a buncha engineers trying to make a fool proof system that does not account for a human being that knows how to fly!! Sheesh.

I like AoA protections. I like rate pitch/roll gradients and maybe some other features of most FBW systems. But it looks like we are trying to provide too many "protections" and then invoke too many back-up modes/laws and such when we lose a few inputs to the FBW computers. The simple fact is that embedded sensors in the flight control computers can provide body rates, gee and attitude and such without depending upon any aero sensors or nav sensors or..... So no reason to panic if the air data goes tango uniform for awhile, such as the AF447 crew did.

Sorry to rant.

gums

23rd Nov 2014, 20:45

I really liked the WSJ article that Winner referenced.

The author pointed out what I experienced in 13 or 14 years of flying the smart fighters. We didn't have automated flight systems that climbed and cruised and descended according to a program. But we had great nav gear and displays of our flight conditions and so forth. In the Viper, we also had AoA protection.

In short, we had to climb for a while after takeoff and use attitude mode on the A/P if it was enabled. We didn't. We trimmed. Ditto for descent from a hunded miles out at 30,000 feet. Look at the HUD flight path vector and trim down to get a 3 degree angle with power retarded. Duhhhhh?

Up to me, I would demand that all line pilots imagine that they were manually flying the jet when it is on A/P. Additionally, I would demand that "x" percent of their flying time was with A/P off!!! I realize that flying around the airport to do manual approaches is expensive, but seems we could have a half-dozen pilots in the big jets take turns. Hell, it ain't like we had to do with a single seat jet at a few thousand $$ per hour to practice or train.

Bottom line from this old pilot is to use the new tech to do the "admin" and leave the "pilot stuff" to the pilots.

_Phoenix_

23rd Nov 2014, 23:10

@gums

Wish you would have been here since 2009 to see the thousands of posts and such. Also know your background.

No problem. I'm rather a newcomer, fascinated by this accident after I watched a documentary on Discovery channel. I leafed through final report, in Annex 3 noticed the THS graph. Then, I realized that this accident is much more complex than the nobrainer "pilot error". However, my knowledge are limited with regarding the FBW system, but I'm an aircraft engineer, former glider pilot(prior to get married:). So, I'm a normal guy, who honestly and freely express his opinions.

What I have seen is a bunch engineers trying to make a fool proof system that does not account for the human being That Knows how to fly!
Bottom line from this old pilot is to use the new tech to do the "admin" and leave the "pilot stuff" to the pilots.

The "bunch of engineers" have a moral duty, they have to answer the question: But, what is happening?
I would suggest: "I do not know, I wasn't there ..."

... let's take a step back and leave the "pilot stuff" to the pilots.

PJ2

23rd Nov 2014, 23:16

Phoenix, welcome to the fray! I have huge respect for engineers, particularly aircraft and aeronautical ones. The best conversations are between those with differing priorities regarding a common subject! Having retired 7 years ago, my work is in flight safety now and I can tell you that there is a ton of things for pilots to learn from AF447 and other accidents. I don't think televised programs can tell the whole story of AF447 and I don't watch any of them, but I would feel comfortable recommending the Vanity Fair article by William Langewiesche, the links to which were posted earlier in this thread. Also, pick up Bill Palmer, (Understanding Air France 447 (http://www.barnesandnoble.com/w/understanding-air-france-447-bill-palmer/1115883136?ean=2940016657394)), and for knowledge of flight safety work, read anything by Sidney Dekker, Tony Kern, Jim Reason, and the pioneer of modern approaches to organizational behaviour, Charles Perrow. Also, I think you would find fascinating, Diane Vaughan's, "The Challenger Launch Decision: Risky Technology, Culture and Deviance at NASA"

gums;
I often hand-flew all my types including the A320, A330 & A340 to cruise altitude and for the approach, sometimes from cruise all the way down. One took into account the airport, the complexity of the SID and/or STAR and the F/O's comfort with setting the autoflight and working the FMS - (rarely found anyone unhappy), but that done, it was a joy to hand-fly these aircraft in all kinds of weather. I also offered the same to the F/O ...I'll punch keys and turn the knobs, you fly, but found very few takers which I thought was a bit sad as it's what we do - but they were not comfortable disconnecting the AT's. The 'bus flew beautifully, in cruise as well as all other phases, even in turbulence. But so did the Boeings, Douglas's and Lockheeds.

Automation is not the problem if one isn't lazy and instead digs in the books. It's only when one relies upon the automation without knowing what's in the back room that it's a problem.

One should never, ever just pass a checkride...

roulishollandais

24th Nov 2014, 00:12

former glider pilot( prior to get married :) former glider pilot (prior to get married:*
recommending the Vanity Fair...You too?:\Have we to replace the BEA and the other official agencies by Vanity Fair and such glamour newspapers? Or are you writing in VF? :ugh:

_Phoenix_

24th Nov 2014, 00:14

PJ2,
Thank you for your kind words and for references. Your posts are exciting and profound.

PJ2

24th Nov 2014, 00:33

Hi Roulis...mais non, mais non!,....I'm not hacking for VF! I strongly dislike glamour and media...a little credit for my years of reasonable posting on the subject,...please!

Somewhere in between the BEA's work and those one-hour dumbed-down television specials which insult the investigative process, we in the industry have to find a way to convey the lessons of AF447, and "me too" thought that Langewiesche article was worth reading even as it does not tell a full story. It's not either/or...but one must choose from the thousands of documents and articles on AF447 and I considered among them, the VF article reasonable.

For me, the BEA did a superb job in both its interim and final reports. However for me, the BEA may not have dealt thoroughly enough with the Human Factors aspect of this, but you will have known that that was my view from all the writing I've done here in the past. Because 30 others faced with the same abnormality made a log-book entry, there is something different about the AF accident that requires addressing because this accident is only partly technical. I have flown thousands of hours on Airbus aircraft and while these airplanes requires different skills and thinking than all the other aircraft I've flown, it is still a superb design and a wonderful design to fly. That said, one has to know one's airplane, thoroughly and the training regimes must support this view.

gums

24th Nov 2014, 02:48

PJ said it all in one sentence.

Automation is not the problem if one isn't lazy and instead digs in the books. It's only when one relies upon the automation without knowing what's in the back room that it's a problem.

Thank you.

roulishollandais

24th Nov 2014, 06:13

Hi PJ2,
Of course, I give you much credit, on this subject and others too.
I did not want to analyse here Langenwieshe's text that BEA could not write. Fatigue of Dubois is highlighted as a shocking scoop to sell paper, as did Otelli already, and first cause of the crash and should be hiden by the BEA.

Why couldn't the two pilots Robert and Bonin manage an UAS and aircraft's attitude on a type between many others ? Have we really to call help to psychology what is only piloting technique with an autotrim FBW? I read anywhere that around 500 persons by Air France were involved in human factors improvement! I cannot share that definition of human factor in a closed loop effective system, and refer to the definition from USAF's General Arquiette in Manas KC-135 dutch roll crash report.
Of course pilots have to rest as soon as they are preparing a flight.
Another thing I didn't appreciate in Langenwiesche is to write about personal conversation with BEA's leader without possible feedback.
He really needs a glamour newspaper to write that, and that is not professional, and worse if he is an expert who knows the rules.
I was amazed how many accepted that.

PJ2

24th Nov 2014, 06:24

Hi roulishollandais;

How the industry must change as a result of the lessons of AF447 as well as other accidents may be up to those agents of change which are beyond/outside of the BEA. That would not be unusual - I suspect the same is true of the Canadian TSB and the American NTSB process - no report can be definitive, and certainly beyond human factors which relate directly to the accident, here, AF447, a report cannot deal with changes which may be needed within the industry.

It was really the last paragraph of the VF article that I thought was entirely relevant and we know that the BEA nor any formal investigative body cannot and does not write that kind of commentary. So I think there is value in what Langewiesche says.

As for media, glamour, television and all those endeavours stand for I dismiss them all, wholly, as untrustworthy for serious work. The fact that they may sell so well around the world and be tremendously profitable for their owners is both a fact and a disheartening reality.

roulishollandais

25th Nov 2014, 07:39

I have nothing against glamour, TV or media, but I don't trust mixing them with investigation or science , unless you are building fake investigation and fake science.
Rigor seems arid but is the onlyway to improve air safety not only in words , and respect victims.

_Phoenix_

26th Nov 2014, 03:11

Winnerhofer, you start me again ;)
This needs a remix!
Remember Robert thought for a second that stall meant an engine stall

It seems that the video reconstruction is based on CVR's listening. At least, it's the most accurate reconstruction so far.
Interesting is that everything is textbook as the CVR except for exclamation "STALL" when thrust levers were advanced to TOGA. See Figure 28 and CVR at 2:10:55 (!). Interesting, isn't it? In CVR we have (!), but in the video they said "STALL" clearly

See video at minute 4:01
https://www.youtube.com/watch?v=dKT3dd_ko8E#t=241

Maybe the crew realized the situation "STALL" from the very beginning

DozyWannabe

27th Nov 2014, 02:33

What I have seen is a buncha engineers trying to make a fool proof system that does not account for a human being that knows how to fly!!
And yet the head of the pilot engineering team was the man who succeeded the legendary D. P. Davies - presumably poached precisely because he had experience in testing and designing around pilots' needs. Sorry gums, but I have to disagree strongly here.

Remember Robert thought for a second that stall meant an engine stall..."...c'est les moteurs..?!"
Rubbish. I think the English translation at that point was "But we’ve got the engines what’s happening (…)?" - which has many possible implications, none of which suggest what you're claiming.

@_Phoenix_ : "(!)" in the CVR transcript indicates an expletive (or swear-word).

RetiredF4

27th Nov 2014, 06:54

Quote:
Originally Posted by gums View Post
What I have seen is a buncha engineers trying to make a fool proof system that does not account for a human being that knows how to fly!!

Answer by Dozywannabe
And yet the head of the pilot engineering team was the man who succeeded the legendary D. P. Davies - presumably poached precisely because he had experience in testing and designing around pilots' needs. Sorry gums, but I have to disagree strongly here.

Yes, gums statement looks harsh, Although I underwrite the first part of his sentence and see the second part more as outcome than as intent.

See the FAST magazine 23 from 1998

Most late-technology aircraft carry the most up-to-date systems to assist the pi- lots in achieving their tasks, without changing the nature of the tasks them- selves. The protections built in the fly- by-wire system is one of them. These systems have been designed to be a COMPLEMENT for the pilots, after a thorough analysis of pilots’ strengths and weaknesses; basically they have been added wherever they could do better than man, to compensate for those weaknesses.

http://www.airbus.com/support/publications/?eID=maglisting_push&tx_maglisting_pi1%5BdocID%5D=17429

Read the whole article, it is interesting in its own way.

Turbine D

29th Nov 2014, 14:31

Dozy,
And yet the head of the pilot engineering team was the man who succeeded the legendary D. P. Davies - presumably poached precisely because he had experience in testing and designing around pilots' needs. Sorry gums, but I have to disagree strongly here.
Who by name are you referring to here, Bernard Ziegler? He was the son of one of the co-founders of Airbus Industries, Henri Ziegler.

Turbine D

29th Nov 2014, 14:57

Winnerhofer,
On a pourtant les moteurs qu’est-ce qui se passe!
"There yet engines what is happening!"
I think if you went back and looked at the discussions about the engines in the early threads, the engine performance data and charts presented in the accident reports and the CVR translations, you would conclude they knew they had working engines and that the engines did not stall.

Bergerie1

29th Nov 2014, 15:50

Turbine D,
Gordon Corps?

DozyWannabe

29th Nov 2014, 19:11

Precisely.

I have it on good authority that BZ was to all intents and purposes a figurehead for the engineering end of things during the actual development and testing work. Gordon Corps was the effective head of the pilot engineering team, and what he brought to the table was a unique understanding of some of the technical and piloting points (having been at the ARB for so long), as well as specific knowledge of the prior work on the control system (having been heavily involved in the Concorde "minimanche" tests). What he could also do - as much as a result of his character as well as his qualifications and experience - was act as a mediator between the test pilots/pilot engineers and the technical (aero/mechanical/software) engineers when it came to disagreements or areas where one side had trouble understanding the other.

If you look at the old Flight articles from the time, you'll note that while Ziegler was briefing the press on the overall direction of the project, it was Gordon Corps who was handling all the briefing on the actual technical end of things.

Turbine D

30th Nov 2014, 00:44

Thanks Bergerie1 & Dozy,

When you read some articles, it appeared that B. Ziegler got nearly all the credit for the FBW Airbus A-320 inventions and ideas with no mention of Gordon Corps.

I did find an interesting article about the early testing of the A-320 and what the design/testing team was trying to achieve with the sidestick operation and some interesting comments on flight envelope protections:
http://www.carry-on.com.au/wp-content/uploads/2014/09/Airbus-A320.pdf

Cool Guys

30th Nov 2014, 03:08

D. P. Davies or Gordon Corps were obviously switched on guys but that does not mean they were infallable. In the era when the AB flight controls were developed complex automation was in its infancy. It is feasible they did not fully understand the consequences of creating a highly automated cockpit and the concept of “automation dependency”. As gums suggested maybe they were trying to develop a foolproof system but did not consider that pilots could lose their manual flying skills. They probably never dreamed that airline cost saving measures would actually ban pilots from manual flying.

DozyWannabe

30th Nov 2014, 03:58

D. P. Davies or Gordon Corps were obviously switched on guys but that does not mean they were infallable. In the era when the AB flight controls were developed complex automation was in its infancy.
No it wasn't - the FMS/autoflight systems of the A320 were of the same generation and layout as those fitted to the B757 and B767, which had been around for eight years when the A320 went into service. The A300 had the first generation of those systems from the mid-'70s.

It is feasible they did not fully understand the consequences of creating a highly automated cockpit and the concept of “automation dependency”.
We're talking about the FBW/EFCS here, which is a completely different concept from autoflight.

If you read Davies' "Handling The Big Jets" - the most recent edition of which dates to 1971 - then it will quickly become apparent that Davies and the ARB were remarkably prescient when it came to determining potential issues with technology and making recommendations to avoid such issues. It also becomes apparent that certain pilots had a knee-jerk negative reaction to what they perceived as "interference" in the flight deck as far back as the introduction of "stick pusher" systems.

As gums suggested maybe they were trying to develop a foolproof system but did not consider that pilots could lose their manual flying skills. They probably never dreamed that airline cost saving measures would actually ban pilots from manual flying.
They were trying to design a flight control system that would assist pilots to a degree that was not previously achievable with older technology. Automation did not really come into it because they were simply adhering to the existing standard as far as that was concerned.

I don't know how many times I've repeated this point, but I'll do so again in the hope that I won't have to repeat it further - the cost savings in pilot training that Airbus touted with the introduction of their FBW types had absolutely nothing to do with increased use of automation, and everything to do with the unprecedented level of commonality in flight deck layout and "feel" between their narrowbody and widebody fleet. The A330 and A340 would handle (and be laid out) more-or-less identically to the A320 - a situation no other builder could offer at the time.

Cool Guys

30th Nov 2014, 06:04

No it wasn't -

yes it was - 1980s?

As for the rest of your post. Maybe you should re-read mine?

gums

30th Nov 2014, 20:16

I feel that Doze does not get my point. But in his defense....

- automated flight path systems were there when I first flew an interceptor in 1966. We had "coupled" approaches, climb gradient, course, even attack steering, et al. The F-106 was even more integrated than my VooDoo. Using datalink from the ground, the sucker would fly the jet to a bandit location so the pilot could lock on and shoot.

- the VooDoo had AoA and gee limiters just like I saw 13 years later. Also had a pneumatic bellows doofer that kept us from pulling too hard on the stick according to dynamic pressure ( basically CAS).

- VooDoo had a pusher that activated according to both pitch rate and AoA.

OTOH:

- The problem with the engineers designing and implementing FBW was trying too hard to "protect" the pilots.

- You really have to look at the FBW implementation and then fly a plane using it to completely understand some of my views.

The so-called "direct law" would not be easy to fly, and not hard at all for a really good pilot. After all, we have not had a lotta cables, pulleys, pushrods and such connecting the yoke or stick to the control surfaces since the late 50's. Springs and maybe active feedback stuff for the stick/yoke would help a lot, and they are available now! Some online flight sims even have force feedback sticks to represent WW2 aircraft forces.

- the Viper had many "protections", but many were intended to represent what all the pilots were used to in terms of rates and gee/stick force and so forth. So our pitch and roll rates were "limited" ( most here know I detest the term "protections"). Our gee and AoA were also limited according to a basic function that allowed 9 gees until 15 degrees AoA, then decreasing to 1 gee at 27 degrees AoA. We had no absolute pitch or roll limits such as the 'bus. Was the nature of our mission, duhhhh.

What got our attention after a few crashes was an idea from the engineers to use our system to pull up according to HAL's idea of imminent ground impact. NO WAY!! The consensus amongst us was to allow us to die if we screwed up!!! Put up the big, flashing "X" in the HUD and have bitching Betty yell at us, but that's all. Same as that Russian jet in Malaysia or Indonesia, when the pilot turned off the ground clearance alert system, but sadly took a lotta SLF with him into the cliff. Don't like being brutal, but that comes from my decades flying a different mission than the commercial folks.

My bottom line goes with PJ's. Fly the jet as much as company policy allows you without getting fired. The "engage otto at 300 feet and disengage for last two miles on final" attitude or procedure deeply disturbs me.

Turbine D

30th Nov 2014, 22:41

Dozy,
the cost savings in pilot training that Airbus touted with the introduction of their FBW types had absolutely nothing to do with increased use of automation, and everything to do with the unprecedented level of commonality in flight deck layout and "feel" between their narrowbody and widebody fleet.

I don't think you interpreted Cool Guys comment correctly:
They probably never dreamed that airline cost saving measures would actually ban pilots from manual flying.

In fact, sadly, airlines have banned manual flying unless some extreme reason calls for it, the gospel according to airline bean counters. Then the airline lawyers chime in with the possibility/probability of tort action resulting in manual flying should something go wrong, not being in auto-flight.

IMHO, what wasn't recognized in the '80s was where the source of pilots was going to come from in the later decades. While Gordon, Bernard and others of the '80s came out of the military experiences of flight training, discipline and introduction to aircraft testing, far more pilots today emerge from commercial, for profit, flight schools and proceed into commercial airlines starting on the commuter level at poverty level pay, without their military experiences. Did Gordon and Bernard take this into account when developing the Airbus FBW systems and sub-systems, or was it based on their personal experiences? What kind of personalities did they have in their leadership roles at Airbus? Was Gordon and Bernard really open to changes/criticisms to the FBW systems they promoted, or were they overbearing/dismissive to subordinates with their supposed greater knowledge and experiences?

Airbus Industries indeed pushed the reduction of training costs to airlines, even beyond that of what was happening with two seat cockpits, i.e., elimination of the flight engineer.

You have an opinion, but you are not the final word in this discussion.

PJ2

30th Nov 2014, 23:59

gums, :ok:

Two thoughts, re "Fly the jet as much as company policy allows you without getting fired. The "engage otto at 300 feet and disengage for last two miles on final" attitude or procedure deeply disturbs me. "...

1) In my experience, which I suspect is not unusual, it is rare not to engage the autopilot right after takeoff, and leave it engaged until about 400' on the approach.

2) Every company flying heavily-automated equipment these days must have an automation policy which clearly states appropriate levels of automation so the carrier's crews know when they can legitimately disconnect and hand-fly.

If an airline is prohibiting or limiting its crews from hand-flying either by direct policy or through inappropriate limitations on hand-flying or is entirely without an "Appropriate Level of Automation Policy", then it is only a matter of time before they will find themselves dealing with an incident in which reduced hand-flying thinking-capability and hand-flying-skills will have played a part. Like not doing flight data analysis, these days that puts an air carrier at risk of liability if anything happens.

We are a very, very long way from absenting such skills in our transports.

Turbine D

Re, "What kind of personalities did they have in their leadership roles at Airbus? Was Gordon and Bernard really open to changes/criticisms to the FBW systems they promoted, or were they overbearing/dismissive to subordinates with their supposed greater knowledge and experiences?

Airbus Industries indeed pushed the reduction of training costs to airlines, even beyond that of what was happening with two seat cockpits, i.e., elimination of the flight engineer. "

I transitioned to the A320 left seat from the B767 right seat in 1992 - the Airbus had been in service for approximately six years by that time.

While I found the airplane "natural" to fly, (including just pulling the thrust levers out of the CLB detent and using them as one would any other transport), I found the course over-emphasized automation and I found when we met with Airbus personnel who came over by invitation to engage those transitioning to the airplane they were dismissive of our thoughts on aspects of the design and of some of our questions, (no one had ever flown FBW; also, we initially flew the A320 without full VNAV, so used traditional methods for descent). Our instructors were capable but just ahead of the class, but that part was okay because the airplane flew just like an airplane so most were comfortable. The hardest part of the transition was actually going from the right to the left seat as there were commander's duties to ensure as well as getting the airplane under one's belt.

It was the first time in my career that I had done my entire transition to a brand new type entirely on the autopilot - hand-flying was discouraged because they wanted a quick understanding of the automated flight features (that they had paid for, in my view). I thought the airplane was exceptional then and now, but the automation was subtely viewed, in my opinion, as "the third pilot", even as that may not have been the intention they were trying to convey.

It was a long time before Airbus actually began to engage "ordinary line pilots", the airline and their collective comments; - after a few incidents and accidents they began to listen, is how I recall it. Once they understood that the end-users had valuable things to add to their own understanding of their aircraft and its substantially-different (but in my view highly-successful) design, it became a good conversation although in my view very late in the game.

As a result, (and you are correct, in my view), airlines indeed accepted the Airbus "push" regarding reduced training costs and the benefits of automation. Having hand-flown everything I ever trained on, I hand-flew the Airbus too, during line-indoc and every chance I got, while our representatives fought to include in the FCOM a paragraph in the SOPs permitting hand-flying; (the only statement governing this in the FCOM was essentially, "the autopilot and autothrust will be engaged shortly after takeoff and disengaged during the landing roll-out".) So if one had an incident while hand-flying, one was in trouble...It was many years and after a number of incidents and accidents in the industry, before a proper automation policy was created and adopted. I have materials going back to 1990 (from AW&ST) discussing this problem which was raised by flight crews at the time. I am still astonished that it took twenty years to comprehend the combined problems of automation dependency and a new generation of pilots raised on computers with little real (vice virtual/cadet) experience.

DozyWannabe

3rd Dec 2014, 14:33

Few points to address, so here goes:

@gums - I think what might be worth bearing in mind is that your Viper was intended to be flown by fast jet pilots, and as such they would routinely be trained in the limits of the aircraft when making extreme manoeuvres. That kind of EFCS exists because the aircraft itself is inherently unstable (in order to maximise manoeuvrability) - a completely different set of requirements from those which would be needed in an airliner.

As such, protection features such as those in the FBW Airbuses and Boeings would be inappropriate in the Viper, because Viper pilots would be expecting to fly the thing at or near the limits on a fairly regular basis - which is absolutely not the case in the airliner use case. What may be "trying too hard" in the Viper may be just about right in an airliner.

Again, this is something I've brought up before, but the Airbus (and later Boeing) FBW "hard" protections are not just about sparing the blushes of the flight crew, and while this aspect was emphasised to the general public (who in 1985 had seen one of the worst years for airline safety on record), the other equally important aspect was that the hard protections allowed the crew to deliberately use full control deflections in an emergency scenario without worrying about stalling/spiralling the aircraft or overstressing the airframe. This is important because - unlike your Viper crews - airline crews would not be regularly expecting to take the airframe to its limits and would therefore not train or practice the need to manually hold the aircraft within those limits.

@Turbine D:
IMHO, what wasn't recognized in the '80s was where the source of pilots was going to come from in the later decades. While Gordon, Bernard and others of the '80s came out of the military experiences of flight training...
To be fair, I think it's worth noting that the situation in Europe regarding airline hiring was somewhat different to what it was in the USA if we're talking about the period between the start of the '60s and the mid-'80s. I recommend Blind Pew's book for a fascinating insight into BEA's cadet programme in the '60s, for example. I think in general, you tended to get fewer ex-military folks crossing over to the airlines on this side of the pond.

That's a bit of a tangent though - the whole point of the Airbus FBW/EFCS development was to be able to encode the experience that Gordon and the other test pilots had gained when testing the airframe into the computers, so that pilots of any ability would be able to draw on that experience transparently. As such, one could almost say that they were absolutely preparing to deal with a wide range of piloting abilities from
the very beginning.

Did Gordon and Bernard take this into account when developing the Airbus FBW systems and sub-systems, or was it based on their personal experiences?
See above. I should also take this opportunity to point out that BZ would have only been involved in the specification of the systems at a fairly high level - it would have been GC and his team who did the actual test cycles and feedback sessions. From what I've been told, it would be inaccurate to speak of the two men in the same breath/sentence in that regard. BZ was senior VP of engineering (and as such largely a ceremonial figurehead), whereas GC was a lead test/engineering pilot in the programme.

What kind of personalities did they have in their leadership roles at Airbus? ... open to changes/criticisms to the FBW systems they promoted, or were they overbearing/dismissive to subordinates with their supposed greater knowledge and experiences?
I can't speak for BZ - though, as I said above, he wasn't really involved in the day-to-day testing/feedback/redesign/tweaking cycle that GC's team were. As far as the A320 project goes, BZ would have been on the flight deck for "marquee" flights (e.g. first prototype flights), particularly where the press were involved - but he would not have been involved in the regular testing and development schedules. GC was the lead engineering pilot and would have been in charge of the "real" work.

I've been fortunate enough to correspond/speak with a couple of people who knew GC - and both of them said that the way he came across was as personable, knowledgeable, meticulous, methodical and inclined to listen and mediate within discussions as BZ could come across somewhat brash. This is one of the reasons why GC had the role he did. I should also point out that GC was involved in the Concorde "minimanche" experiments (where what became the Airbus sidestick design was first developed and tested), whereas BZ was not.

Something which folks may find interesting is that the groups who are most vocal in criticising Airbus like to bring up BZ's character, chequered history, brashness and his foot-in-mouth tendencies at the drop of a hat - but in my experience barely acknowledge GC at all, either in terms of his character or his greater technical contributions to the project. My personal belief regarding this is that to do so would tend to rather undermine their position and argument.

I've repeatedly put forward the viewpoint that had GC lived longer, the festering distrust in some piloting circles towards Airbus would never have taken hold - and I think the manner of his passing speaks volumes about his character. After the A320 testing project concluded, he transferred to the position of deputy flight safety director. In that position he did not necessarily have to personally visit accident sites, but clearly felt compelled to do so. Sadly this led to his death from altitude sickness when personally overseeing Airbus's safety team on a crash site in the Himalayas.

even beyond that of what was happening with two seat cockpits, i.e., elimination of the flight engineer.
Two-seat flight decks had been the norm in Western narrowbodies/short-haul types since the mid-60s (e.g. BAC 1-11, DC-9, Jurassic 737). The A300 may have been the first two-seat widebody (and indeed the first long-range twinjet), but Airbus were only following an already existing trend - the B767 was also a two-seater twin, flying for eight years before the A320 went into service.

@PJ2 - As usual, a very cogent post, though I have to wonder:
It was the first time in my career that I had done my entire transition to a brand new type entirely on the autopilot
I suspect you'd have faced the same situation had you been doing a type conversion to, for example, the B757 (which had an FMS/autoflight setup practically identical to the A320). On balance, everything I've read indicates that a move to increased use of automation was industry-wide and related to the period of time rather than the type.

I'm just "thinking out loud" here, but I wonder if the emphasis on training the automation in the early days of the A320 may have had something to do with the fact that most of the short-haul crews undergoing conversion training at that time would have been used to aircraft two generations older (e.g. Caravelle, BAC1-11, DC-9), and as such, the change in automation technology might have been considered the biggest change to overcome, and prioritised accordingly?

It was a long time before Airbus actually began to engage "ordinary line pilots", the airline and their collective comments;
May I ask how long, in your experience? Again, based on what I've read I agree absolutely that Airbus did seem to drag their heels in that regard - but at the same time I wonder if other builders were much different back then. There have been several examples I can think of where manufacturers were reluctant to respond to queries/criticism (e.g. Bryce McCormick to Douglas regarding possible total hydraulic loss on the DC-10 and Boeing's efforts to suggest B737 rudder PCU problems were in fact handling mistakes by the crew).

RetiredF4

3rd Dec 2014, 16:22

Again, this is something I've brought up before, but the Airbus (and later Boeing) FBW "hard" protections are not just about sparing the blushes of the flight crew, and while this aspect was emphasised to the general public (who in 1985 had seen one of the worst years for airline safety on record), the other equally important aspect was that the hard protections allowed the crew to deliberately use full control deflections in an emergency scenario without worrying about stalling/spiralling the aircraft or overstressing the airframe.

It was and still is a clever move to sell the flight envelope protections only as a device to protect the aircraft from the pilot inputs and to allow them to use maximum control imputs without thinking too much about stalling or overstressing the airframe. Those envelope protections are a necessary gadget to prevent the FCS in a flightpath stable setup from exiting the flightenvelope with no corrective intervention by autothrottle, autopilot or human pilot. It is probably a philosophical point which need was first, to implement a system which sets limits to the FCS and regains the necessary positive static stability at the edge of the flight envelope or to implement the system to aid in piloting the airframe at the borders of the flight envelope. Both purposes are served well. But without those protections the flightpath stable C* design would hardly have been certified by the authorities.
But I agree, the official version sells better.

jcjeant

3rd Dec 2014, 19:58

AF447 : Commentaires - Page 30 (http://avia.superforum.fr/t1524p580-af447-commentaires#57063)

Item 2 of the BEA:
- Inappropriate actions on orders destabilizing the trajectory;
Certainly, if the shares were appropriate there would have been no accident.
Regarding the first few seconds, extracted from forensic report:
The pilot responds to the alarm ... ... his first actions are consistent with the pursuit of mastery of the path by controlling jerk reaction based on the information available ...
This is consistent with the indication of the tendency bar flight director whose order is guiding nose ...
It is said at the beginning, so good ... then it goes bad ... Why?
Well, because ... see the list of the post before and its consequences on the steering screens:
http://www.via-caesar.fr/PATRICK/PFD%20fle%CC%81che%CC%81.png
Enough is enough.
Noting two points:
• the difficulty of driving a hybrid law, little change in the pitch axis but almost doubled rates on the roll axis that mobilized too pilot resources which could not cope with everything else, including consequences of the reactivation of the FD, the Flight Director.
• To underestimate the difficulty of the action suddenly doubled roll rate, experts have reconstructed the drivers as follows:
- 5 sessions of simultors some dedicated solely to the acquisition of control in Alternate 2B, without any failures elsewhere.
- Day demonstration flight in good weather, with no parasite fault, no uncontrolled descent commissioning, no setting unexpected turn, no ECAM messages and alarms of various failures, and especially no effect surprise.
Knowing what was going to happen, the pilot obviously moved with his shy moderation Sidestick to conclude:
"Compared to conventional aircraft, the pilot of the aircraft alternate 2 law, at high altitude, is very easy."
In these circumstances, I want to believe ...
To overwhelm the pilots could not do better than this travesty of flight "demonstration" ...

PJ2

3rd Dec 2014, 21:58

Dozy;

My experience is one of thousands as are my impressions of the process and the airplane.

I remember the move to 2-pilot wide-body aircraft - our B767's had a third seat but by the time I trained on the airplane everything was up front. I loved the FMC technology...we were experimenting with early versions on our B727s. I trained on every transport we had except the B747 and no course was focussed so strongly on the automation as the A320 one was. There was perhaps an approach or two on raw data/no FDs and a few with all ELACs/SECs gone, (differential thrust & trim used to land the airplane, er, simulator) but aside from that, the entire simulator course was on the autopilot and I did the licensing ride and the command ride entirely on the autopilot. I know very well that others would have been different.

Regarding other manufacturers, it wasn't so much the visits but the diffidence with which our entreaties were handled, at least in 1992. It changed massively after 1999 or so, and so did their publications which I think are among the best in the transport world in terms of sharing information, flight safety and support for users. In fairness I have to acknowledge that the floor tours I've had of the Boeing plant at Everett were second to none in terms of openess from the senior pilots taking us around, (just as the first three B787s were rolling off the assembly line, bound for ANA).

It's tremendously complex and I respect others' views that inevitably will be different than mine regarding this whole introduction to automation - which, I have said, I love and used on all types with great enthusiasm as I did the control column or sidestick and non-moving thrust levers!...one can't really categorize it so much as recall impressions and experiences. It's like trying to perceive the British Museum in the dark using only a small flashlight as one's guide!

gums

4th Dec 2014, 19:25

I do not like correcting Doze or others, but have to clear up the comparison with the 'bus "protections" and the Viper "limits".

Make no mistake, the intent and implementation of the AoA and gee and pitch rate and roll rate limiters on the F-16 were exactly what we have been talking about. Duhhh? Gums! What do you mean? ( now that PJ has opened up, I feel I owe all the same courtesy)

I was one of the biggest advocates of a mechanism to override the F-16 limiters. Problem was I didn't understand FBW system implementation or design. This is back in 1974.

I flew the VooDoo 1966 - 1967, and it had an AoA and gee limiter in some modes. It also had a "pusher" for excessive pitch rates as well as pulling thru the mechanical limit for AoA. So I was there with some of the "interference" with we cosmic pilots that could do anything, fly anything , heh heh. Nevertheless, the sucker had an electro-mechanical analog system for flight envelope protection and an actual flight path autopilot ( called it the coupler). I even used the coupler to launch a Genie rocket at a drone because it was better able than me to steer and avoid the dreaded "pitch up" ( had a poor set up, and was sorried about pulling too hard). I also used it every now and then for a coupled ILS approach, but we didn't have autothrottle, so we pilots still had a few duties ( think Asiana airspeed monitor duties).

The Viper limiters were exactly what we are talking about with the extreme envelope 'bus "protections". They are there to keep Joe Baggodonuts from over stressing the bird or losing control at the edge of the envelope. But the 'bus folks go way beyond that, so we have pitch corrections for attitude and bank angle limits and such in the "normal" mode. It is more like a Playstation or old Atari game than the Viper.

So my point is we lowly lite folks had a system ( first fully-electronic FBW in active service with no mechanical back of any sort) that allowed us to fly to the limits of the jet no matter how hard we pulled or rolled or.... As with the 'bus, our operational/mission requirements ruled. I will grant that we had a vastly expanded flight envelope ( big time), but the intent and the implementaiton was almost the same.

The biggest difference was our degraded mode. We had only one, and that was there in case we lost air data or selected alternate flaps!!! It used fixed values for the "gains" depending upon the gear handle position. So you can see why I got interested in AF447. Our back up was almost transparent, and we did not lose all the other "goodeis" that the 'bus has because we didn't have them at the outset. The deep stall override function was not considered a back up mode, but it was direct command of the stabilators as the 'bus has in "direct".

So that's my story, and I am stickin' to it.

mm43

5th Dec 2014, 07:35

@ gums

A very interesting comparison between the AB and the military perspective of the time. In real-life, it also displays the disparity between the "gun slingers" and the "craddle carriers".

The important difference, is that those that flew the "gums era" FBW were actually aware of their aircraft's limitations, and acted accordingly. Hopefully, a new era is upon us where those involved in air transport ops will also have the same awareness.

Thanks again for your little bits of "Viper" reminiscences.

Turbine D

5th Dec 2014, 14:28

mm43,
I wonder if the "new" military "gun slingers" are moving closer to the "cradle carriers" in some respects rather than vice-versa:

KenV Post #247 F35C first deck landing:

The F-35 (like the F-16) is fly by wire all the time. There is no back up mechanical flight control system. If the computers go away or the wiring goes away, flight control goes away. And in the case of the F-35 "flight control" includes the engine. The engine is integrated into the F-35's flight control system.

However, there are different FBW "normal" modes and different "degraded" modes. The "manual" degraded mode does NOT mean it reverts to some kind of mechanical sytem of control. "Manual" means that the feed-back motors in the stick and throttle are gone so the pilot flies wihout any tactile feedback. Only the pilot's eyes and "seat of the pants" provide feedback as to what the flight control computers are doing. Basically in "manual" mode the F-35 flies somewhat like an F-16. No stick feedback about what the computers are doing with the control surfaces. But unlike the F-16, the F-35 flight control computers also completely control the engine. When in "manual" mode the pilot gets no throttle feedback what the flight control conputers are doing with the engine. So the "manual" mode of the F-35 is sort of like all FBW Airbus aircraft in "normal" mode with the autothrottle engaged. It is completely computer controlled with no stick and no throttle feedback. Which means that if there is a massive computer failure in the F-35 , there is only one option: the ejection seat.

VNAV PATH

5th Dec 2014, 20:23

Following industry reflexion, Boeing has modified his UAS procedure on all types. Implementation has been progressive in the last year and a half.

They also revised approach to stall and stall recovery. All types

They also gave caution advise for using PLI = pitch limit indication and FPV flight path vector. 777

d2h

5th Dec 2014, 21:16

Absolutely. Thanks for your true approach of problem.:D

VNAV PATH

6th Dec 2014, 12:49

@winnerhofer :

Amended "stall recovery" maneuver on all Boeing aircraft types changed early 2011. (2009 + 2)

Actually not directly UAS related, but more widely to global surveys of these problems.

PS : you should quit real estate... I read all this topic, but where you talking of an aircraft or a flying computer ? My comment obviously sarcastic .. but not as much as ..

gums

6th Dec 2014, 16:26

Yep, the cosmic FBW system and all its "potections" will prevent stalling the jet. Right. Well...... maybe due to excessive pilot control inputs in "normal" law and fairly benign pitch and roll attitudes.

So over 35 years ago, our small group learned that you could, indeed, stall the F-16, despite all of its "protections". One way was to command max roll rate while at a high AoA and an assymetric load ( think a thousand pounder on one wing and nothing on the other, and a jet that weighs about 22,000 pounds in basic combat mode). So the sucker would depart controlled flight, and the rudder/anti-spin logic resulted in a quick recovery. I actually did a tail slide one day due to a stoopid maneuver while looking at the "bandit". Straight up and got too slow for effective control surfaces. I just let the thing fall over and waited. Sucker came right out once speed got above 100 knots or so.

Our "deep stall" ( not deeply stalled as AF447) mode had the same entry conditions and pilot inputs as AF447. Although we had a dramatically higher pitch attitude, the process was identical. Command a pitch attitude and have the jet lose energy faster than thrust can overcome. As with the 'bus that night, the thing would settle into a fairly gentle "falling leaf" mode. Unlike the 'bus, we had to use a manual mode fo the stabilator, as we had no pitch down authority, but plenty of pitch up authority. So "rock" the pitch attitude and a cycle or two later the nose came down long enough to get effective control.

The big difference in our system was it believed the AoA!! It did this if our pitot-static system went awry. It used the last AoA probe that showed "movement" if the other two were static or frozen.

PJ's war story about his checkout using otto for 90% of the profile scares the hell outta me. I can understand the emphasis upon all the things otto can do, will do, is supposed to do. But first ya gotta learn to fly the plane, huh?

The new jets with FBW are easy to fly, regardless of what features otto has. There's no reason to avoid flying the things "manually", IMHO. It keeps you in the loop, and the Asiana crash shows the result of assuming otto is taking care of business except for pointing the nose.

I do not like the 'bus throttle implementation that has no feedback in most modes. Throttle should move if otto commands the engines to change thrust. The new F-35 has a similar mode for the vertical landing process, admittedly an unusual aircraft maneuver, and the FBW system controls actual thrust according to stick and throttle inputs. Hit the big "mode" button and now throttle controls forward or backward, while stick controls up or down or left/right. Whew!!! Lots easier than the Harrier. The biggie is that the F-35 stick and throttle have "force feedback" determined by control surface load and engine thrust. So you know that you have reached the limits of what otto is trying to do for you.

All for know - poof!

PJ2

6th Dec 2014, 17:14

gums, re, "PJ's war story about his checkout using otto for 90% of the profile scares the hell outta me. I can understand the emphasis upon all the things otto can do, will do, is supposed to do. But first ya gotta learn to fly the plane, huh?"

Well, at the time it wasn't worrying because we knew how to fly transports; we knew high-altitude, swept-wing flight from experience having flown the DC8, DC9, B727 and whatnot so learning the automation was a natural progression.

That was then and now is now, and we have been witnessing the results of that largely-unexamined training policy/priority and yes, it concerns me greatly, otherwise quite frankly I wouldn't be spending time writing about it so often - I believe here we are speaking to a great many new pilots who know less about flying an aircraft than they do about automation, (I hope I am wrong), and so hopefully this discussion from the old guys who truly believe have something to say in this instance, will have some effect in what I consider a very real and pressing problem in our industry, (and in others as they permit their professional responsibilities to be removed to the software engineers' desks).

It is a matter of record that as pilots we brought these issues to the fore decades ago, but the problem was essentially invisible to those governing the industry until AF447 and a few other stall accidents. The difficulty faced is the inertia generated by an entire generation focussed on the magenta line, so to speak.

The individual "testimonials" offered are less relevant than the shift in thinking regarding how automation must serve and not rule or supplant our thinking. That is traditionally a very difficult area for those who are primarily aviators or airline management to think in and do something about.

mm43, re, " Hopefully, a new era is upon us where those involved in air transport ops will also have the same awareness.", I am hopeful too and I see changes but nowhere near sufficient to counter the "vector" that automation has taken us. We are infatuated with technique at the expense of, and which has displaced "the art".

gums

6th Dec 2014, 18:18

I could not agree more with 99% of PJ's thots and opinions. All accrued from thousands of hours ( but prolly less landings than I had with 4,000 hours in lites, heh heh).

Perhaps we need a new thread to air out philosophy and "war stories" and such.

The F-16 was the first USAF jet that a teen age Atari troop could fly with zero knowledge of aerodynamics or anything. Remember, our cosmic system would prevent stalls or pulling too hard or.... We were very concerned about the newbies, and I was the dude that had to develop and conduct the academic training for them.

Well. the fact of the matter was all the brown bars had flown "normal" planes and we only had to remind them that they could not get away with murder exploiting our neat system. So most training was about navigation and tactics, and not how to fly the jet.

Sounds like the new transport checkout concentrates on systems management like we did back in the early 70's in the A-7D and then in the 80's with the Viper and Eagle and Hornet. The big, really big difference for us was that the mission-critical phases of flight required basic airmanship and were not automated.

Thots about a new thread?

PJ2

6th Dec 2014, 23:07

gums, I'll chime in with some thoughts - see how it goes...I'm quite open to starting a new thread, but if I may...

It seems that the AF447 accident attracts these kinds of discussions; - twelve thread's worth in fact! We might even say they're the "go-to" or perhaps the springboard when discussing the kinds of human factors and technical aspects of aircraft automation that this accident in particular, has highlighted and that they're applicable to a wide range of technical and engineering endeavours. We can include the notion of competency, and what it looks like (because it is certainly changing!). What I like about staying on the AF447 threads is that those who may be seeking the lessons from this and other, similar accidents know that this is the place to come.

I''m particularly concerned that those who manage large aviation organizations who may or may not actually fly and who may drop in to PPRuNe will click on "AF447" and begin reading a discussion that is both directly related to their oversight responsibilities and has broader lessons to offer those who have grown up with software/hardware/firmware "solutions" to commercial flight and may not be aware of the "principles of aviation".

I think it is fair to agree that the carrier involved in the accident has lessons for all carriers and operations, both military and commercial, large and small. The mark of a "just culture" is the willingness to discuss such issues with a view to taking the lesson without judgement, for judgement in aviation will always make a fool of one, eventually. The reason why is simple - many carriers are still not learning from others' mistakes...

I have heard first-hand the comment from pilot-managers that their carrier was "beyond an accident" as they had "learned the lessons". I have heard comments that their fleet type doesn't need flight data analysis, for example, because, unlike other fleets (which did have flight data analysis and had "events"), their pilots were good and followed the SOPs and nothing was being reported. Seriously - I have heard this. I am quite sure things have changed since then; I hope so.

Such attitudes are, in and of themselves, precursors to an event. Such attitudes would have a corporate history and a "supporting cast" where groupthink and the value of "concensus" are the unwritten rules by which one maintains one's position within the organization, and who may not even know that their tolerance of such statements fosters the normalization of deviance and a culture of enhanced risk.

I think those interested in finding ways to recognize and possibly change their airline's culture may visit something to do with "AF447" because of the well-known human factors and organizational issues behind the accident. While I believe strongly in the examination of ideas, (philosophy) and also in hangar-flying, not everyone may gravitate to a discussion which would be, in my view, a very worthwhile thread but which value may not be immediately apparent. Despite the contributions wishing to persuade readers one way or another regarding the legal or technical specifics of the causes of the AF447 accident, these twelve threads hold a treasure-trove of experience for new players, in both cockpit and the office.

For most, the lessons of AF447 are now quite far beyond the actual accident itself, and the value of such discussions from contributors who know their stuff and have lived it and can write, like gums for example, is immeasurable for those with eyes and ears and a strong keeness and skepticism.

Lonewolf_50

8th Dec 2014, 13:20

Here's a thought:

It's been about 5 and a half years since AF 447 went down.
Been about three years since the recovery of enough information to understand why.

What has changed?
a. In the industry?
b. In that company?

As I understand it, there was a review/renewal of how to proceed when all three air speed indicators go on holiday at once. (But then, the Pitch and Power chorus already had that answer before the aircraft itself was pulled out of the ocean).

I also understand that upset training has gotten more support.

Does anyone have a sense of the answers to a and b beyond those two points I have there?

vilas

8th Dec 2014, 13:25

Improved equipment, installation of BUSS on airbus aircraft.

VNAV PATH

8th Dec 2014, 14:12

@ Lonewolf 50 :

French DGAC has published an 18 page agenda regarding BEA recommendations and for involved airline. It's a slow process.. document is in french, I think that's unpublishable..

May be our friend Winnerhofer could make us some kind of synthesis as he should have it too.

A33Zab

8th Dec 2014, 22:57

BEA Final Report:

When airspeeds are below 60 kt, the stall warning is no longer available, even though it may be beneficial for it to be available at all times.
Consequently, the BEA recommends that:
EASA require a review of the conditions for the functioning of the stall warning in flight when speed measurements are very low. [Recommendation FRAN-2012-051]

With BUSS activated the SW complies to this recommendation.
this option is still not installed on AF fleet (except on A380 because it is standard equipment)
The BUSS option was available BEFORE AF447.

It seems that requiring an action from the crew to re-engage this automatic system would, on the one hand, lead to a consistency with the autopilot and the autothrust, and on the other hand stimulate a check on the modes and the consistency of the commands presented at the time of the re-engagement.
Consequently, the BEA recommends that:
EASA require a review of the re-display and reconnection logic of the flight directors after their disappearance, in particular to review the conditions in which an action by the crew would be necessary to re-engage them; [Recommendation FRAN-2012-047]

FD will not re-display without crew intervention.

Turbine D

9th Dec 2014, 14:51

Winnerhofer,

You seem to be implying that had AF447 been equipped with BUSS, the accident could have been avoided. An old posting friend of mine jogged my memory regarding the BUSS system which was discussed in previous AF 447 Threads. Having it on AF447 may not have made a difference. First of all, the crew had to recognize the problem was UAS, it seemed that they did recognize the loss of speed, i.e., "We've lost the speeds", but then the AF447 crew never performed the memory UAS/ADR check procedure nor did they recognize what alternate law they were in. The BUSS system simply replaces the pitch and thrust tables which would have been part of the trouble shooting and isolation procedure after UAS recognition and aircraft stabilization, if stabilization corrections were required. The BUSS system becomes active only after all ADRs are shut off. By shutting off all three ADRs with the BUSS, the stall warning protection remains active. Without the BUSS, shutting off 2 ADRs, the stall warning protection remains active. However, if the remaining ADR is affected as in the case with multiple pitot tube icing, the data generated may be inaccurate and flying the pitch and thrust table settings would be the only safe thing to do. In earlier thread discussions regarding the BUSS, my posting friend pointed out that he recalled the BUSS isn't available in altitudes above 25K and once it is enabled, the flight laws can't be change from the direct law it reverts to (a technical discussion item?).

UAS can be a difficult problem to recognize as it can be caused by multiple scenarios which lead to it. IMHO, rapid UAS recognition training is the key ingredient to enhance the crew's ability to quickly detect a UAS situation and then correctly handle it. While the BUSS system is helpful, so were the pitch and thrust tables that were never used…

A33Zab

9th Dec 2014, 18:45

You made some wrong assumptions regarding BUSS.

BUSS is more than a replacement of pitch/thrust tables.
BUSS replaces the speed scale and consists of GREEN, AMBER and RED areas based upon AoA and S/F CONFIG, goal is to fly the GREEN.
next to the scale is a pointer which represents the AoA.
The scale range is 10° AoA CLEAN and 20° in any other CONFIG.

BUSS is not inhibited above FL250 but since frozen pitots is only a temporary issue the FL250 restriction is added to the UAS/ADR CHECK procedure.
Initially there was NO FL restriction at all, however switching off 3 ADRs to activate the BUSS comes with increased workload (FMS, Cabin Press and ALTERNATE law).

The law reversion is to ALTERNATE and NOT to DIRECT LAW.

Having it on AF447 may not have made a difference.

You may be right but it could also have made a different outcome.

john_tullamarine

9th Dec 2014, 19:35

UAS can be a difficult problem to recognize as it can be caused by multiple scenarios which lead to it.

Perhaps .. but this highlights one of the greybeards' concerns in these days of super-automation.

In days past, regardless of widgets, bells and whistles, the flying pilot was always aware of the underlying pitch and thrust settings in relation to what the aeroplane was required to be doing at the time .. ie looking throught the FD to the ball.

If the picture didn't quite gel, there was something awry .. just what that might have been may not have been quite obvious at the time .. but the immediate problem of control was addressed by a constant monitoring of pitch and thrust aligned with comparison between attitude systems to identify what was telling the truth.

If need be the pilot would discount the bells and whistles and go back to DC3 techniques. Not elegant, perhaps, but generally functional.

Progress can have its downside ..

Turbine D

9th Dec 2014, 20:49

A33Zab,

Thanks for your clarifications about the BUSS and the law reversion.
BUSS is more than a replacement of pitch/thrust tables.
I just quoted directly from an Airbus safety article and tried to keep it simple. The article statement read:
In order to decrease the crew workload in case of unreliable speed, Airbus has developed the Back-Up Speed Scale (BUSS) that replaces the pitch and thrust tables. The article was written by Airbus' Flight Operations Engineer and gives some other details such as AOA information being provided through the IRs and not through the ADRs which enables selection of all ADRs off without the loss of stall warning protection. Then, if and when the crew does shut off all 3 ADRs, the Back-Up Speed Scale replaces the PFD speed scale on both PFDs. Also, GPS altitude replaces the Altitude Scale on both PDFs. So then, keeping the pointer in the green (out of the amber or red) is the goal to be achieved by adjusting thrust and pitch thereby keeping above stall speed and below maximum structural speed. The BUSS speed scale was shown with the statement, "Fly the green."
The author concluded with this statement: "In case of any doubt, the pilot should apply the pitch/thrust memory items and then refer to the QRH to safely fly the aircraft and to positively determine the faulty source or sources before eliminating it or them."

Gysbreght

10th Dec 2014, 13:12

With all ADRs off, the stall warning threshold is not adjusted for Mach. Therefore the green band will not keep the airplane out of natural stall warning (buffet) above FL250. Airbus does not recommend the use of BUSS above FL250.

4listair

12th Dec 2014, 20:48

Released today by BEA:
Animation of history of flight [AF 447] based on CVR/FDR data, (12/12/2014):

http://www.bea.aero/fr/enquetes/vol.af.447/videos/animation.deroulement.du.vol.mp4

(This is a 204MB MP4 video streaming download that can be played with the VLC player)

DozyWannabe

13th Dec 2014, 00:21

Yes and AF still don't want it on their existing fleet bar A388 because they spend on marketing rather than safety
On what evidence do you base this assertion?

(And how does a decades-old issue regarding throttle control on Audi cars have anything to do with AF447?)

BUSS is not inhibited above FL250
Right, but as Gysbreght says (and as I'm sure you already know), its use is not recommended above FL250 because the constants used for calculating stall regime become less accurate above that altitude. This is not restricted to the BUSS system, but is likely to be similar on other builders' systems (including Boeing's).

tupungato

13th Dec 2014, 10:26

If someone prefers Youtube version of official BEA animation/simulation released yesterday:

http://www.youtube.com/watch?v=n-hbWO0gL6g

Turbine D

13th Dec 2014, 17:43

Winnerhofer,
To do with Thales Pitots...
Glad you clarified that, I would have never guessed.:confused:
BEA Vid
Instant replay:rolleyes: - See Post #1009 by 4listair

CONF iture

13th Dec 2014, 22:10

Thanks for the YouTube presentation.

But why on earth didn't they include :

The live audio for the warnings and cautions ?
The actual transcript of the CVR ?
The THS movement and position ???

NeoFit

14th Dec 2014, 00:06

4 - The RUDDER movement and position ?

Machinbird

15th Dec 2014, 02:28

As a tactical jet type pilot, the flopping around of the aircraft depicted in the animation instruments is sufficient to identify a stall. I've seen that type of movement before many times.

Too bad none of the guys in AF447's cockpit had ever full stalled and then recovered a jet.

There have to be a number of swept wing former military trainers that could be made available to teach the subject of jet stalls to today's overprotected, computer swaddled, crop of pilots.

I doubt the airlines will fund such training voluntarily. They would have to be directed to by the regulators.

CONF iture

15th Dec 2014, 12:22

But you have to remember how the manufacturer had initially pretented to have eliminated the stall ...

RobertS975

16th Dec 2014, 02:08

The stall warning system shuts down at slower airspeeds. Each time they did the correct move, adding power and/or decreasing AOA, the airspeed would increase and the stall warnings would commence again. Thus , they believed they were doing something to lead to a stall, and they reversed whatever they had done.

If the stall warning system was designed not to shut off at very low airspeeds when the plane was not in the landing config, they might have clearly recognized that they were in a stall.

Qantas_A380

16th Dec 2014, 03:04

I don't buy the argument about blaming the accident on the SW system. The crew ignored it more than 50 times in a row. Why would they suddenly start taking heed of it? And any pilot knows that pulling your nose up will only exacerbate a stall.

I doubt anyone envisaged a pilot pulling up so far into a stall that the airspeeds would make the SW system unreliable. The only way in which I can fault the design of the aircraft in this accident is that it didn't force the nose down in response to the repeated attempts by the co-pilot to pull up. That could have possibly prevented the accident. But also opens a whole new can of worms at the same time.

jcjeant

16th Dec 2014, 05:24

RobertS975
If the stall warning system was designed not to shut off at very low airspeeds when the plane was not in the landing config, they might have clearly recognized that they were in a stall. Not sure as Dozy will answer you that for almost 50 second (at the beginning of the event) the stall warning alarm was active and sounding and the pilot continued to pull on the stick with the result of put the aircraft in a stall
You must find better

rudderrudderrat

16th Dec 2014, 07:45

If the stall warning system was designed not to shut off at very low airspeeds....they might have clearly recognized that they were in a stall.
It certainly may have helped. If you look at the BEA animation posted earlier, none of the pilots seem to have recognised the Altitude Alert "C - Chord " was sounding continuously. It was only interrupted by "Stall Stall" right up until impact. No one attempted to cancel the noise.

That shows how ineffective a constant aural warning becomes. When work load is high, your brain filters out back ground noises and they get ignored. The stall warning needs to have another stimulus, BEA recommended a visual clue. I wish they had gone further and insisted on a hand vibrator through the side sticks as well.
The sound warning alone was ignored in this case, and was completely ineffective.

Oakape

16th Dec 2014, 09:18

I wish they had gone further and insisted on a hand vibrator through the side sticks as well.

So the Airbus doesn't have the equivalent of a stick shaker? How did they get away with that?!

CONF iture

16th Dec 2014, 13:50

Why would they suddenly start taking heed of it?
Because that continuous stall warning period ceased, but unfortunately came back when the left seater applied the most wanted procedure ... which made him quit his stick pushing and confirmed his doubt on the overall FCS integrity.

And any pilot knows that pulling your nose up will only exacerbate a stall.
But the stall warning came back precisely when finally the left seater was pushing the nose down ...

I doubt anyone envisaged a pilot pulling up so far into a stall that the airspeeds would make the SW system unreliable.
The stall warning system behaved as by design but not as by regulation ...

The only way in which I can fault the design of the aircraft in this accident is that it didn't force the nose down in response to the repeated attempts by the co-pilot to pull up.
AUTO THS

BOAC

16th Dec 2014, 15:29

I wish they had gone further and insisted on a hand vibrator through the side sticks as well. - I wish they had adopted my boxing glove system....:sad:

roulishollandais

17th Dec 2014, 01:48

In France Regulators, Airlines, Airbus are connected and not independant:ugh:

vilas

17th Dec 2014, 05:18

We keep going round and round in this thread but I cannot agree that this could have been prevented by this crew who were dealing with a threat they were ill equipped to handle. When it happened they did not know the unreliable air speed procedure, they did not know stall recognition and recovery procedure at high altitude and there was no way they were going to discover by accident. UAR procedure is conducted with attitude and power and this crew was neither hearing any warnings nor looking at PFD. Their actions were as if they were trying to recover blind folded. Why they were so incompetent is another matter. Their airline training procedure for this situation, their performance assessment during that and recurrent training will have something to say.

wiggy

17th Dec 2014, 22:09

There is a lot of cultural baggage behind that reluctance

I take it you are perhaps referring to something along the lines of never ever criticising someone at their place of work....

As an expat living in France I couldn't possibly comment any further.....

DozyWannabe

17th Dec 2014, 22:21

The stall warning system shuts down at slower airspeeds.
That's an inaccurate statement. The SW system is active at all times - but it can't function without valid data from the AoA vanes, and the AoA vanes are only certified to operate above 60kts IAS. The ADRs treat AoA data as invalid below that IAS, but the knock-on effect on the SW system was likely unforeseen.

As QA380 said:
I doubt anyone envisaged a pilot pulling up so far into a stall that the airspeeds would make the SW system unreliable.

I wish they had gone further and insisted on a hand vibrator through the side sticks as well.
It might have helped, but the truth is that the tactile shaker has also been ignored or disregarded on a significant number of occasions in the past.

So does the B77W do it better?
Different scenario entirely (failed IR accelerometers in the ADIRU - air data was OK). Indicated airspeed never dropped below 158kts. It's been pointed out repeatedly on earlier threads that other manufacturers have been very quiet on the subject of what invalid AoA data will do to their SW systems, which I suspect indicates that the result (SW cessation) would be similar on other types.

In France Regulators, Airlines, Airbus are connected and not independant:ugh:
Rubbish. The French state currently holds less than a 12% stake in Airbus Group (formerly EADS): Airbus Group - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Airbus_Group)

DozyWannabe

17th Dec 2014, 23:12

I don't know - in what scenario do you mean?

DozyWannabe

17th Dec 2014, 23:34

Right, but it's not really particularly relevant - all it means is that for brief periods, both the AoA and IAS data were effectively NCD. It wouldn't make much difference.

Peter H

18th Dec 2014, 00:10

DozyWannabe Right, but it's not really particularly relevant - all it means is that for brief periods, both the AoA and IAS data were effectively NCD. It wouldn't make much difference. IIRC it shut off the stall warning horn until the measurements recovered.

Shutting off the stall warning cannot have helped the pilots understanding of the situation.

IIRC the stall warning came back on again just after somebody had tried nose-down, a combination of events which could be considered positively misleading.

DozyWannabe

18th Dec 2014, 00:51

NCD? What is it?
No Computed Data - i.e. the value is invalid and cannot be used for further processing.

IIRC it shut off the stall warning horn until the measurements recovered.
That was a secondary consequence (or "side effect" in engineering-speak) of the systems design as a whole. The SW ceased because it was no longer receiving valid data from upstream - there was no design intent to "shut off" the SW directly.

Shutting off the stall warning cannot have helped the pilots understanding of the situation.
Undoubtedly.

IIRC the stall warning came back on again just after somebody had tried nose-down, a combination of events which could be considered positively misleading.
Yes - but we've got to remember that what we're talking about with AF447 is a scenario which would have previously been considered a massive outlier on the probability curve. Namely that the crew would deliberately put the aircraft into a stall condition, hold it there through almost a minute of stall warning and continue to pull up until the airflow over the sensors rendered the information nonsensical.

We've been over this many times in earlier threads, and the fact is that if you latch stall warning for one scenario, it runs the risk of giving false information in several other scenarios. It's a very difficult system to make completely failsafe across the board - and as I repeated above, the silence from other airframers does tend to suggest that their systems would have behaved in a similar manner.

(And as an aside - a pilot with any basic knowledge of aerodynamics should be able to work out that a SW triggered by a nose-down input means something hinky is going on...)

jcjeant

18th Dec 2014, 15:58

Dozy
(And as an aside - a pilot with any basic knowledge of aerodynamics should be able to work out that a SW triggered by a nose-down input means something hinky is going on...) No basic knowledge of aerodynamics ?
So what the hell does these 3 pilots in the pointy end of a A330 ?
Who (allow) permit that ?

Calapine

18th Dec 2014, 19:01

Hello. Question from a layperson following the discussion: The BEA report states that 61 sec after the AP disconnect all three pitot probes were working again. Would it have been possible for the pilots at this point to return to Normal Law and possibly activate the AP again? Or would have the stall (near stall?) situation prevented that?

DozyWannabe

18th Dec 2014, 19:47

@jcj - I didn't say the crew had no basic knowledge of aerodynamics, I just stated that a pilot with a basic knowledge of aerodynamics should (given sufficient time to think) be able to work out that something was wrong if the SW sounded in response to putting the nose down (and consequently *reducing* AoA).

What we've discussed several times in these threads and many others is that while all pilots must have a grounding in the basics of aerodynamics (principles of flight, thrust, lift, AoA, stall etc.) in order to get their PPL - it seems that once in the ATPL world, recurrent training does not seem to refresh any of that knowledge periodically.

Once the plane is in ALT, it remains in ALT until overseen by maintenance.
Not exactly - Alternate Law is only "latched" (as in cannot revert to Normal) if the divergent conditions last for more than 10 seconds. A transient condition of less than 10 seconds will allow for a return to Normal Law in flight.

In this case the pitot tubes were blocked for too long and Alt2B was latched.

Qantas_A380

18th Dec 2014, 20:45

I must say I agree with Dozy in regards to the stall warning shutting off without valid data. Allowing it to operate with invalid data may indeed see more false stall warning alarms and pilots may begin to distrust the system.

It was unfortunate that the SW activated in response to ND input but basic airmanship must come into play here and identify that a nose down input cannot exacerbate a stall.

Does anyone know how SW systems operate on other aircraft without valid data?

DozyWannabe

18th Dec 2014, 23:30

There are no "land phases" to "bar".

Alternate Law transitions to Direct when landing gear is selected down - the only significant difference (other than minor changes in handling characteristics) between that and normal operation is the possible need for manual pitch trim correction. And as such the "USE MAN PITCH TRIM" message is displayed on the PFD.

All in all it should be fairly transparent with no "gotchas".

CONF iture

19th Dec 2014, 05:31

Alternate Law transitions to Direct when landing gear is selected down - the only significant difference (other than minor changes in handling characteristics) between that and normal operation is the possible need for manual pitch trim correction. And as such the "USE MAN PITCH TRIM" message is displayed on the PFD.
Rubbish too.

Bpalmer

19th Dec 2014, 07:01

Alternate law transitioning to Direct at gear down is an A320 not A330

Alternate law pitch control is similar to normal law. Alternate law has maneuver protection, automatic pitch trim, and ground and landing modes identical to normal law. Therefore, at 100 ft RA pitch control enters landing mode, which is close to direct law - but not exactly.

Flare mode affects only pitch and provides a direct stick-to-elevator relationship. Automatic pitch trim is disabled, but manual pitch trim is available if needed. Therefore the airplane exhibits its natural aerodynamic positive speed stability (that is, it tends to pitch down if slowed below the trimmed airspeed).
The Flare mode is blended in from Flight mode over a period of two seconds when descending below 100 feet radio altitude.
At 50 feet, a slight pitch down elevator order is applied. The purpose is to generate a more natural feel in the flare where the pilot has to move the sidestick aft to achieve a progressive flare and allow the nose to derotate after touchdown.
In contrast, if the flight-mode pitch law were to remain in effect, the sidestick would have to be neutralized once the flare attitude was reached and then after touchdown moved forward to lower the nose before the tail became aerodynamically ineffective.
Airbus has described Flare mode as “a smoother Direct law” as it has some damping provided by load factor and pitch rate feedbacks. High angle of attack protection and bank angle protection are both provided in the flare mode, though neither component is available in the actual Direct law. Pitch attitude, load factor, and high speed protection, however, are not provided.
In cases where both radio altimeters are inoperative, the normal trigger point for the Flare mode to engage cannot be determined, so Flare mode engages when both the autopilot is off and the landing gear is down. In that event, alpha floor (an autothrust function) also remains available, though it is normally disabled at 100 feet RA.
Upon touchdown, Ground mode blends in over a two second period for pitch, and the roll mode is blended in within two seconds of being on the ground and the pitch attitude decreasing below 2.5°.

DozyWannabe

19th Dec 2014, 13:45

Alternate law transitioning to Direct at gear down is an A320 not A330

Correct - I was having trouble finding hard data on the A330/340, so went with this A320 document: http://www.737ng.co.uk/a320training.pdf

in the interim.

(Page 15 of the PDF, Page 13 : "Normal Procedures") of the document.

VNAV PATH

19th Dec 2014, 16:27

quoting Herr Winnerhofer, post 999

Yes and AF still don't want it on their existing fleet bar A388 because they spend on marketing rather than safety so you see that the BEA's recommendation to make BUSS standard is not implemented just as their long list which has invisibly fallen by the wayside.
Incredibly, none of AF's pilots even whispered the issue of BUSS so it really takes two to tango.

Definitely not about AF A380 BUSS option..you should learn better tango.

Just from insider old chap, A 380 driver: AF 380 have been BUSS equiped and from the beginning of deliveries.

PS: ah nos bons vieux MD avec leurs sièges en cuir. Cheers.

A33Zab

19th Dec 2014, 18:14

A380(& A350) comes with BUSS standard, there is NO option to leave it out. :ok:

C_Star

19th Dec 2014, 18:24

Hi A33Zab,

Apologize for posting slightly off-topic, but since you're here (and the subject has been touchhed in posts above),

Is the Flare Law in the A330 similar to the A320? The FCOM wording seems to differ a bit between the two. I wonder if it's just a wording issue, or the A330 Flare Law is implemented differently, due to size of the a/c or other reasons...

C_Star

19th Dec 2014, 19:09

Airbus has Laws, Boeing has Modes.... :8

VNAV PATH

20th Dec 2014, 03:12

From Airbus FCTM and from instructor support :

FLIGHT MODE ANNUNCIATOR
The FMA is located at the top of the PFD screens. It is divided into 5 columns
which indicate the operational modes of the AP, A/THR and FD. The columns
are numbered from the left and indicate the following:

The relation between the pilot input on the stick and the aircraft response is called the CONTROL LAW which determines the HANDLING CHARACTERISTICS of the A/C.

A33Zab

20th Dec 2014, 07:11

@C_Star:

BPalmers explanation is extensive and correct if all works as advertised.
In ALTERNATE - if due to multiple ADIRUs faults - do not rely on Hi AoA protection/Vc protection (ALT1) to kick in.

@Winnerhofer:

C_Star is correct: it is FLARE LAW not FLARE MODE.

vilas

20th Dec 2014, 08:21

Winnerhofer
Basically Law is manner of flight controls response to side stick input. It uses the word mode as ground mode, flight mode and flare mode to define different laws in operation during that phase. Also it uses word mode to define phase of FMGC like Take off, Descent cruise etc. For instance in one document it says Thrust levers are also mode selectors meaning they can change the phase. It is used loosely.

roulishollandais

20th Dec 2014, 17:47

After five+ years of discussion about AF447 flight laws we start to search the definition of the words "law" and "mode" ...:{

Calapine

20th Dec 2014, 17:54

Quote:
Originally Posted by Winnerhofer http://www.pprune.org/images/buttons/viewpost.gif (http://www.pprune.org/tech-log/539756-af-447-thread-no-12-a-post8788871.html#post8788871)
Once the plane is in ALT, it remains in ALT until overseen by maintenance.

Not exactly - Alternate Law is only "latched" (as in cannot revert to Normal) if the divergent conditions last for more than 10 seconds. A transient condition of less than 10 seconds will allow for a return to Normal Law in flight.

In this case the pitot tubes were blocked for too long and Alt2B was latched. Thank you both. :)

I have been lurking on the forums a while, but left the discussion to the experts. So with the big disclaimer that this is all coming from a non-pilot, there is one aspect that has been standing out for me:

It is astounding how much into a 'tunnel visoned' Bonin must have been to miss that he was having the plane in climb for a total minute. It was night outside and it seems he left all the ECAM trouble shooting to his partner, so his eyes must have been on the PFD. Yet he seemed to ignore the altitude display, with the numbers constantly changing, aswell as the the climb/sink rate rate gauge.

After around 25 seconds in, at FL 368 Robert tells him to mind his height, and Bonin explicitly acknowledges it ("Ok ok je redescends"). Some nose-down inputs on the stick follow, but, for a lack of better phrase, the stress must have pushed "height awareness" out of his mind again, as he continued climbing up to finally FL 378.

It seems during those 60 seconds pre-stall a simple realisation like "My supposed FL is 350. I am 2000 feet above my FL, I must descend!" never materialised.

In this thread and in the BEA report the term "startle effect" is brought up several times and it feels to be spot on. It's very hard to read the transcript and not think "If only Robert had been more insisting after he noticed the wrong attitude".

CONF iture

20th Dec 2014, 18:48

it is FLARE LAW not FLARE MODE
FLARE MODE does exist too.
Actually Airbus is not too sure how to name it ...

EMIT

20th Dec 2014, 23:07

The official BEA video representation of the recorded flight data is meant for professionals.
So, how does it look for a professional?

First of all, of course, a professional had already read all the available reports, interim and final. From the data, presented in those reports, a professional had already understood fully what had transpired on the flight deck of AF447.
Still, reading data from graphs, spread out over several pages, makes it somewhat awkward to integrate, for instance, the stick movements with the aircraft attitude variations.
The video does this information integration very nicely.

Earlier in the whole discussion about AF447, somebody made a remark about the steering commands of the PF as if he was stirring mayonnaise in a mixing bowl. The video nicely illustrates that concept. The wild left / right gyrations of the sidestick do not seem to be justified by aircraft roll behavior.

The total lack of situational awareness is illustrated by the useless slam forward / slam backward movements with the thrust levers and by the utter disregard for the pitch attitude.

One can understand the tendency to initially start a correction in the upward direction, because the altimeter did dip down a couple hundred feet at the start of the event. However, there seems to be no target at all to strive towards resettling at FL350. It is all just blind panic to yank on the stick.

An airliner at optimum cruise level has a pitch attitude of about 2.5 degrees nose up. The usual climb rate when optimum cruise level is reached, is 1.000 to 1.500 ft/minute. When a step climb is made, the engine thrust is sufficient only to sustain an increase in pitch attitude of about 1 degree!
In normal words, an airliner at cruise level is as fit as an old geezer. There is no way that an airliner at cruise level can sustain 10 or 15 degrees pitch up attitude without massive loss of airspeed.
Still, the video shows that just before the apex of the pull-up, there is a pull movement of the sidestick that shortly yanks the nose up to a whopping 18 degrees.

The only reasonable explanation for the steering behavior is a panic mode, right from the start – but, the text from the CVR transcript had already shown that, the hapless comments, …. .

Secondly, the video opens up again the hamster wheel of arguments about, if this had been different in Airbus, or that had been different in Air France - Baloney!

Judging from accidents worldwide and on all types of aircraft, a certain percentage of pilots has no clue about real flying, no matter how many hours they have cruised airliners through the sky. Would stick shakers, interconnected yokes or simple old fashioned flight control systems have made any difference? NO.

Look at West Carribean MD-82, 16 august 2005, over Venezuela, stick shaker ON, stall and yoke fully back all the way from FL330 into the ground. Besides the rattling stick shaker, there was also the call from the First officer, "Captain, this is full stall, full stall!"

Look at Swiftair MD-83, 24 july 2014, yes, this year, over Mali, stick shaker ON, stall, wingdip over left and guess what were the yoke inputs all the way down from FL310 until just before impact? Full backstick and right roll!

Especially in that latest case, there is no excuse possible along the lines of – how could we know? Well, by soaking up aviation knowledge perhaps, after all that has been discussed in the aviation world since 1 june 2009, the fatal date for AF447.

A33Zab

21st Dec 2014, 06:41

Actually Airbus is not too sure how to name it ...

True,

AMM is more consequent about naming:
FLARE LAW if as a function of EFCS
FLARE MODE if as a function of AP/FD.

vilas

21st Dec 2014, 10:46

A33Zab
As I said these terms are used loosely. Following is from A330 and A320 FCOM respectively where it says MODE. There is a little bit of difference between A330 and A320.

FLARE MODE

Ident.: DSC-27-20-10-20-00000273.0001001 / 23 JUL 12

Applicable to: ALL

When the aircraft passes 100 ft RA, the THS is frozen and the normal flight mode changes to flare mode as the aircraft descends to land. Flare mode is essentially a direct stick-to-elevator relationship (with some damping provided by the load factor and the pitch rate feedbacks). At 50 ft, a slight pitch down elevator order is applied. Consequently, to flare the aircraft, a gentle nose-up action by the pilot is required.

FLARE MODE

Ident.: DSC-27-20-10-20-00001071.0001001 / 23 JUL 12

Applicable to: ALL

When the aircraft passes 50 ft RA, the THS is frozen and the normal flight mode changes to flare mode as the aircraft descends to land. Flare mode is essentially a direct stick-to-elevator relationship (with some damping provided by the load factor and the pitch rate feedbacks).
The system memorizes the aircraft's attitude at 50 ft, and it becomes the initial reference for pitch attitude control.
As the aircraft descends through 30 ft, the system begins to reduce the pitch attitude to -2 °nose down over a period of 8 s. Consequently, to flare the aircraft, a gentle nose-up action by the pilot is required.

A33Zab

21st Dec 2014, 13:33

You have convinced me,
They should change MODE here into LAW (like in FCTM/ISD/AMM) to prevent confusion with AP/FD Flare Mode.

jcjeant

22nd Dec 2014, 15:15

EMIT
Judging from accidents worldwide and on all types of aircraft, a certain percentage of pilots has no clue about real flying, no matter how many hours they have cruised airliners through the sky. Would stick shakers, interconnected yokes or simple old fashioned flight control systems have made any difference? NO.However Air France through his spokesman E. Schramm said maximum competence was present in the person of the 3 pilots in the cockpit of AF447
It just remains to explain why these 3 pilots have not practiced these skill during the decisive 4 minutes of the flight Rio Paris

Cool Guys

23rd Dec 2014, 21:54

Emit

Would stick shakers, interconnected yokes or simple old fashioned flight control systems have made any difference?

How much difference do the side sticks, detents, laws, sub laws, modes, conditions that only occur if the plane above a certain speed, hight, wheels down etc etc etc etc etc etc make? Im not saying these things are totally useless but a modern western commercial plane with significantly less of these complexities does not have a noticably higher accident rate? Does does the extra complexity counter their potenial benifit. Genuine question.

Qantas_A380

29th Dec 2014, 22:20

It would appear at this stage to be related to the thunderstorm activity along the flight path.

We all thought that we wouldn't see pilots pulling up into a stall again repeatedly but it happened in the swift air MD-83 accident this year.

If this turns out to be a stall/weather related accident that will be the 5th in the last 10 years (West Carribean, Colgan, AF447 & Swift Air so far).

Perhaps it is time to install stick/yoke pushers that automatically push the nose down upon repeated Stall Warnings?

DozyWannabe

29th Dec 2014, 23:07

Why didn't the BEA do this filmed just as TSB did?

Presumably because it was a different scenario. As I've said before, with SR111 the most glaring outcome regarding procedure was that the cockpit smoke procedures were not fit for purpose because the procedures took too long to follow and did not take into account the possibility of an immediate need to land. With AF447, the crew did not follow any published procedures, so there was no need for that kind of experiment.

Perhaps it is time to install stick/yoke pushers that automatically push the nose down upon repeated Stall Warnings?

The problem with that is that in the event of sensor/air data failure, there's always the possibility that the sensors could return a false Stall Warning. Airbus (and presumably Boeing, MD et al.) made a design decision that in the event of such failures, the presumption should be that the pilot knows more than the systems, and that the systems should therefore defer to the pilot.

Turbine D

30th Dec 2014, 22:06

Originally posted by Winnerhofer:
Club 410, Club 430 and QZ's QRH

What, if anything, does this have to do with this thread, AF 447? We need to be told…

noske

31st Dec 2014, 13:39

Club 410, Club 430 and QZ's QRH

What, if anything, does this have to do with this thread, AF 447? We need to be told…
Regarding Club 410, the connection would be that the Pinnacle crash was mentioned in the AF447 report, since it involved a stall at cruise altitude. Other than that, there are more differences than similarities.

The Pinnacle crew were quite aware that they were pushing the performance limits of their aircraft, and they had already made a request to descend. The stall occured after ATC had told them to stand by, and apparently they feared the stall less than a descent without clearance (which would have drawn more attention to the foolishness of their little joyride).
The Pinnacle crew recovered from the stall at first, losing only about 3000 feet, if I recall correctly. That would somehow fit with the description of the accident Captain by one of his colleagues as "the best stick-and-rudder pilot" he could think of.
Anyway, while the stall was an essential part of that accident sequence, too, it was not the immediate cause of the crash.

Turbine D

31st Dec 2014, 14:41

Originally Posted by Winnerhofer:
Here, for instance, is a Brazilian A330 crew dealing with a similar airspeed malfunction in 2003, according to a BEA report:
36 incidents of UAS on A-330/A-340 aircraft were tabulated prior to the BEA issuing Interim Report #2 on AF 447. The Brazilian incident was one of them. All 36 crews managed to recover safely by recognizing and executing recoveries by one method or another.
What I would like to point out to you is the fact that there is a wealth of information about AF 447 contained in the previous 11 Threads. Going through the threads would save you internet surfing time and repeating AF 447 information that has been already covered and discussed.
Below is a chart that was presented and discussed in AF 447, Thread #8…

http://i1166.photobucket.com/albums/q609/DaveK72/UASEvents.png (http://s1166.photobucket.com/user/DaveK72/media/UASEvents.png.html)

Qantas_A380

1st Jan 2015, 23:36

Looks like nearly all those events occurred in tropical regions. These days it may pay to be on extra alert when traversing tropical thunderstorms (especially if you cannot divert upwind) and be ready for either iced pitot tubes or iced AOA vanes.

Surprising how many events triggered stall warnings. I assume they were generated because of pilots pulling back on the stick upon autopilot disconnection. Baffling why Bonin was the only pilot who didn't drop the nose upon stall warning though.

Dperk

1st Jan 2015, 23:50

I just watched a tv special on AF 447.

In my plane I have a Garmin 696 that will display GPS derived flight instruments. Ground speed, Altitude, Vertical speed, Heading, and Turn.
I have it in case my no backup instruments (G 300) fail. It seems such data might have have helped with the confusion created when the pitot tubes iced.

Is such data available in an airbus?

Turbine D

2nd Jan 2015, 00:23

Hi Qantas_A380,

I think what happens is this: The ice buildup rates temporarily exceed the capability of the anti-icing pitot heater. The entrance to the pitot tube is blocked, but the pitot probe drain hole remains open. The sensed Pt drops quickly towards static pressure (Ps). The IAS drops quickly towards stall speed (or stick shaker if one is present), hence the stall warning. The IAS remains affected, usually for a short period, until the heater catches up once again and the blockage is cleared.

I don't know exactly why nose up occurs in some situations, each one may be different depending on what the crew observes and decides to do. For instance, if the crew decides they need more power to overcome a perceived stall, they may apply TOGA thrust which will cause a pitch-up in aircraft where the engines are mounted under the wings. Anyhow, I hope this explanation helps…

Qantas_A380

2nd Jan 2015, 02:39

I was of the understanding that Stall Warning is based on AOA rather than IAS?

A33Zab

2nd Jan 2015, 09:36

True but there is MACH involved to set the AoA SW limits.
Now a lower MACH will increase the AoA SW limit but it's the suddenly returning MACH (some overshoot)
which will trigger a complete "STALL STALL" or incomplete "STALL ST" SW.
Whether it was a false (UNDUE) or actual STALL WARNING (Hi AOA) is not mentioned in the table.

RobertS975

2nd Jan 2015, 13:31

As stated previously, the stall warning system shuts down below a certain IAS... cannot recall exactly, but 80kts or so. So one factor which I believe contributed to the confusion in that cockpit was that when they made the moves to reduce AoA and increase airspeed, the stall warnings would activate as the plane accelerated past 80kts (or whatever the stall system cutoff is). They then reasoned that whatever they had just done put them into a stall, and reversed their control inputs to make the situation worse.

Early to speculate, but let's keep our eye on this stall warning inactivation/activation speed as a potential factor in Air Asia.

DozyWannabe

2nd Jan 2015, 22:22

As stated previously, the stall warning system shuts down below a certain IAS... cannot recall exactly, but 80kts or so.
The AoA vanes are only certified to produce valid information above 60kts IAS. As I said earlier:
No Computed Data - i.e. the value is invalid and cannot be used for further processing.

That was a secondary consequence (or "side effect" in engineering-speak) of the systems design as a whole. The SW ceased because it was no longer receiving valid data from upstream - there was no design intent to "shut off" the SW directly.
...
We've been over this many times in earlier threads, and the fact is that if you latch stall warning for one scenario, it runs the risk of giving false information in several other scenarios. It's a very difficult system to make completely failsafe across the board - and as I repeated above, the silence from other airframers does tend to suggest that their systems would have behaved in a similar manner.

...They then reasoned that whatever they had just done put them into a stall, and reversed their control inputs to make the situation worse.
I also stated in that post that a bit of thought on that point should have indicated a problem with the SW system rather than the ND input causing a stall, because lowering the nose reduces AoA, and basic aerodynamic knowledge (which pilots should have) of the facts states that it is effectively impossible to go from an unstalled state to a stalled state by reducing AoA.

Put in more basic terms, there is no way that lowering the nose (and reducing AoA) should stall the aircraft. It may have added to the confusion, but I'd be surprised if they thought they'd put the aircraft in a stall by commanding Nose-Down.

If we're going to speculate on the AirAsia front, I reckon this thread should go a bit quieter now...

jcjeant

4th Jan 2015, 15:49

Details here for this AD 2014-0267-E and 2014-0266-E
Airplane Flight Manual – Undue Activation of Alpha Protection – Emergency Procedure
EASA Airworthiness Directives Publishing Tool (http://ad.easa.europa.eu/page-3)

Machinbird

10th Jan 2015, 20:16

Having flown gliders, fast jets, (and the boxes they came in :}) I believe I'm able to comment.
Personally, I don't think glider flying would help that much. Bonin, for example was alleged to be a glider pilot, but when the chips were down, he became another Whac-A-Mole pilot, responding to roll deviations with great speed but ignoring pitch deviations and losing the big picture.

The best training I have encountered for aircraft handling at the edge of the envelope is ACM (Air Combat Maneuvering against another aircraft of similar performance). To do good ACM requires an AOA gage of some sort. Unfortunately the required equipment is not available to most pilots who could benefit from that type of training.

By comparison, thermaling competitively against another glider in the same thermal is a pale imitation.

Maybe what pilots need is solid skill at flying the aircraft manually so that when Hal no longer computes, you can take over successfully and avoid having to demonstrate superior maneuvering skills.

VNAV PATH

10th Jan 2015, 20:35

Indeed, Machinbird

If glider is certainly a good step in early pilot curriculum, I do not see his benefit for kind of recurrent training (same idea for light aircraft recurrent training)

How a glider, a Cessna, whatsoever, could be helpful to restitute pilot feeling when this pilot will probably fly an aircraft with autotrim, without real effort restitution on joystick, without moving thrust levers and different flight controls laws...

Illusion..

etudiant

10th Jan 2015, 23:39

Cedric Bonin, the PF on AF 447, was a qualified glider pilot.
So the flying experience gained in gliders does not automatically translate into superior airmanship when facing turbulence at night with unreliable instruments.

Machinbird

11th Jan 2015, 19:24

A/P was not responsible for lowering the nose, either to increase airspeed or otherwise. Winnerhofer, are you planning on recreating the AF447 discussions?:rolleyes:
Every aspect of this accident was dissected in fine detail in the voluminous threads on the subject. Just read through them and understand them, painful though that may be.

For myself, I'm always willing to listen to new evidence, but a rehash just turns my stomach.

john_tullamarine

12th Jan 2015, 10:02

Concur .. if a need to look back is considered necessary, please just link to the old post of note and add any new data/thoughts.

jcjeant

12th Jan 2015, 19:32

Hi,

VNAV PATH
How a glider, a Cessna, whatsoever, could be helpful to restitute pilot feeling when this pilot will probably fly an aircraft with autotrim, without real effort restitution on joystick, without moving thrust levers and different flight controls laws...

It's like learn and train in this .....

http://i.imgur.com/7qgDZtC.jpg

For drive this ....

http://i.imgur.com/4y3eycZ.jpg

Bpalmer

13th Jan 2015, 03:21

Unfortunately, we don't know much, if anything, about his glider qualifications. We don't know if he took a weekend glider transition course or had 1000 hours.

As a glider pilot myself (and A330 Capt), I was surprised when I first learned that Bonin was a glider pilot yet failed to push the nose down in reaction to a stall warning that persisted for over 50 seconds! Obviously, in the glider, there is no other recovery available. We fly on the edge of a stall routinely, recognizing the impending stall condition by feel - as there is no audible warning system.

I remain a strong advocate of hand flying aircraft such as gliders to counteract a case of flight director addiction ( which I will go out on a limb and accuse Bonin and Robert of having).

In 1986 we could assume that anybody that showed up in an airline course already had thousands of hours of round-dial instrument flying. Checking out in an advanced aircraft (757 at the time) was a matter of teaching the automation. Now, the assumption of those skills is a poor bet. Throwing a guy out of flight school into the right seat of an A320, then A330/340 and rarely if ever practicing those FD off skills is like asking an adult to perform the piano song he learned as a child - on stage, under pressure, with no notice.

Yeah, I DO think my glider time has helped me keep some skills. But only because I put some effort into it. I try to think about the aerodynamics, the micro-meteorology, and such things because they are key to success in a glider.

It's easy to sit back, do whatever the FD says (it's never been wrong yet...), punch on the AP, and type my way to the destination. That does take knowledge and skill, but its a different knowledge and skill than hand flying the machine with out any automation, in alternate law, at altitude, in a storm at night. The later requires some practice. Practice few long haul guys get much of.

PJ2

13th Jan 2015, 15:13

Capt. Palmer;

Even as late as the A320/A330/A340 Airbus types, I still recall the value of "looking through" the FDs to the real picture / situation behind.

If I recall correctly, the Japan Airlines DC8-62 accident, (report) (http://www.airdisaster.com/reports/ntsb/AAR70-02.pdf) resulted from the captain not understanding the FD and followed it taking the aircraft below the glide slope.

Those of us now retired or about to retire may still recall the elementary FDs of Douglas and Boeing aircraft, (the L1011s was a bit more sophisticated at the time) and quietly developed the habit of looking through the directors to the actual information on the HSI, (for others, Horizontal Situation Indicator).

The value of this subtle, psychological "work-around", (evolving as it did through lack of sophistication of the FDs at the time, and a mistrust and a lack of training/knowledge of the FD) remained a useful (and for situations like AF447, and indispensible) "tool" as it was always the "sober second opinion" when more sophisticated FDs such as the Airbus' FDs were incorporated with the autoflight system.

Not saying ignore the FDs...just bear in mind what's actually going on "behind" them - one is for real, the other tells you what the autoflight is going to do, not necessarily what it's doing!

When it came time for manually flying a raw-data, (no FDs) ILS approach, the view of the actual aircraft situation without the FDs and other symbols was "normal"... even as the standards people might frown on such methods.

The simulator can, and today should, be used for such basic skills training and examination.

Try the following exercise next time there are a few moments spare time, (rare, I know) in the sim:

Establish level flight at 10,000ft, 250kts. With no FDs, no heading bugs and no autopilot or autothrust, begin a coordinated climb to 15,000ft while turning 90deg to the left and when reaching that heading, turning back to the original heading, all at 250kts, capturing the target altitude smoothly, (ie, most "passengers", (this IS the sim!), would not know you've leveled off. Then immediately begin a descent to return to 10,000ft, maintaining 250kts, while turning to the right 90deg and then when reaching that heading, turning back to the original heading, leveling off at 10,000ft. Remember, no autothrust! - you've got to know the power settings, attitudes, control-column/stick pressures to do it all well and your scan has to be near-flawless, whether steam or glass.

Variations while doing these climbing/descending S-turns would be to start the exercise at 10,000ft with the first or second flap selection made, then begin the climbing S turn while cleaning up, accel to 250kts, level off, then reverse the process ending up at the flap selection/speed one began with.

These weren't standard in the sim but they weren't rare either. They test one's abilities far better than the standard V1 cuts and should be in the syllabus for every sim session, (takes about a half hour of time).

Enjoying your book...many thanks for writing it.

vilas

13th Jan 2015, 15:48

PJ2
For a long time now Airbus has introduced Entrée level training for non jet experienced pilots. The type rating starts with 8 sessions of Flight and Navigation Procedure Training out of which first four sessions consists of raw data flying without any automation whatsoever including climbing and descending S turns as you mentioned. It goes on to execute departures, arrivals and ILS approaches with introductions to some abnormal conditions with aim to develop control and multi crew cooperation. This is to be conducted in a flight training device may be in SIM without motion. Procedures are taught at later stage. However to save cost airlines opt for a shorter course which is mostly conducted in a procedure trainer instead of FTD. That requires trainees who have better hand eye coordination than average.

john_tullamarine

13th Jan 2015, 19:49

Try the following exercise next time there are a few moments spare time

We used this as the standard endorsement introduction on the 737 albeit with an accel/decel requirement to push the scan rate. Once the student demonstrated competence on this basic exercise, we threw in a few more demanding exercises for polish.

Gentle encouragement and patter (where useful) saw rapid progress for the great majority of pilots. Conversely, the exercises even more rapidly identified the few who were way out of their depth.

Likewise, throughout the endorsement, we took advantage of 5 minute vignettes here and there to run the close in part of a raw data, hand flown ILS to progressively decreasing minima .. worked a treat with most achieving a good 0/0 landing by the end of the endorsement program ... great confidence builder.

PJ2

13th Jan 2015, 21:14

Indeed it is, John, interesting to know you've seen it in action too. I agree completely with the approach taken...gentle encouragement and patter.

I think there is far less to the differences between small, single/no engine types and large transports than may be generally assumed. Most can quickly learn the need for staying ahead of the aircraft , whether it is a half-mile or six miles - the learning of the "art" comes together in all-of-a-sudden ways by plateaus so to speak, doesn't it?

In fact I will go out on a limb and say that this approach can make a 250hr pilot an able and keen learner who goes on to become a very competent aviator.

I don't think there's more to the automation "problem" than the re-introduction of such basic manoeuvres. Automation is then relegated to serving the pilot, and when it goes pear-shaped taking over becomes a non-event.

And, it would accomplish that second purpose as well - identifying those who were (currently) way out of their depth so that they could either benefit from further training or help identify that subtle place that may say, "this isn't for me".

john_tullamarine

13th Jan 2015, 22:32

I will go out on a limb and say that this approach can make a 250hr pilot an able and keen learner who goes on to become a very competent aviator.

Indeed.

Having trained numerous cadet pilots in that experience bracket I have seen it work well .. a lack of depth, naturally enough, which comes with subsequent line exposure ..

One of my favourite students from quite a few years ago was a young Chinese cadet pilot with Xiamen .. keen as mustard, a very quick learner, and good stick and rudder technique. Last I heard he was a left seater in a widebody and doing quite nicely in his career.

DozyWannabe

14th Jan 2015, 21:28

Unfortunately, we don't know much, if anything, about his glider qualifications. We don't know if he took a weekend glider transition course or had 1000 hours.

The AF447 final report notes that he qualified as a glider pilot in 2001. Alas, I can no longer find the specific details, but I do recall there was once an article online which enumerated F/O Bonin's gliding experience and qualifications. Based on what I remember (caveat emptor, as usual), he had dedicated significant time and effort to the practice with a couple of advanced qualifications to his name. I don't know how that translates to specific hours logged, but the implication was that he'd had significant time and was very competent at one stage.

CONF iture

14th Jan 2015, 21:30

Unfortunately, we don't know much, if anything, about his glider qualifications. We don't know if he took a weekend glider transition course or had 1000 hours.
Apparently, part of the ab initio training at AF, the students spend one week in St-Auban.
min 41 in the TV program : AF en quête de sécurité

Clandestino

19th Jan 2015, 21:52

Look at Swiftair MD-83, 24 july 2014, yes, this year, over Mali, stick shaker ON, stall, wingdip over left and guess what were the yoke inputs all the way down from FL310 until just before impact? Full backstick and right roll!Yup, it seems that demise of Spanish crew, flying Spanish registered narrowbody, built in USA and out of production, plowing the skies of Africa, does not produce enough outrage to make the PPRuNe discussion worthwhile. Also it would somehow damage the positions of those who claim that kids today can't fly and are stalling aeroplanes because they are inexperienced to note that the commander was 14 000 hrs TRE.
Judging from accidents worldwide and on all types of aircraft, a certain percentage of pilots has no clue about real flying, no matter how many hours they have cruised airliners through the sky.

It is not that simple, especially if we use AF447 as the starting point of the discussion since the report's greatest weakness was total absence of references to pilots' previous performance. That's something NTSB is very keen to explore, no matter whether they are investigating 4- or 400-seater occurrence but now with BEA we are left wondering whether the fatal crew breakdown came without previous warning, was at the end of unbroken chain of marginal performance or somewhere in between.

If I present you with three pilots who met their fate by a) flying Centurion into CB that tore it apart b) trying to pull his Decathlon through mountain pass on hot day at density altitude she just couldn't cope with c) being part of the crew that made 90 deg heading mistake, putting their aeroplane on the collision course with mountain, would you say "Now there are pilots who didn't know how to fly"?

Would you change your mind if I told you those folks were a) Scott Crossfield b) Steve Fosset c) Don Williams. Maybe it would help if I explain they were a) NAA engineer and X-15 test pilot b) pilot who flew solo around the world without landing c) USAF instructor of the year (1986. IIRC).

AF447 crew couldn't cope with the problem they had, at the time they had it. Whether they were fine pilots that were too fatigued from Rio layover to think straight for a fraction of a second or marginal ones, being lucky that far they never had to cope with serious malfunction, we just don't have a way of telling.

Even if one does not know anything about Airbus, mere fact that 40-something 330/340s passed through similar ordeal, with autopilots tripping and flight controls system degrading to ALTN law till landing, with no injuries or damage, is indication enough that aeroplane is no culprit.

Heck, if there would be just one thing worth learning from AF447 demise, IMHO it would be:

DON'T PANIC

Maybe it should be written on QRH covers? Or on another cockpit placard?

gums

20th Jan 2015, 03:50

We are finally getting to the core of flying safety here, and we must take into account technology, human factors and the bottom line $$$$.

Late here, and will opine later, but first.

Few of us here arrived on this forum without having experienced one or more situations that were not planned or we could not avoid with all our skill and planning. Face it. Sierra happens. Mechanical things break. Weather is not what the troop told us. and the beat goes on.

The bottomline is how we handle the unexpected and how were we trained. Along the way, how do we fly day-to-day? Do we assume nothing bad will ever happen? Or do we think "what would I do if "x" happened this instant". I can tell you what this old survivor did. And I'll do it later, as just got back from TDY and hitting the rack.

Winnerhofer

21st Jan 2015, 22:49

Last paragraph:
Vol AF 447 Rio-Paris : reconstitution des minutes qui ont précédé le crash | Vanity Fair (http://www.vanityfair.fr/actualites/international/articles/vol-af-447-rio-paris-reconstitution-des-minutes-qui-ont-precede-le-crash/23618)
AF says it vehmently denies that its crew were incompetent and that the article makes no mention of Airbus' systems that induced piloting errors.

DozyWannabe

22nd Jan 2015, 01:19

Airbus' systems that induced piloting errors.

Er, what systems do you believe "induced piloting errors"? At no point in the sequence did the crew act in a concerted manner to either apply the appropriate procedures or perform logical problem-solving operations.

TC-DCA

22nd Jan 2015, 21:51

gums

22nd Jan 2015, 22:57

@ TC

Best I can tell from the FCOM stuff I have gotten courtesy of the folks on this thread, until in "direct" law, the system tries to maintain one gee corrected for pitch attitide. So airspeed and AoA are not the biggest drivers even when in alternate laws.

And then the reversion sequence is not all that clear depending upon what sensor or computer you lost. Sheesh.

On the thread about the Indonisian event, the comments about Airbus flight contol law and reversion sequencces are confusing. If you look at the laws in the FCOM, they try to "protect" the plane ( not the pilot) as long as the computers deem the inputs reliable.

So we go from "complete protection" from anything to protection about some roll, pitch angles. Uhhhh, AoA? Gee? What else? Lemme get out that checklist or use the electonic display ( if available) to see where we are. Meanwhile the plane is climbing without a pilot command. The autothrottle might also be doing stuff we have not commanded. Sheesh.

Later, as this old pilot is weary of all the "gotchya" crapola of the new systems. And remember that this old fart flew the first fully electric jet and out reversion sequence was very simple.

TC-DCA

23rd Jan 2015, 10:40

@gums

Thanks for the answer, but I dont have a real answer to my question it s a little complicated.

So as I said, is that true that in the case of AF 447, EVEN if the stick was at NEUTRAL position AFTER the beginning of the stall by the PF, the aircraft would have maintained elevators AT FULL NOSE UP to maintain 1G as it's Airbus rule, and with stick FULL FWD, the elevators will be also in nose up but in half nose up position. True ? If thats true, I think it´ll be stupid !

Can anyone explain this ?

Especially the Airbus Load Factor 1g demand, it´s horrific to hear that the plane computers demand full nose up in a stall by itself, with neutral stick, it wouldnt be the same with a conventional plane.

So it'll be impossible to recover the aircraft even with full fwd stick, also aggravated by the THS that was at FULL NOSE UP due to pilot actions. True ?

I don't understand exactly this function on Airbus FBW, as it's not detailled in the manuals of the aircraft, anyone to answer this Load Factor with this 1g, what is the link between 1g rule and elevators ?

Thanks !

vilas

23rd Jan 2015, 14:17

TC-DCA
In pitching plane when the stick is out of neutral pilot is asking for some load factor from flight control computers and it is proportionate to how much the stick is out in fore and aft plane. The elevators and stab position themselves to give you that by pitching up. When the stick is released and is neutral the elevators will maintain 1G. In normal law when speed(AOA) goes below Valpha prot the stick demands AOA and not load factor as in that zone between Valphaprot and Valphamax AoA is more critical and relevant. How ever in alternate law there is only Vsw(stall warning) and no V alphaprot or V alphaMax. So below VLS is it load factor or AoA demand is not clearly mentioned in the manual. As far as stab going full up you have to understand that the pilot kept the stick back all the time even below Vsw giving the system no choice. However the system design would have gradually kept trimming back once the nose was up even with stick neutral to keep 1G. Similarly if the stick was pushed forward it would have translated in to negative load factor demand and the elevators and stab would position to give you that and ultimately recover from stall but the pilot never did that for any length of time. Every time stall warning came he pulled the stick back instead of pushing forward. AF447 was manoeuvred beyond its design considerations by a pilot who was not competent to deal with unreliable speed situation nor was he capable of recovering from the resultant self induced stall. Conventional airplane don't trim back but they have been stalled by pilots through mishandling and crashed because of faulty stall recovery procedure. AF447 pilot would have never recovered from the stall in any aircraft.

gums

23rd Jan 2015, 15:16

It's hard for folks used to conventional flight controls to "appreciate" all the "protections" or "limits" as I prefer. Once you abandon a direct stick/yoke movement or pressure on a hydraulic valve and the corresponding action at the control surface, all kinda neat things are possible to smooth out the ride and then make it easier for a pinball wizard to fly a jet.

The gee command is hard to understand unless you see it during training. As in the Viper, AoA plays a role if the sensors are deemed reliable ( although the Viper AoA was deemed reliable if weight was off the gear - we had different criteria for "reliable" sensors than the 'bus). With a neutral stick and the jet trimmed for any gee, it would maintain the gee until the AoA reached the "limit", then ride the AoA limiter until speed increased/AoA decreased. We did not correct the gee for pitch attitude due to our mission requirements, huh? So we had a simple function that related gee to AoA. At 27 degrees or so AoA, max gee was 1 gee!!! At 15 degrees, max gee was 9. Sucker would even command zero gee to stay at 27 degrees AoA or below. So I would demo a loop to Joe Baggadonuts student by trimming to 3+gee, and let go of the stick. Sucker would smoothly pull up and then reach max AoA as it slowed, unload over the top, then increase gee as we came down the back side and AoA allowed. Due to our awesome vis, you could look back at the horizontal stabilators and see them almost maxed out as we came over the top ( nose down command just about as much as it could, but not quite. If nose wasn't moving and stabilators were maxed out, you were in a deep stall).

I mentioned this before, but our first group of youngsters in the Viper were of the Atari generation ( Xbox and Playstation 20 years away). We were worried that they would forget basic aerodynamics, as the jet was very easy to fly without getting into trouble. However, they had accumulated 250 or so hours in "conventional" jets that had no auto-anything!!! They did just fine, and went on to fly other jets after the Viper.

The key is to have a decent amount of flying in simple airplanes and no auto anything. Some "refresher" training is also highy recommended.

Finally. @engineers, quit trying to protect the plane so much when the primary modes go tango uniform. A straightforward reversion that can be easily understood seems logical, and I think I saw a comment to that effect in the accident report.

BTW, my pearl of wisdom I alluded to earlier was to do thousands of "thought" emergencies. What if? Sitting in the barbershop, waiting for a bus/train/plane. When the actual emergency happened, I had a personal procedure someplace in the back of my brain. I also had a philosophy of "hold what you got", at least if the plane wasn't tumbling end over end.

So what did I do when this happened shortly after lifting the gear handle?

http://i120.photobucket.com/albums/o196/gatlingums/rightwing.jpg

flyingchanges

23rd Jan 2015, 17:22

So what did I do when this happened shortly after lifting the gear handle?

Eject.....

gums

23rd Jan 2015, 20:24

C'mon, Flying.....

The jet is on the ramp, right where I started an hour earlier. Flight was about 15 minutes, and taxi for takeoff about 10. Taxi back was about 3 or 4 minutes, and you can see some on the video.

http://www.sluf.org/misc_pages/lef-landing.m4v

May have to find a good video player, but the landing was recorded in case I could not get down O.K. We had a limited FDR on the seat and the HUD video/audio was fairly survivable, and we got useable tape after several bad crashes.

TC-DCA

23rd Jan 2015, 21:19

@gums

Wow ! I read a part of the LE problem, that's just amazing.
I'll continue to read the article, that's really interesting !

@vilas

Thanks for these informations !

So as we know, with stick at neutral, ELAC's try to maintain 1g with elevators, until we don't "request" another load factor demand by pushing or pulling the stick, but what I don't really understand is that, if we pull back the stick and then return it to neutral position at 10° for example, the aircraft will maintain it, so what is the purpose of the 1g rule here, the pilot normally demand a stable pitch of 10° "not a stable g" normally ?

That'll be strange for a pilot to see his aircraft pitching up with stick at neutral in a particular condition, like a turbulence, and then, they'll note it to the maintenance log as "uncommanded pitch and altitude changement in cruise/climb/descent", that's what I don't understand, so the aicraft is not really stable and doesn't maintain the pitch ?

Can you explain that complicated rule of Airbus Captain please, with a simple example ?

For another example, here the g limit, if we do a turn of 50 degrees with holding the stick, (or a pitch up to the maximum limit of 30 degrees), the aircraft will be at approximately 2-2.5g, and as positive g limit in clean config. is 2.5g, is that true that we'll nearly or completely loose the pitch during a steep turn for example, to don't exceed the limit imposed by the computers as we are already near 2.5g in a steep turn ?

EDIT: "However the system design would have gradually kept trimming back once the nose was up even with stick neutral to keep 1G."

How is it possible that computers orders nose up with elevators with stick in neutral, and when it does that, normally even in a stall condition, with stick at neutral, the aircraft must maintain the last commanded pitch, so it continue to stall but it normally should t command the g ? True ?

vilas

24th Jan 2015, 03:47

TC-DCA
I didn't explain 1G fully. In conventional aircraft you directly move the elevator that creates some load factor to raise the nose to 10 degrees of pitch and then trim yourself to keep it there, if you didn't trim and left the yoke aircraft will pitch down as it is not in trim. FBW treats side stick movement as a certain load factor demand and computers give you that through the required amount of elevator to raise the nose up and when you return the stick to neutral keeps it there by auto trimming. Maintaining 1G is same as maintaining same degree of pitch what ever you set it. So it trims to maintain the pitch but when the thrust is not sufficient only then FBW will keep pitching up to maintain 1G flight path, otherwise the nose will drop resulting in some minus G. The advantage of treating side stick movement as a load factor demand is that when you move the stick back one inch the load factor ordered is same at all speeds but the elevator movement is varied to give the load factor, thus the aircraft response to the movement of the side stick is same at all speeds unlike normal aircraft where you have to pull the stick more or less to achieve the same degree of pitch depending on the speed of the aircraft. There is nothing complicated while flying the aircraft you just fly like any other aircraft.
As far as 2.5g is concerned it is achieved in a level turn at 67 degrees of bank so if you reduce bank you can pitch up otherwise not. You are flying a commercial jet and not a combat aircraft. Conventional aircraft how much it can pitch up depends on speed at higher speed you can pitch it up beyond its structural limitations causing structural failure. In FBW you cannot.

PJ2

24th Jan 2015, 07:03

vilas, that's a very nice description of the Airbus system and should help a lot for someone trying to understand FBW.

TC, it's also an important point to emphasize that FWB is not the same as "protections".

Protections may be built into the system but they are separate from a FBW flight control system.

In terms of controls like the thrust levers, they could be dining-room dimmer switches for all the system cares! They are "shaped" like throttles out of convention and on the Airbus act more like "engine room telegraphs", setting power regimes in the various detents in which the autoflight/autothrust system then respond.

In the end it is most important to understand that the Airbus is just another airplane and can be flown just as any other aircraft. When one is trained on it and as a pilot, puts appropriate work into learning the airplane, it is a straight-forward machine and a treat to hand-fly both for the approach/landing and at cruise, (although not in RVSM airspace which legally requires the autopilot remain engaged!

The autoflight system for the A320 & A330/A340 is described at Smart Cockpit - a visit there would be enlightening. Happy reading!

Clandestino

24th Jan 2015, 07:56

Is that true that in the case of AF 447, even if the stick was at neutral position AFTER the beginning of the stall by the PF, the aircraft would have maintained elevators AT FULL NOSE UP to maintain 1G as it's Airbus rule, and with stick full fwd, the elevators will be also in nose up but in half nose up position. True ?If the stick were held at neutral, FCS would try to maintain constant vertical flightpath which would tend to exacerbate the stall but FCS does not use elevators alone to achieve demanded G, it uses THS full time - unless THS inhibition threshold is reached (e.g. less than 0.5G actual vertical acceleration)

So it'll be impossible to recover the aircraft even with full fwd stick, also aggravated by the THS that was at FULL NOSE UP due to pilot actions. True ? False. Push forward and FCS moves THS and elevator towards nose-down position to comply with G demand.

As we know, in clean config, the g load limit is +2.5g positive, so with a bank to 67 degrees for example, (or a high positive pitch), the load factor will be approximately 2.5g, so does it means that we'll loose authorities in pitch even by pulling it full back or full fwd as we are in g limit ? Is that true ? It's true 67 degrees banked coordinated turn demands 2.5 G so no pitch up authority is available but high positive pitch does not automatically imply 2.5G. It's about pitchup rate, not angle.

Say, whaddaya need 67 deg banked turn on transport aeroplane for?

I remember the Gulf Air crash with that.

GF072 nevere came anywhere near G or bank limits. Have a look at the final report. (http://www.bea.aero/docspa/2000/a40-ek000823a/htm/a40-ek000823a.html)

On the thread about the Indonisian event, the comments about Airbus flight contol law and reversion sequencces are confusing. Because they were wrıtten by confused posters. Any similarity between this thread and that is not coincidental.

If you look at the laws in the FCOM, they try to "protect" the plane ( not the pilot)
Lack of ejection seats on FBW Airbi makes pilot and aeroplane inseparable until the aeroplane has come to complete halt. Therefore protections are not at all ill-conceived.

Meanwhile the plane is climbing without a pilot command.What plane are you referring to? FBW Airbus will maintain constant vertical flightpath but to climb, demand must be made by the pilot and it was in AF447 case. Very emphatically.

the aicraft is not really stable and doesn't maintain the pitch ? It is vertical flightpath stable up to 33deg bank. It adjusts the pitch to maintain flightpath.

That'll be strange for a pilot to see his aircraft pitching up with stick at neutral in a particular condition, like a turbulence, and then, they'll note it to the maintenance log as "uncommanded pitch and altitude changemente in cruise/climb/descent"In real life, such a TLB entry would lead to tech refresher at the very least.

if we do a turn of 50 degrees ...intentionally, flying the line, in Airbus, you get fired and unemployable.

Conventional airplane don't trim back but they have been stalled by pilots through mishandling and crashed because of faulty stall recovery procedure. I suppose you mean "not following procedure", not procedure being faulty per se.

vilas

24th Jan 2015, 09:37

Clandestino
I mean both. AF447 did not follow proper procedure while previous procedure of slamming the thrust before lowering the nose itself was incorrect.

Clandestino

24th Jan 2015, 10:22

Hmmm.... could you please provide an example of an accident/incident where application of "Approach to stall recovery" instead of "Stall recovery" was a factor?

vilas

24th Jan 2015, 12:01

Earlier stall recovery procedure was based on approach to stall but after a few accidents in the US where the thrust increase prevented the pilot from lowering the nose FAA asked for a review of the procedure. There is a video by Airbus on the new thinking on stall recovery. Experts agree that even for a test pilot it is difficult to make out the approach to stall and full stall. So there is a standard recovery procedure now that recommends reducing the angle of attack first and once the stall warning has stopped increase thrust as required not necessarily TOGA.

gums

24th Jan 2015, 15:52

@ cland, et al ....

I go with vilas for the most part. Ditto for PJ.

My problem is folks describing to novices the "effect" of a control law versus the "intent", and actual code for HAL. PLZ convince me that the 'bus control law for pitch is primarily programmed for an attitude versus a gee. I realize that correcting the gee command for pitch attitude achieves the "percieved pitch" command versus a gee command. Our primitive system had no correction for attitude for fairly obvious reasons. So establish a 30 degree pitch attitude and stay at same power as the jet loses energy. Instead of 0.87 gee, the sucker tried to maintain trimmed gee, which was ususally one +/- a few hundreths. So pitch attitude gradually increased to maintain one gee ( Nz). Horizontal stabs "auto trimmed", just as AF447. Unless our AoA limiter failed, we were headed for a deep stall.

- I feel your pain, Cland, about no means to jettison the jet. Seems that should be a serious incentive to learn as much about the jet and its systems as possible and practice a few things when able.

- Our limits were intended to keep the pointy end forward and keep us from putting too many gees on the airframe and bending the wings if we rolled too fast under a decent gee load.
So our laws were a combination of "protect the jet" and "let the pilot command max performance without having one eye on the gee meter or AoA indicator or.........." So we could command maximum performance at any time and she gave you what she could. Maintenance troops loved it, as pervious jets could easily be over-geed. We would come back with ripples on the upper skin of the wings. Bad. "Bad pilot, bad", heh heh.

I like the 'bus clontrol laws in "normal" . They are about what I would expect for the mission and the mechanical design limts of the jet. So my problem is with reversion laws and lack of indications that the jet has reached trim l;imits or AoA limits or.......

- My comment about continuing a climb with stick in "neutral" stands. Until the Alpha stuff comes into play, PLZ show me where the jet will nose over or act like the "old" ones most of us flew years ago. In other words, if energy and AoA allow, the jet will continue to climb after you relax the stick. It will also trim the THS as long as it can.

Goldenrivett

24th Jan 2015, 15:54

Hi Clandestino,
...could you please provide an example of an accident/incident where application of "Approach to stall recovery" instead of "Stall recovery" was a factor?
"The trimmed position of the stabiliser, combined with the selection of maximum thrust, overwhelmed the available elevator authority."
http://www.aaib.gov.uk/cms_resources.cfm?file=/Summary%20-%20AAR%203-2009%20Boeing%20737-3Q8,%20G-THOF%2006-09.pdf

PJ2

24th Jan 2015, 19:07

gums, re, "I like the 'bus clontrol laws in "normal" . They are about what I would expect for the mission and the mechanical design limts of the jet. So my problem is with reversion laws and lack of indications that the jet has reached trim l;imits or AoA limits or.......

- My comment about continuing a climb with stick in "neutral" stands. Until the Alpha stuff comes into play, PLZ show me where the jet will nose over or act like the "old" ones most of us flew years ago. In other words, if energy and AoA allow, the jet will continue to climb after you relax the stick. It will also trim the THS as long as it can. "

The continued climb is the normal result of increased pitch and added thrust, (MACH/SPEED A/T mode when autothrust engaged) to maintain speed - little if any autotrim due speed being maintained. The Alpha stuff doesn't come into play under these circumstances.

In Alt I & Alt II laws, alpha floor is inactive as we know. If the speed reduces as per the scenario you describe, the pitch is gently reduced with reference to speed, (not AoA), as the aircraft approaches within 5 to 10kts of Vs. The pilot can override this pitch down demand. At the same time, the autoflight system reverts to Direct Law.

It would be an odd, though not an unknown set of circumstances for a pilot to increase pitch, or not increase thrust / reduce pitch in response to decreasing airspeed, (see Goldenrivett's link), but just leave the airplane to its own devices, (ie., permitting speed loss, as in the linked incident and for the AMS B737 fatal accident). A pitch-up order from the SS or AP/AT for the A320/A330/A340 series would result in increased thrust in Normal law because the AT's would be in either MACH or SPEED mode. If the AT is disengaged for some reason, (that would be rare/odd - Alt I & II Laws, etc or someone just hand-flying), then the above nose-down demand applies.

Regarding the incentive to learn about one's airplane, I couldn't agree more strongly. However, there seems a "sea-change" in attitude regarding the knowing-of-one's-airplane where NTK has overtaken N&B's learning. Don't know how prevalent such surface knowledge is regarding knowing the machine that is always trying to kill one, but I'm not impressed with some of the incidents seen in that their "character" has changed from weather/navigation/system-failure/mid-air to LOC & CFIT, both of which have robust prevention systems, providing one knows one's airplane and one's craft.

TC-DCA

24th Jan 2015, 21:19

@vilas

Thanks for that very nice explanation Captain !

"I didn't explain 1G fully. In conventional aircraft you directly move the elevator that creates some load factor to raise the nose to 10 degrees of pitch and then trim yourself to keep it there, if you didn't trim and left the yoke aircraft will pitch down as it is not in trim."

Understood, like the 737. Thanks !

"Maintaining 1G is same as maintaining same degree of pitch what ever you set it. So it trims to maintain the pitch but when the thrust is not sufficient only then FBW will keep pitching up to maintain 1G flight path, otherwise the nose will drop resulting in some minus G."

Understood I think, can you correct me if I'm wrong, so maintaining 1G is pretty the same as maintaining same degree of pitch that we set. To take an example, if we encounter some turbulence and that this turbulence decrease a little the pitch, the g will also decrease in the same time so aircraft will pitch up to regain 1g (to regain the pitch of before the turbulence) thanks to THS/elevators.

"The advantage of treating side stick movement as a load factor demand is that when you move the stick back one inch the load factor ordered is same at all speeds but the elevator movement is varied to give the load factor, thus the aircraft response to the movement of the side stick is same at all speeds unlike normal aircraft where you have to pull the stick more or less to achieve the same degree of pitch depending on the speed of the aircraft"

Also understood, with conventional aircraft, control surface deflection is directlyproportional to control yoke deflection meaning that we have to pull/push more in low speed while on highspeed you have to be more soft, whereas with Airbus control surface deflection is not proportional to sidestick deflection. Meaning that with the same ss deflection, the aircraft control surface will be large at low speed and small at highspeed.

As far as 2.5g is concerned it is achieved in a level turn at 67 degrees of bank so if you reduce bank you can pitch up otherwise not. You are flying a commercial jet and not a combat aircraft. Conventional aircraft how much it can pitch up depends on speed at higher speed you can pitch it up beyond its structural limitations causing structural failure. In FBW you cannot."

Roger, thanks captain !

@PJ2

Thanks Captain, that's right "Airbus is just another airplane and can be flown just as any other aircraft."

@Clandestino

Thanks a lot also for these detailled answer !

"If the stick were held at neutral, FCS would try to maintain constant vertical flightpath which would tend to exacerbate the stall but FCS does not use elevators alone to achieve demanded G, it uses THS full time - unless THS inhibition threshold is reached (e.g. less than 0.5G actual vertical acceleration)"

So by saying " would try to maintain constant vertical flightpath " we can translate it to try to maintain a pitch the aircraft trim back, true ?

"False. Push forward and FCS moves THS and elevator towards nose-down position to comply with G demand."

Understood, thanks !

"It's true 67 degrees banked coordinated turn demands 2.5 G so no pitch up authority is available but high positive pitch does not automatically imply 2.5G. It's about pitchup rate, not angle.

Say, whaddaya need 67 deg banked turn on transport aeroplane for?"

As said vilas, I undestood that also.

Thanks again !

TC-DCA

24th Jan 2015, 23:02

@Winnerofer

I saw that article it's also well detailled but don't really talk about the 1g rule.

And I also want to add something, I just spoke with an EZY pilot and he told me that there will be normally not a pitch up during a stall in alt. Law and that it´s an requirement of certification by EASA (cs-25) that no abnormal nose up pitching will occur in a stall ?

DozyWannabe

25th Jan 2015, 01:25

As far as 2.5g is concerned it is achieved in a level turn at 67 degrees of bank so if you reduce bank you can pitch up otherwise not.
No. The bank angle limit of 67 degrees at full stick deflection is a completely separate definition from the 2.5g limit. Obviously, the closer one is to 67 degrees of bank, the more conservative the system will be when it comes to applying pitch input, but at no point will the system prevent response to pitch input entirely.

...I saw that article it's also well detailled...
It also contains blatant minsinformation.

e.g. ...Shortly after the accident, the crew and Air France are singled out without any concrete evidence...
A complete fabrication - at least in terms of the official investigation. The BEA are prevented by their own charter from apportioning responsibility or blame in any for their reports. Obviously the press can say what they like, but that doesn't really hold any weight.

All this helps explain so completely rational rise initially to recover its altitude
There's no way that a temporary drop in indicated altitude of 300-350ft would require a nose-up command of 15 degrees to correct.

...Airbus serve only send "requests" of the pilot to computers, applications accepted or not.
Incorrect. In Alternate Law, the human pilot's commands will override every protection mechanism there is by design.

How to explain that we have put almost two years to find a wreck that was less than 12 km from its last position?
Because deep-ocean search operations are extremely difficult!

jcjeant

25th Jan 2015, 02:42

Hi,

Dozy
Because deep-ocean search operations are extremely difficult! Certainly it's difficult
But the first search phase was made in a zone under the LKP but unfortunately not with all the assets ( Investigation underwater gear like Remus) to make a research with the greatest chance of success
So ... in this case this further increases the difficulty !

DozyWannabe

25th Jan 2015, 03:38

Right, but that doesn't imply any wrongdoing. Sometimes it just works out that way. Famously, the joint IFREMER/Woods Hole Titanic expedition of 1985 started with the IFREMER team getting massively strong responses on their high-resolution sonar equipment. They assumed (reasonably) that the equipment was faulty, pulled it up and did a full diagnostic and repair. They then spent many weeks trawling the depths with no success. Dr. Bob Ballard and the WHOI team returned and used their US Navy-funded video sled (Argo) with only a few days to go, and elected to start from the original start position - and in doing so found the Titanic's wreckage within a day or two. As it turns out, the initial response on IFREMER's equipment was not a malfunction - but they assumed it was, because they didn't dare to hope they were as close as they turned out to be.

The point being that this kind of deep ocean search is not an exact science, even with the best minds and equipment available assigned to the task.

vilas

25th Jan 2015, 04:40

DozyWannabe
When you hit the stick to one side and hold you keep 67 degrees bank and if you are holding your altitude all the while then you see on the system display above or below the clock 2.5g. Now there is no way to increase pitch without exceeding 2.5g. unless bank is reduced. Off course this is another way of reaching g limit which can be reached simply by pitching with wings level. But 67 degrees bank limit is not in the design by accident.

DozyWannabe

25th Jan 2015, 05:17

Maybe so, but as I understand it there's enough "wiggle room" to add a pitch component at 67 degrees of bank (even if only a small pitch component) - just as you can command a small (but effective) amount of bank while commanding Alpha Max.

jcjeant

25th Jan 2015, 06:35

Dozy,

I am very sorry .. but those who have done the research in the first phase have done a nonchalant way and was as expected a failure
They did not have adequate resources (and those were available) which was postponed two years the discovery of the wreck
It was not only the scrap that one is looking .. but also the bodies of victims expected by families
Everything had to be implemented .. this was not the case
Two years of waiting .. not to mention the money wasted in vain other research ....
That's my opinion

vilas

25th Jan 2015, 06:52

DozyWannabe
At 67degrees when you maintain level you reach 2.5 g where is the question of any wiggle without exceeding 2.5? At Valphamax it is different it is not a wiggle but you can bank up to 45 degrees for short term. Unlike 2.5g Valphamax is not a fixed but variable value.

markkal

25th Jan 2015, 13:28

An air France captain view and comments on Airbus systems following the AF 447 crash

PNC Contact, hôtesse de l'air, Steward, formations PNC et informations hôtesse de l'air. ? AF447 ? Le rapport de contre-expertise d?un pilote (http://www.pnc-contact.com/2015/01/20/af447-le-rapport-de-contre-expertise-dun-pilote-29131)

The full version is in french have translated some exceprts below.

How can a stalled a/c enter a deep stall and then not recover ?

Looks like Airbus series have been designed as "Stall Proof" a/c, algorithms in their systems and flight controls will not be able to deal with stalls and their recoveries

Few minutes after the captain of AF 447 left the flight deck at 02:00 AM, alarms start to ring in the cockpit.
Autopilot disconnects; ATHR (autothrottle) disconnects as well.
These alarms ring continuously for 34''

A/C starts to be unstable due to switching to 'ALT LAW' mode as a consequence of erroneous speed readings due to clogged pitot tubes which at first glance the crew had no way of knowing.

First issue confusing the crew in their analysis of the situation is that the 'FWC' malfunction management system, able to warn the crew on erroneous altitude readings (NAV ALT discrepancy) is unable to do so for erroneous speed indications. the ECAM screen ( Displaying malfunctions and necessary actions to treat them) will be of little help.
Only a NAV IAS DISCREPANCY feature would have helped, but it is not available on the ECAM.

This particular issue provided it is positively identified, can only be adressed via a paper checklist, and as the BEA ( Bureau Enquetes Accidents) clearly states pp. 181 and 203 in the final report: ''ECAM does not provide any indication likely to enable the crew to spot a speed indication malfunction''
The BEA unlike Airbus raises this issue p. 182 and makes a series of recommendations.

Another point which will have a bearing as events unfold is that as a consequence of pitot tube clogging There is a loss of altitude, however marginal this loss ( 350 to 350 ft ) this point is crucial in the understanding of the sequence of events as it explains the crew first move is to pitch up in order to regain the lost altitude (BEA p.179)

Airbus features provide efficient aids through FD (Flight Director) and ''Speed Trends'' (an arrow indicating a speed prediction within the next 10 seconds), very useful during the deceleration and acceleration phases of flight.

FD's are bars helping the pilot to follow his trajectory.

In the time lapse between the onset of the trouble and the stall these aids have been confusing the crew, the Speed Trend indicating an acceleration tendency (!) after the stall warning bell went on for a mere 2'' before going silent again . (BEA p.100, p.186) At the same time these tendency bars went on and off erratically further impairing the pilot s judgement (BEA p.204)

All these events have been unfolding in a degraded environment, at night, in the vicinity of a storm, in a cockpit beset by alarms and bells...with multiple malfunctions to handle and an unstable manual pilotage in ALT Law mode, compounded with erroneous indications of overspeed and tendency bars ordering a pitch up.....(BEA p.183)

As the stall warning went on briefly (BEA p.195) for a mere 2'', whereby the ATHR bell rang continously for 34'', in such a saturated an stressful environment it could easily have gone unnoticed

45'' after the alarms rang, there have been alternate actions to pitch up and down by the crew
And here we need to bring up the peculiarity of Airbuses joysticks and TRIM.

Joysticks only function is to send inputs to the computer management system which either accepts them or rejects them (Hence the motto that airbuses cannot stall)

Whenever the computer acts on a control surface, the joysticks don't move and have no pressure feel, preventing the crew from receiving any sensorial feedback. Left and right joysticks are non interconnected preventing any feedback among the crew members themselves.

And the TRIM: On the Airbus series the trim is automatic, silent, and never used by the crew in normal operations.

The trim on the elevator works as follows: The pilot commands an action which moves the rear part of the elevator ( 1/3 of the surface) the computers then manage the 'trimming action' moving the PHR or ''Fixed part'' forward section of the elevator (2/3 of the surface)

The elevator of AF 447 within 45' from the triggering of the first alarms moves from straight and level to full
pitch up when the stall warning briefly goes on. (BEA pp.64. 66)

This elevator design would also prevent recovery from the stall as a pitch down push action on the yoke to reduce angle of attack would be acting on the rear portion of the elevator only (1/3 of its surface) , the remaining computer controlled 2/3 surface remaining unaffected unless the system senses the stall which may not be in the algorithms as by nature Airbus series are stall proof.

On p.193 of the accident report it is stated that it is not necessary to exert a pitch up action to compensate for a speed decay to maintain lift.

Therefore on the Airbus 330 with its uncoordinated joysticks with moving surfaces and auto trim! The crew have little or no sensory feedback to determine a speed decay.

One would wonder how a pilot would keep pulling on the stick while the stall warning is ringing.
This brings us to the peculiarity of the stall warning on the Airbus.

As noted above the stall warning rings for a mere 2'' in a stressful environment where the ATHR bell goes off consistently may have been overlooked by the crew, considering at this moment the Speed Trend bars show a speed increase tendency (!)

THE STALL WARNING ON THE AIRBUS DOES NOT COMPLY WITH CERTIFICATION REQUIREMENTS and prevented the crew from identifying the stall.

On pp. 143 however the BEA states that it '''complies with the certification requirements in in force at the time of type certificate approval'' though it is also stated (p.47) that if CAS speed values are below 60 Kts stall warning is inoperative (!!!!!!!)

This feature is destined to prevent triggering the warning while the a/c is on the ground.
Airbus considering that whenever the speed is below that value the a/c is on the ground.
Or is it ?

In contrast Boeing considers that an a/c is sitting on the ground when the front gear leg is compressed under its weight.

With reference to the ''Certification Specifications for Large Airplanes'' CS25
CS 25.207.c reads that the stall warning bell should be ringing continuously whenever pitch angle is above stall speed.

On AF447 during the deep stall speed was below 60 kts, with the Stall Warning inop per design.
What further aggravates matters is that it goes on again whenever speed increases to that value, ringing during a nose down action to reduce angle of attack.(BEA pp. 196, 197)

The PF made a corrective pitch down action (BEA p.25) when the a/c was in a deep stall at 40 deg pitch up fully stalled. He was confronted to a Stall Warning deactivating when he was pulling and activating again when he was pushing.

So here we have a situation where the ECAM does not say what is happening, pilot s aids are malfunctioning, the trim helping the a/c stall and a Stall Warning that works the other way around, how could any crew operate in such degraded environment ?

In this cockpit built by engineers, pilots did what they could.
Airbus a/c are by no means dangerous, they are ergonomically flawed, they are as easy to operate on a daily routine basis, as they are tricky and dangerous in critical situations.

There have been a series of stall incidents and accidents, and we can only hope that the Air Asia crash will not be a Rio bis

oldchina

25th Jan 2015, 13:35

An incompetent crew didn't follow the "unreliable airspeed" procedure and flew a perfectly flyable aircraft into a stall of their own making, and which they didn't even recognise.

AfricanSkies

25th Jan 2015, 13:42

Thanks for a well written, concise, informative post.

It should also set the cat amongst the pigeons!

His dudeness

25th Jan 2015, 13:47

An incompetent crew didn't follow the "unreliable airspeed" procedure and flew a perfectly flyable aircraft into a stall of their own making, and which they didn't even recognise.

whilst that is true I don´t see the same thing happening on an airplane with 2 interconnected sticks...when the bloody column hits your stomach, you get the message that the other dude is holding it back...

Sailvi767

25th Jan 2015, 13:49

It is worth noting that a Delta Crew encountered the same situation as the AF crew in a 330 on a Pacific flight. It was considered somewhat a non event. The crew flew the aircraft using pitch and power until they exited the weather and icing.
As far as the above post about control columns I don't see that as the problem. The issue is not back driving or interconnecting the controls be they sides sticks or yokes. I suspect if Airbus could revisit the issue the side sticks would be back driven. They won't do it now because of liability fears if they did not retrofit every aircraft.

Herod

25th Jan 2015, 13:49

ALL aircraft are ergonomically flawed; man is a low-level, low-speed, 1g animal. It's just the degree of flaw that varies.

Clandestino

25th Jan 2015, 13:54

Are Airbus a/c ergonomically flawed ?

No.

All of the BS contained in the original post has been already posted and busted repeatedly in 12 AF447 threads but attention seekers are just not giving up and removing of "As this is anonymous forum..." doesn't help.

Entertaining option would be merging this thread with 12th AF447 thread since OP says absolutely nothing about Airbus outside AF447 scope. Useful option would be letting it die.

Capetonian

25th Jan 2015, 13:55

If Pprune had a 'post of the week' thread for the best and most concise comment ........ this should be this week's winner :

ALL aircraft are ergonomically flawed; man is a low-level, low-speed, 1g animal. It's just the degree of flaw that varies.

His dudeness

25th Jan 2015, 14:03

As far as the above post about control columns I don't see that as the problem. The issue is not back driving the controls be they sides sticks or yokes.

If I understand the report correctly, the guy in the L/H seat never understood that Bonin held back the stick for quite some time if not all the time. If the other 2 guys would have understood that, they most likely would have taken the correct action, I believe.... maybe I´m wrong....

Uplinker

25th Jan 2015, 14:55

I fly Airbus A330. A lot of what the French captain apparently says is interesting and certainly food for thought - I don't see it as BS, perhaps someone could enlighten me - I don't think I could wade through all the AF447 threads again to pick out the facts from the nonsense.

Another interesting thing is that in all my recurrent LPC/OPC SIMs since AF447, I have not been presented with the situation that AF447 had. Yes, we have practised a bit of high level manual handling, and stall recovery, and unreliable airspeed, but I have not had everything thrown at me at once and at high altitude; Flying along at FL350 and without warning received unreliable airspeed, alternate law, A/P, A/THR and F/D, all dropping out, different FL presentation, a possibly confusing speed trend arrow, and several alarms going off all at the same time.

I think we should all be presented with this in our SIMs as an un-briefed surprise, and to enable us to possibly experience the confusion the AF447 crew had.

My trainers have so far not taken the opportunity to do this, which is odd.

PJ2

25th Jan 2015, 21:20

Uplinker;

So long as you know your memorized drills and the SOPs for running the ECAM and the paper checklists and set aside the initial surprise, you should be fine. Slow, deliberate actions, coordinated with the PM is all it takes - loss of airspeed indication is not an emergency at cruise altitudes, and the training for the drill provides (or should...it's an Airbus document), for the "flight not at risk" decision, (as opposed to just after takeoff or on approach).

Many here have expressed that they now pay much closer attention to both power and pitch attitudes during the flight and so are ready for "normal" should the airspeed indication be lost, while they get out the QRH for the precise numbers. That's just basic airmanship.

If you've done an unreliable airspeed event, you'll have seen what AF447 initially saw and experienced - you'll have lost the AP & AT with associated audible warnings and ECAM caution messages, (including lost ADRs), you will have dropped into Alternate Law and will have the greyed-out sections on the PFD where data has been lost, (no trend arrow). Not sure what else you wish to experience. But you could pull the sim up to 15deg and watch the THS, stall and watch the rate of descent. You can recover by holding the stick fully-forward until the FPV begins to come up from the bottom of the PFD. You'll feel when the wing begins flying again - takes about 45" and about 12,000ft, roughly, from FL380. Most level D sims will "simulate" the stall behaviour but it isn't based upon flight-test data as you've probably read numerous times.

As far as articles in magazines go, while they may hold interest for some, the best policy for those who fly these aircraft is to stick with just one book and know it thoroughly - the FCOM.

jcjeant

26th Jan 2015, 00:04

loss of airspeed indication is not an emergency at cruise altitudesIn an Airworthiness Directive (AD) effective January 14, 2013 (2012-24-08) on the B737, the FAA maintains that the loss of speed information is a risk "catastrophic" that could cause the aircraft go of the flight envelope "we Are Issuing this AD to prevent prevention ice from forming on air data system sensors and therefore loss of airspeed indication or misleading airspeed indicating indication on all systems, who could lead to loss of control of the airplane. "

It is interesting to read in this AD the FAA's response to Boeing that has the same arguments as EASA and Airbus, "if pilots follow the procedure it's going well": Boeing Stated That loss of, or erroneous, airspeed indications do not Necessarily lead to loss of control Because --other indications Can Be Safely used to fly the airplane. Boeing Noted That in multiple events-have service without loss of control Occurred When The flight crew procedures Followed That Mitigate the loss of air data.

FAA Response: whether or not a procedure does not change, the loss of speed information is a catastrophic risk. We disagree / ... / ALTHOUGH Some In-Service events might-have Occurred without loss of control, loss of, or misleading airspeed indication is all airspeed indicating indication systems can, in fact, lead to an unsafe conditions of loss of airplane control. FAA Advisory Circular (AC) 25-11A, dated June 21, 2007 Typically classified loss of all airspeed displays (Including the standby display) as a '' catastrophic 'failure condition.

EMIT

26th Jan 2015, 05:40

Unreliable airspeed events are a bit like phishing events for non-pilots:

If you receive an email requesting you to provide your bank account numbers and secret codes - nothing happens if you just do not reply, but all hell breaks loose (financially) if you are stupid enough to provide all the requested information.

With airspeeds indications going unreliable, nothing happens if you just keep the attitude and thrust as they were hours on end previously - however, if you react solely to the erroneous airspeed, all hell breaks loose, physically this time.

How do you distinguish between true and false? As a daily internet user, that should be as common as fish and chips in case of phishing attempts. As a pilot, same in case of unreliable airspeed.

EMIT

26th Jan 2015, 06:14

The questions about bank angle 67 degrees and g limit +2.5 appear to me to imply that people forget how airplanes are maneuvred.
Aircraft are maneuvred with LIFT, i.e. in the pitch direction.
If you want to turn, you roll to point the lift vector in the direction that you want to turn and then you pull to increase lift. If you dissect the lift vector you will find that in a horizontal turn, the vertical component of lift just counters the weight of the aircraft, and the horizontal component of the lift does the turning bit.
Now, if you are banked 67 degrees in your Airbus, or Boeing, which also has a g-limit of +2.5 and you want to climb, then the most efficient way is NOT to increase your pull on the stick, but to roll towards level, so that the lift will point more up.

Sometimes, you see referrals to high speed stalls - and then replies along the line of, well then just fly slower, that ends the "high speed stall" or an accelerated stall, which happens in a turn, etcetera.
Please note that stalling has to do with angle of attack (jeez, what an aggressive term by the way, couldn't we change that into a politically more palatable expression?). What is usually described on the forum here, as a stall, is the stall in level flight, at 1 g, which indeed will happen at the minimum speed, or stall speed. However, it is possible to increase angle of attack by just pulling back on the stick at any airspeed and in any attitude. Likewise, it is possible to be NOT STALLED at any airspeed, in any attitude by just unloading, pushing the stick untill you are weightless in your seat - the airplane then also needs no lift.
This latest sentence may attract engineering wonders that will figure out super efficient flight, no lift needed, so less engine thrust needed, etcetera, but of course, no lift means that gravity will succeed in pulling the aircraft closer towards earth, so it can only be used temporarily, e.g. to get out of a stalled situation - regaining level flight is than an item lower on the priority list.

Questions about getting the Airbus into Direct Law by pilot action - if needed, push 2 buttons. There are 3 air data computers (ADR, air data reference unit) - switch OFF 2 of them and the system will fall back to direct law. If attention was payed during type qualification, procedure should sound familiar.
Concerns about upsets - when outside normal pitch and roll limits, then system reverts to abnormal attitude law - in that law, the flight controls will act "like in a normal aircraft again", no "interference by unwilling computers anymore".

Derfred

26th Jan 2015, 06:22

If Airbus pilots are not trained to regard the aircraft's attitude indicator as their primary instrument, then we have a problem.

I don't care about laws, sticks, bells, alarms, ecams, modes or ergonomics.

If Airbus pilots are not trained to regard the aircraft's attitude indicator as their primary instrument, then we have a problem.

vilas

26th Jan 2015, 09:23

EMIT
"Questions about getting the Airbus into Direct Law by pilot action - if needed, push 2 buttons. There are 3 air data computers (ADR, air data reference unit) - switch OFF 2 of them and the system will fall back to direct law."
No it doesn't. It will change to alternate law and not direct law. Even all three ADR fail you go to alternate law but without protections and 67 degrees bank and 2.5 G is well beyond the demands of commercial flying. It is just theoretical discussion. If Airbus pilots were not trained to regard attitude indicator then they would not have installed it. Pilots are trained to monitor speed and glideslope and again and again we find they don't. SFO B777 last year and Bangalore in 1990 on Airbus are mirror reflections.

EMIT

26th Jan 2015, 10:40

You are correct Vilas, switching OFF 2 ADR's indeed puts system in ALT law, not yet DIRECT. However, with the protections gone, it is still enough to get out of a hypothetical overspeed pull up such as being advertised on the Air Asia thread. Have been too long away from the bus now to get it right the first time.
Agree fully with your remark with regards to basic flying.

karnc

27th Jan 2015, 10:29

Flying Airbus is not like flying conv. Airplane. It's not that simple and easy to fly when in atn law and so many warning plus some protection the computer is confusing about.

When the Bus is messed up, your conventional pilot skill can't help much because when you pull the stick, the plane may not respond by raising up the pitch.

Pilots with thousands of bus hours still have difficulty pulling a level 45 bank in altn or direct law. I am a sim instructor and believe me, i see this all the time.

FBW from boeing and airbus are so different. With airbus, you don't feel anything. It s very easy to fly when there is nothing wrong, much less workload than boeing. But when things get fk up, airbus can confuse the pilot even he has ten thousand hours.

Uplinker

27th Jan 2015, 11:25

Uplinker;

So long as you know your memorized drills and the SOPs for running the ECAM and the paper checklists and set aside the initial surprise, you should be fine. Slow, deliberate actions, coordinated with the PM is all it takes - loss of airspeed indication is not an emergency at cruise altitudes, and the training for the drill provides (or should...it's an Airbus document), for the "flight not at risk" decision, (as opposed to just after takeoff or on approach).

Many here have expressed that they now pay much closer attention to both power and pitch attitudes during the flight and so are ready for "normal" should the airspeed indication be lost, while they get out the QRH for the precise numbers. That's just basic airmanship.

If you've done an unreliable airspeed event, you'll have seen what AF447 initially saw and experienced - you'll have lost the AP & AT with associated audible warnings and ECAM caution messages, (including lost ADRs), you will have dropped into Alternate Law and will have the greyed-out sections on the PFD where data has been lost, (no trend arrow). Not sure what else you wish to experience. But you could pull the sim up to 15deg and watch the THS, stall and watch the rate of descent.........

Yes quite, but my point was I have not done all the above simultaneously at high altitude. Nor have I been shown a deep stall and its recovery.

In fact my response to an unreliable speed event in the SIM (at about FL150), when it was obvious that only my speed tape and trend arrow were going crazy while the PNF's and the STBY were rock solid, was that I did nothing except keep attitude and power. But I got marked down for that because the TRE wanted to see me do the unreliable speed drill !

When the Bus is messed up, your conventional pilot skill can't help much because when you pull the stick, the plane may not respond by raising up the...

When does this happen? You should be able to stabilise an Airbus just as you can a Boeing, as long as you look at your instruments and fly Pitch + Power = Performance.

Even if you have lost all your ELACs and SECs or PRIMs and SECs, you can still maintain the approximate flight path with the THS and rudder - both under direct pilot control - while PNF starts resetting the computers.

vilas

27th Jan 2015, 11:56

karnc
I am really aghast at your statements. Alternate law is no different than normal law except the protection part then why would Airbus not pitch up when you pull the stick? If that were to happen the aircraft wouldn't be allowed to fly.
Pilots with thousands of bus hours still have difficulty pulling a level 45 bank in altn or direct law. I am a sim instructor and believe me, i see this all the time.
Any body who wants to do 45 degrees turn in alternate law/direct law surely has to be out of his mind. You are not training A320 aerobatic team are you? You are wasting their precious SIM time. About piloting skills first you have to have them and they will stand by you the accidents we are discussing the pilots have shown alarming lack of it.

PJ2

27th Jan 2015, 16:36

vilas;
Any body who wants to do 45 degrees turn in alternate law/direct law surely has to be out of his mind. You are not training A320 aerobatic team are you? You are wasting their precious SIM time. About piloting skills first you have to have them and they will stand by you the accidents we are discussing the pilots have shown alarming lack of it. Sorry, I'm confused by your post because there is a disconnect in your statements above.

How can practising basic piloting skills be a waste of sim time? Isn't this one of the aspects of these accidents being discussed...that pilots are losing their basic handling skills?

Fourty-five degree bank turns to the left and right are standard simulator exercises. That they are done in alternate and direct law for the A320 is even better because in Direct Law, the pilot has to trim manually.

The exercise is a quick way of determining a pilot's flying skills, and then on with the rest of the sim. If problems show up here, that is the place to stop for a moment and instruct/practise.

In fact, there is a discussion about such handling exercises back a few pages in the thread, beginning at: http://www.pprune.org/tech-log/539756-af-447-thread-no-12-a-56.html#post8823573, regarding "S-turn" exercises, which are a bit more difficult and are certainly worth the time in the sim.

Regarding your statement, "About piloting skills first you have to have them", of course, and the way to get them is to practise, practise, practise. All pilots should be able to do these exercises with a high level of accuracy and finesse. If they can't, then they need the sim practise to raise the level of skill so that they have them.

Once they can do the 45deg bank turns and the normally-banked S-turns with changes of altitude and speed, (in Alternate or Direct Law, with manual thrust) they could be considered to have a high degree of manual handling skills.

Such an accomplishment and level of skill is a great builder of confidence in oneself and the airplane. These are building blocks, upon which an understanding of the Airbus systems and procedures can then be built. This works even if one has been flying the Airbus for years.

karnc;
Flying Airbus is not like flying conv.I agree with you; in fact knowing that the Airbus is different is necessary before one can begin learning about the Airbus when transitioning from a Boeing or other type.

To emphasize, there are differences between the Boeing and Airbus and those differences need to be understood by the instructor and taught to the students. The number of hours a pilot has may not help if the pilot hasn't been taught how to fly the Airbus or doesn't understand the fly-by-wire system, (known as C* or C-star laws).

Fly-by-wire is something like CWS, (Control Wheel Steering) in a Boeing, (but for very different reasons!).

While the airplane is different to fly, it is also simple to fly but one must first understand the fly-by-wire system, (which is completely different than "the protections" which can be learnt later).

Forgive me if you know fly-by-wire systems; - the following may help others.

When one pitches up/down or banks a conventional aircraft, after doing so one neutralizes the controls of course but a conventional aircraft will wander a bit in pitch or bank so one continuously, subconsciously makes tiny corrections to keep the airplane where one wants.

With Airbus FBW, when one pitches or rolls using the sidestick, one is asking for an amount of 'g' in pitch, and a roll-rate in bank.

When there is no further "request" for more/less 'g' or roll-rate from the stick, the flight control system actively maintains the last pitch attitude and/or bank angle.

Put another way, the autoflight system (not the autopilot but the FBW system), will act to maintain the last pitch and bank angle "selected" by the stick. So long as the stick is neutral, no further "orders" are being sent to the ELACs/SECs and the pitch & roll attitudes will remain until changed by the pilot.

When pitch increases, with the autothrust engaged the engines will increase power just as we would in a conventional aircraft. If one is in manual thrust, one adds power as in a conventional aircraft.

Also, the autoflight system will trim the aircraft if such is required. Similarly, with bank angles up to 33 degrees, the flight control system will work to maintain the last-ordered bank-angle, increasing thrust and trimming as required. Beyond 33 degrees the THS will not trim and the pilot must pull on the stick to maintain altitude say, in 45-deg bank turns. If the autothrust is engaged, it will add thrust to maintain speed.

You can hopefully now see why this is similar to the Boeing CWS but is actually, fundamentally quite different than CWS.

If your pilots are having difficulty with 45-deg bank turns that is just a sign that their basic handling skills require gentle verbal correcting and then practise, with encouragement and feedback from the instructor.

Flying a 45-deg bank turn in any transport aircraft is a challenging exercise precisely because we don't do it often and need the practise.

Flying 45-deg bank turns in Alternate and Direct Laws is the same as doing the exercise in a conventional aircraft.

The stick is smaller than a standard control column so you have to make gentler and smaller adjustments otherwise the airplane will feel quite sensitive to control inputs - other than that, it just requires practise.

The added benefit in doing steep turns in Direct Law is that one must trim just as in a conventional aircraft, by rolling the trim wheel back.

Doing it with manual thrust is even better as the coordination required is significant, and is the measure of the level of handling skills every pilot should have.

Such exercises should never be a "test" - they should just be done in the sim until each pilot is proficient at the exercise. It takes about 20 minutes of sim time unless some instructing and practise is needed.

If the exercise does turn out to be a bit of a mess, help by gently correct the pilot and try again. A high number of flight hours does not guarantee skill or understanding, nor does a low number of hours prevent skill or understanding.

With practise pilots should be able to do it, maintaining both speed (+/-10kts) and altitude (+/- 100ft), rolling out on specific headings. Again, those limits aren't a "test", they're a goal, and when achieved they show that the pilot has the necessary manual handling skills for his or her aircraft. As John T. says in the previous discussion, gentle encouragement and suggestions produces very good results and confidence.

The climbing and descending S-turns described at the above link would be the next step in the practise and exercising of handling skills

Once one knows these differences and understands them, the Airbus is a delight to fly - as easy as the Boeings, in climb, cruise and descent. I've flown Douglas, Boeing, Lockheed and Airbus types in all regimes and they do not present a problem hand-flying them.

In my opinion, anyone claiming that the Airbus is "difficult to fly at cruise, like balancing a ruler on the tip of one's finger", doesn't fly transport aircraft let alone the Airbus, doesn't know the Airbus and shouldn't be saying such things to others who read their stuff when they don't know such things, no matter how many letters are in front of or after one's name...

Uplinker;

In 2006, Airbus issued guidance on how the UAS drill & checklist should be handled. The Airbus document may be found at http://home.base.be/fabrot31/airbusunreliablespeeds.pdf. The guidance is also in all FCTMs that I've examined, all of which were in the Manual prior to June, 2009.

Along with the standard sim exercises, your employer should be teaching the UAS drill because it is a known issue. The reason why accident reports should be required reading for air carrier managements is to understand why certain training priorities and regimes should be planned and appropriately resourced. If the requirements of the requlator are such that sim time is already at a premium and there is no time for the basics then that needs addressing first within the individual carrier, (why is there no spare time?) and then in proper venues in communications with the regulator...much slower, less effective I know but speaking up is the only way things change.

BTW, "deep stall" only refers to T-tail aircraft in which the horizontal stabilizer & elevator system is blanked by the low-energy airstream from the stalled wings. AF447 was not a deep stall, and in fact the tail was never stalled, (and the airplane could have been recovered using elevator alone if the stick had been held fully-forward long enough...they just stopped too soon because they didn't comprehend their situation and the re-occurence of the stall warning confused them. The indications of a full stall were however, present - an inability to arrest a high rate of descent when the nose is pitch up, etc., etc.).

I would like to add a link to a BBC Radio 4 discussion on cognitive science that may be found in the Air Asia thread on R&N because I think it is worth listening to. The broadcast is at: http://www.bbc.co.uk/programmes/b0505zw1

CONF iture

27th Jan 2015, 19:28

In fact, there is a discussion about such handling exercises back a few pages in the thread, beginning at: AF 447 Thread No. 12, regarding "S-turn" exercises, which are a bit more difficult and are certainly worth the time in the sim.
That would be an excellent practice to be repeated every 6 months, but the reality is very different as every sim session is already largely overloaded to try to fit the program as specified by the local Transport Ministry.
Another positive development would be to allow each pilot a 20 min period to practice whatever he likes ...

the Airbus is a delight to fly
Not too sure about that ... had always the feeling to have to wait for the trim to do what I would have done before ... 757 was a delight.

In 2006, Airbus issued guidance on how the UAS drill & checklist should be handled. The Airbus document may be found at http://home.base.be/fabrot31/airbusunreliablespeeds.pdf
The guidance is also in all FCTMs that I've examined, all of which were in the Manual prior to June, 2009.
This was an incomplete document especially following the multiplication of UAS In cruise phase. A simple procedure should have been published to specify what a crew has to concentrate on :

Pitch 2.5 deg
ENG N1 80%
And wait ...

alf5071h

27th Jan 2015, 23:24

Many posts in this thread and elsewhere infer that crews’ lack flying skills, yet none of the accident reports substantiate this. Even the researches have mixed results when looking at skill degradation with autopilot use.

There is no indication from everyday flights that handling skills for normal operations are less than required; however non-normal indicators suggest otherwise. Thus the safety focus should be on how non-normal situations are encountered, - handling skill or awareness. Many LoC accidents were self-inflicted, the unsafe flight condition was created by the crew – they stalled the aircraft, and having done so by ‘conscious’ action might be less amiable to reconsider the situation and changing the course of action. These are mental skills not manual skills.
Thus the need is to improve appropriate awareness in these unusual and rare situations, the skills of assessment, and reconsidering and changing actions.

More manual flying in benign conditions is unlikely to improve skills for LoC recovery. Some manual flight might improve skills of awareness, but not necessarily be effective in self-created surprising conditions.

There is no easy solution; greater background experience and skills in non-normal situations could help, but never guarantee that every situation will be covered nor that the crew will call upon the skills.
Protecting crews from these situations in general has been successful, except of course when the protections are degraded, yet again not every situation can be foreseen.
Instead of chasing the negative aspects of this accident, seek to understand how those crews who avoided or recovered from the same situations; then do more of what they did.

AF447, the protections degraded; improve the protections ... action in hand.

vilas

28th Jan 2015, 05:14

PJ2
In a 45 degrees turn you need to monitor bank, pitch, VS and speed so it is a good exercise in commercial jet to develop a efficient scan and not because you will be required to do it. As an airbus pilot you will understand you only get direct law with gear down and you don't do steep turns with gear down. Direct law is a short term state given to you as a flare mode of alternate law to help you keep a steady pull on the stick during flare and landing. That is why it transitions to that only with gear down when you don't even bank 10 degrees. I have five type ratings(including one in the US and one in France) and nobody ever asked me to do steep turns with gear down notwithstanding the FBW. As far as alternate law is concerned it is same as normal law except the protection part so any one who cannot do a steep turn in alternate law won't be able to do in normal law either. You need to inculcate respect for Alternate law by emphasizing careful handling within the envelope and not ask them to do steep turns. The S turns (climbing level then descending) you are talking about are the first thing that are taught to non jet pilots in flight and navigation procedure training(FNPT). The type rating begins with this and raw data flying FDs, bird and ATHR off departures arrivals and approaches in fix base SIM. However many airlines have their own syllabus called MCC which is a bad short cut in which they perform only one or two sessions in FTD and the rest in MFTD or APT as it is called now. These trainees struggle in the sim. Ultimately it is a business as any other and financial pressures make a mockery of professional requirements of cockpit crews.

PJ2

28th Jan 2015, 05:55

CONF iture, thanks. Yes, have done such compressed sessions and one never feels as though one accomplished anything, but ticked the boxes. Retirement certainly has its pleasures...

Re,

Pitch 2.5 deg
ENG N1 80%
And wait ...

Agree with you, - as I stated in July of 2009 and hence, essentially "do nothing", http://www.pprune.org/tech-log/376433-af447-179.html#post5058695 ... ;-)

alf5071h, as always, a pleasure to read your thoughtful posts - no big disagreement with your thinking here, but still a question mark perhaps, beside the manual-handling-skills item in the list. Thanks for adding to the dialogue.

vilas, thanks for the reminder on Direct Law & the gear. Seven years away has its downside...

vilas

28th Jan 2015, 06:35

CONF iture
... had always the feeling to have to wait for the trim to do what I would have done before ... 757 was a delight.
Can you explain a little what exactly you mean by that.

RetiredF4

28th Jan 2015, 06:50

Vilas
As an airbus pilot you will understand you only get direct law with gear down and you don't do steep turns with gear down. Direct law is a short term state given to you as a flare mode of alternate law to help you keep a steady pull on the stick during flare and landing.

I have no intent to argue with your POV, but to clarify things up I have one question:

Are you saying, that direct law will not happen due to system degradation or any other FBW malfunction except with gear down and therefore flying in direct law with gear up has not to be trained, or is direct law in the sim only achievable by putting the gear down?

I think the point of the mentioned exercises by PJ2 is, that if you can do a 45° bank coordinated turn without crashing you can do turns with less bank as well and the execution uses less brain cells when trained to the extreme than when untrained and unexpected events arrise. And doing them in normal law with all gadgets working seems a bit easy in the bus regardless of bank angle.
Concerning alternate law being like normal law without orotections I like to remind that it comes with two different sublaws, one of them Alt2B with roll direct like in AF447, where Bonin had a hard time to cope with roll from the beginning.
"Lazy eights" like we military pilots had to practice would be a good exercise to expierience the different roll characteristics in Alt2b under a variety of speeds which come with the maneuver.

@alf507h
Theoretical knowledge is essential for handling skills, but never can replace actual handling. When germany was in the middle of the "Starfighter crisis", the MOD Steinhoff ordered more flying practice to increase the flying skills of the pilots, and while the flying hours went up the losses went down. It is not either improvement of theoretical knowledge or increase of manual flying skills, it is both.

vilas

28th Jan 2015, 11:33

RetiredF4
There are only two listed failure which put the aircraft in direct law. One is transitory and pilot recovers to alternate law. The other is permanent when you loose both the ADIs and have to fly by the standby system so no help. You don't need steep turns in direct law. PJ2 understood what I am saying. Alt1 or Alt2 there is nothing to practice except fly it properly within the envelope. Please leave AF447 out as it is a long list of what not to do and what he didn't know how to do. Even normal law protections are not meant to be evoked through sloppy flying. There are hundreds of airbus pilot retiring every year without actual experience of any protections. Problem is pilots are becoming complacent with automation and loosing their scan and not monitoring speed or attitude or bank. They need basic raw data practice nothing to do with any law. Unlike military there is a commercial pressure on training. Airlines would rather save money on training for something that is not likely to happen or just do it to tick the boxes.

Microburst2002

28th Jan 2015, 11:52

Flying 45-deg bank turns in Alternate and Direct Laws is the same as doing the exercise in a conventional aircraft.

Negative!

DIRECT LAW handling characteristics are NOT like a conventional airplane's, no matter what Airbus claims.

Sidesticks give no clue of airspeed, like conventional airplane yokes do. Specially in steep turns, g force feeling is a cue that will tell you when to ease the bank, get back to altitude and roll to 45º again. Sidesticks give no clue of anything.

btw, I think steep turn training is a waste of sim time.

vilas

28th Jan 2015, 12:02

MB
Off course it is not same but he saying as reply to my objection to practice steep turns. You can do few 25 degrees bank turn in direct law to see how it feels but 45 degrees with gear down is crazy and waste of time. agreed.

Microburst2002

28th Jan 2015, 13:02

Yeah

Airbus should give more clarification on what the control laws really are.

All the old stuff in the FCOMs and bulletins is not clear and it is old.

imho, DIRECT law is a very degraded control law (not at all like a reversion to conventional control system). You could never certify an airplane with such system.

In the 330 DIRECT law comes in fewer occasions. You can land in ALTN (it has a flare mode)

Lonewolf_50

28th Jan 2015, 16:17

There is no indication from everyday flights that handling skills for normal operations are less than required; however non-normal indicators suggest otherwise.

Thus the safety focus should be on how non-normal situations are encountered, - handling skill or awareness. Many LoC accidents were self-inflicted, the unsafe flight condition was created by the crew – they stalled the aircraft, and having done so by ‘conscious’ action might be less amiable to reconsider the situation and changing the course of action. These are mental skills not manual skills.
Sir, any so called "manual flying" still includes significant mental skills, particularly when flying in instrument conditions.
Thus the need is to improve appropriate awareness in these unusual and rare situations, the skills of assessment, and reconsidering and changing actions. More manual flying in benign conditions is unlikely to improve skills for LoC recovery.
While true, you have to have good basic flying skills to take on the more advanced flying tasks. Building block training approach. For example, it does you little good to try and teach aerobatics or spin training if basic flying skills do not meet standards yet, or if perishable skills have atrophied. Some manual flight might improve skills of awareness, but not necessarily be effective in self-created surprising conditions.
Yes, that takes task loading to saturation to find out where the gaps are in mental processes. Sims can be great for this when properly used. Instead of chasing the negative aspects of this accident, seek to understand how those crews who avoided or recovered from the same situations; then do more of what they did. We will get another round from the Pitch and Power Chorus, I hear the humming offstage. :ok:

DozyWannabe

28th Jan 2015, 19:32

Airbus should give more clarification on what the control laws really are.

All the old stuff in the FCOMs and bulletins is not clear and it is old.
The fundamentals are actually more-or-less identical to what they were in 1988. The crucial point (which to the best of my knowledge has always been in FCTM/FCOM etc.) is that in ALT or Direct Law, it is possible to stall the aircraft.

DIRECT law is a very degraded control law (not at all like a reversion to conventional control system). You could never certify an airplane with such system.
How so?

In the 330 DIRECT law comes in fewer occasions. You can land in ALTN (it has a flare mode)
You can land in any mode on any of the Airbus FBW types- how do you think they did the flight tests? The only addition Flare mode makes is requiring a degree of gentle, progressive back-stick to simulate conventional input to some degree. In Direct Law as long as you use the ADI to manage your flare you should be fine!

alf5071h

28th Jan 2015, 19:37

PJ, :ok: but which ‘manual handling’ skills …
… and what range of skills is required to ‘avoid’ vs skills to ‘recover’, and to avoid or recover from what?

There seems to be greater opportunity for improving safety by reconsidering the role of the human, not as an item to be controlled (a hazard to be improved by training), but as a resource to be used before the event, not after when the skills demands are greater.
It’s better to stay within a relatively well defined operating area than attempt to train for a much wider range of scenarios outside of the norm, often unknown or predictable.
Thus which skills are required to keep within the normal envelope?

@F4, yes knowledge, but which theory, what depth and form of training, how much; there is no simple answer only a balance of judgements which are more often wrong after an event.
The industry requires foresight, often only available with hindsight.

Many contributors, perhaps all of us, suffer from ‘OOS-HEV’. (http://humanisticsystems.com/2014/11/13/occupational-overuse-syndrome-human-error-variant-oos-hev/) The link identifies the symptoms, contributory factors, and identifies treatment and prevention.

alf5071h

28th Jan 2015, 19:57

Lonewolf, ‘ "manual flying" still includes significant mental skills’, obviously yes, but which comes first.
It may be of greater value to consider the physical and mental skills together as a process; one process for hands on flying and another for auto flight. Thus we need alternative skill sets or differing emphases’ on components of the basic skills; what to use (to look at, to consider, to do) and when.
Unfortunately many contributors use "manual flying" to mean exactly what they mean, which is not always interpreted having the same meaning when read.

Please no more ‘Pitch and Power Chorus’ :ok:

Has the industry investigated the differences between AF447 and those A330 crews who successfully managed ASI malfunctions, or those who avoided ice crystal encounters, similar to the A330 in the same area as AF447 (I have mislaid the link to the graphic of other traffic and tracks).
Whatever those crews did – skills, actions, etc, might provide a better basis for training in order to avoid LoC accidents; promote and train the successful skills.
The industry must review some of the basic operational and training assumptions – double loop learning. (www.mtpinnacle.com/pdfs/v010p0ii21.pdf)

vilas

29th Jan 2015, 08:02

DozyWannabe
"In Direct Law as long as you use the ADI to manage your flare you should be fine!"
Dozy, in any law or any aircraft flare is done visually, looking out side and not on any instrument. I am surprised nobody has hauled you over the coals especially your friend Conf.

Lonewolf_50

29th Jan 2015, 13:23

It may be of greater value to consider the physical and mental skills together as a process;
agree, I think that was my point.
one process for hands on flying and another for auto flight.
related processes in any case.
Thus we need alternative skill sets or differing emphases’ on components of the basic skills; what to use (to look at, to consider, to do) and when. On this we agree.
Please no more ‘Pitch and Power Chorus’ :ok:
I am making a humorous allusion to both a classic trope in Greek Tragic theater and Verdi's Anvil Chorus.
Has the industry investigated the differences between AF447 and those A330 crews who successfully managed ASI malfunctions, or those who avoided ice crystal encounters, similar to the A330 in the same area as AF447. Whatever those crews did – skills, actions, etc, might provide a better basis for training in order to avoid LoC accidents; promote and train the successful skills. You'll get no argument on that score.

DozyWannabe

29th Jan 2015, 14:05

Dozy, in any law or any aircraft flare is done visually, looking out side and not on any instrument. I am surprised nobody has hauled you over the coals especially your friend Conf.

Fair point, but then I never claimed to be a pilot! ;)

PJ2

29th Jan 2015, 18:56

The safety-fication of everything (http://humanisticsystems.com/2014/11/05/the-safety-fication-of-everything/), even better - referenced in the OOS-HEV article. Could not agree more. These days, one cannot move either physically on our roads or socially where landminds which will give "offence" are everywhere, without running into a set of physical or social barriers accompanied by a real or imaginary person with a hat, whistle, safety-vest, clipboard and, above all, authority. O, deliver us...

Re, … and what range of skills is required to ‘avoid’ vs skills to ‘recover’, and to avoid or recover from what?

There seems to be greater opportunity for improving safety by reconsidering the role of the human, not as an item to be controlled (a hazard to be improved by training), but as a resource to be used before the event, not after when the skills demands are greater.
It’s better to stay within a relatively well defined operating area than attempt to train for a much wider range of scenarios outside of the norm, often unknown or predictable.
Thus which skills are required to keep within the normal envelope?Allow me to start with the assumption, If one can do the basics...ie., fly the airplane and keep it in or return it to, stable flight while navigating (meaning keeping it out of hazards, not doing airways work!), then one has sufficient skills under high demand to handle "events".

The example here is that of the thirty-one other crews who flew their A330 during a UAS event. I think that would as good a "metric" as any for such events.

In this, it is clear that I believe basic flying skills as described above may no longer be something that can be taken for granted.

I accept that the examples when handling skills are required are few these days. I accept that transports these days require systems-management skills and do not require manual skills, until they do.

On the rare occasions when such capability is required I think the data supports the view that there is a high degree of correlation between the capacity to fly an airplane and the successful resolution of abnormalities or emergencies.

Aside from their relationship to cognitive clarities and the practice of "muscle memory", (I play piano and it works as well there), the reason I chose to focus on manual handling skills in the original post is because such exercises are "tells" in terms of cognitive capacity and the capacity of "autonomic" learning, (muscle memory, as in playing the piano, etc.) I am not trained as a pyschologist, but I know from experience that when flying an aircraft is "in the muscles", the mind has less to distract it, so to speak.

You likely know this but in the spirit of "the exchange" I would like to establish these notions.

It's a way of saying that "average skills" are what aeronautical engineers and all members of the engineering/design team know they must design towards. The machine and/or system must be useable by those of average ability and capacity, "average" being defined as someone who has been trained to competency as measured by examination and as assumed by some level of experience with the machine/system in question, or who would be recognized by another pilot with experience, as "competent", (Johnston's Substitution Test - the notion applied here to "normal flying skills). The "tells" emerge as signs of competency levels, (clearly, some judgement of the presence of "competency" is involved as one cannot always measure experimentally in controlled circumstances).

Approached this way, I wonder if the notions being expressed as OOS-HEV become sidebars?...(that is not my intent, - I haven't thought it over enough yet! - I'm just positing that while legitimate, the relevance of OOS-HEV in the context of LOC accidents may not be high in the determination of needs, and I do take seriously your comments regarding hindsight & learning).

I would say at a minimum, that if one can handle aircraft with a high level of intuitiveness borne of thorough training, practise, reasonable exposure, (experience, in other words), in short...one can "fly", then one already has sufficient skill to handle all except perhaps rare, extreme encounters.

To make the connection between this response and the original long-ish post regarding 45-deg bank turns and "lazy eights" then - having some experience with these - I considered that one way to measure such skill in a pilot candidate (in initial or recurrent training/checking), was to do these exercises first to see if further training/practise was needed, and as a way of practising one's craft, which, first, is to fly the airplane.

CONF iture

29th Jan 2015, 19:07

Fair point, but then I never claimed to be a pilot!
Then maybe quit writing as you was one ...

Uplinker

30th Jan 2015, 07:34

Unusual attitude recovery (in a PA28), was part of my ATPL syllabus, as I hope it was for many others.

(For any who don't know; at a suitable safe altitude you would take your hands and feet off the controls and close your eyes while the instructor would put the aircraft into an unusual attitude - nose high, nose low, plus bank etc. On command of "recover", you would open your eyes and by reference to the instruments would have to quickly return the aircraft to straight and level flight and correct speed).

This was a very useful exercise. However, I have never done this in any airliner SIM that I have flown. (I did once spin a Shed for real, but that's another story.....).

We also did instrument exercises involving a series of 360 turns, linked with straight sections and including climbs and desents; Ours were called pattern A and pattern B. These had to be practised and then flown accurately under test conditions. Again, I have never done anything like this in an airliner SIM.

From my many years of airline flying and recurrent LPC/OPCs I think that TRI/TRE's get so wrapped up with the compay's program, the SOP's and the 'flavour of the month', that the basics are given very scant regard. We do do manual flying with no flight directors, but that is usually carefully controlled under radar vectors to an ILS, so it doesn't involve much attitude change.

Derfred

30th Jan 2015, 11:42

That's interesting. Have you flown other than Airbus aircraft?

My airline schedules regular UA/Upset recoveries in our Boeing simulator cyclic program, and always has.

And yes, I was also exposed to it in a light aircraft, but not for ATPL, for private licence. (And exposed to many more doing aeros but that's irrelevant).

alf5071h

30th Jan 2015, 21:09

Lonewolf, PJ2, obviously we have similar views, but within this agreement, some differences.
PJ, considering your ‘assumption’ in a wider context, then there is an inference that the ‘average skills’ within the overall flying process will ‘always’ be used at the appropriate time; i.e. both having and knowing which skills to use, and when.

However, this point might be refuted in the differences between previous events and AF447.
All crews encountered adverse conditions; some initially reacted as AF447, but at a later point transitioned to a successful outcome. Why; what attributes, skills, behaviour, etc, led them to revert to appropriate actions whereas AF447 did not.
As far as is known all crews had ‘identical’ (acceptable) ‘average ability’ based on training, checking, normal operations, etc (but I am prepared to debate that). Thus the key issue is the ability to switch between alternative courses of action, which in turn involves awareness / understanding, knowledge of procedures, and ability to recall them (including cognitive resource).
The latter point includes surprise which appears to dominate in AF447 and other LoC events; thus how do crews use their skills when subject to surprise?

This line of argument can be applied to other ice crystal (non) events in A330s. We do not know how many other crews have been confronted by ice crystal conditions, but either due to less severe weather or appropriate change of track, they did not suffer an adverse event. Again what led crews to take these courses of action. It appears that this involves similar qualities of ‘skill’ (judgement) within the overall flying process as required in the incidents, but were used at an earlier time. Thus key issues are when to change the course of action and what mental abilities are required to understand the situation and choose the correct action.

The above concentrates on mental skills with all the problems of influences, bias, training, knowledge, and constraints of human factors.
Outwardly this involves TEM and Time; Avoid (detect and react a threat), Detect and react to an error (revise the course of action), Mitigate (recover), before the situation degenerates to an accident – the importance of timely thoughts.

… does the above challenge the assumption that average crews have sufficient skill for all reasonable situations (what is reasonable); if not then how are these aspects to be taught, checked, practiced, and then how can we ensure that they will be used.
The alternative is to minimize the occasions where crews are exposed to adverse situations.
Neither is a perfect solution, and there may not be one, because the variable human is involved; could there be a compromise, and if so what (assuming that this form of safety activity is required).

Uplinker

31st Jan 2015, 07:34

Derfred,

Commercial airline types I have flown are SD360, Dash 8-200/300/Q400, BAe146, and Airbus 320/321/330.

Interesting that your ATPL did not include unusual attitude recovery. I take it that you did spinning and spin recovery? I did mine in a Zlin.

Ian W

31st Jan 2015, 11:54

However, this point might be refuted in the differences between previous events and AF447.
All crews encountered adverse conditions; some initially reacted as AF447, but at a later point transitioned to a successful outcome. Why; what attributes, skills, behaviour, etc, led them to revert to appropriate actions whereas AF447 did not.
As far as is known all crews had ‘identical’ (acceptable) ‘average ability’ based on training, checking, normal operations, etc (but I am prepared to debate that). Thus the key issue is the ability to switch between alternative courses of action, which in turn involves awareness / understanding, knowledge of procedures, and ability to recall them (including cognitive resource).
The latter point includes surprise which appears to dominate in AF447 and other LoC events; thus how do crews use their skills when subject to surprise?

This line of argument can be applied to other ice crystal (non) events in A330s. We do not know how many other crews have been confronted by ice crystal conditions, but either due to less severe weather or appropriate change of track, they did not suffer an adverse event. Again what led crews to take these courses of action. It appears that this involves similar qualities of ‘skill’ (judgement) within the overall flying process as required in the incidents, but were used at an earlier time. Thus key issues are when to change the course of action and what mental abilities are required to understand the situation and choose the correct action.

The above concentrates on mental skills with all the problems of influences, bias, training, knowledge, and constraints of human factors.
Outwardly this involves TEM and Time; Avoid (detect and react a threat), Detect and react to an error (revise the course of action), Mitigate (recover), before the situation degenerates to an accident – the importance of timely thoughts.

… does the above challenge the assumption that average crews have sufficient skill for all reasonable situations (what is reasonable); if not then how are these aspects to be taught, checked, practiced, and then how can we ensure that they will be used.

Automation Surprise is often misunderstood. It is not surprise every time automation that you depend upon fails, it is the initial surprise for that particular failure. Once that particular failure has surprised you once, you do not suffer from the same impact again. This makes it hard for human factors testing as you can only catch people out once so it is difficult to do comparisons of behavioral changes in slightly altered situations with the same crew.

So it may be that in the other cases the particular training or experiences of the crews had put at least one of them through a very similar loss of pressure instruments and a drop into Alternate Law at height - or they just had pilots who reacted to their automation surprise differently.

By its very nature, 'Surprise' leads to indeterminate responses from the human 'subject' and can lead to cognitive tunneling on inappropriate actions such as trying to follow a failed FD as that 'always works' and disregarding other disagreeing valid inputs.

Once that surprise has happened and the responses corrected then it will not happen again. Unfortunately, in some cases the results of the first surprise are such that there is no second chance.

alf5071h

31st Jan 2015, 14:21

Ian W, :ok:, but I remain open minded; “… surprise, once happened it will not happen again. Even though this is qualified by “… and the response corrected”.
How can we be sure that the response has been corrected (learnt), and even if learnt will it be used in a future event.
“By its very nature, 'Surprise' leads to indeterminate responses from the human …” :ok:

There is an interesting study on Sim Stall Models (www.skybrary.aero/bookshelf/books/2986.pdf), which concludes that surprise can be generated in simulation. However, it interesting that many of the pilots who suffered surprise were already trained in stall recover and may have experienced some of the evaluations previously; also, they were briefed that the training (evaluation) exercise was stalling, … and yet they were still surprised. What surprised them; the situation which led to the stall, the severity of the simulation, or the complexity of recovery – and consider the number of pilots did not recover according to the book.

Surprise depends on context, the situation and all those aspects which affect the human assessment and understanding of the situation at that time – same technical failure, different situation, … surprise!

Pilots might be taught to tolerate or mitigate surprise; how, and without assurance of success.
Pilots could be protected from ‘surprising’ situations; how and in what range of circumstances.
Perhaps aspects of both, training (experience) and protection, but even then the risks are only minimised.

It’s time to look beyond the human and automation in isolation, look at the total operating system and how it functions. Consider the operational processes, revisit the assumptions about humans and automation and compare these with the desired level of risk (safety is what is done to contain risk).

Ian W

1st Feb 2015, 12:18

alf5071h (http://www.pprune.org/members/72276-alf5071h) I do not think we disagree.

Normal surprise when something even expected happens without warning is unsettling and cause errors. Automation surprise, has the effects of normal surprise but is also "what :mad: is it doing now?". The system exacerbates the pilot confusion by an overload of alarms of all different sorts and often (as in AF447) the loss of the information that was relied on almost to the exclusion of everything else - that is the automation failure was a surprise and what it was doing was a surprise. These surprises were never recovered from as the intermittent FDs appear to have been trusted each time.

Perhaps an older pilot with more pre-automation skills would have (as many on this thread suggest) have disregarded the hubub and the loss of speed indications and just flown 'pitch and power' accepting the turbulence and then tried to sort things out. But that isn't the way the new pilots are trained they are trained to use the automation, it is always right and will protect you from doing things wrong. Or as was said on another thread - "protections are not lost even in alternate law". Well guess what you can zoom climb to above coffin corner in a high nose up attitude and protections in Alternate Law won't stop you and presto you are stalled. But you CANNOT be stalled - all your training says that protections are always there and will stop it so disregard all the stall warnings - you cannot be stalled. Then when I put the nose down I get stall warnings and the aircraft is going down fast so I want to follow the flight director UP but it doesn't work however hard I pull.

Total automation surprise and cognitive overload. Not helped by the 60Kts stall warning cut off, or the FD coming back when the aircraft is stalled etc etc.

The real underlying error I believe is that what has been inadvertently taught to the younger pilots is 'always trust the automation' which is completely the opposite to the more 'experienced' who NEVER fully trust automation. So the expectations of experienced pilots are met when the automation fails, and it comes as an unwelcome and confusing surprise to the younger pilots.

You may be interested in http://csel.eng.ohio-state.edu/productions/xcta/downloads/automation_surprises.pdf which is a paper on the subject biased to aviation.

Arfur Dent

1st Feb 2015, 16:05

Ian W - absolutely agree. Also, in the Far East for sure, a whole lot more attention should be devoted to staying well away from CuNims and NEVER deciding to climb over them anywhere near the max cruise altitude of the aircraft at that time.

Mr Optimistic

1st Feb 2015, 16:06

Yes the FD business was most confusing. If the IT reckons they should be switched off then why not just do it and let the crew switch them back on if they insist. Also, was the aoa inhibit below 60 knots flagged on any display?

vilas

2nd Feb 2015, 04:15

Ian W
The real underlying error I believe is that what has been inadvertently taught to the younger pilots is 'always trust the automation' which is completely the opposite to the more 'experienced' who NEVER fully trust automation.

I do not agree with that statement of yours. Automation if it is not reliable would not have been installed. But a professional pilot has the responsibility to monitor that it is working and experience has nothing to do with it. In SFO experienced pilot was under check and they dropped speed by 30 KTS on approach even the check pilot did not notice it. Thirty three years ago same thing was done this time in A320 in Bangalore India. Thickness of the Log book can hide inadequacies that can develop over a period of time and due to the heavy log book you may not get critically assessed in your refreshers. An important point some pilots are missing out is that whether with automation or without, pilot's scan does not change. In manual flight you scan and make the changes, with auto pilot you scan to ensure it is doing it. This needs to be emphasized in training and not build a mistrust with automation. Mistrust builds fear. How would you do a CAT3 approach if you didn't trust the system? Also you have made some outrageous statements about airbus protections and alternate law etc. clearly indicating that you know very little about them. An automation that is untrustworthy would not have been installed similarly when automation reaches the perfection that it will not need a monitor the pilot,won't he be replaced?

seagull967

7th Feb 2015, 02:30

A question that may have already been answered, and if so, I apologize.

I am not an Airbus pilot, but have some familiarity. I have been informed that there is a display of checklists after a system failure, is this correct? If so, in the case of AF 447, did the system display a checklist or a procedure in any manner following the UAS situation? If not, is there any circumstance when it would? Finally, if it does display such a checklist or procedure, does it advise to turn the FD's off, as most UAS checklists do as a first step? If not, are there circumstances it would display that?

Thank you.

roulishollandais

7th Feb 2015, 07:49

EXCELLENT LINK ! Thank you Winnerhofer.

infrequentflyer789

7th Feb 2015, 13:03

EXCELLENT LINK ! Thank you Winnerhofer.

Particularly like the comment on XL-888, the author has clearly discovered and entirely new species of Airbus law - direct law, but with auto-trim and C*. Either that or he hasn't read the XL report or doesn't understand what direct law is, or both.

Shame, as he was doing quite well up to that point...

PJ2

7th Feb 2015, 20:02

seagull967;

1. I have been informed that there is a display of checklists after a system failure, is this correct? Yes, it is call the "ECAM" - Electronically Centralized Aircraft Monitor". It serves the same purpose as the EICAS on the B767 & B777.

2. If so, in the case of AF 447, did the system display a checklist or a procedure in any manner following the UAS situation? No. The actual "checklist" is a series of memorized steps to be actioned immediately in response to a loss of airspeed indication. The actual process is, the pilot-flying calls for the drill while continuing to fly the aircraft. The pilot-not-flying actions the memorized items and then the checklist items.

If there is immediate risk to the aircraft, (ie., near to the ground right after takeoff), the memorized drill requires that the autopilot/flight director & autothrust be disconnected, a pitch attitude of 15° be established with TO/GA thrust set, and when at circuit height or minimum safe altitude, to troubleshoot the problem. If at/above higher altitudes, a 5° pitch is set and thrust is placed in the "CLB" detent. In either case, once the memorized items are accomplished by the pilot-not-flying, the paper checklist from the QRH - Quick Reference Handbook - is read and actioned and the aircraft secured for continued flight.

3. If not, is there any circumstance when it would? Finally, if it does display such a checklist or procedure, does it advise to turn the FD's off, as most UAS checklists do as a first step? Not applicable as you'd see, but the ECAM does display the system losses and checklist items which are actioned and cleared, again using the same process as described above. Turning off the FDs is the first memorized item in the UAS drill.

4. If not, are there circumstances it would display that? No - turning off the FDs is done in response to drills and/or checklists. Also, if one is not going to follow the FDs, (and there may be legitimate reasons for this), then they must both be turned off.

Gysbreght

8th Feb 2015, 11:22

Only if you don't read the report.

A33Zab

8th Feb 2015, 12:35

EXCELLENT PART:

And of course if the pilot is unfamiliar with stall recovery and inputs the natural (and absolutely wrong) control back command the situation gets even worse.

Machinbird

8th Feb 2015, 15:29

Particularly like the comment on XL-888, the author has clearly discovered and entirely new species of Airbus law - direct law, but with auto-trim and C*. Either that or he hasn't read the XL report or doesn't understand what direct law is, or both.I think the sarcasm here is a bit harsh. The XL A320 got its stabilizer trim setting in Normal Law (with defective AOA operation). Then at the moment of stall, airflow assymetry caused an ADR problem that dropped them into Direct Law. The aircraft pitched up uncontrollably (without manually running trim down) and finally entered Abnormal Attitude Law when it was too late and the nose too high to recover in the altitude available.
Too bad they didn't drop a wing early on and convert some of that pitch up into turn.:(
Really too bad they didn't consider the consequences of what might happen if their checks did not go as planned. :{ Didn't even have a minimum airspeed stopping point!!!!

Machinbird

8th Feb 2015, 16:08

With regard to the F-GLZU incident of July 2011, it is interesting to see how long it took PF to mentally re-engage with the aircraft.

If t=0 is the time that the overspeed started, here is how it went down:

t=3 seconds, PNF reflexively disengaged AP and pitched up
t=8 seconds PF extended the speedbrakes
t=13 seconds PF retracted the speedbrakes
t=24 seconds PF adjusted his Nav Display ??
t=53 seconds PF surprised to be at FL380
t=1 minute 18 seconds, PF trying to control aircraft thru AP
t=1 minute 42 seconds, PF aware of A/P disengage and at that point appears to be properly engaged with the aircraft.

If this is typical for long range cruise operations, then there is a major problem with the man-machine interface!:mad:

At least in this case, the aircraft remained in Normal Law.

A33Zab

8th Feb 2015, 18:55

@ MACHINBIRD:

If this is typical for long range cruise operations, then there is a major problem with the man-machine interface

t=3 seconds, PNF reflexively disengaged AP and pitched up
t=8 seconds PF extended the speedbrakes
t=13 seconds PF retracted the speedbrakes

IMO if after these actions BOTH pilots lacks the monitoring of their instruments(Altitude, Airspeed+trend, V/S, Attitude, FMA)
and the lack of CRM after audible warnings accompanied with MW then there is a major problem with the MEN.

Machinbird

8th Feb 2015, 19:34

IMO if after these actions BOTH pilots lacks the monitoring of their instruments(Altitude, Airspeed+trend, V/S, Attitude, FMA)
and the lack of CRM after audible warnings accompanied with MW then there is a major problem with the MEN.
A33Zab, I understand where you are coming from, but it goes deeper than that. The present autoflight interface in cruise allows the pilots to completely mentally disconnect from the process of flying the aircraft. All they have to do is be sure that every few minutes they come back to the big picture of where they are and make sure things are on track.

It is humanly impossible to maintain full mental involvement in the flight process while a computer carries out the real work. After a period of time, the mind drifts elsewhere, despite the best of intentions.

The interface needs to more fully involve the pilots in the flight process. There is no reason that the pilots could not actually fly the aircraft while the computer looks ahead for a possible altitude bust and performs the instructor function to improve pilot skill. How that is best done is up to the software development folks, but I am willing to bet there is a solution.:ok:
Might want to swap the PF/PNF functions every 15 minutes or so however.

Clandestino

8th Feb 2015, 19:44

Earlier stall recovery procedure was based on approach to stall but after a few accidents in the US where the thrust increase prevented the pilot from lowering the nose FAA asked for a review of the procedure.I don't doubt it but I would still like to know what these "a few accidents in the US" were. I'd appreciate links to reports. In context of old procedure being inadequate, Goldenrivett and Winnerhofer's suggestions that example was G-THOF incident were slightly off mark as:

The stall recovery techniques recommended
in the manufacturer’s Flight Crew Training
Manual (FCTM) were not fully applied. ...whatever they were at that unenlightened age.

PLZ convince me that the 'bus control law for pitch is primarily programmed for an attitude versus a gee. For the umpteenth time: it is :mad: not! It holds the flightpath! Not :mad: pitch or :mad::mad: G!

It's the place in manuals where "needs to know" meets "unable to understand". If Aırbus wrote "maintains vertical flightpath" instead of "maintains 1G corrected for pitch up to 33 deg bank", already high number of confused manual readers would increase even more. So why did Airbus made the system that is so difficult to describe? To make it simple to operate! It works just like the conventional controls with nose following control displacement unless you: hit the protection, stall the aeroplane or have your flight controls disabled. I still haven't found a pilot that would have problems learning or unlearning the sidestick.

lack of indications that the jet has reached trim l;imits or AoA limits AoA limits? There is cue on speed display, aural stall warning and strong natural pre-stall buffet.

My comment about continuing a climb with stick in "neutral" stands.If initial flightpath is horizontal, it maintains it with stick neutral. If it was descending, it descends with stick neutral. Your point be?

So by saying " would try to maintain constant vertical flightpath " we can translate it to try to maintain a pitch the aircraft trim back, true ?No. If speed changes, it will adjust the pitch to maintain flightpath.

I just spoke with an EZY pilot and he told me that there will be normally not a pitch up during a stall in alt. Law and that it´s an requirement of certification by EASA (cs-25) that no abnormal nose up pitching will occur in a stall ?HTBJ chapter on stick pusher provides enlightenment on how aeroplanes behaving badly were certified way before Airbus.

whilst that is true I don´t see the same thing happening on an airplane with 2 interconnected sticks...when the bloody column hits your stomach, you get the message that the other dude is holding it back...It might clarify the situation if we introduce into discussion BEA's report on AF447 accident, chapter 1.18.6 where cases of holding interconnected yokes into stall are discussed. Meanwhile, there was another sad case of holding the controls fully up till ground impact in Mali.

It is worth noting that a Delta Crew encountered the same situation as the AF crew in a 330 on a Pacific flight. It is also worth noting that out of 36 cases of unreliable airspeeds on 330/340 that preceeded AF447 and were listed in interim 2, 6 happened to AF crews. No damage, no injuries.

I fly Airbus A330. A lot of what the French captain apparently says is interesting and certainly food for thought - I don't see it as BS, perhaps someone could enlighten me

First, enlightement on BS, from the worlds foremost expert:

It is impossible for someone to lie unless he thinks he knows the truth. Producing
bull**** requires no such conviction. A person who lies is thereby responding to
the truth, and he is to that extent respectful of it. When an honest man speaks, he
says only what he believes to be true; and for the liar, it is correspondingly
indispensable that he considers his statements to be false. For the bull****ter,
however, all these bets are off: he is neither on the side of the true nor on the side
of the false. His eye is not on the facts at all, as the eyes of the honest man and of
the liar are, except insofar as they may be pertinent to his interest in getting away
with what he says. He does not care whether the things he says describe reality
correctly. He just picks them out, or makes them up, to suit his purpose.

Purpose of that certain French capiten was to portray FBW Airbi as dangerous machines. To this end he picked just what suits his agenda, ending up whit statements that might sound true but are either not complete truth or totally meaningless e.g:

FD's are bars helping the pilot to follow his trajectory. True but not always, especially not at the edge of the envelope, thence BS.

There is a loss of altitude, however marginal this loss ( 350 to 350 ft ) this point is crucial in the understanding of the sequence of events as it explains the crew first move is to pitch up in order to regain the lost altitude (BEA p.179)It might explain initial climb but not why then the level was severely busted or why climb even after PNF prompts to go down, thence BS.

Joysticks only function is to send inputs to the computer management system which either accepts them or rejects them True, but worthless without explanation for rejection or that rejections happen very, very seldom or that pitot clogging in AF447 case disabled 'rejectıon' and so FCS tried to deliver pılot's command, thence BS.

(Hence the motto that airbuses cannot stall)Delivered by who? Weasel words. BS.

45'' after the alarms rang, there have been alternate actions to pitch up and down by the crewTrue, but overall pıtch-up actions were of larger displacement and longer duration, omitting this is BS.

Need more?

If Airbus pilots are not trained to regard the aircraft's attitude indicator as their primary instrument, then we have a problem.There is no other way to fly Airbus. Problem is not that simple, has nothing to do with Airbus and was far better understood by Langewiesche père than fils.

When the Bus is messed up, your conventional pilot skill can't help much because when you pull the stick, the plane may not respond by raising up the pitch. DF Wrong! When it is messed up, it won't stop you from nominating yourself for Darwin Award.

I am a sim instructor Arguments from authority are worthless on anonymous fora.

Fly-by-wire is something like CWS, (Control Wheel Steering) in a Boeing, (but for very different reasons!).Slight difference being CWS is attitude hold, Airbus is flightpath hold.

DIRECT LAW handling characteristics are NOT like a conventional airplane's, no matter what Airbus claims.I had the pleasure of trying it only in the sim, for about 5-6 hours hands on time and I partially agree; it's not like ATR-42 or Q400; A320 in direct law is far nicer and easier to fly.

Sidesticks give no clue of airspeed, like conventional airplane yokes doUh-huh. So, the crew of G-THOF got the message from their yokes they are flying too fast? Hey, artificial feeling was pushing hard against their hands, providing tons of feedback.

DIRECT law is a very degraded control law (not at all like a reversion to conventional control system). You could never certify an airplane with such system.FAA disagrees. Maybe your congressman can do something about it?

A33Zab

8th Feb 2015, 22:22

It is humanly impossible to maintain full mental involvement in the flight process while a computer carries out the real work. After a period of time, the mind drifts elsewhere, despite the best of intentions.

If even the ATTENTION GETHERS cannot get the attention they require and get them out of 'slumber' mode then I am afraid there is no hope.

PJ2

9th Feb 2015, 00:59

Clandestino;
Slight difference being CWS is attitude hold, Airbus is flightpath hold.
Ack. Was looking for a broad comparison and know the reasons for the difference are nevertheless fundamental. ;-)

CONF iture

9th Feb 2015, 01:59

If even the ATTENTION GETHERS cannot get the attention they require and get them out of 'slumber' mode then I am afraid there is no hope.
If only the main attention getter had been generated ... AP disconnection.

To give priority to a PA over essential stuff is not the best idea ... but how to label a concept that allows a crew to manipulate his flight control command for 6 seconds and as far as 3/4 to stop without being clearly visible to the other crew ?

A33Zab

9th Feb 2015, 07:53

CONF iture:

but how to label a concept that allows a crew to manipulate his flight control command for 6 seconds and as far as 3/4 to stop without being clearly visible to the other crew ?

Now that's a good excuse, you forgot to mention the non moving thrust levers.

FCTM 09 Jan 2007:

VMO/MMO EXCEEDANCE

In turbulence, during climb, cruise or descent, the aircraft may slightly exceed
VMO/MMO with the autopilot (AP) engaged.
To prevent such an exceedance, adapt speed or Mach target.
If severe turbulence is known or forecasted, consider the use of turbulence speed.
If the current speed is close to the VMO (maximum operating speed), monitor
the speed trend symbol on the PFD.
If the speed trend reaches, or slightly exceeds, the VMO limit:
. Use the FCU immediately to select a lower speed target.
If the speed trend significantly exceeds the VMO red band, without high speed
protection activation:
. Select a lower target speed on the FCU and, if the aircraft continues to
accelerate, consider disconnecting the AP.
. Before re-engaging the AP, smoothly establish a shallower pitch attitude.

If the aircraft accelerates above VMO with the AP engaged, the AP will disengage
on reaching the high speed protection. The high speed protection will apply a
nose-up order up to 1.75 g, in addition to pilot input during VMO recovery.
Therefore, make a smooth pitch correction in order to recover proper speed.
Speedbrakes may be used in case of high speed exceedance, but the flight crew
should be aware of pitch influence. In addition, speedbrakes will be used with
caution, close to the ceiling.
High Speed Protection may also result in activation of the angle of attack
protection.
In all events, check the AP engagement status, and re-engage it when
appropriate. It may have tripped and the associated aural warning may have
been superseded by the overspeed aural warning.

CONF iture

9th Feb 2015, 12:29

Now that's a good excuse
Not an excuse, merely a characteristic of the Airbus concept that allows one crew member to manipulate his flight control command with large amplitude and for consequent period of time without the other crew members being able to directly seeing those inputs. The 310 was the last one in Toulouse to not suppress such interesting first hand data.

infrequentflyer789

9th Feb 2015, 12:52

I think the sarcasm here is a bit harsh. The XL A320 got its stabilizer trim setting in Normal Law (with defective AOA operation). Then at the moment of stall, airflow assymetry caused an ADR problem that dropped them into Direct Law. The aircraft pitched up uncontrollably (without manually running trim down) and finally entered Abnormal Attitude Law when it was too late and the nose too high to recover in the altitude available.

Exactly - and that is why it has precisely nothing to do with a supposed design issue with C* in stall - they were not in C* in stall.

Nor is the trim up a C* or bus issue - it will happen exactly the same on a conventional, depending on AP mode, if speed is allowed to decay. I think XL is closer to G-THOF (a 737, thats how much C* has to do with it) than to AF447 - both crews had difficulty recovering due to being out of trim, both crews omitted to trim, G-THOF ended better only because they reduced thrust to get elevator authority back.

If XL (and G-THOF) illustrate any design flaw it is with underslung engines, not C* - but in my opinion every design decision has compromises, no design is perfect in every scenario, and what it really illustrates is the perils of trying to recover a pitch upset by adding thrust when your thrust line is below COG.

argyle

9th Feb 2015, 14:16

The ECAM message AP OFF that comes on after pushing the take-over button is coloured red not amber, as in the report.

A very well written report that brings out many good points and traps.

Lonewolf_50

9th Feb 2015, 14:45

For the umpteenth time: it is :mad: not! It holds the flightpath! Not :mad: pitch or :mad::mad: G! It's the place in manuals where "needs to know" meets "unable to understand". If Aırbus wrote "maintains vertical flightpath" instead of "maintains 1G corrected for pitch up to 33 deg bank", already high number of confused manual readers would increase even more.
That is no excuse for writing an ops or a training manual that doesn't educate as well as train. You have to know how your system works to operate it professionally.
So why did Airbus made the system that is so difficult to describe? To make it simple to operate! Actually, your sentence makes sense if you omit "that is so difficult to describe." As above, there is no excuse for not taking the effort to describe it clearly to the operators. You are carrying the trusting public in your aluminum tubes with wings.
AoA limits? There is cue on speed display, aural stall warning and strong natural pre-stall buffet. Since we are discussing AF 447, we may wish to remember that in this case airspeed indications had gone on holiday thanks to a voting procedure. (And some ice in the tubes). Granted, that eventually resolved itself but by then the crew were behind the aircraft. HTBJ chapter on stick pusher provides enlightenment on how aeroplanes behaving badly were certified way before Airbus. A point worth remembering.
Meanwhile, there was another sad case of holding the controls fully up till ground impact in Mali. Lesson: there is no collective experience, there is no collective memory. A given crew only has its experience, memory, professional education, and professional training.
It is also worth noting that out of 36 cases of unreliable airspeeds on 330/340 that preceeded AF447 and were listed in interim 2, 6 happened to AF crews. No damage, no injuries. Indeed worth noting.
It might explain initial climb but not why then the level was severely busted or why climb even after PNF prompts to go down, thence BS.
So what does explain that, in your humble opinion?
FAA disagrees. Maybe your congressman can do something about it? Not if he knows what's good for his wallet. ;)