AF 447 report out [Archive] - Page 2

Lyman

9th Jul 2012, 18:19

@carjockey

"Agreed. But we should remember that those experts who deny 'Global Warming' tend to be associated with companies who are (in theory) complicit in it's proliferation and stand to lose lots of cash if controls were implemented.
Whereas those experts who warn of the dangers of 'Global Warming' have no such agenda.
So who are you going to believe?"

You are accepting of the "experts" who warn of disaster due "climate"?

I am glad you brought this up. People sometimes rely on comfort rather than critical thinking when venturing into an agenda laden minefield. That is what "consensus" is all about: comfort, validation, and 'safety'.

There is always an agenda, if only the fuzzy feeling "agreement with others" may bring.

Dispassionate and pure objective analysis is as rare as bananas in the Arctic. There is always the prevailing politics of the perceived outcome that drives the deceit dwelling in the person of our "guardians". You trust Government? Without rancor, the concept of a trustworthy politic is laughable. It is only when we put on our G issued blinders that we start to slide down the slippery slope. People tend to bud and bond with those with whom they affiliate, it is a given in a social society. This is especially true of the professions.

Government entities/agencies are wildly expensive, all the more when something as important as public safety is involved. The fealty derives from who signs the paycheck, pays the retirement; government is no exception. Loyalty, therefore, is to the politic, not the citizen.

BEA dances to the tunes selected by the powers that reign in the arena in which they operate. This is not surprising, and the standard of any market.

Think of the structure: a standing army of professionals, biding their expensive time between a/c accidents. You think they are best used in compliance? Any agency responsible for the public safety must be dependent on independent resources as to gathering and analysing evidence. Remember the "Memo"?

A purer and more damning bit of proof of weak and 'kept' personnel cannot be found. The actual process is frequently simply tacit, allowing for wildly blatant wet kisses such as the memo.....

chubbychopper

9th Jul 2012, 18:34

AF447 Conclusion: The pilots pulled instead of pushed. The end.

Indeed, but why? And the answer, which is plain to most, except perhaps those who earn their remuneration flying the Airbus, and dare not admit the aircraft's shortcomings, is:

One pilot pulled. The other pilot, as a result of not being connected to the loop due to Airbus design, hadn't got a fkucking clue what the PF was doing, so he just let him pull!

robertbartsch

9th Jul 2012, 19:05

Are there too many recommendations in the offical report? ...seems like these two could be sufficent:

1. Don't fly into a storm
2. Don't pull back on the stick and ignor stall warnings....

Clandestino

9th Jul 2012, 19:17

Clandestino
You who are so conceited why did you ignore my sentence:

Sorry, missed it. Beg your pardon.

If I remember well some fuel had been transferred to the tail (which I suppose happens automatically during cruise, like on MD11, to reduce fuel consumption) making it even more hopeless, if they wanted and had tried, to exit the condition of deep stall they were in.Almost accurate but largely irrelevant.

It is true fuel was transfered to trim tank to move CG aft and thereby reduce trim drag. It is true that aft CG tends to exacerbate the problem of stall recovery. It is also true that crew did not recognize unreliable airspeed. It is true stall was completely CM2 induced. It is true no one on flightdeck ever verbalized the recognition of stall warning or need to perform stall recovery. Term "deep stall" has very specific meaning: it denotes stall that can not be recovered from by using controls normally available to crew. While no A330 before AF447 has ever ventured into such a high alpha range, there are indications in FDR data that nose could be lowered and AoA decreased as there were three occasions where the nose nodded downwards: first time when power was reduced briefly, second and third time when elevators just moved from full nose up to half nose up position as first right, then left stick briefly went ahead of neutral so it seems A330 are not prone to deep stalls/locked-in condition.
1. Don't fly into a storm

They never did.

soylentgreen

9th Jul 2012, 19:47

Clandestino wrote...

Soylentgreen wrote...

Given an identical situation, what % of professional pilots (or perhaps '3 man groups of pilots') would flub it and crash the plane?

Those who have been paying attention know that between Nov 12 2003 and Aug 07 2009, there were 37 recorded cases of unreliable airspeed on A330/340 worldwide. 36 of them ended without damage to aircraft or injury to anyone. One ended up in airframe write-off and death of all on board.

Study you proposed has already been done. Results are in the final report. Your notion that:

A big part of this was the human-machine interface, which did an extremely poor job of letting the pilots know what was actually going on.

...is not confirmed.

Thanks to those who liked my post

You are welcome, even as I liked it as a very good example of bad science.

Let's assume that the 1 out of 37 failure data that you quote was a true experiment (it wasn't, it's an observational quasi-experimental design, but let's ignore that for now).

1 out of 37 is about 2.7%, meaning that based on this data, roughly 3% of crews in identical situations would crash the plane.

Of course, we know from basic statistics that small sample sizes are problematic. Plugging the #s into a confidence interval calculator gives us a margin of error of roughly +/- 7%, at the 99% confidence level.

In plain English, with a sample size of 37, we can only say with confidence that actual rate of crashing in this situation will be between 0% and 10%.

Care to explain your "Bad Science" comment? If you don't have doctoral-level statistics knowledge and don't understand this, I'd be happy to explain in more detail?

I think your point that "the study...has already been done..." is valid, only if you accept that results between 0% and 10% are acceptably precise. Do you?

Lonewolf_50

9th Jul 2012, 20:55

For anyone interested:

If you go to the tech log forum, you will find the following point excerpted from the BEA report.

The UAS (Unreliable AirSpeed) procedure memory item of turning off the FD's was not accomplished. (FD = Flight Director).

There are even some handy pictures and graphs that show when the FD was receiving good data, and when it wasn't. Mind you, neither pilot was aware of when it was good and when it was bad, but given the procedure as stated, they should not have needed to.

This opens the question: was the PF using FD as a reference, or a primary reference for his instrument scan, even though it was not being reliably sourced by the data it is usually fed?

The reasons behind that might be habit, might be training, might be a lot of things. One of the things CVR's and FDR's don't do is read minds, so one can only guess at that. I think he at various times tried to follow the FDR. I am not on perfectly solid ground in that estimation.

For Sassypilots wife:
The Tech Log discussion features no small number of pilots who post there: gums, Machinbird, PJ2, Retired F4, CONFiture, Clandestino, bubbers44, and numerous others. I discuss things there now and again, though I have not flown much of anything in a few years, and never flew heavy metal ever. I have flown and taught flying in multipiloted aircraft, taught instruments, and instructed in simulators where you try to work a crew very hard to see how strong their systems knowledge and airmanship are. I have also investigated mishaps, including mishaps with fatalities. :{

I would point out that Tech Log is now where ALL of AF447 threads resides, which John T has kindly explained in the preface to the various threads.

The first three IIRC started on the R & N forum.

Rockhound
What about the following remedy for the situation?:
throttling back one engine to force a wing drop, to drag the nose out of its 40-degree up angle into a dive.

Not a good idea. See below.

SLFinAZ, Indeed, jcj - Rockhound's 'pilot' was talking out of his seat cushion. Actually he was entirely correct.

Not so much. He missed a fundamental detail: the difference between pitch angle and angle of attack.

So...in the early stages of the upset the statement is entirely correct...
The pilot in question was advocating this method of recovery for the last two minutes of flight, i.e. when AF447 was deep into the stall.

Not quite.

According to the FDR, the nose wasn't 40 degrees up, ever. It was somewhere around 15 degrees up, more or less, at its peak. The AoA, while there was more airspeed, began somewhere between 4 and 6 degrees as the aircraft neared and entered stall (it seems to have been a dynamic event so maybe stall AoA was passed a few degrees higher). Note that even with a roughly fixed pitch, (more or less 15 degrees) the plane slowed AND the AoA increased as airspeed decreased. This should not surprise any pilot who has done stall training.

Based on the analysis of the pitch angle and airspeed, AoA got upwards of 40 degrees as the plane went more deeply into the stall.

Sooo, Rockhound .... maybe that pilot you referenced ought to make sure he understands the problem before he suggests a solution.

Case One
Could any of you professionals here explain what knowledge of flight physics is taught to pilots in their training

This: CDBDA AADCD BAADC CADCB BABCD AACDB BACDA. I kid you not
What?

He was explaining how to answer a multiple choice test on flight physics.

I laughed. :ok:

I have found the tech log discussions, though full of some chaffe, to have a lot of good nuggets.

I find this thread, after three years of learning about AB, AB330, FBW, sidesticks, control laws, and a few other things, somewhat entertaining.

Mind you, it is also filled with chaffe.

Fly safe. Fly the plane.

KBPsen

9th Jul 2012, 21:11

...full of some chaffe...Some? I have found all of the threads repetitive and full of chaffe. Go to any of the threads, be it one from 3 years ago or from yesterday, and you will find the same people saying the same things over and over and over.

20000+ turns of a broken record.

BEagle

9th Jul 2012, 21:38

The reasons behind that might be habit, might be training....

Whatever 'training' these incompetents had was clearly totally inadequate. Either that or they didn't listen and weren't properly tested.

Read the CVR transcript from long before the stall and you'll get an idea of the level of professionalism displayed by this so-called 'crew'. Remarkably reminiscent of AF4590 crew behaviour.

The captain couldn't even readback or recall simple HF allocations as PNF.....

Petrolhead

9th Jul 2012, 21:44

No Clandestino, the radar had not been set up correctly:

<<<02:07:00 (Bonin) On est apparemment à la limite de la couche, ça devrait aller.
We seem to be at the end of the cloud layer, it might be okay.

In the meantime Robert has been examining the radar system and has found that it has not been set up in the correct mode. Changing the settings, he scrutinizes the radar map and realizes that they are headed directly toward an area of intense activity. >>>

If they had not entered the area of severe icing the incident would not have happened:

<<<At 1h 36m, the flight enters the outer extremities of a tropical storm system. Unlike other planes' crews flying through the region, AF447's flight crew has not changed the route to avoid the worst of the storms. The outside temperature is much warmer than forecast, preventing the still fuel-heavy aircraft from flying higher to avoid the effects of the weather. Instead, it ploughs into a layer of clouds.

At 1h51m, the cockpit becomes illuminated by a strange electrical phenomenon. The co-pilot in the right-hand seat, an inexperienced 32-year-old named Pierre-Cédric Bonin, asks, "What's that?" The captain, Marc Dubois, a veteran with more than 11,000 hours of flight time, tells him it is St. Elmo's fire, a phenomenon often found with thunderstorms at these latitudes. >>>

On the Airbus it is possible to have the radar on but not displaying anything - that was my point.

Case One

9th Jul 2012, 21:49

Thanks Lonewolf. :O

Not how I was taught though, perhaps that's why I didn't recognise it.

This really is getting tediously circular. :bored::bored::bored:

Clandestino, PM sent.

angelorange

9th Jul 2012, 22:39

Well done Clandestino (and others with a sound understanding of flying and the perilous state of affairs that this industry has become). At last some comments that help destroy the myths and pointless rants that sometimes appear on these threads.

Ten years before this accident, Airbus Chief Test Pilot Capt W Wainwright wrote an article on Stall recovery - it is doubtful many Airbus pilots have read it. Had the AF447 crew been taught and applied these techniques history would be different:

http://www.google.co.uk/url?sa=t&rct=j&q=airbus%20stalling%20advice&source=web&cd=8&ved=0CG4QFjAH&url=http%3A%2F%2Fwww.airbus.com%2Fsupport%2Fpublications%2F% 3FeID%3Ddam_frontend_push%26docID%3D17431&ei=g17fT7O0Fsab1AXNt-H7Cg&usg=AFQjCNG9znzDNZilTLePNBc9_0_SR-U9Sg

Adding power when stalled is poor stall recovery advice. For FAR 25/JAR25 machines with underslung engines, stall recovery for flight test: Unload by reducing AoA - no thrust is added until around 20% above Vs due to the negative effects of adding thrust. It also happens on light propellor aircraft where adding power alone also adds yaw which can induce incipient spin.

How does a glider recover from a stall?

An aircraft can be stalled at any airspeed depending on wing loading - so speed alone is not the only factor.

NASA carried out a stalling project from FL450 with a B757 some years ago. The machine was held at the stalling AoA (only a few degrees nose/pitch up) with full TOGA thrust. It continued to decend at over 5000fpm until standard stall recovery (reduce AoA) technique was used.

Whilst Deep Stall recovery requires a very large AoA reduction (not just lowering a few degrees of pitch), the reason the A330 was heading for the ocean floor almost tail first was because of high thrust vector and aft control column inputs.

I have to completely disagree with the concept of adding full thrust and/or banking to break a stall whatever the altitude. All that is doing is creating a worse Upset senario for both the pilots and (if a high speed dive ensues) the structural integrity of the aircraft. Using roll control when stall buffet is present can also lead to a spin.

The only time to add full TOGA thrust would be in a low level pre full stall senario in conjunction with an AoA reduction. Without auto trim, adding power alone in both an underslung engine and a tractor propellor aircraft will cause a nose up (relative to pilot) pitch which is traditionally negative longitudinal stability.

Whilst W&B have their part, in general (unlike straight wings), swept wings also trend to provide further negative longitudinal stability at the stall with a nose up (relative to pilot) pitching moment as the spanwise flow is modified and the boundary layer thins from the wing tips first. Without wing fences/ Vortex Generators, this also reduces any outer wing/aileron control effectiveness.

We have already seen in the past few years several major incidents and accidents where pilots just adding power to try to recover form a stall:

Thomson Fly B737 Bournemouth UK

:http://www.skybrary.aero/bookshelf/books/875.pdf

Norwegian Merlin Student Stall:

Fatal Merlin crash puts spotlight back on stall recovery (http://www.flightglobal.com/news/articles/fatal-merlin-crash-puts-spotlight-back-on-stall-recovery-365685/)

Even a tractor prop aircraft at high IAS with a sudden reduction in power will (for stable design) result in a pitch down - this is positive longitudinal stability which helps to reduce AoA and therefore would unload the wings.

Clearly, what is permissable within the flight envelope of a Fighter jet (some of which are capable of 10G per sec wing loading changes) is not so with an airliner.

Banking an aeroplane to a high AoB is fine for aerobatic and military machines where a high Rate of Decent is required. For larger hardware it can be fatal - not only at low level in the following examples but due to in flight breakup in the subsequent recovery form a high speed dive.

B52:

B-52 Crashes while flying a 90° bank turn - YouTube

C17:

Fatal crash of a C-17 Globemaster III (Alaska, 28 July 2010) - YouTube

The other issue is Va (manoeuvre speed) which is the maximum certified wing loading at the stall (stalling at max "g") and permits ONE control to maximum deflection, ONCE - not simultaeous or multiple roll and pitch control inputs:

American Airlines Flight 587 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/American_Airlines_Flight_587)

angelorange

9th Jul 2012, 22:41

My understanding of Deep/Super Stall is the stage after the initial stall when the aircraft is not recovered immediately - i.e: held in the stall (in AF447 case through aft control column, and full aft tailplane trim along with full thrust). This prolongs deceleration (due drag rise) and despite fairly benign looking attitude (perhaps 8 deg pitch up) leads to a massive increase in the incidence (effective AoA) as the flight path becomes more of a sinking than forward motion.

DP Davies devotes around 6 pages to the subject in his book Handling the Big Jets. He was chief test pilot for the UK Airworthiness Authority (pre CAA) and tested all manner of machines from ultra lights to the B707, B747 and Concorde. He categorically states that Deep/Super stall recovery is only possible where elevator authority exceeds the nose up pitching moment post stall (caused by wing sweep, change in chordwise lift distrubution after initial stall, forward fuselage lifting body effect and now add in AF447 aft stick, trim and TOGA underslung engines).

To quote DP Davies:

"...aircraft that have been lost to such manouevres finally reached the ground substantially level laterally, having defied all efforts to roll or spin them out of this stabilised condition,....with little or no forward speed, rotating only slowly in yaw, ... exposed to massive angles of incidence (AoA) and enormous vertical velocity"

"At one time it was thought that an attempt to roll or spin the aeroplane would offer the best chance. This idea has now been withdrawn (1971), because even assuming that this (additional) upset could be achieved, the resulting very steep nose down attitude, the lack of proof of spin recovery capability, he very high rate of decent and the large height range required (for subsequent) recovery makes it unlikely this method offers any advantage at all"

" The best recovery technique (super stall) is now considered.......persist in full forward elevator control, put the flaps to the postion recommended by the maufacturer and wait for the aeroplane to pitch down and recover from the stall"

"...... pitch attitude is not enough guide to the recovery.Too early a recovery from a gentle dive, following assumed recovery from a super stall, will again increase incidence and ensure the aeroplane remains locked in."

"Without incidence information, a nose down pitch with an increasing speed is no guarantee that recovery has been effected and an up elevator movement at this stage merely serves to keep the aircraft stalled"

Turbine D

10th Jul 2012, 01:16

angelorange, Just to clarify something:

My understanding of Deep/Super Stall is the stage after the initial stall when the aircraft is not recovered immediately - i.e: held in the stall (in AF447 case through aft control column, and full aft tailplane trim along with full thrust).

A "Deep Stall/Super Stall is confined to an airplane design having a "t-tail". What happens is, under a severe pitch-up and speed decay situation the wings stall and the turbulent air coming off the top surfaces of the stalled wings renders the horizontal stabilizers and elevators useless in terms of recovering from the stall condition. The C-17 crash is a prime example of this phenomenon as was the NW B-727 accident out of JFK in December 1974. I am only aware of one successful recovery from a deep stall on a t-tail aircraft. It occurred during the B-727 test program where the test pilots had enough altitude and were able to rock the wings to get the nose down and regain speed and lift on the wings.

AF447 never suffered from this sort of condition. The THS and elevators still had lift in the stall and a prolonged forward stick probably would have recovered the aircraft. The design of the aircraft matters a lot.

Cool Guys

10th Jul 2012, 02:10

I am an electrical engineer with considerable experience in highly automated equipment that can kill people when things go wrong. Hence I am highly interested in these discussions about the plane’s automation. I have very limited flying experience.

A reason for the AF447’s pilot illogical behavior has been given as the “startle factor” or “information overload” The key trigger for this was the mode change to alternate law, At this point recognition of a stall was unnecessary because the plane was not stalled. The UAS was the trigger for the mode change but the UAS was recognized by the pilots. What appears to have been misunderstood was the consequences of the mode change. If the pilot recognized that the mode change disabled the AOA protection and the consequences having no AOA protection I do not think he would have pulled the stick fully back prior to the plane becoming stalled.

The plane was in a non optimum state, the computer recognized this state and implemented some counter measures to supposedly keep the plane flying. The key counter measure (from my very limited understanding) was removing the AOA protection and handing the elevator control over to the PF who supposedly with his superior senses and analytical skills can continue flying the plane with feedback from various other sources including the computer. However his ability to cope with the situation is dependent on how well he understands the situation from his prior training, what he can decipher from the environment and what the computer is telling him.

A modern computer has a lot of processing power and lots of available memory allowing for a complex program. With a complex computer program, when there is a reversion to “manual mode” better feedback indicating the status of the equipment (an aeroplane in this case) as seen by the computer is required. Note, I am referring to the computer status. While feedback of the PF’s physical body status can be determined better with control columns what I am talking about is the status of the plane as seen or determined by the computer. With simpler programs indicator lights, aural warnings and text messages suffice but as the computer actions get more complex better feedback to the operator (pilot in this case) is required.

In industry we now have better tools for providing such feedback. In complex automated applications we now implement touch screens with pictorial representations of the equipment. A picture contains 1000 words. There appears to be limited pictorial representation of the plane’s status as determined by the computer. In the AF447 case we get messages indicating UAS and a mode change. The pilot has to understand the consequences of the mode change, one of which is the removal of the AOA protection. He must also understand the consequences of the removal of the AOA protection and that the side stick inputs now control the surface deflection and not the G (as far as I understand) and a plethora of other things crucial to the survival of the plane and its contents. Good, simple computer feed back of the status of the equipment from the computer’s viewpoint enables better understanding of the situation and better pilot ability to cope with the situation. In this case a message indicating the mode has changed was announced and it is up to the pilot to know the resulting complex changes to the flight controls. There is a lot of understanding here that the pilot is required to bring to the front of his analytical thinking in a short space of time. What is required in such complex computer programs is good simple feedback to help the operator understand the status of the equipment as determined by the computer. Rather than announce a vague description such as a mode change the pilots need to know exactly what is happening with the controls. In this case the AOA protection (among other things) has been lost. A display with a pictorial view of the plane with the elevators color changing from green to orange would be a good start. This would indicate there is some abnormality with the elevator control and further to this there would be some indication showing the AOA protection is lost etc. This is an example, I am sure a pilot would have better ideas as to how this should operate.

Note, I may have errors in my aeronautical descriptions, which I apologize for but please understand the main point of my post is to highlight the need for better computer feed back as computer programs get more complex when there is a reversion to “manual mode” (alternate law).

Turbine D

10th Jul 2012, 02:16

Originally posted by Lyman:
You are correct, the Tail tanks were full at the time of a/p loss (2:10:04.6). 10.5 thousand pounds of fuel. Initially the Cg computed by BEA was released to be right at the margin for flight (37.6?). Later, that value was retracted and replaced with ~ 28.7. In turbulence and experiencing rolling and pitching moments, the Cg may have been well aft, and exacerbated the inability to recover from the initial upset at a/p quit.....

So as not to confuse everyone here, especially the new posters, here is the CG chart for the A-300-200. The red dot indicates where the CG was on AF447. It wasn't unusual for the weight of the aircraft.
http://i1166.photobucket.com/albums/q609/DaveK72/cg.jpg

Here is a statement regarding this:
The use of wing sweep and stability augmentation on modern commercial airplanes makes them more fuel efficient. However, flight crews must understand the effects of CG and altitude on performance and handling qualities. For example, operating at an aft CG improves cruise performance, but moving the CG aft reduces static longitudinal and maneuvering stability. Many modern commercial airplanes employ some form of stability augmentation to compensate for relaxed stability. However, as long as the CG is in the allowable range, the handling qualities will be adequate with or without augmentation. An understanding of static and maneuvering longitudinal stability is an essential element of flight crew training.
It comes from Boeing, not Airbus.

Turbine D

10th Jul 2012, 02:54

Lonewolf 50 in Post#265 made an excellent suggestion:

For anyone interested:

If you go to the tech log forum, you will find the following point excerpted from the BEA report.

The UAS (Unreliable AirSpeed) procedure memory item of turning off the FD's was not accomplished. (FD = Flight Director).

There are even some handy pictures and graphs that show when the FD was receiving good data, and when it wasn't. Mind you, neither pilot was aware of when it was good and when it was bad, but given the procedure as stated, they should not have needed to.

To make it even easier for those interested, here are the memory items:
http://i1166.photobucket.com/albums/q609/DaveK72/i-GnmPntp-L.jpg
There has been considerable discussion in the Tech Log regarding whether or not the safe conduct of the flight was impacted or not in the case of AF447 at cruise. Ultimately, flying pitch and power and/or getting out the pitch and power tables after checking and completing the memory list items would have saved the day.

Additionally, a great deal of information regarding the A330-200 is given in this presentation:
http://www.smartcockpit.com/data/pdfs/plane/airbus/A330/systems/A330-Flight_Controls.pdf

An interesting article by Boeing can be found here:
Aero 08 - Erroneous Flight Instrument Information (http://www.boeing.com/commercial/aeromagazine/aero_08/erroneous_story.html)

Happy reading !!!

ChrisJ800

10th Jul 2012, 03:34

Or was PF trying to implement the wrong UAS procedure, namely 15 degrees pitch up and TOGA, given that is what he would have mostly trained on in the sim for a UAS event? With Normal Law protection, the plane would not have stalled following this procedure (or even adding full pitch up with no thrust change) but in the stress of the moment he didnt register that it had reverted to Alt 2 Law.

Carjockey

10th Jul 2012, 03:57

@Organfreak (http://www.pprune.org/members/371556-organfreak)

Mr.Organ,

I am not confused re your position.

I am not being dismissive re 'piloting experts', but I am entitled to question their opinions.

As for being 'uncool', it is not really something that bothers me. I leave that to those aged around 14 or 15.

ironbutt57

10th Jul 2012, 05:47

NW B-727 accident out of JFK in December 1974.

Another classic case in failure to unload the wings, the pitch in this case was actually quite pronounced nose down, but since the FPA was almost straight down, the aircraft remained stalled, and in the end, the horizontal stab failed structurally, and the aircraft crashed...airspeed unreliable was also the initial cause of this accident...(frozen pitots)

http://www.fss.aero/accident-reports/dvdfiles/US/1974-12-01-US.pdf

ironbutt57

10th Jul 2012, 06:03

On the Airbus it is possible to have the radar on but not displaying anything - that was my point.

Thats true on almost any type of weather radar in any aircraft...other info includes a prog chart, assumed to be provided to the crew, and of course...LOOKING OUT THE WINDOW.....one might have seen the wall of lightening ahead and adjusted the radar sooner.....(what a novel idea)...

Nemrytter

10th Jul 2012, 06:31

1. Don't fly into a storm
They never did.
They did - and a bad one at that. Depending on the statistics you use the storm cloud formation that they encountered was in the 'top' 1-3% of all storm clouds in that region during the last 6 years. Cloud-tops up to FL600, temperatures below -90C and very strong convection. Not a great place to fly.

ironbutt57

10th Jul 2012, 08:27

Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data (http://www.weathergraphics.com/tim/af447/)

Interesting stuff, survivable in itself, but with airspeed unreliable in the middle of it??...

PanPanYourself

10th Jul 2012, 09:34

I am an electrical engineer with considerable experience in highly automated equipment that can kill people when things go wrong. Hence I am highly interested in these discussions about the plane’s automation. I have very limited flying experience.
I am a software engineer with experience in the development of life-critical software systems including healthcare patient diagnosis, and command & control systems. I'm also an aviation enthusiast, so I am highly interested in these discussions as well.

I think your post was spot on with regard to the lack of sound HCI principles in the design of the autopilot system. If this kind of automation is going to be in place, it should not completely crumble upon the loss of one input parameter (albeit a very important one).

The flight computer is aware of the weight, the altitude, the AOA, the last indicated reliable airspeed, and almost everything else the pilot will use to perform his own calculations to decide on the best course of action. If the autopilot just hands over control as it did in this situation, and the PF is supposed to go 85% N1 and 5% AOA (or whatever it is), then I think the autopilot should do that for him, and just display a very big warning. The pilot always has the option to disconnect the autopilot if it starts doing something stupid, this would at least give them more time to think and react.

Heck, can't the autopilot even handle stall recovery? It had the vertical speed parameter intact and it knew AOA, thrust settings, elevator position, trim, as well as weight etc. so it should be able to preempt a stall even without knowing airspeed. Am I wrong? I'm tempted to write the code for that and send it to Airbus, though most of it probably already exists in flight simulator software.

BOAC

10th Jul 2012, 11:09

Cool and PPY - these are indeed valid queries you have raised. The basic answer is that the 'task' presented to the crew was a very simple one as far as we can tell from the report - fly the a/c, set a 'safe' attitude and if necessary then adjust power while the rest of the actions were completed. As you can read to the point of complete boredom and disillusionment on all these threads, both pilots failed this task.

The idea of a 'straight and level' 'fallback' autopilot function is a good one, except that as you will both doubtless know, once you start coding for this you will find there will probably be situations where that is not the best solution.

However, the idea has merit and is worthy of discussion here. Something needs doing as we all recognise. The ideal is having pilots that can undertake a relatively simple task, but if we fail there your system may have to come into play.

We need to take it step further, of course, to the ?eventual? pilot-less a/c and when this mode would be triggered and under which parameters. Not easy!

fotoguzzi

10th Jul 2012, 11:09

[Not a pilot] We learned over the Hudson that "my airplane," "your airplane" works well to establish change of control. Is there a similar convention for unexpected events? That is, if over Buffalo the pilot had said "tailplane stall," the copilot might have been able to say, "let's try increasing the speed first." At least the investigators would know what the pilot was thinking after the worst had happened. The same for the possibly suicidal pilot who seemed to be pushing while the co-pilot was pulling. Saying "nose dive" would only help the investigators, but if the pilot were not suicidal, he would have had the chance to offer his view of the situation.

In AF447, if someone had said, "classic stall," (and perhaps this was stated at one point) would there have been a better chance that the pilot in command would have thought to lower the nose?

This kind of summary would not seem to help in cases where the co-pilot was supposed to be calling out, e. g., air speed, but was not, but some kind of impromptu summary would seem helpful in rapidly developing events that do not have an established procedure or where the proper procedure is not immediately apparent.

angelorange

10th Jul 2012, 13:24

From an aerodynamics perspectiive a deep stall is not confined to T-tail aeroplanes. It applies where an aircraft is not recovered in good time from the initial symptoms (heavy buffet, nose drop (longitudinally stable machines), sink, possible wing drop). A deep stall can be quite stable as DP Davies explains and requires extremely persistent and large AoA reduction.

Yes of course the T tail has the disadvantage of loss of elevator authority due to the change in wake from the stalled wing but that is more a case of a "locked in" condition. And most pilots think deep stalls only apply to Javelins, DC9s etc...

PanPanYourself

10th Jul 2012, 14:34

The idea of a 'straight and level' 'fallback' autopilot function is a good one, except that as you will both doubtless know, once you start coding for this you will find there will probably be situations where that is not the best solution.
The code is basically a series of conditional statements: "if x is true then do y" so any situation that can be foreseen can be written into the code. In situations where that 'straight and level fallback' is not the best solution, other options could be in place, including reverting to the current logic (handing control to the pilot).

A lay pseudocode example of an obvious stall avoidance scenario:
"If altitude>35,000, if airspeed unreliable, if thrust idle, if TCAS not blaring, and if AOA >10% set pointNoseDownFast=true! otherwise do nothing"

Add some better thought-out version of the above logic to the flight computer and without affecting anything else you could avoid this accident.

My issue is more with the piecemeal approach to this automation, where pilots are not just pilots, they're computer operators interfacing with the software that actually does the flying. Either pilots should be rigorously trained in the software (including how it was written), and that software should be responsible for handling all possible scenarios (loss of airspeed being quite a common one) while providing intuitive feedback to the "computer operator", or it should be removed apart from the simplest functionality (more along Boeing lines).

BOAC

10th Jul 2012, 14:52

Several points there, PPY. Firstly memory is not unlimited in the system. I am 'OK' with coding, but your 'lay' line is all 'ANDS'. Now write in options for unreliable altitude, AoA, thrust and attitude and any combination of these, and you will 'hand control back to the startled pilot', no doubt, at some point - now even more 'startled' because he expects HAL to cope with most things.

Your last phrase is the only viable one, since it is the only one that will cope with actual computer failure/malfunction.

Way back we discussed the 'big red button' option, which I am in favour of, where when pressed it does exactly the S&L function, based on last know valid parameters, but only when a conscious call is made, and not when 'IT' decides.

We need some more discussion, here, guys and girls. Is this a way forward?

sevenstrokeroll

10th Jul 2012, 15:16

does the airbus have a PITCH HOLD mode(selectable by human pilot) for the autopilot?

DOVES

10th Jul 2012, 15:30

Clandestino
Wrote on his Post 263

Quote:
Originally Posted by robertbarsch
1. Don't fly into a storm

"They never did".

If, in one of those many endless dark nights when the silence was broken only by the whistle of the engines and the air on the fuselage, and, gossips of flight engineer, I spent over the Atlantic since more than forty years ago, I had seen on my radar a chain of cumulus nimbus clouds (and I've never failed to detect one) like those in the images that ironbutt57 has kindly procured, I would not hesitate to deviate to the left 300 nm since INTOL.
If this had been done, now we would not be talking about this tragic accident.

ironbutt57

10th Jul 2012, 15:37

In normal law the aircraft maintains attitude selected by last stick I put, within certain boundaries...sort of like permanent CWS for you Boeing folks

vovachan

10th Jul 2012, 15:52

The key counter measure (from my very limited understanding) was removing the AOA protection and handing the elevator control over to the PF

Why was the AOA protection shut off? The computer continued to receive valid AOA info (which is not available to the pilot btw).

BOAC

10th Jul 2012, 17:21

I had seen on my radar a chain of cumulus nimbus clouds (and I've never failed to detect one) like those in the images that ironbutt57 has kindly procured, I would not hesitate to deviate to the left 300 nm since INTOL.
If this had been done, now we would not be talking about this tragic accident. - don't forget that those images were not what you would have seen on your shufti-scope - the colours are synthetically produced based on temperature I believe and we just do not know what would have been seen on their radars.

We are definitely seeing the Oozlum bird circling around now - we've had an outbreak of 'deep stall' again, a few 'they flew into a thunderstorms' (as above) and we are now well overdue for another outbreak of 'coffin corneritis'.:ugh:

DOVES

10th Jul 2012, 17:49

BOAC
Can I humbly reveal a secret?
Once upon those time my radar scope had only one color (with various shades): GREEN

BOAC

10th Jul 2012, 18:11

Yes, my secret - I've used green ones too. This did confuse me though

"and I've never failed to detect one) like those in the images that ironbutt57 has kindly procured,"

I assume you didn't really mean that? Was that another 'secret'?

For those who do not seem to grasp it

THERE IS NO EVIDENCE THEY FLEW INTO A CB

Nemrytter

10th Jul 2012, 18:46

THERE IS NO EVIDENCE THEY FLEW INTO A CB
As I said on the last page: They flew right into the middle of one of the most intense storms seen in that region in the past 6 years. Numerous different platforms - not just those using temperature - detected heavy rain (near the upper limit of their capability), extreme convective activity (again, near the limits of their capabilities) and very cold clouds that exhibited large differences with height (indicative of an intense storm).

Based on those the Wx conditions the radar on AF447 should have had no problems picking up the storm. Radar systems similar to aircraft Wx radar (but space-based) detected the conditions with ease and as far as I remember from the report other aircraft changed course to avoid the same cloud formations - so they must've seen the problem.

DOVES

10th Jul 2012, 19:17

BOAC
My other two secrets:
-I've never seen near the equator a cb with a top lower than 38,000 to 42,000feet (and I swear that I would never even overfly them with any separation).
-And by the way among ‘..those … images that ironbutt57 has kindly procured’ there is Figure 10. Cross-section of Air France 447 flight track through thunderstorm cluster, which depicts extension and altitude of clouds in scrutiny.

Mr Optimistic

10th Jul 2012, 19:33

Having read through the cvr I was struck by the apparent lack of clarity in the pre-incident chatter and also by the apparent frequent ellipses during the incident. Surprising to have so much non-relevant chatter given the circumstances ..........

Lonewolf_50

10th Jul 2012, 19:54

Nemrytter, a rather thorough analysis of the g-data from the FDR shows that no significant turbulence was encountered that would have hampered handling. They DID in fact encounter the icing problem, and if we do a very tight root cause analysis, we discover that without iced-up pitot tubes NONE of the rest follows.

The point a lot of people have made, pilots and others, is that UAS from frozen up pitots is a known malfunction for which there are some effective procedures. Likewise, if the FD goes wrong, or if UAS is the general problem, you turn the FD's off and take some other concrete actions, work through the procedures step-by-step, and get yourself back into the flying condition you desire.

Also of note, the data show that the UAS itself was intermittent, which to me means that the pitot's being rendered INOP sort of cleared itself up, but apparently not all at once. Trouble is, that wasn't necessarily obvious to the pilots, but a UAS procedure was available to deal with the fact that the airspeed input was acting up.

I appreciate your point on Wx avoidance, and also Robert's resetting the radar to a more suitable mode, which I concur let to the (late?) heading correction made (12 deg IIRC) to at least partly avoid what he diagnosed as Wx he'd rather not hit.

That leaves the crew with a malfunction which, had it been handled one way, we'd never have known about unless it was added to the other 36 UAS events that have been discussed at some length on the Tech Log forums.

The response instead included a possible misdiagnosis, and what appears to have been a low-alt tailored response to a high alt UAS event ... and it all ended in tears. :{ (Points on training, recency, and currency apply here in the human factors facets of this event).

It isn't as simple as Wx penetration being the cause.
There was still plenty of room NOT to end in tears, even with entering a bit of rougher weather than they intended to.

To make a rough analogy of a different way to die while hauling pax from place to place ...

I can make a turn in the wrong direction in bad weather near an airport. (perhaps on the way into Islamabad in rainy weather somewhat recently???)
If I notice my mistake (or hear from ATC that I am off course?) and make the proper correction to that error, I don't hit the mountain. If I instead keep my error in, and then do something that isn't correcting my heading error, I hit the mountain and it ends in tears.

The Wx didn't cause that, but poor Wx contributed to it -- right?

Nemrytter

10th Jul 2012, 20:12

Lonewolf_50

10th Jul 2012, 20:26

nemrytter:
We have an accord.

Apologies if I took your remarks out of context. :O Oops.

Flight Safety

10th Jul 2012, 20:27

I don't understand the stall warning logic of the A330. If you have an indicated airspeed of less than 60kts, and there is no weight on wheels (i.e. the airplane knows it's airborne), aren't you stalled?

Why the arbitrary cutoff of the aural stall warning at 60kts? I understand the AOA won't be reliable at that speed, but who cares, if you're airborne at less than 60kts IAS in an A330, you're stalled.

Diamond Bob

10th Jul 2012, 20:54

This opens the question: was the PF using FD as a reference, or a primary reference for his instrument scan, even though it was not being reliably sourced by the data it is usually fed?

I found an article which expands on this theory that the PF was following the Flight Director and that this might explain his pitch-up inputs.

Final AF447 Report Suggests Pilot Slavishly Followed Flight Director Pitch-Up Commands | Aviation International News (http://www.ainonline.com/comment/1627)

After the autopilot and autothrottle disengaged, as the flight control law switched from normal to alternate, the flight director’s crossbars disappeared. But they then reappeared several times. Every time they were visible, they prompted pitch-up inputs by the PF, investigators determined.

glad rag

10th Jul 2012, 21:03

I don't know for certain [:)] but I think it may come down to the certification requirements of primary flight instruments viz reliability modus of wow sensors...

Lyman

10th Jul 2012, 21:32

For everyone who thinks PF blundered in 'neglecting to turn off his FD', remember the drill, and try to focus on when the crew became sufficiently sure of UAS to mention it. For to turn off the FD without knowing if UAS drill obtains, remember that in an emergent situation, it is very difficult to consider 'options' rather than pressure one's self to act decisively. The PF did not turn off his AP, either. It remained for the Captain to switch it off mere seconds before the impact. Please know that in the first several seconds, the solution rapidly lost focus for anyone, even you. It is clear that the plot became lost for both quite rapidly, even PNF lost his confidence quickly.

To follow a drill, one must first establish the need for it. It is not wrong to say that once these pilots got behind, catching up became extremely difficult. The FD seems seductive enough to have tempted PF, and the counter intuitive SW was no help. The planning for this "common" event (UAS), at the program level, seems to me to be arbitrary, even haphazard. The complexity of the challenge was in so many ways artificially induced; at the time when one needed simple, one was deluged, and having no training in the necessary skillset seems to me to be wildly negligent on the part of both Airline and Airframer.

Comes Captain, and he too is immediately drenched in a deluge of data, to the extent that he did not notice some truly simple things.

Is there a ready explanation for the very smooth line of THS increase to max, vice a more herky response to actual (commanded) pilot inputs? It looks graphically as though the THS was deploying to a "target" position, independent of pilot command?

xcitation

10th Jul 2012, 21:46

fotoguzzi
In AF447, if someone had said, "classic stall," (and perhaps this was stated at one point) would there have been a better chance that the pilot in command would have thought to lower the nose?

The word "stall" was stated about 70 times surrounded by chirps/crickets by the flight systems. Not once did any of the 3 pilots acknowlegde the stall verbally nor did they follow the stall recovery procedure. This is very hard to understand as it trumps all other warnings.
Training in the airline transport industry was focussed on avoiding the stall rather than recovering from it. This contrasts with light aircraft training where stall recovery is experienced and practiced.

Lyman

10th Jul 2012, 21:51

Has anyone bravely listed all possible reasons the Stall (Warn and actual) was never acknowledged?

Clandestino

10th Jul 2012, 22:55

If you don't have doctoral-level statistics knowledge and don't understand this, I'd be happy to explain in more detail?Nice example of paternalistic appeal to authority (http://en.wikipedia.org/wiki/Appeal_to_authority). I'd be happy to see more details.

Care to explain your "Bad Science" comment? Sure. You have proposed a method whereby 100 x 3-man crews would be put in a multi-day full-experience simulator. At some point, each crew would get on 1% of their flights an AF447-type scenario. No warning, it just happens. From this you would see what percentage "flubs" the scenario and determine from this whether it was pilots or machine the root cause of the AF447 demise. So far so good. Methodology seems sound, logic too. So it could be scientific. Why is it bad?

Because it is based on monumental misunderstanding of aviation and human factors in it. Logically correct conclusion from false premises is still false!

Or maybe in either case, we need to consider the human-machine interface as the thing that must change?So whatever we conclude from study, the premise of human-machine interface being inadequate must be confirmed. Why making the study at all if initial bias is confirmed no matter the outcome?

Get 100 x 3-man crews, and put them in a multi-day full-experience simulator.If you crash in the simulator, you can restart. Nonavailability of this feature in real life is very important factor when proverbial hits the fan and largely increases chance of inadequate response and panic.

Fullt-time AOA sensors. While they are demanded by certification standards, mother nature has shown total indifference to righteous demands of outraged public that demands the letter of the certification laws be followed. There is no AoA probe that will work well and reliable both at 1 kt and 0.82 Mach. Make fame and fortune by inventing one.

From this study, we calculate the ultimate data point: what % of crews survive. And perhaps more interestingly: what % of crews survive for the right reasons.So wealth of data available to make good case studies out of a few occurrences is just thrown away to make one-or two conclusions out of very small sample statistics? I'm glad BEA took different path.

No Clandestino, the radar had not been set up correctly:At least you could have properly credited your quotes to Popular Mechanics article (http://www.popularmechanics.com/technology/aviation/crashes/what-really-happened-aboard-air-france-447-6611877) mainly based on Jean-Pierre Otelli book. Monsieur Otelli had valid commercial reasons to make his book a bit more sensationalist than very technical and dry BEA report on AF447 since sales figures are of more practical value to any author than truth.

Fact that CM1 changed the mode of WX absolutely does not imply it was set incorrectly! It is perfectly normal to change range, elevation and gain to get the complete picture of weather systems ahead!

On the Airbus it is possible to have the radar on but not displaying anything - that was my point. As it is possible on each and every radar with wx brightness adjustment. All of them nowadays come with such a feat so it is possible to set it too low on any wxrad equipped aeroplane. What is the point of singling out the Airbus?

Interim report number two was published on 30. Nov 2009. By that point, it had been clear from AF447 ACARS messages its pitots were blocked. Analysis of 13 similar incidents in cruise was made and all of them happened near the storms but never inside the convective cloud.

Interim report number 3 was issued at 29.07.2011. FDR and CVR were found and analyzed. They absolutely confirmed conclusions of interim2: UAS events happen near the storm tops, not in them. AF447 was avoiding the weather well, G trace shows only light turbulence as speed dropped to unrealistic values, quickly reducing to no turbulence at all. That's definitive proof that no storm penetration occurred!

They did - and a bad one at that. Depending on the statistics you use the storm cloud formation that they encountered was in the 'top' 1-3% of all storm clouds in that region during the last 6 years. Cloud-tops up to FL600, temperatures below -90C and very strong convection. Not a great place to fly.That contradicts the BEA report. What is the source for this statement?

If the pilot recognized that the mode change disabled the AOA protection and the consequences having no AOA protection I do not think he would have pulled the stick fully back prior to the plane becoming stalled.That's beyond reasonable doubt.

The plane was in a non optimum state, the computer recognized this state and implemented some counter measures to supposedly keep the plane flying.Plane did no such thing. Aeroplane keeps flying out of its own accord and no matter the law, it remains aerodynamically the same. Protections are discarded so their untimely application based on false data does not chase the aeroplane out of envelope or into the ground.

A modern computer has a lot of processing power and lots of available memory allowing for a complex program.Complexity still does not imply intelligence.

In complex automated applications we now implement touch screens with pictorial representations of the equipment.While being exposed to constant 1G acceleration. That's the luxury we don't have in the aeroplanes.

In this case a message indicating the mode has changed was announced and it is up to the pilot to know the resulting complex changes to the flight controls.One look at PFD is sufficient.
A display with a pictorial view of the plane with the elevators color changing from green to orange would be a good start. Painting the elevator actuators yellow is already reserved for flight controls failure!

does the airbus have a PITCH HOLD mode(selectable by human pilot) for the autopilot? PITCH HOLD is flight director mode. Airbus doesn't have it. Airbus FD has less modes than those fitted to modern turboprops. It's not a bad thing.

I had seen on my radar a chain of cumulus nimbus clouds Me too. Today. Both our experiences are completely irrelevant and absolutely unrelated to AF447. RTF report.

In normal law the aircraft maintains attitude selected by last stick I put, within certain boundariesIt maintains flightpath. Constant pitch is consequence of neutral stick and constant speed.

As I said on the last page: They flew right into the middle of one of the most intense storms seen in that region in the past 6 years.

you know bad weather doesn't necessarily mean turbulenceIf bad weather definition encompasses fog, true. Active storm cells always come with a lot of turbulence.

barek

10th Jul 2012, 22:55

From the report:

The crew not taking into account the stall warning, which could have been due to:
- A failure to identify the aural warning, due to low exposure time in training to stall phenomena, stall warnings and buffet,
- The appearance at the beginning of the event of transient warnings that could be considered as spurious,
- The absence of any visual information to confirm the approach-to-stall after the loss of the limit speeds,
- The possible confusion with an overspeed situation in which buffet is also considered as a symptom,
- Flight Director indications that may led the crew to believe that their actions were appropriate, even though they were not,
- The difficulty in recognizing and understanding the implications of a reconfiguration in alternate law with no angle of attack protection.

jcjeant

10th Jul 2012, 22:56

A simple question
What are the effects (in general) generated by descent from 37,000 feet to 0 feet in a time of 4 minutes on the ear drum (pressurizing system operating normally)
Personally (frequent traveler) I feel symptoms during descents or climbs (normal) of the aircraft
If there are symptoms .. is that this does not be also be an input (sensory) for pilots?
This could be as a source of concern in the cabin ? (Ref CVR multiple calls from a cabin attendant to cockpit)

Clandestino

10th Jul 2012, 23:15

Why was the AOA protection shut off? The computer continued to receive valid AOA info (which is not available to the pilot btw). Because flight controls computers must constantly crosscheck AoA info against measured airspeed and known weight to see whether they are valid and can be safely applied when alpha protection is needed. Firing AoA protection based solely on alpha info seemingly did not sit well with fellows developing and certifying Airbus flight controls. Firing stall warning is fine - it still leaves the last line of defence, the pilot, to determine whether AoA vane measures realistic AoA and its advice is best heeded or it got damaged and stall warning is to be disregarded.

EDIT: I have to stand corrected on this; system is a bit simpler as FCCs don't crosscheck AoA vs speed, they just check whether both signals are valid, not consistent with each other. Inconsistency won't trigger law degradation, jut CHECK GW mesage on MCDU.

Life in a cockpit can get tough sometimes.

svhar

11th Jul 2012, 01:19

- don't forget that those images were not what you would have seen on your shufti-scope - the colours are synthetically produced based on temperature I believe and we just do not know what would have been seen on their radars.

I do not know what equipment you have been using, but you are talking about things you have no idea about. All weather radars display level of precipitation.

The rainbow of colors on the new radar, representing variations in rainfall rate, create a display which is easier to interpret than the older monochrome sets.
BLACK VERY LIGHT OR NO RETURNS Less than 0,7 mm/hr
GREEN LIGHT RETURNS 0,7 - 4 mm/hr
YELLOW MEDIUM RETURNS 4 - 12 mm/hr
RED STRONG RETURNS > 12 mm/hr
MAGENTA VERY STRONG RETURNS > 25 mm/hr

Source: Boeing.

I once knew a guy who talked like a professional pilot in the cafeteria with endless stories of his adventures in Africa, but there always where holes in his stories. He was able to fool everyone for a long time and was adored by lots of guys and girls. No one really cared to blow his cover because he was in fact good company. Always called "The Captain". He had a PPL and worked as an ambulance driver. Reminds me of BOAC.

soylentgreen

11th Jul 2012, 01:52

If you don't have doctoral-level statistics knowledge and don't understand this, I'd be happy to explain in more detail?

Nice example of paternalistic appeal to authority. I'd be happy to see more details.

Well, on the one hand, that's not appeal-to-authority precisely, since I was prepared to tell you why I disagreed (rather than just saying "Trust me, I'm a doctor"), but upon re-reading my words, they did come across snarky and like a cheap shot, so I apologize.

Care to explain your "Bad Science" comment?

Sure. You have proposed a method whereby 100 x 3-man crews would be put in a multi-day full-experience simulator. At some point, each crew would get on 1% of their flights an AF447-type scenario. No warning, it just happens. From this you would see what percentage "flubs" the scenario and determine from this whether it was pilots or machine the root cause of the AF447 demise. So far so good. Methodology seems sound, logic too. So it could be scientific. Why is it bad?

Because it is based on monumental misunderstanding of aviation and human factors in it. Logically correct conclusion from false premises is still false!

To be fair, I did not mean to suggest this was the perfect experiment that would end all debate. I said "it would be fun" and "The outcome would be quite interesting."

Obviously, simulator-based research has a number of flaws, the biggest one (which you mention) is called Ecological Validity (http://en.wikipedia.org/wiki/Ecological_validity) though I think that it could be argued that simulator research might present a lower bound on the %crash% estimate. The logic being that the pilots may suspect this is not a routine test, and they know they aren't going to actually die, may be less likely to panic, etc.

Again, I'm not familiar with this research, so I'm just speculating.

Or maybe in either case, we need to consider the human-machine interface as the thing that must change?

So whatever we conclude from study, the premise of human-machine interface being inadequate must be confirmed. Why making the study at all if initial bias is confirmed no matter the outcome?

Not at all. Some things (bad weather in the ICTZ, human frailty) we can't change. Some things we can: training and machines. I'm simply saying that
we should think of the big picture here, and improve the things that we do control.

Get 100 x 3-man crews, and put them in a multi-day full-experience simulator.
If you crash in the simulator, you can restart. Nonavailability of this feature in real life is very important factor when proverbial hits the fan and largely increases chance of inadequate response and panic.

Agreed -- see above.

Fullt-time AOA sensors.

While they are demanded by certification standards, mother nature has shown total indifference to righteous demands of outraged public that demands the letter of the certification laws be followed. There is no AoA probe that will work well and reliable both at 1 kt and 0.82 Mach. Make fame and fortune by inventing one.

Not me, but perhaps someone else? This video Google's next driverless car goal? 1,000,000 miles (http://www.autoblog.com/2011/10/22/googles-next-driverless-car-goal-1-000-000-miles/) is interesting and relevant: Google claims to have driven 160,000 miles in their robot car with only one fender-bender (which they claim was human error).

How many miles do we need google's robot cars to have accident-free before we trust them?

Seems like this technology (using LIDAR, GPS, and a bunch of other data) could be useful as a "third eye" autopilot that normally sits in the back and is quiet, but occasionally speaks up "Hey guys, uh, I know you are the bosses here, but we seem to be falling towards the sea in a strange attitude. I can show you on this 3D display just what I'm seeing..."

From this study, we calculate the ultimate data point: what % of crews survive. And perhaps more interestingly: what % of crews survive for the right reasons.

So wealth of data available to make good case studies out of a few occurrences is just thrown away to make one-or two conclusions out of very small sample statistics? I'm glad BEA took different path.

I'm not sure I understand you here, but I'll try to make my points again.

The "naturalistic" study shows that 1 of 37 crews in similar situations crashed. As I mentioned, that's such a small sample size that we can't say whether the actual percentage is closer to 0% or closer to 10%.

I hope that if the actual number is 10%, you'd agree with me that something is wrong, either with pilot training, or with the human-computer interface, yes?

My proposed simulator study would vastly increase the N to, say 100.

The statistics show that if 1/100 crashed, our confidence range narrows to roughly (0% to 3%).

If we had 1000 crews run through the simulator, and 1 crashed, then the interval shrinks further (about 0.5% to 1.5%).

Then, a naive analysis could be made (*with a ton of assumptions which we shall ignore*)

Let p1 be the % of flights on which the pitot tubes freeze and the autopilot drops out.
Let p2 be the % of times where the crew crashes when the autopilot drops out.

Then the overall risk of this = p1 * p2.

To me (again, not a pilot, but interested in cognitive psychology and statistics) both of these numbers are relevant here.

From what I know, the airline industry likes the risks to be in the one per million range or lower, and if there's a suggestion that it's anywhere near to 1% or 3% or even 10%, yikes!

Interlude

11th Jul 2012, 03:14

I understood that BOAC was commenting on the satellite images ironbutt57 presented in post #281 rather than the aircraft radar.

svhar

11th Jul 2012, 03:35

These images are totally useless. They only display what can be seen from above.

Clandestino

11th Jul 2012, 05:45

... though the page ironbutt57 linked to is somewhat useful as it very often used for those still peddling the idea AF447 entered the storm.

Some examples of weather-induced inflight breakups at higher altitudes are Northwest Flight 705 which was downed at FL250 in the Everglades in 1963; NLM Flight 431 which crashed in the Netherlands inside a thunderstorm; and Pulkovo Aviation Flight 612.

Northwest 705 was high altitude upset that resulted in low altitude break-upPROBABLE CAUSE: "The unfavourable interaction of severe vertical air drafts and large longitudinal control displacements resulting in a longitudinal "upset" from which a successful recovery was not made." Who would have thought it is possible to make large longitudinal control displacement with yoke?

NLM 431 hit tornado, not something you meet at high levels. I can't find exact reference what was its altitude at the time but I don't expect that flight shorter than 100 km would climb very high.

Pulkovo 612 is example of trying to climb above ceiling in aeroplane that is prone to deep stalls. I couldn't find any reference to in-flight disintegration or any damage prior to ground contact in flat spin.

I cannot doubt Tim Vasquez's expertize on meteorology but filing these accidents under "high altitude weather-induced breakups" is quite a bit of stretch.

While AF447 operated in the area of storm activity, all the data collected so far point that the crew was aware of the severe weather and circumnavigated it successfully. "Don't fly into storm" is valid lesson yet it was heeded by the AF447 crew so you can't make them poster-children for it.

Nemrytter

11th Jul 2012, 07:39

That contradicts the BEA report. What is the source for this statement?
An analysis of the Wx conditions done by UK met office and the owner/operator of the satellite used in Vasquez's webpage. It's not yet published but should be in a month or two. If you're interested (and I remember!) then I can PM you a copy when it's out.

Also, it doesn't contradict the BEA: They state that with the - very limited - data they had available they couldn't conclude if the conditions were exceptional.

These images are totally useless. They only display what can be seen from above.
Not strictly true, by using different wavelengths of radiation you can gain some insight into vertical structure. As I said before the area was also overflown by a radar satellite (TRMM) that has a decent vertical capability.
Even for instruments that can only see the cloud tops it is possible to use computer models to determine the internal structure of the cloud with a reasonable degree of success (better than a forecast could manage, for instance).

However this is irrelevant to the AF447 discussion, so if there's anything else to talk about then maybe it'd be appropriate to continue in a thread in jetblast.

deSitter

11th Jul 2012, 08:31

Several questions..

At what point was the "deep stall" unrecoverable? What exactly is a deep stall? Was the trim issue the main obstacle to recovery? Thanks in advance.

opherben

11th Jul 2012, 08:54

Whatever you are flying, whenever and whatever the situation:
Proper Pilot selection, training and qualification will warrant safe, economical and predictable results. The rest are unimportant details.

ironbutt57

11th Jul 2012, 08:55

Was the trim issue the main obstacle to recovery?

Since the stick was never pushed forward in an effort to unload the wing (reduce angle-of-attack thereby breaking the stall), it's hard to say...but having done an "amateur" reproduction of this event in a 320 simulator, I found it impossible to reduce the pitch below 12deg down, and the aircraft remained stalled, as the FPA was around 40deg....it required manual inputs to the stab trim in the nose down direction (as it had obediently driven to the full "nose up" position) to achieve the negative pitch down to reduce the angle-of-attack...keep in mind my experiment was from reading the report, not in the least bit a scientific-based simulator back-drive...

aterpster

11th Jul 2012, 13:38

ironbutt57:

Was the trim issue the main obstacle to recovery?

Could have been, but shouldn't have been.

Turbine D

11th Jul 2012, 14:21

ironbutt57,

For comparison to your experience, here is what PJ2 reported based on his SIM experience. It is in Post #165, Tech Log.

Quote by PJ2: In the sim exercises, for recovery the SS was held full nose-down from the beginning of the stall warning at about FL360 until the wing was unstalled at about FL250, about 40 seconds total time, with a maximum achievable ND pitch of about -12 deg with an average of -10deg. The thrust levers were in the CLB detent and the THS was initially at 13.6deg and was returning to the normal cruise setting.

With the FPV symbol available, the FPA could be observed just above initially at -40deg, (pitch -10deg).

It began to move, initially very slowly up, about 15 seconds after full ND SS;

- at 29 seconds after full ND SS, the FPA had moved from -40deg, (pitch at -11) to -25deg, (same pitch);

- in the next 5 seconds it moved from -25 to -15, (FL257);

- at 38 seconds after full ND SS the FPA was -9deg, (pitch -5deg) with the wing unstalled and the CAS at 255kts.

TripleBravo

11th Jul 2012, 15:01

Nose down side stick would have "corrected" the THS whether they recognized the setting or not. Recognizing that nose down was required was the issue.Correct. It even actually had corrected and the THS was not stuck in its rear position. You can read that from annex 3, page 3 (raw DFDR data, right elevator position): Once the stick was pushed forward at 2:12:34 or 2:13:47, the THS moved in the forward direction. They just should have let go with the stick. Autotrim was not an issue.

The integrator never unwound over the rest of the flight (fall) to impact.It did. See above.

This was the reason for AP disconnect on AF 447 which subsequently led to the demise of the aircraft and all on board!No AP disconnect is any reason to get scared. If pilots can't fly the aircraft without AP, they shouldn't be sitting in the first row.

6: If I remember well some fuel had been transferred to the tail (which I suppose happens automatically during cruise, like on MD11, to reduce fuel consumption) making it even more hopeless, if they wanted and had tried, to exit the condition of deep stall they were in.I understand your question is whether they would have been able to exit the stall (not so much about the trim logic itself). I say: yes. You see in annex 3, page 6, that every significant "stick down" input was followed by a) THS forward movement, b) pitch decrease and c) airspeed increase.

Is there a ready explanation for the very smooth line of THS increase to max, vice a more herky response to actual (commanded) pilot inputs? It looks graphically as though the THS was deploying to a "target" position, independent of pilot command?Yes, it's a smoothing function, designed to reduce stick workload. It never ceased to react to stick inputs, see above. The sticks were just pulled too much almost all the time. (Should answer deSitters question as well: It wasn't an obstacle.)

The aircraft data say it more precisely than any statistics and sattelite imagery: The icing indicator never indicated anything, turbulences were only "light" by ICAO standards. So, "storm" wasn't a factor, as pointed out several times now. Except for creating an atmosphere where icing could happen to the pitot tubes without being indicated... but that is not limited to thunderstorms or the ITCZ. The flight path was choosen carefully right, at least one error they didn't make.

As to usage of pitot tubes: Mass flow sensors need an additional (second) temperature sensor. Which can fail. Heating can fail. The metering wire can rip while flying through hail. These failures are interrelated with AND, multiplying failure probabilities.

Pitot tubes indicate indicated airspeed (IAS), which takes air density automatically into account, by physics, not by processor. Quite convenient. GPS (ground) speed is no feasible backup - ever heard of upper winds, let alone jet streams that can make 100 knots difference? It's airspeed that makes an airplane fly, not ground speed. The difference is the wind, which hast to be measured. There you are again with air speed.

And there is sort of a backup sensor for the pitot tubes, which is the AOA sensor. You could hand fly the airplane without speed, just with AOA. But if even the stall warning gets ignored altogether...

angelorange, thanks to bring back the Airbus publication FAST #24 (http://www.airbus.com/support/publications/?eID=dam_frontend_push&docID=17431). It is especially interesting to read CPT Wainwrights comment on the "fighter style" recovery actions that are proposed every now and then, as well as his warning to teach deep stall in the simulator, which could lead to completely wrong conclusions (the simulators do not simulate deep stall).

EDIT: For those that have not yet read, I like to quote the Airbus Chief Test Pilot in said article:
We manufacturers were very concerned over the types of manoeuvres being flown in simulators and the conclusions that were being drawn from them. Simulators, like any computer system, are only as good as the data that goes into them. [...] It should be obvious that firm conclusions about aircraft behaviour can only be drawn from the parts of the flight envelope that are based on hard data.

In fact, this is a perfectly adequate coverage to conduct all normal training needs. But it is insufficient to evaluate recovery techniques from loss of control incidents. Whereas, the training managers were all in the habit of demonstrating the handling characteristics beyond the stall; often telling their trainees that the rudder is far more effective than aileron and induces less drag and has no vices! In short, they were developing handling techniques from simulators that were outside their guaranteed domain. [...] It is worth saying that there was never any difference of opinion between the three test pilots on the group. [Airbus, Boeing, Bombardier]And, with Boeing's words (http://www.smartcockpit.com/data/pdfs/flightops/flyingtechnique/Airplane_Upset_Recovery_by_Boeing_%28Part_1%29.pdf):
However, airplane upsets often will involve g load excursions and these cannot be duplicated within the simulator environment. They have not been designed for the purpose of replicating upsets, and as such, whenever maneuvering involves vertical or lateral loading, the realism degrades.
This is a very important point for both the trainee and the instructor. Instructional content must acknowledge this limitation and fortify instructional content based upon the trainee’s prior flight experience with g load excursions. Without this instructional input, a positive learning goal can be transformed into a negative learning experience. [...] However, flight data are not typically available for conditions where flight testing would be very hazardous.So, very limited use to conclude from sim experience to real life once talking about stall.

The AF447 crew's lack of CRM reminds me on an opposite case with Lufthansa on 20th March 2001 (http://aviation-safety.net/database/record.php?id=20010320-0&lang=en), where the crew faced a major stick malfunction just after take off. Since they changed control immediately, everybody survived. In the mentioned incident (BFU report in German (http://www.bfu-web.de/cln_030/nn_223532/DE/Publikationen/Untersuchungsberichte/2001/Bericht__5X004-01,templateId=raw,property=publicationFile.pdf/Bericht_5X004-01.pdf)), the captain (PF) recognised that his actions were in vain and handed over... that saved the day. AF447 had several minutes to see that pulling the stick was in vain, not just seconds!

These are my main questions as to the crew's psychology: Why did nobody of FO or CP take control earlier, e. g. the captain request to sit in his chair and see for himself, and second why was the SO trying on his own for so long without requesting the others to take over? I'm sure I would ask for help / take over.

The only potentially explaining metal picture I have of the PF is that he was feeling very uncomfortable, in particular at this altitude which he considered to be too low (asked the CP to climb, but this was refused). He even wasn't familiar with St. Elmo's fire. Not the best precondition to master the next events. So the very first action after AP disconnect was to pull the stick.

The aircraft climbed accordingly. And the altitude increased unnoticed EDIT correction: without consequences. Why? What was the PNF doing? This is puzzling me just as much as why the PF was pulling all the time.

jcjeant

11th Jul 2012, 15:14

Hi,

Triplebravo
The aircraft climbed accordingly. And the altitude increased unnoticed. Why? What was the PNF doing? This is puzzling me just as much as why the PF was pulling all the time. Not exactly ...
CVR extract:

PNF
2 h 10 min 31,2 Go back down
2 h 10 min 32,2
According to that
we’re going up

PNF
2 h 10 min 33,7
According to all
three you’re going
up so go back down

PF
2 h 10 min 35,2 okay
PNF
2 h 10 min 35,8 You’re at…
2 h 10 min 36,4 Go back down
PF
2 h 10 min 36,7
It’s going we’re
going (back) down

At this very moment the best action of PNF was to slap the PF in the face and take commands
Nothing of this happen

Lyman

11th Jul 2012, 15:40

Diamond Bob, #302, barek, #308....

Thank you both, I appreciate any information that helps me understand the pilots' situation that is absent vitriol and condescension. Many thanks....

At this point I would like to ask if information could be supplied in the same manner relating to the "AP2 ON" switch, throughout. It was left on like the FD, and I wonder if it had anything whatever to do with the climb, as the FD may have.....

The drill calls for AP OFF, and if left on, does that resemble "Re-Select" in any way? The accident might boil down to a drill unobserved, and if so, the tragedy assumes some logic, absent thus far.

It has been explained that AP is not available after degrade to AL, but does that mean Unavailable if re-selected, or does it include "if left on".....

LarryW727

11th Jul 2012, 15:47

jc, I agree with you, a good slap to the face of the PF could have saved the day. That being said, I see two GLARING mistakes; 1) Pushing back from the gate knowing the severity of the weather insteading of delaying departure for improvement of known severity of WX. 2) After making mistake #1, going to the back to take a nap with the IRO in the left seat with known severe wx to be dealt with. That pretty much sealed their fate. FWIW, I am not a Airbus driver, I have been in the Boeing products all of my career (727, 757, and 747) so my knowledge of Airbus is zip. However, on the Boeings, we are always trained, that when things are going bad and only getting worse: **** can ALL automation and FLY THE AIRPLANE. It is the first line on all Emergency Checklists. :confused:

TripleBravo

11th Jul 2012, 16:00

jcjeant: thanks, inaccuracy corrected. You said what I was trying to say.

notfred

11th Jul 2012, 17:03

I'm not a pilot, but have read the full report.

One thing I found interesting in the report was that the pilots may have mistaken the stall buffet for overspeed buffet (as mentioned in post 308) and yet the report asserts that the A330 doesn't suffer from overspeed buffet.

Is this true for other modern jets? And how many pilots know if their type suffers from overspeed buffet or if buffet is always stall buffet?

hetfield

11th Jul 2012, 17:32

And how many pilots know if their type suffers from overspeed buffet or if buffet is always stall buffet?

Hopefully all.......

Turbine D

11th Jul 2012, 17:43

svhar,
Your post #311 is essentially incorrect except for the Boeing part.
Those colors are in agreement with the local TV weather radar reports during episodes of severe weather, TS and potential tornados.

However, Quote by BOAC: - don't forget that those images were not what you would have seen on your shufti-scope - the colours are synthetically produced based on temperature I believe and we just do not know what would have been seen on their radars.

Quote by svhar: I do not know what equipment you have been using, but you are talking about things you have no idea about. All weather radars display level of precipitation.
If you go back to ironbutt57 post #281 and click on its content, you will discover it does not refer to weather radar in the imagery at all except for one small image a vertical slice through the CB provided by NASA CloudSat. All the other major images are indeed thermal imagery from satellites, some enhanced by the author or others.

Quote by svhar: I once knew a guy who talked like a professional pilot in the cafeteria with endless stories of his adventures in Africa, but there always where holes in his stories. He was able to fool everyone for a long time and was adored by lots of guys and girls. No one really cared to blow his cover because he was in fact good company. Always called "The Captain". He had a PPL and worked as an ambulance driver. Reminds me of BOAC.

IMO, an apology is in order to BOAC for your snarky remark...

fantom

11th Jul 2012, 18:16

Do any of you know who BOAC is?

I do, and you'll REALLY eat those sarcastic comments if you learn the truth.

Mr Optimistic

11th Jul 2012, 18:51

I couldn't see any reference to the crew giving any meaningful brief to the cpt on return . As it appears not to have been articulated is it reasonable to suggest that he never knew of the mode change and was therefore ignorant of the loss of some protections ?

BOAC

11th Jul 2012, 19:01

Very briefly, guys, I appreciate your comments. I had 'blanked out' this buffoon on the forum and only now seen his latest comments. Best leave the creature to his own world, I fancy.

lomapaseo

11th Jul 2012, 19:48

One you spend enough time on this forum you will find that it is a great mistake to guess at outting a person from under their name cover in a posting.

Best to just imagine them as idiots rather then blowing your own cover :)

Organfreak

11th Jul 2012, 20:25

Best to just imagine them as idiots rather then blowing your own cover

Well I really AM one! ;)

stepwilk

11th Jul 2012, 21:27

1) Pushing back from the gate knowing the severity of the weather insteading of delaying departure for improvement of known severity of WX.

It was my impression that the report said the met was just another night in the ITCZ. And haven't we put to bed this canard that they "flew into a thunderstorm"? Certainly there's nothing on the CVR (or the FDR) to indicate that, other than a cabin announcement about some routine turbulence with a bit more to be expected ahead.

Lyman

11th Jul 2012, 21:49

My question above, Retired F4, had to do with the CVR, which quoted the Captain, "Wait, the Autopilot, (noise of switch, CAM)"......This occurred late in the chronology, and I assume it meant that the Autopilot (AP2) was left on. I know the AL defeats Reselect, but what does it do with an AP left ON? The Flight Director was left ON, and may have caused some mischief. What does the computer do with an Autopilot that is left ON?

Let me add my dudgeon to the snark directed at BOAC. I have found him to be a remarkably kind and patient expert here, and his credentials are probably understated, if I may say.....

suninmyeyes

11th Jul 2012, 22:09

LarryW727 you said That being said, I see two GLARING mistakes; 1) Pushing back from the gate knowing the severity of the weather insteading of delaying departure for improvement of known severity of WX.

So you obviously believe that all the other aircraft that successfully flew that route that night should also have delayed their departure? You might delay takeoff for bad local weather but not for routine ITCZ weather that requires en route deviations. Taking off when they did was not a mistake.

vovachan

11th Jul 2012, 22:38

Pulkovo 612 is example of trying to climb above ceiling in aeroplane that is prone to deep stalls.

Actually Pulkovo climbed too well at 10 m/sec - they blamed the pilot overcorrecting the up down pitching for the crash

DozyWannabe

12th Jul 2012, 01:02

Salaries and benefits of employees at BEA are partially paid by the revenue stream at Airbus...

Utter rubbish. The income that sustains my employer comes in part from organisations with whom I disagree. Does that factor change my personal or professional opinion?

No - and any tenuous link you try to draw between the French state stake in Airbus and BEA conclusions is utterly reprehensible. Did the RAE skimp on the Comet enquiry despite the aircraft's state subsidies? Does the NTSB frequently do the same ("Hoot" Gibson case aside)? With all due respect I think you need to find another hobby.

I know the AL defeats Reselect, but what does it do with an AP left ON?

It turns it OFF and latches it OFF until ground crews perform maintenance.

Lyman

12th Jul 2012, 03:05

Sorry, Doze, I answered you in the other thread. Briefly, Airbus itself warns to turn OFF A/P with UAS. If it is latched off by the computer and cannot be reselected, why does A/B warn against its "re-selection"? Why bother, if as you say the A/P is shut down completely and forever until ground maintenance? The FD is obviously not treated in the manner you suggest, it came back on, in different modes, several times. Are you sure you know whereof you speak? No offense.

Cool Guys

12th Jul 2012, 08:29

Layman

"I have found him to be a remarkably kind and patient expert here"

I concur. Most people are polite and helpful but there are a few who wish to show they know best by putting others down.

As PJ2 so eloquently sates in one of his posts "those who roast others without all the facts just want their name inlights perhaps, while those who know are either simply heads-downquietly doing the daily work or can't be bothered arguing."

SadPole

12th Jul 2012, 09:35

Let me add a few points (from an engineer's perspective – If I am saying something stupid – I do expect a very strong – WTF are you talking about – see below).

1. We are fooling ourselves that human beings are capable of logical reasoning, especially when it comes to split-second decisions in a stressful situation. Decisions like that are made on instinct – driven by pre-programed associations. In most cases, when exposed to danger, a person instinctively runs from danger any way he/she was programmed to run. The hero of our story wanted to run from danger but he didn't know how.

2. For this reason, training is absolutely essential so that proper ways to run from danger are instinctive, which clearly was not present in this case. A kid who practiced for say an hour a day for a few weeks on a toy simulator on some game station would most likely have a better instinctive reaction to the stall warning than the hero of our story did.

3. For this reason, there is something fundamentally wrong, I think, with counting hours of watching autopilot do its thing as “flying experience.” With the emergence of present day-autopilots the process of judging pilots' experience should have been redefined long ago. One way to do it would be to count takeoffs and landings, which would promote pilots who did time on smaller planes long before they were allowed to touch commercial jets. However, I do not see pilots talking about changing that system. Maybe they should.

4. It is absolutely true that a true ace pilot, one that committed his whole life to aviation, could NOT be affected by even most illogical configuration of plane controls. Even if someone/something all of a sudden re-wired the whole damn sidestick backwards, a guy like that would figure it out in a few seconds, because he committed his whole life into merging his mind and body with every flying device he could put his hands on. But, the point is, many of the pilots probably are not aces like that, they looked for something to do and they did/learnt exactly what the “system” required them to do and absolutely nothing more. Now we are getting into my favorite model of stereotyping people into aces and vegetables, or wolves and sheep.

5. Clearly, the guys flying AF447 were not aces, and it was probably by design even if nobody will dare to admit it. Here is why: Every society outside state of war for survival just LOVES vegetables and tries to suppress the aces/wolves. At the end, this is extremely illogical process, but outside real emergencies, vegetables are so much nicer and easier to deal with. They like one another and don't fight with each another like aces do, they are loyal to the system not their trade, they don't cause trouble(at least until trouble finds them), they are not adrenaline junkies like some of the aces are, etc, etc.

6. For above reasons, the whole system was demonstrated to be a complete failure, and there is no way to see it anything but that. Someone allowed “vegatable” pilots behind the controls who were more than happy to do little beside watching autopilot do its thing. Then a small problem arises, the whole automatics shuts down and expects our heroes to suddenly, on a second's notice become ace pilots capable of handling the plane almost without any idiot-proof protections they instinctively learnt to rely on. The main idiot-proof system that still works (the stall-warning) provides completely fraudulent feedback (disconnects at deeper stall, reactivates itself at the attempts to recover from stall). Nothing wrong with this picture?

7. To make matters more interesting, due to lack of communication and specifics of the sidestick design, the PNF has absolutely no idea what PF is pulling back on the stick and that he is doing it even after he pretends to agree to not do it. When PNF finally masters enough courage to try to take controls himself, he has no idea that the other guy counters his actions, which discredits the only attempt to recover from stall as action that brings no result.

8. If you think vegatable pilots are bad, imagine vegetable engineers, people who never had any desire to create new things, and are perfectly happy to do little besides playing office politics. Yes – the corporate engineering is full of those and this is why good pilots should not be shy about criticizing stupid things the corporate engineering came up with on the premise that “they know what they are doing”. As every real-world engineering is ALWAYS over budget and late, fixing screwups found late in the process is very hard because it risks massive delays. Tremendous pressure is always put on those who, loyal to their trade and not office politics, want to fix the screwups. They are often portrayed by the bean counters as people who want to destroy the good company with their idiotic “nitpicking”. Therefore, the only chance to fix engineering screwups comes up after a major FUBAR.

9. I have never worked for Airbus, so I don't know how bad (or good) things are over there. But the companies I worked for, the things that I have seen made my skin crawl. Worse yet – if I told anyone the details, I would be sued and “the law” would destroy me rather than help me. That's today's corporate culture which in my view has nothing to do with healthy capitalism, which I always believed in.

10. My view that human beings are inherently illogical comes precisely from watching “vegetable engineers” do their thing. If you scratch your head over 2 pilots doing completely stupid thing for 2 minutes, imagine watching 30+ engineers doing similar thing for months. Having weeks and weeks to think about it and still doing it. Generally, one vegetable engineer, most likely the boss's top ass-kisser would come up with the idea in order to promote his position, then convince everyone that that's what the boss wanted. Then everyone goes along and does not dare to question things. Not daring becomes its own logic and so it goes. Not thinking is running from danger of risking the alienation of the management and co-workers. The only way to stop such nonsense outside complete FUBAR where the crew would lose their jobs would be someone being brave enough walking to them and saying something like: WTF are you IDIOTS doing? It is sad but in my experience only a strong shock like that can make people think in such lock-down situations. A direct, UGLY challenge where they have to prove they were not screwing up or lose face. Needless to say, being loyal to my trade first and foremost, I had the pleasure and the privilege to be the one doing it over and over. At one job, I was expressly forbidden by the boss from using word “idiot”, which I interpreted in my own way as a challenge to learn more English synonyms of the word idiot, which I printed out of thesaurus and framed on the wall. I never lost my means of survival doing things like that – but I would never lie to anyone and pretend that it was easy.

11. The “WTF are you IDIOTS doing” story brings up the last point. The PNF is half-aware that PF is not doing what he should be doing, but he never masters enough courage to properly assert this point. Calling for the captain to come to the cockpit is pretty much the extend of his bravery. If he mastered enough courage to do “WTF are you doing” and properly asserted taking over the controls, he could have prevented the disaster. When planning the shock/upset simulator training, it would also be a great idea to test the pilots if they are able to properly identify the situations where the other pilot does something completely idiotic, and assert control to prevent disaster.

TripleBravo

12th Jul 2012, 09:43

Quote:
I know the AL defeats Reselect, but what does it do with an AP left ON?It turns it OFF and latches it OFF until ground crews perform maintenance. As an addition: annex 3, page 2: The AP2 disengaged at 2:10:06, 3 seconds before ATHR disengaged, and never went on again. (AP1 not shown.) By the way, the FD1 + FD2 were off for the better part of the last 3 minutes, so no "flying after the FD all the time" as suggested somewhere else.

As to the BEA relation to Airbus or Air France: Despite I had my doubts before (mainly due to the mishandling of the Mulhouse case), I don't think anymore that there is any relevant or "protective" link. Perhaps BEA knew about their public image since they almost always invited experts from other countries (at some points they had to according to ICAO annex 13) and documented crucial moments with pictures such as the openings of the flight data recorders. All facts I can crosscheck are correct, the conclusions I can draw from the raw data in the annexes are basically the same as they did, no major discrepancies found so far.

Perhaps we should face that supposed-to-be-professionals screwed up entirely for more than three minutes, not just for one wrong hand movement in the wrong second.

Why are certification requirements not adapted to recent findings? Why are aircraft marketed with bold statements like "the pilot can't do wrong, the plane sorts out his errors"? Did this add to the mental picture the PF had? As someone said, handing back from computer to pilot as a safety backup strategy does not work anymore for a generation that is flying computers immediately after ATPL. Do we have to rethink safety strategies?

They weren't suicidal, they fought for their own lifes as well and sadly lost. But how come that their abilities were so limited, despite thousands of hours?

As individuals: How come that flying manually is something not much appreciated in the industry? How could they build up certain skills when "managing computers" is the work description? How could they avoid wrong reactions (TOGA at high alt) when this is standard sim drill, since high altitude flying is almost entirely ignored? Why is basic flying in simple aircraft not fostered more in order to build basic skills?

As a team: The captain wasn't in his seat, and due to his CV I'm convinced he would have had the abilities to handfly without major problems. But how was he trained and tested to lead a crew? Great pilots are not automatically great leaders. Did he overestimate the skills of his PF? Was he reluctant to interfere more vigorously, being a nice guy? Hierarchy was a negative factor in KLM4805, JAL123, ... but without any hierarchy (clear roles) seems to be just as bad. Where was CRM??

DozyWannabe

12th Jul 2012, 14:28

(mainly due to the mishandling of the Mulhouse case), I don't think anymore that there is any relevant or "protective" link.

There wasn't before. The BEA did nothing wrong during that investigation - but in order to pre-empt the criminal proceedings, Capt. Asseline's lawyers spread a lot of muck around via the press in the hope that some of the mud would appear to stick.

The irony of the situation was that the BEA's AF296 report itself lay most of the cause at the door of Air France (due to serious organisational failings), and had Asseline's lawyers not tried to muddy the waters by making it about Asseline vs. Airbus, then Asseline himself would have probably got away with not much more than a slap on the wrist.

DozyWannabe

12th Jul 2012, 15:05

1. We are fooling ourselves that human beings are capable of logical reasoning, especially when it comes to split-second decisions in a stressful situation.

Actually, experience suggests that some are and some aren't. The problem is that it is very difficult to tell which person will fall into which category until it actually happens.

A kid who practiced for say an hour a day for a few weeks on a toy simulator on some game station would most likely have a better instinctive reaction to the stall warning than the hero of our story did.

Speculation with no supporting evidence. There's a *massive* difference between experiencing the sequence in the sim versus doing it for real (especially when doing it for real involves a body clock expecting circadian rhythms). Also, the chances of making a successful recovery hinge on being prepared - I hadn't touched the controls of an aircraft since I last climbed out of a Chipmunk trainer in 1993, yet managed to recover an A320 sim with the AF447 conditions programmed. This doesn't make me a pilot - my advantage was entirely because I knew what to expect.

4. It is absolutely true that a true ace pilot, one that committed his whole life to aviation, could NOT be affected by even most illogical configuration of plane controls. Even if someone/something all of a sudden re-wired the whole damn sidestick backwards, a guy like that would figure it out in a few seconds, because he committed his whole life into merging his mind and body with every flying device he could put his hands on.

Then please explain why there are at least five dead astronauts and cosmonauts who were lost in training accidents. No matter how good you are, sometimes it's just not your day.

With all due respect, I find your use of "aces/wolves" versus "vegetables" not only insulting but incredibly distasteful. It's a lot more complicated than that.

8. If you think vegatable pilots are bad, imagine vegetable engineers, people who never had any desire to create new things, and are perfectly happy to do little besides playing office politics. Yes – the corporate engineering is full of those...

Not when developing new products in aviation you don't.

9. I have never worked for Airbus, so I don't know how bad (or good) things are over there. But the companies I worked for, the things that I have seen made my skin crawl.

...

Generally, one vegetable engineer, most likely the boss's top ass-kisser would come up with the idea in order to promote his position, then convince everyone that that's what the boss wanted. Then everyone goes along and does not dare to question things. Not daring becomes its own logic and so it goes.

Were any of those companies in the aviation business? I've worked on many software projects, running the gamut between being brilliantly run and managed and being a complete train-wreck, but I don't think the latter methodology would wash in a top-drawer aviation engineering department. Airline management is another story, and PJ2 absolutely filleted some of the more modern practices in a post on the other thread.

As for Airbus, my old Software Engineering Prof (RIP) - who was a dyed-in-the-wool FBW sceptic - visited Toulouse in 1994 and came away impressed. Mind you, he still held their feet to the fire in public...

lomapaseo

12th Jul 2012, 15:23

Let me add a few points (from an engineer's perspective – If I am saying something stupid – I do expect a very strong – WTF are you talking about – see below).

.....

imagine vegetable engineers, people who never had any desire to create new things

Every profession has these vegetables. They rarely rise to command where processes are defined against standards and regulated by outside sources.

Thus in this case it's only imagination

jcjeant

12th Jul 2012, 16:25

Page 83 Final report
The first search phase aimed at detecting and locating the acoustic signals transmitted
by the Underwater Locator Beacon (ULB) fitted on each flight recorder
(8)
. As a priority,
the aeroplane’s planned flight path as well as the greatest possible area inside the
40 NM circle was swept by two Towed Pinger Locators (TPL)
(9)
.
No signal from either of the beacons was detected by the sensors deployed in the
area despite TPL passing by, on two occasions, not far from the debris field, on 22
and 23 June 2009.
Sonar imaging systems with the ability to recognise components on the sea bed were
deployed during the phases that followed.I don't find any explications about why the signals were not detected
I don't find any in the BEA report about investigations on this problem (if the beacons were active at time .. or if they find some defects for explain the failure of detection ...)

Clandestino

12th Jul 2012, 17:13

upon re-reading my words, they did come across snarky and like a cheap shot, so I apologize.No need to apologize, harshness was mine.

I said "it would be fun" and "The outcome would be quite interesting."Agree it could turn out to be fun & interesting, not necessary for the same reasons, though.

Some things we can: training and machines. I'm simply saying that
we should think of the big picture here, and improve the things that we do control. Agree, but big picture is autopilots resigning almost daily in cruise levels (no need to have UAS) and most of the occurrences getting sorted out without anyone noticing. AF447 is just a detail, very significant and very ugly though.

How many miles do we need google's robot cars to have accident-free before we trust them?Aviation has it covered in certification processes. As soon as robots show functionality and reliability of human pilots, we'll have pilotless aeroplanes. Don't hold your breath waiting for it, key issue is still functionality, with latest computers being no significantly better than ENIAC.

The "naturalistic" study shows that 1 of 37 crews in similar situations crashed. As I mentioned, that's such a small sample size that we can't say whether the actual percentage is closer to 0% or closer to 10%.My point was that since a) level of safety currently achieved makes sample very small b) there are so many variables that affect the outcome, if we want to learn something in order to further advance aviation safety, we can not rely on statistics to get any meaningful result. That is something known since at least mid 90ies (that's about time I started paying attention) - at the time "swiss cheese" and "accident chain" analogies were accepted and it was recognized it wasn't enough just to analyze accidents but also a close calls, where all safety features failed except one or two and result was no one hurt, no damage when it could easily ended otherwise.

Now if we apply numerology, and boldly and deceptively call it statistics, to the sample provided by BEA in interim 3 by assuming that survival means no problem while crash means manual handling of the aeroplane deficiency, we'd come to conclusion that it's not such a big deal if just 3% of crews are unable to control the aeroplane when hit with UAS. Of course it is deeply wrong conclusion and you were on the right track when you mentioned "survived for wrong reasons". To discover what were wrong reasons, we need detailed case studies, not just statistical analysis of contributing factors. BEA has analyzed 13 out of 36 discovered cases of UAS and added one which couldn't be analyzed; case of TAM 332 on Nov 12 2003. Both pilots pulled as airspeed was lost but then pushed when stall warning went off so we need to resolve why some pilots perceived and understood the warning while some didn't.

Chapter 1.17.1.5.4 is also pretty damning.

It's not yet published but should be in a month or two.I'm not holding my breath.

At what point was the "deep stall" unrecoverable?
Insufficient data to tell whether it was unrecoverable. No one felt suicidal enough to fly the AF447 profile for real.

What exactly is a deep stall?Something of no concern on A330/340.
Was the trim issue the main obstacle to recovery?Not trim, crew.

every significant "stick down" input was followed by a) THS forward movement, b) pitch decrease and c) airspeed increase.Not quite, THS remained at full nose-up, elevators moved from full nose up to half-nose up and that was enough for nose and AoA to go down. Good indication there was no deep stall but not definite proof - now this sentence should give ammo to conspiracy theorists.

Is this true for other modern jets?I guess not, especially for those that need to have mach trim e.g. 757. Issue is that if you know procedures, recognize when they need to be applied and follow them, you need not to know whether your aeroplane suffers from mach buffet or not.

We are fooling ourselves that human beings are capable of logical reasoningMost of the time, they are.

true that a true ace pilot, one that committed his whole life to aviation, could NOT be affected by even most illogical configuration of plane controls.False. Air has no respect for anybody. It is ignorant who coined the phrase "beginner's mistake". Experience is double edged sword, as the experienced "ace" often does not recognize the times he tempted the fate and is bound to repeat the feat. With a bit of luck, such an "ace" can live to retirement.

the whole system was demonstrated to be a complete failureYou condemned the whole system based on single accident. Such a feat can not be excessively serious.

imagine vegetable engineers, people who never had any desire to create new things, Vegetable is as vegetable does. Just because you don't like some aspect of the machine, it doesn't mean it's bad or that improving it would cause massive degradation of other aspects.

mishandling of the Mulhouse caseCare to elaborate?

Why are certification requirements not adapted to recent findings?Accident investigators have only the power of advice. Also their scope is limited to accident at hand.

They weren't suicidal, they fought for their own lifes as well and sadly lost.They fought for their lives by tying the noose around the neck and jumping off the stool, without ever recognizing there's a rope.

How come that flying manually is something not much appreciated in the industry?PPRuNe is not the industry.

The captain wasn't in his seat, and due to his CV I'm convinced he would have had the abilities to handfly without major problems.Have a go at BEA's report. While there were deficiencies noted, 36 crews given the manual control of the aeroplane performed well enough not to kill anyone. I doubt they had more manual training at high levels than AF crews. Some were AF crews.

Then please explain why there are at least five dead astronauts and cosmonauts who were lost in training accidents.

If extend the scope to display flying, we may add Rimantas Stankevičius, Buran test pilot, to the list. Devoted, experienced, professional. One day overhead Salgareda he entered split-S too low.

svhar

14th Jul 2012, 01:01

It does not enter my mind to apologize to BOAC. He belitteled my first post ever on Pprune, and I have seen him do it to others in many threads on various topics. He thinks he knows it all. I have always detested such persons.

svhar

14th Jul 2012, 01:21

Who is so dumb, with only 20 posts, to argue with the king of Pprune with more than 15.000 posts. Only me is that stupid. When does he sleep? Time for family? Let alone, when does he have time to fly for a living? I know the type.

And even, if BOAC retired when he startet posting, it is like asking the Wright brothers to comment on the 787.

Organfreak

14th Jul 2012, 01:37

svhar,
I'm still a (non-piloting) newbie here, and I've been flapping my lips here for 200 posts in a quest for knowledge, no doubt revealing my utter unsuitibility to sit at this table. Please note that Clandestino, whom I often don't wholly agree with, has never once singled me out for public (or private) humiliation. Why not?

So you are forced to consider that an interaction between two people has two contributors, and one of them is you. Anyway, the problem will doubtless be resolved when the moderators realize that you're resorting to deeply sarcastic and personal remarks, noticeably lacking in any on topic content. :\

ChrisJ800

14th Jul 2012, 01:44

Hi Svhar, You wont get on with everyone on this forum and I dont either, but suggest you call a truce. Well done on winning the Eurocup in football by the way!

Turbine D

14th Jul 2012, 01:46

svhar,

Quote by svhar:Only me is that stupid

I have to agree with you...

svhar

14th Jul 2012, 01:51

You are right, Organfreak. My respect to you. I'll withdraw from this discussion as from now. And sorry, BOAC, I just had to pay back.

Organfreak

14th Jul 2012, 02:11

You are right, Organfreak.

Oh, you'll soon get used to that!

I'll withdraw from this discussion as from now.

Seems unnecessary...

DOVES

14th Jul 2012, 15:58

BOAC
have nothing to say to svhar?
No "secret" to reveal?
And I refuse to believe you are so venal as to give your opinion only on payment.
I repeat always three, four, five ... times my advice to my students.
If we want to reform this "kind of aviation" with our experience we must not stop withstand the exuberance of youth who want to follow in our footsteps.

Organfreak

14th Jul 2012, 16:42

I beg Clandestino's pardon; apparently I was confused about who was fighting with whom. Guess it was BOAC. Ooops!

BOAC

14th Jul 2012, 17:02

have nothing to say to svhar? - no. I suspect the 'put down' referred to was under another of svhar's usernames.

The rest leaves me bewildered. Can we return to the thread topic?

Lonewolf_50

14th Jul 2012, 17:30

Can we return to the thread topic?

Capital idea.

This thought seems to be worth comment within the context of the accident under discussion.

3. For this reason, there is something fundamentally wrong, I think, with counting hours of watching autopilot do its thing as “flying experience.”

With the emergence of present day-autopilots the process of judging pilots' experience should have been redefined long ago.

One way to do it would be to count takeoffs and landings, which would promote pilots who did time on smaller planes long before they were allowed to touch commercial jets.

However, I do not see pilots talking about changing that system. Maybe they should.
There is quite a bit to chew on regarding this nested set of thoughts. One of the ways the "system" mitigates for errors in selection is that there is a team, a crew, on the flight deck who are, if you believe the CRM principles in vogue, in a position to detect and correct one another's errors, or help out when task loading factor is greater than one pilot.

This isn't the only accident where two pilots were not enough, due to a variety of factors.

Also, I find "takeoffs and landings" a bit misleading, since the entire terminal phase, and into landing, is a more apt area for needing experience. Wrecks in terminal phase are often marked by failure to reach the runway.

As to "takeoff," I'd want to address the entire departure phase for experiential basis.

AF447 happened during cruise, which is not the most common phase for mishap.

Lyman

14th Jul 2012, 17:37

Quote:
Quote:
I know the AL defeats Reselect, but what does it do with an AP left ON?
It turns it OFF and latches it OFF until ground crews perform maintenance.

BBB... Right....but the A/P appears to have been "ON" throughout? Isn't that potentially lethal?

Clandestino

14th Jul 2012, 21:30

the A/P appears to have been "ON" throughout? Isn't that potentially lethal? Kinda reminds me of Rip Van Winkle. If we are discussing the AF447 in this thread, then AP dropped off and was never re-engaged. My apologies if it is me who is posting in the wrong thread.
I beg Clandestino's pardonHuh? What? Why? Whatever.

golfyankeesierra

15th Jul 2012, 08:19

Contacted:I'm not so sure this is sufficiently trained into us.
How about not trained at all?
I have never been in or seen a (high altitude) full stall in the sim. Only the customary straight-and-level bleed the speed off till the buffet comes.

Quote from Boeing'sAerodynamic Principles of Large-Airplane Upsets (www.boeing.com/commercial/aeromagazine/aero_03/textonly/fo01txt.html)
A stall must not be confused with the stall warning that alerts the pilot to an approaching stall. Recovery from an approach to stall is not the same as a recovery from an actual stall. An approach to stall is a controlled flight maneuver; a stall is an out-of-control, but recoverable, condition.

BobnSpike

15th Jul 2012, 12:44

High altitude full stall recovery training is making its way into the sims. I did it last week.

In the Boeings you have to work at it to keep it stalled, but we were doing a falling leaf, descending at 11000 ft/min, 10 degrees nose up at firewall thrust.

The recovery required 20-30 degrees nose down and lots of patience (and altitude) waiting for the speed to build to the point where the stall to became a nose down unusual attitude you could fly out of without entering a secondary stall.

I do not have any time in Airbuses. I can say that all you folks who are saying it should not/would not happen and to whom it would not have happened were not (thankfully) there in the middle of the night in the middle of the ocean in the middle of the weather dealing with contradictory information in a situation that went from straight and level to deadly in the span of a few breaths.

I bow to your mad airmanship skills.

deSitter

15th Jul 2012, 14:49

HWell Bobn, can you provide some more detail on what you did?

The Ancient Geek

15th Jul 2012, 15:03

In the Boeings you have to work at it to keep it stalled, but we were doing a falling leaf, descending at 11000 ft/min, 10 degrees nose up at firewall thrust.

Would the recovery have been easier without thrust ?, it depends on geometry but those underwing engines are likely to generate a nose up tendency.

ironbutt57

15th Jul 2012, 15:38

Would the recovery have been easier without thrust ?, it depends on geometry but those underwing engines are likely to generate a nose up tendency.

most assuredly yes...

deSitter

15th Jul 2012, 16:07

Let's say you have a properly trimmed airplane that for some reason gets into a nose-high attitude and begins to fall as AF447 did. Is there a regime in which you just cannot get out of it? Will the nose always come down if you have proper trim and take the thrust down to idle if necessary? Is there a danger of entering a flat spin? How to avoid that?

I keep thinking some sort of emergency reaction control to push the nose down might work. Some small solid rockets just for emergency use.

Carbon Bootprint

15th Jul 2012, 16:11

I keep thinking some sort of emergency reaction control to push the nose down might work. Some small solid rockets just for emergency use.That might be a little extreme. I think a better avenue would be for AB to work with the key stakeholders (sorry if that sounds cliche) to review the software and AP policies and notification methods therein.

ironbutt57

15th Jul 2012, 16:14

Is there a regime in which you just cannot get out of it?

some t-tail jets, the BAC-1-11 had a famous one during flight testing, have deep stall tendencies, where the horizontal stab is rendered useless...in an airplane with a conventional horizontal stab, it seems impossible, provided sufficient altitude is available to recover...even the 727 was found to NOT be prone to deep-stall tendencies...in the AF crash, it appears no positive effort was made to recover from the stall...simply lowering the nose down 5deg is not sufficient to reduce angle of attack to below stall when the aircraft flight path is much greater..Airborne Express DC-8 on a test flight is another example of flawed stall recognition and recovery training...

Carbon Bootprint

15th Jul 2012, 16:24

Trying to avoid the dreaded Pprune edit nonsense, but I would like to append my earlier post to reinforce that there still needs to be a greater focus on training and making sure the pilots really know how to fly the airplane by hand and understand basic aerodynamics. I've seen so many industries lose their way on fundamentals, and I would like to see the aviation industry avoid that. Too many lives are at stake.

BOAC

15th Jul 2012, 16:29

At the risk of waking the Oozlum bird who has managed the odd 5 minutes sleep here:

As far as we know:

447 was kept in a nose-high attitude by

a) a nose up demand on the sidestick
b) TOGA
c) Full nose-up THS delivered by the software and sidestick demand.

Whenever either a or b was relaxed, the nose appeared to drop. I think it is safe to assume that had the stick been held forwards and the power reduced it would have recovered (given sufficient altitude). This appears to have been a 'foreign' concept to AB pilots at the time.

Jazz Hands

15th Jul 2012, 16:48

I keep thinking some sort of emergency reaction control to push the nose down might work. Some small solid rockets just for emergency use.

I suspect rockets would cause all sorts of regulatory problems (they've been suggested for ejecting flight recorders, but faced similar issues). I seem to recall that at least one of the T-tail airliners had a booster in the rear during test flights just in case.

DozyWannabe

15th Jul 2012, 17:22

In the Boeings you have to work at it to keep it stalled

Same with the Airbus - remember the PF was holding between 50-100% back stick for the majority of the sequence.

In the sim experiments we did, you had to really hold the stick back to keep the nose where the crew had it - because as the speed bled off, the nose clearly wanted to come down. Even with the THS all the way back, it was possible to recover using forward sidestick alone - which we did as we came back down through FL320, during which time the trim wheel obediently rolled back forward - and come out of the descent at around FL180.

c) Full nose-up THS delivered by the software and sidestick demand.

The software aspect isn't really relevant - it was only doing what was asked of it by the pilot, as any other aircraft would.

MountainBear

15th Jul 2012, 17:42

AF 447 crashed because the pilots allowed it to stall. The pilots allowed it to stall because they pulled back on the stick. They pulled back on the stick because they were confused. They were confused because the automation left them in the lurch. The automation left them in the lurch because of a mechanical problem with the speeder tuber thingies. The speeder tuber thingies failed because they got clogged up with frozen water particulates commonly called "ice". The ice was formed because the pilots didn't go far enough left right up down backwards forwards sideways to avoid the storm. The pilots didn't avoid the storm because the captain failed to take the crossing of the ICZ seriously and instead went to sleep in his bunk with a woman. The captain didn't take the crossing of the ITZ seriously because he was complacent due to his vast experience. The captain achieved this vast experience by flying the plane too much. The captain flew the plane too much because Air France allowed the plane to take off from the ground. Air France allowed the plane to take off from the ground because the passengers payed them money. THEREFORE The passengers are to blame for the crash of AF447 and the proper judicial verdict is one of mass suicide by airliner.

fantom

15th Jul 2012, 17:52

Bear, that is brilliant.

I agree...apart from the last bit.

BEagle

15th Jul 2012, 19:36

AF 447 crashed because the pilots allowed it to stall.

Correct

The pilots allowed it to stall because they pulled back on the stick.

No. Because they made totally incorrect control demands.

They pulled back on the stick because they were confused.

No. Because they were completely incompetent and had received utterly inadequate training.

They were confused because the automation left them in the lurch.

No, it didn't. The AFS acted correctly and disconnected with a clear annunciation. The idiots at the helm didn't follow the QRH, let alone commonsense.

The automation left them in the lurch because of a mechanical problem with the speeder tuber thingies.

By 'speeder tube thingies', I presume you mean pitot tubes. They failed, it is true. However, all that did was to cause an entirely recoverable situation for properly trained pilots.

The rest of your post is utter tripe. An ill-disciplined, poorly trained crew killed themselves and everyone on board through their own inadequacy.

oldchina

15th Jul 2012, 20:42

"The captain ... went to sleep in his bunk with a woman".

It's outrageous that you say such a terrible thing. Do you have any proof that he slept?

DozyWannabe

15th Jul 2012, 20:48

@BEagle:

I don't think MountainBear was being entirely serious. :}

kwateow

15th Jul 2012, 21:14

I read somewhere they were all knackered because of too much bonking in Rio.

bubbers44

15th Jul 2012, 21:21

Pulling back on the side stick sounds totally correct to me. Without stall protection any aircraft will stall with the stick way back. The reason for the loss of control is obvious. Why these two couldn't fly an airliner with one failure, AS, which caused the AP to disconnect is beyond me. Experience level is still my guess. Monitoring an autopilot again does not count for quality experience.

deSitter

15th Jul 2012, 22:38

I still don't have an answer to this question - if they are in this very low forward-air-speed, very high nose-up situation, is it easy with the right inputs to bring the nose down in time? How long does it take? That seems very important. You are falling, and the solution is to hold the stick/yoke forward and trim the stabilizer to help and reduce thrust, even if it takes 30 seconds to get a result. That would require a lot of discipline. To do that, you'd have to be damn sure that it was going to work. So would it?

Another thought is - have we found the Achilles heel of the modern wing? The unspoken factor in this crash is the wing design. Does it have this ability to fall like a leaf in honey because otherwise it is so very efficient?

DozyWannabe

15th Jul 2012, 23:11

I still don't have an answer to this question - if they are in this very low forward-air-speed, very high nose-up situation, is it easy with the right inputs to bring the nose down in time? How long does it take?

http://www.pprune.org/tech-log/460625-af-447-thread-no-6-a-85.html#post6793521

The first experiment involved setting the conditions to night IMC with CBs in the vicinity, having set the autoflight to take us to 35,000ft and hold us there. We had a friend of his who is a TRE sitting in the LHS to provide guidance and monitor what we were doing. He then failed the ADCs, leading to autopilot disconnect and a drop to Alternate (without speed stability) and we tried to follow through and maintain a 15 degree pitch angle. Things we noted:

I'd suspected it would involve considerable effort to hold the sidestick there for a significant amount of time, but I was genuinely surprised at just how much.
The zoom climb occurred exactly the way we expected
The Alternate Law (no speed stability) on the A320 seems to have a hard trim limit of 3 degrees nose up
It was definitely possible to hold the aircraft in the stall with 3 degrees of nose-up trim and full back stick, but it required effort
The aircraft wanted to nose down and recover itself, and with about 10 degrees of nose-down maintained with the sidestick at the moment we passed about 30,000ft, we managed to effect a recovery with the speed coming back up to a point where we could level out safely at about 20-25,000ft judging by the standby altimeter.

The second experiment was the same as the first, but as my pal had noted, the A320 has a hard limit of 3 degrees NU trim available via autotrim in the secondary Alternate Law. We tried again, this time winding in full nose-up trim manually just prior to the point of stall. This time:

The aircraft seemed more willing to hold pitch with the trim at full-up, but to hold it at 15 degrees still required considerable effort
We had to add a touch of rudder (on the TRE's advice) to control the roll.
Despite full nose-up trim, we elected to start a recovery as we came down through about 35,000ft this time, just to see if it was possible using sidestick only
Following the same 10 degree nose-down sidestick demand as before, the trim rolled forward with the sidestick demand, returning to around neutral within about 5-8 seconds, and we came out of the stall as before.

Based on this, as far as the A320 is concerned at least, recovery is possible using autotrim via sidestick only even when the trim has been manually wound fully nose-up. Given more time we'd have liked to see what happened attempting recovery at lower altitudes, but the general take-away seems to be that with sufficient forward sidestick demand it is possible to recover from stall even with trim forced to where it's not supposed to be.

jcjeant

16th Jul 2012, 01:32

Hi,

DeSitter
How long does it take? That seems very important. You are falling, and the solution is to hold the stick/yoke forward and trim the stabilizer to help and reduce thrust, even if it takes 30 seconds to get a result. That would require a lot of discipline. To do that, you'd have to be damn sure that it was going to work. So would it?One thing the pilot know (or must know) :
That's keep pulling on the stick will not help for recovery
So why not take the chance to push on the stick .. and pray ..
At least .. better try to recover instead the contrary .. !

RetiredF4

16th Jul 2012, 11:22

@ DozyW concerning your experiment in an A320

It´s about time to rethink the value of the your tests and the result it presented. If it would have been that simple then BEA would have adopted that kind of cheap and easy testflight and would have presented the results out of it.

But as we can see in the following excerpts from the final report BEA has completely missed that possibility (which i doubt) or BEA came to the result, that such a test would be far off from reality. They even could have used an A330 simulator instead an A320 like you did, but again, they didn´t.

So we should accept your A320 test as an experiment with some discussion value in the period before the final report came out, but without reference or firm basis for answering questions, even BEA didn´t dare to.

Let´s focus instead on the report, there is enough potential for discussion and rethinking of former own positions and asumptions in it.

BEA FR 1.16.4.1
The validity of the model is limited to the known flight envelope based on flight tests. Consequently, it was possible to conduct the simulation on the period from 2 h 10 min 00 s to 2 h 10 min 54 s.

BEA FR 1.18.4.2
ˆValidation (proof-of-match) tests compare the behaviour of the simulator with that of the aircraft. A set of technical data (the data package) compiled during flight tests and aircraft certification serve as reference data for this objective comparison. The data only covers the aircraft’s known flight envelope;

In a developed stall situation the aircraft has left its known flight envelope. The data package does not contain any data relevant to this situation. The simulator is not representative of the aircraft in a developed stall situation; it does not reproduce the deterrent buffet effect.

1.18.4.5 Information reported by the manufacturer and the operator:
The information provided by Airbus and Air France managers highlighted the following:

ˆˆThe data currently available in the data packages prevents the simulator’s flight envelope from being extended, since the data in this package is limited to the aircraft’s known flight envelope;
ˆˆSimulators do not indicate to the pilots and instructors that the simulator has been taken outside the envelope validated by the data packages.
Improvements to this situation would appear, however, to be possible;

1.18.4.6 Work currently underway on simulator fidelity and training:
Following the accident to the DHC-8-400 operated by Colgan Air(17) on 12 February 2009, one of the NTSB’s recommendations (A-10-24) was that operators (notably of public transport aircraft) should define and codify minimum simulator model fidelity requirements to support the training of pilots in how to recover from stalls, including stalls that are fully developed. These simulator fidelity requirements should address areas such as angle of attack and sideslip, motion cueing, proof-of-match with post-stall flight test data, and warnings to indicate when the simulator flight envelope has been exceeded.

ˆSimulator fidelity must be improved to avoid the risks of negative training;

2.1.3.5 End of the flight:
At about 2 h 12, descending though FL 315, the aeroplane’s angle of attack was established around an average value of about 40 degrees. Only an extremely purposeful crew with a good comprehension of the situation could have carried out a manoeuvre that would have made it possible to perhaps recover control of the aeroplane. In fact, the crew had almost completely lost control of the situation.

BEA 2.2.5
However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to its point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the sidestick.

€EASA modify the basis of the regulations in order to ensure better fidelity for simulators in reproducing realistic scenarios of abnormal situations; [Recommendation FRAN‑2012‑045]

I´m not saying that recovery would not have been possible at all, but to base such saying on your experiment after BEA report is out and BEA did not perform such a test or did not consider it as valid enough to include it in their report is far fetched.

BobnSpike

16th Jul 2012, 12:04

Aircraft Accident Report - Uncontrolled Flight into Terrain, Airborne Express DC-8, Narrows, Virginia, December 22, 1996 (http://www.ntsb.gov/news/events/1997/narrows_va/index.html)

Turbine D

16th Jul 2012, 12:38

I basically agree with your post concerning SIM discussion concerning AF447 recovery from stall or not. If you refer to my post #219 in the Tech Log, it explains, IMO, why the BEA didn't get into the whether or not recovery was possible. It isn't in their charter to figure that out, as factually, no recognition of a stall was made by the crew of AF447.

Lyman

16th Jul 2012, 12:52

TurbineD

Howdy. Can you clarify? Are you saying that the actual STALL was left off because the pilots hadn't acknowledged it? Seems like odd criteria to drive an investigation. A major disappointment has been the lack of attention given to this area by the BEA. We are left to wonder about this.

My problem with BEA in this area has to do with their lack of substantiation that the STALL WARN was not heard, ignored, or actively disregarded by crew.

Thus far, we are missing the statement: "throughout the recorded conversations and CAM, there was no hint nor evidence that the Stall Warning was acknowledged in any way." Is there? Because when redacting or witholding, some purpose and conclusion needs to be stated, lest the public be left wondering. I wonder about the CVR, of course. It is a mystery.

Lonewolf_50

16th Jul 2012, 13:50

Lyman:
Between this thread and a number of AF 447 threads in Tech Log, there have been posts by credible contributors that indicate that a good estimate <---- of the time it takes to unstall that aircraft (depending on when recovery was begun and how stalled it was) lies somewhere between 10,000 to 15,000 feet. Maybe.

Part of that estimation seems to be based upon "if you hold it in for X long" it takes you longer to recover than if you begin recovery right after stall onset.

What the collective judgment seems to be is that the longer one holds it in (as the crew did) the higher the AoA will become (up to a limiting value?) hence the longer to recover (time it takes to change AoA to "flying" rather than "stalled")
IF AND ONLY IF
the crew discerns that "we are stalled, time to commence recovery"
AND
the crew begin to lower the nose, lower the AoA, and adjust power (???) as appropriate.

BEA seems to me to be in a "damned of you do and damned if you don't" position if they open that can of worms.

The DATA they are working from never shows stall recognition.

Therefore, BEA can't guess how high the AoA MIGHT have been when initiation of recovery was commenced, and they thus cannot speculate on how possible it was to recover.

To toss out a few examples:

Were stall recognition made at 36,000 feet (fairly early into the stall), you'd have one estimate of how long to recover if X nose down was done.

If "we are stalled" recognition is made at 30,000, another estimate

If "we are stalled" recognition is made at 25,000, another.

And so on.

There is also, due to lack of a standard trained response for stall recovery (fleet wide?), unanswerable recovery methods such as
-how much nose down
-what power
-configuration

which can only be derived in hindsight regarding the following:

"Well, how much nose down can you expect the crew to use to unstall?"

All BEA might be able to speculate about is where the point of no return might have been. They have insufficient data (IMO, to include training and wetware issues) to work with to allow them to approach an analytical statement like the following strawman:

"Had they acknowledged stall at 13,500 feet (or some such number) or less, it would not have mattered, since it takes more than that to unstall from X AoA. Had they arrived at the conclusion that "we are stalled" at 14,000 feet, we believe for reasons x, y, and z that the crew would have had a good chance at recovery ... "
NOTE: Numbers for illustrative purposes ONLY. (This for the journos and gadflies who read here ...)

I will repeat, due to my belief on how important this is, that since the initial condition for recovery

"Mon dieu, those crickets were telling the truth, we are stalled!"

was NEVER encountered, the BEA cannot make a valid finding, and can do speculation rather than analysis.

What they can ask the industry to do is figure it out, which the industry might not do.

Getting those kinds of test points isn't just expensive, it can be dangerous to the flight crew, and may or may not be worth the money invested.

Based on what a number of sober and credible professional airline pilots and engineers (I do not include myself in that company) have contributed in these discussions, I suggest to you that chasing that set of data points has less expensive, less risky, and more pilot friendly alternatives.

I believe the BEA came to a similar conclusion.

DozyWannabe

16th Jul 2012, 13:51

@franzl (RF4) and TD:

The test was primarily to determine *systems* behaviour, and does not attempt to answer questions outside of that scope. The question was whether forward stick would be enough to either overcome or counteract the THS position in the time available, for which the answer was affirmative.

In addition, the recovery procedures we attempted were performed in the early phases of the stall - right after to the point where the THS rolled back. We did not hold the stall to the point where the sim behaviour would deviate significantly from the real thing due to the data from the real aircraft never having been gathered in those conditions.

TD - you're absolutely right about the BEA's remit, and that extends also to other factors that some on here complained about (e.g. pinger behaviour and search/recovery post-mortem). The BEA is an aircraft accident investigation bureau, they are not specialists in deep-ocean recovery, nor was stall recovery assessment part of their duties in this case. That getting the nose down, building up speed and returning the wings to flight is the proper stall recovery procedure should be a given. I would only expect them to comment on that aspect if any systems or airframe anomalies had presented themselves during the course of the investigation.

My problem with BEA in this area has to do with their lack of substantiation that the STALL WARN was not heard, ignored, or actively disregarded by crew.

Given that it does not seem to have been acknowledged at any point, either verbally in terms of "we have a stall warning" or physically in terms of definite attempts to fly a stall recovery procedure - I'd say it's a fairly valid inference.

Because when redacting or witholding, some purpose and conclusion needs to be stated, lest the public be left wondering. I wonder about the CVR, of course. It is a mystery.

They have stated more than once that the only redactions from the transcript relate to non-pertinent statements (i.e anything not relating to the conduct of the flight). This was borne out in the unofficial book, which restored these.

If you're trying to infer that they have redacted pertinent content for nefarious purposes, don't be shy - come out, say it and explain your reasoning.

Organfreak

16th Jul 2012, 14:10

There are probably any number of objections to this idea, not least, it would be very expen$ive. What about this?

Procure an old 332. Fit it with robo-remote-controls (pilotless). Fit it with advanced recording/telemetry equipment. Fly the thing out over an ocean, and stall the thing.

That airliners are not tested for actual stall characteristics is emerging as unacceptable, IMHO.

Discuss. (Runs, hides.)

deSitter

16th Jul 2012, 15:48

That's an excellent idea in fact.

Let's assume the worst and it's not possible to recover wings-level from 40 nose up at 60-100 air speed and dropping fast at 25k. Can you apply differential thrust and roll out of it? Wouldn't that in fact bring the nose down by itself?

If this airplane is discovered to have a stall regime in which recovery is difficult or impossible even from a substantial altitude, would that be enough to cause some airworthiness action?

Organfreak

16th Jul 2012, 15:57

Thanks, deSitter,

I think the tentative answer to your first assumption has been, yes, probably, maybe, but not verifiable, it might have been recoverable by standard nose-down/throttle adjustments (see Thread #9) and your second question has already been answered a few times in this thread, as (paraphrased), 'not necessary.'

jcjeant

16th Jul 2012, 16:19

The BEA is an aircraft accident investigation bureau, they are not specialists in deep-ocean recovery,But .. unfortunately .. the BEA was in charge of deep-ocean recovery ..
Why mandate the BEA ? and over all why let him organize and coordinate (the BEA have the last word but are.. from your own words .. no specialist of deep - ocean recovery)
Page 85-86 final report

1.16.1 Underwater search and recovery operations
The BEA was mandated after the end of the search and rescue operations (SAR) with the
organisation and coordination of operations carried out by France for the search and
recovery of the wreckage. Given the distance from the accident and the topography
of the sea bed, this particular mission required the considerable mobilisation of air,
naval and underwater forces and, even more so, of multidisciplinary skills (safety
investigators, scientists, the army, underwater search experts, etc).
The wreckage of the Rio-Paris flight aeroplane was found on 2 April 2011, 22 months
after disappearing. A special document on the four sea search phases and on the
recovery phase will be the subject of a separated publication.

The lack of success during the first three search phases led the BEA to undertake a
complete review of both the means used and the zones explored. Drawing on all the
elements provided by various partners in the searches (scientific institutes, statistical
analysts, oceanographers, etc), and comparing them with the result of the previous
phases, the BEA decided to redirect its search strategy by leading a final systematic
search operation in all the areas not explored during phases 2 and phase 3, beginning
within a circle of 20 NM from the last known position.
The Phase 4 operations took place from 25 March to 9 April 2011. The REMUS 6000
AUVs were used again in the search during this phase. They were operated by WHOI
from the Alucia, property of Deep Ocean Expeditions.
Discovery of the accident site
On 2 April 2011, the data from the 18th AUV mission was recovered, and analysis of
the sonar images brought to light a concentration of backscattered parts on the sea
bed distributed over a rectangular area of about 600 by 200 metres.
A mission to identify the type of components by photographs was immediately
scheduled. This mission ended on 3 April 2011 and the photos taken confirmed that

Turbine D

16th Jul 2012, 16:23

@ Lyman,

Lyman Quote: Howdy. Can you clarify? Are you saying that the actual STALL was left off because the pilots hadn't acknowledged it? Seems like odd criteria to drive an investigation. A major disappointment has been the lack of attention given to this area by the BEA. We are left to wonder about this.

In essence, that is what I am saying. It isn't odd at all. We know and the BEA knows why they stalled, the fact the crew never recognized they were in a stall and never attempted to remove themselves from the stall. Therefore the BEA is not obligated to speculate as to whether recovery from the stall could be achieved or not. In fact, by crew non-recognition, recovery from the stall was not possible as was demonstrated. The reason for not investigating is no data exists for what parameters were entered into in this accident. However the BEA did address this in several sections of their final report as RetiredF4 pointed out. In fact, the BEA addressed this in section 4.3.6 (english version) titled Improving Flight Simulators and Exercises and in their recommendation to EASA FRAN-2012-045. We will see how the EASA responds to this in part or full.

The point is, had the AF447 crew recognized and attempted to recover from the stall they were in, but failed, then the BEA may have been obligated to examine if the aircraft was recoverable or not and provided an answer the question. If this were the case, SIM experiments and characterization of the event at the stall point would have to be developed for the SIM and testing accomplished. But I believe the outcome and conclusion would have been hedged absent actual aircraft testing.

Lyman Quote: Thus far, we are missing the statement: "throughout the recorded conversations and CAM, there was no hint nor evidence that the Stall Warning was acknowledged in any way." Is there? Because when redacting or witholding, some purpose and conclusion needs to be stated, lest the public be left wondering.
From the BEA Final Report, SYNOPSIS, Page 17:
- - The crew not identifying the approach to stall, the lack of immediate on its part and exit from the flight envelope,
- The crew's failure to dianose of the stall situation and, consequently, the lack of any action that would have made recovery possible.
Also,
Page 198 - CONCLUSION - 3.1 - Findings
- Neither of the pilots made any reference to the stall warning or to buffet.

- Neither pilots formally identified the stall situation.
Now don't you think if there were anything in the contrary to the above statements in the CVR, it would have to be stated by the BEA? Hint: Review the worldwide participants the BEA drew into the investigation....

DozyWannabe

16th Jul 2012, 16:25

@jcj:

I'm sure they delegated the actual technical co-ordination of the search to the team contracted to do the work. The BEA's brief probably only extended to "we need to find this wreckage - here's where we think it is".

jcjeant

16th Jul 2012, 16:33

"we need to find this wreckage - here's where we think it is"Yes .. it's indeed the most important ... and this lead to 4 phases of researches ..
When you are "mandated" for "organize" and "coordinate" .. this mean you bear all the responsibilities .. you are the chief of operations
Who mandated the BEA .. when know that they are not specialists in researshes .. ?

DozyWannabe

16th Jul 2012, 16:37

@jcj:

I suggest you do a little background reading into just how difficult deep-ocean search and salvage operations actually are before passing judgement on the BEA.

jcjeant

16th Jul 2012, 16:40

I suggest you do a little background reading into just how difficult deep-ocean search and salvage operations actually are before passing judgement on the BEA. I suggest you review the first phase of research .. just after SAR end
That was a big failure cause not use appropriate material (as used in phase 4)
Who take the decision for not use additional material in phase 1 (more than just pingers detection ... as they know the area was flat so easy to be scrutinized wit material as used in phase 4)
The phase 1 was triggered (location) cause ACARS (who indicated a stall)
Why phase 2 was not a remake of phase 1 with appropriate material ?

DozyWannabe

16th Jul 2012, 16:47

Such issues are mentioned in the report, as well as an admission that they'd learn from their mistakes and do better next time.

Is there a point to this line of discussion?

Lyman

16th Jul 2012, 18:13

I do not know who mandated the search be controlled by BEA, the Court?

Right wrong or indifferent, my guess is someone wanted the custody of the evidence to be tightly controlled, and protected. Something from ACARS motivated the quick retrieval of the avionics bay, and the seats, again, who knows why....

RetiredF4. Hi Franzl. For what it's worth, I would not fall over in a faint if it was demonstrated that parts of the report are "managed". If it is accurate, and I believe it to be so at some future time, I would consider booking a flight on Air France. Til then? Not so much....

DozyWannabe

16th Jul 2012, 18:40

Something from ACARS motivated the quick retrieval of the avionics bay, and the seats, again, who knows why....

Maybe because it would provide answers to questions they'd already wanted answered? Maybe because the avionics bay is one of the things you'd want to look at first on an airliner as technically advanced as the A330?

What's convinced you that they're hiding something - and why? There's no motive for doing so.

Lonewolf_50

16th Jul 2012, 19:34

Dozy, my brother and I talked about this mishap again last week.

Based on my recommendation to him well over a year ago, Air France is not on his approved travel list.

I was modestly gratified to find out that he had discussed this with his manager, who after listening to the argument (informed somewhat by my inputs) agrees with his 'block' order for international travel fare comparisons before choosing a carrier.

Thankfully, there are other airlines who service the same South American cities (to include Rio).

edmundronald

16th Jul 2012, 19:36

They could have stopped looking for the plane, filed it all under "unproven cause" and let the insurers pay out.

The reason why such a huge amount of effort was expended to find the plane was that 50 million french people including politicians and company CEOs fly in those aircraft, and are piloted by guys trained in those procedures, and that it was really felt by everyone involved that an answer however unpleasant was better than no answer.

And in fact there is one thing gained from the report. The certainty that in addition to some updates to airspeed measurement instruments, it will be necessary to update pilot training so that civilian pilots have at least minimal flying skills.

The debate about confusing computer messages, sidesticks etc will probably take a few more accidents to progress usefully, I fear.

Clandestino

16th Jul 2012, 20:27

Who mandated the BEA?

United Nations.

RetiredF4

16th Jul 2012, 20:31

DW @franzl (RF4) and TD:

The test was primarily to determine *systems* behaviour, and does not attempt to answer questions outside of that scope. The question was whether forward stick would be enough to either overcome or counteract the THS position in the time available, for which the answer was affirmative.

There is no evidence at all, that such system behaviour can be evaluated in a simulator outside the designed envelope, therefore your test proves nothing. If BEA would be as certain as you are, they would have made the same test and would have come to the same answer.

In addition, the recovery procedures we attempted were performed in the early phases of the stall - right after to the point where the THS rolled back. We did not hold the stall to the point where the sim behaviour would deviate significantly from the real thing due to the data from the real aircraft never having been gathered in those conditions.

There is no evidence, at what point your simulator would behave different to the actual A320, despite the fact that we are talking about an A330 here. It´s no difference wether we talk about somewhat stalled or sustained stalled, as the simulator has no validated database for either one to do that.

It was an interesting experiment when no other values where available and BEA had its cards still hidden, but now the final report is out and i see no sense in supplementing the report with own non proofed experimental data like they are real hard facts. .
BEA clearly states that the aircraft was not tested outside its normal flight envelope and that no data are available, period. We have to accept that and work from there.

mm43

16th Jul 2012, 21:03

Lyman;I do not know who mandated the search be controlled by BEA, the Court?ICAO Convention Annex 13 provides that mandate to the State of registration for an aircraft lost in International waters. The BEA is the designated responsible entity in French law.

Any Search and Rescue response is that of the State in who's SAR AREA the accident occurred; in this case Brazil. The BEA was able to consult with Maritime experts and put together an initial TPL search for the ULBs without impinging on the Brazilian SAR efforts - be they misplaced or not. But in like vein, the BEA was able to enlist the naval and air resources of the French state to work with the Brazilian Military.

The BEA was always ultimately the legal custodian of any bodies or items recovered during the SAR phase or later. Not having the resources in the initial stages to handle/store recovered bodies, that task was left to the Brazilians. Once the Brazilians declared the SAR operation to be complete, the BEA was left unfettered to proceed at its leisure to instigate its own Search and Recovery plan. One small complication was the criminal investigation proceedings commenced in France, which gave the court the power to place evidence under seal.

Dont Hang Up

17th Jul 2012, 11:42

...the fact the crew never recognized they were in a stall and never attempted to remove themselves from the stall. Therefore the BEA is not obligated to speculate as to whether recovery from the stall could be achieved or not.

Perhaps it depends whether an accident report is there to allocate blame, or to reduce the chances of a recurrence.

I for one would hope the report is there for the latter reason.

Lonewolf_50

17th Jul 2012, 14:37

DontHangUp, I added the {brackets} for ease of reference
... the fact {A}the crew never recognized they were in a stall and {B}never attempted to remove themselves from the stall.
I'll nitpick slightly here and point out that while {A} looks to be true, {B} may not be so clear cut. Point being, if stall was at any point recognized, by either pilot he may not necessarily have said anything. All that they said is not all that they saw, experienced, and decided. It seems well established that the CRM and crew synergy wasn't at its best in this mishap, nor that the pilots were other than task loaded early on. There is also the impression I get of a frustrated PNF calling the captain back, perhaps thinking " I can't work with this guy!" but I am on thin ice with that.

Early on, you get the PNF asking, in re the crickets, "what's that?"

Is that an indication that at least one of crew was concerned with a stall, or approach to one? We can't be sure. Verbalization of that concern is not recorded, or if recorded was redacted. (<--- very unlikely)

Another tidbit shows us that early in the event, the PF set TOGA and the nose up (12-15deg?). He may have been trying to avoid a stall (crickets chirp finally gets through?) by using a low altitude response to stall warning, or he may have been applying a response to low altitude UAS, which procedure is tailored to landing and approach environment.

We don't know what was going through his mind.

I agree that best estimate is {A}, then {B}.

Given some of the actions taken, we are left in some doubt as to what was actually going on in two brain housing groups in the LH and RH seats.

BOAC

17th Jul 2012, 14:44

Lonewolf - I'm having difficulty with the concept of pulling the nose up to 'avoid a stall'??

Turbine D

17th Jul 2012, 16:14

Hi Lonewolf 50,
Quote:
... the fact {A}the crew never recognized they were in a stall and {B}never attempted to remove themselves from the stall.

The above quote actually came from me in a post I made to Lyman. It was my words echoing what the BEA Final Report stated in the Synopsis:
- The crew not identifying the approach to stall, the lack of immediate on its part and exit from the flight envelope,
- The crew's failure to dianose of the stall situation and, consequently, the lack of any action that would have made recovery possible. and, in the CONCLUSIONS - 3.1 - Findings:
Quote:
- Neither of the pilots made any reference to the stall warning or to buffet.

- Neither pilots formally identified the stall situation.
To the best estimates of {A}, then {B}, I would add a {C}. As the BEA stated:
The possibility that the FD is presenting handling instructions that are contrary to expected pilot actions for an approach to stall
The FDs were not turned off as they were supposed to be. You can read the discussions of this on pages 188 & 190, BEA Final Report. Also, you can read the discussion regarding the application of TOGA thrust on pages 180-181, BEA Final Report.

Lyman

18th Jul 2012, 00:57

Lonewolf: "Early on, you get the PNF asking, in re the crickets, "what's that?" "... I don't think so.... I submit that is not a conclusion made by BEA. Though close in chronology, (I think "what's that..." is too close to the sound to allow for PNF's processing it. If he did mean to link it to the SW, I would think it was rhetorical, of course he knew what it was...Don't you also attribute a comment "it is impossible" to Captain on his return to cockpit? I think that is PF, late, after,"we are going to crash..."

TheShadow

18th Jul 2012, 02:09

One of the apparent "unknowns" is whether a deep stall is recoverable once an A330 is embedded in the condition. It was never flight-trialled by Airbus (i.e. neither the possibility nor the high altitude ballistic entry conditions with various trim states and engine powers). There would be many variables including weight, CofG, pitch attitude and pilot control inputs.

One paramount determinant would be the relative airflows once stabilized in a descent at greater than 40 degrees angle of attack. The effectiveness of a tailplane is a function of its lever arm and (even more vitally) the airflows across it. The Lever arm is its distance from the wing's Centre of Pressure (which "moment arm" itself changes at 40 + degrees angle of attack,
particularly with underslung engines at high power). Wind that trimmable horizontal stabilizer into a fully nose-up deflection and its chord-wise airflows are very adversely affected. At 40 degs AoA those chordwise flows would be minimal and so the tailplane's efectiveness would be greatly compromised.

In fact the whole Lift/ weight /thrust /drag relationship becomes significantly distorted for pitch-control, once "stuck" in this aerodynamically distorted flight regime. Elevator and tailplane pitch control authority are no longer a "given" at that excessive angle of attack. The "forward flight" model has now become a "falling leaf" model.... and the wind-tunnel is now an elevator shaft. A feather on a bird works well aerodynamically. A feather falling has no aerodynamic qualities whatsoever.

Something that seems to be lacking in the BEA report is the sensory deprivation of the pilots in respect of what they'd normally expect from a stalled flight condition. Uppermost in that category would be airframe buffet. Because that would be quite absent in a deep stall (there being no bathing of the empennage in turbulent flows from the wings), the resultant eerily smooth flight would induce an atmosphere of "unreality" and nothing conducive to any perceptions (whatsoever) of stalled flight. A similar sensory deprivation occurs in a super-fast lift ascending or descending in the bowels of a skyscraper. The impression of vertical speed is quite lacking once acceleration stops. However, unlike the skyscraper analogy, in AF447 the initial downwards acceleration into the deep-stall was subliminal and undetectable. That was partly due to the inadvertently optimized pitch attitude at entry caused by an inexperienced pilot's unintended or incompetent sidestick input (as well as high power, thin air and a fully deflected THS).

To sum up, as I have said before in Pprune, the pilots were suddenly operating well beyond their experience in a very alien flight regime. It's unsurprising that they ended up non-plussed and quite out of ideas. The cutback-in of the aural stall warning amidst the cacophony of other alerts and alarms only served to confound them further. It was not conducive to any concerted (or even continued) attempts to lower the pitch attitude. In fact, it was a straight-out deterrent to doing so. That was one of the few tangibles that they had to work with, but it was lethally misleading and working 180 against the (otherwise) logical solution.

If you ever wanted to construct a labyrinthine, bizarre and Byzantine conundrum for an unprepared coterie of fat, dumb and happy long-haul cruise pilots, you'd have to go a long way beyond this pitot-ice induced nightmare of countervailing automation.

Lyman

18th Jul 2012, 02:22

That is a very well said piece. I have one question. Since the return of Stall Warn may have seemed to alert to Stall entry why did the pilot Pull Up when it first came in through the "back door"? May be a nit pick relative to your choice of wording, but rather than confused, wasn't his response confusing?

In other words, he may have been confused, but his actions were wrong either way the Stall Warn fired? In a way, it did not matter, whichever way the SW appeared, he acted similarly.

At 60 knots IAS, or at actual Vsw, the horn should mean "reduce incidence"?

Loerie

18th Jul 2012, 02:47

I have been avidly and carefully following this thread since the fateful,terrible loss of AF 447 between Rio and France,with all of her crew and passengers.Shocking.
The posts seem to go on and on ad inifininitum,but one fact is clear----the crew screwed up through lack of training combined with the (slightly) lesser malfunction of the pitot tubes which were unable to cope with the ice incursion.
There seems to be little wrong with the Aircraft---it seems to be a "fly the Aircraft" situation which was not followed in real time.....surely its now time to put this to rest?On and on by armchair scientists.....it was an "accident",which are certainly never intentional!Move on everyone and let the Litigators sort it out money-wise,as sharp as they are....There is nothing wrong,it seems,with AB or Boeing or whoever.Lets put this to sleep.....

Organfreak

18th Jul 2012, 03:14

Loerie:
.....surely its now time to put this to rest?On and on by armchair scientists.....it was an "accident",which are certainly never intentional!Move on everyone and let the Litigators sort it out money-wise,as sharp as they are....There is nothing wrong,it seems,with AB or Boeing or whoever.Lets put this to sleep.....

B-but......then.....what would we do all day???

Here's an idea! let's all chip in and buy Loerie a space bar for his keyboard. :cool:

mm43

18th Jul 2012, 05:45

TheShadow;Wind that trimmable horizontal stabilizer into a fully nose-up deflection and its chord-wise airflows are very adversely affected. At 40 degs AoA those chordwise flows would be minimal and so the tailplane's efectiveness would be greatly compromised.I don't believe the tailplane was as compromised as you posit. AF447 - Thread No.6 (http://www.pprune.org/tech-log/460625-af-447-thread-no-6-a-23.html#post6663753) will provide you with an alternative viewpoint.

TripleBravo

18th Jul 2012, 15:17

The BEA did nothing wrong during that investigation They did. Local police did. Nothing to do with Asseline's lawyers.

Quote:
8. If you think vegatable pilots are bad, imagine vegetable engineers, people who never had any desire to create new things, and are perfectly happy to do little besides playing office politics. Yes – the corporate engineering is full of those...
Not when developing new products in aviation you don't. What makes the difference between the average quality company and aircraft engineering? Holy Spirit? Provocation aside, I been there, done that, got the t-shirt: I can confirm that there *are* "vegetable engineers", including higher ranked positions, including supposed-to-be-decision making individuals. Sorry to bring the illusion of the all-too-perfect aviation back to the level of mortal beings.

Not quite, THS remained at full nose-upYou are correct, I mixed that.

Care to elaborate?The FDR was not in BEA's possession all the time. It was never officially clarified where it had been for a couple of days before BEA begun its investigations. Missing data where some should exist, wrong lead tape in the FDR, etc... Too much to be all accidental, no need to have a hang for conspiracy theories. You could object that it wasn't exactly the fault of BEA for not handing over the FDR to them etc., but then I extend that to the French government who was setting the rules for them, for the police, the federal prosecutor, the manufacturer. It is imperative to avoid any doubt in any such investigation, even the distant possibility of forging must be excluded.

Now we have nearly the same constellation for the AF447 investigation. But as I said, I see absolutely no indication for any irregularities this time.

Accident investigators have only the power of advice. Also their scope is limited to accident at hand.I spoke about known incidents - so *known before* AF447. Why did Airbus extend their internal requirements against the ones from the authorities? Because they knew better and were even more careful than the authorities. EASA obviously never adapted, at least that's my understanding.

Have a go at BEA's report.First: When stating that somebody could handle something this does not imply the statement that others don't - by the laws of logic.
Second: The other crews did not face the same situation, so not 100% comparable anyway.
Third: I referred to the captains abilities as opposed to the ones sitting in the front row during flight AF447, not opposed to other crews.

So: My point was that being a potentially great pilot (knowing intuitively how to get out of the situation once at the controls) does not automatically imply to be a good captain who has to actively regain control. Pilot in command (captain) should be ultimately in command, not just watching / advising. The fact that he still let the controls to the least experienced crew member when it was obviously already screwed up was bad crew management in itself.

My personal conclusion is something like that the PF indeed messed it up. But he was left alone by his captain (give comments is not enough), by his training, by crew structure, by checks, by PNF not insisting more to break his mental deadlock, by SOP (like only AP on if possible, never hand flying even in severe CAVOK), by almost everything.

Lonewolf_50

18th Jul 2012, 21:53

Lonewolf - I'm having difficulty with the concept of pulling the nose up to 'avoid a stall'?
BOAC:
Given that I used to teach stalls and spins in smaller aircraft, I am as well.

What I understand is that, if you are in the low altitude/terminal environment, on approach, and you get a warning of approach to stall, the response isn't typically trained in AB 330 as "lower the nose" but instead (and I think the assumption here is in Normal Law) to set an attitude (nose above horizon) and max power and fly out of it and away from the ground.

With Normal Law, the protections would usually help you not stall in the process. That habit pattern, likely trained, and possibly even the most recent in terms of a sim event, would heavily inform the response of a pilot being surprised by a stall warning. But then, we are not so sure that "stall warning" even penetrated, and as BEA finds, it is not shown that it ever did.

Granted, more of the folks discussing this take the PF's actions as a sort of remedy to UAS ... but did the crew ever really declare and establish that they assessed UAS as their condition? That isn't clear either.

If I misunderstand the general response and actions action taken to avoid a stall when stall warning goes off, my apologies to AB pilots.

bubbers44

18th Jul 2012, 22:16

It is obvious the PF was oblivious to what was going on but the PNF getting the captain back to the cockpit instead of taking over the aircraft puzzles me. Did he not have enough confidence to say " Ive got it". Take over the aircraft and worry about his job on the ground if it didn't follow company procedure?
I understand the left seat can push a button and the right SS will disengage.

Lyman

18th Jul 2012, 22:49

A maneuver the Airbus flight system performs is Escape from CFIT. I do not recall the part, if any, Stall Warn played...

If CFiT is imminent, in Normal Law, The stick can be pulled .back to to the stop, throttles to TOGA, and if a turn is needed, the stick moved to the stop either right or left.

The aircraft will fly on the edge of STALL, at maximum bank, and climb, turn at max allowable as determined by the a/c, not the pilot. It nibbles at STALL, and the a/c Escapes, or not, depending on the proximity of the obstacle.

It is an emergency maneuver, and since PJ2 was involved in the discussion, I take it to be accurate, as I can remember it...

I am assuming Approach to STALL can be taught in similar manner, (or confused with it), but I am unclear what effect the Warning has on the performance, or the LAW. I think this was one of the drills Asseline was going to perform. The a/C cannot suss obstacles, and at the time had issues with sequencing inputs when RA and wow became operant....my assumption is that the a/c, if healthy, can be flown at any AoA short of Stall, and will simply sink if thrust is not increased. Seems like a pretty impressive system...theoretically, I think, had there been no trees, the 320 would have sunk onto the runway, had there been one, or if throttle had been advanced sooner, the aC would have performed as advertised.

Please take this at face value, it is from memory, and may contain errors.

Lonewolf_50

18th Jul 2012, 23:01

CFIT is not the same as a stall, nor is response to stall necessarily related to stall near the ground, though it can be. A colleague of mine died thanks to an OCF condition that was recovered but then ended up not so nice due to an accelerated stall during recovery. :{

I was in no way relating a CFIT escape with an approach to stall response. I suppose that both would be related in that you'd tend to approach the limit of AoA for the condition during both maneuvers, but it would vary with situation.

I have also lost friends to CFIT. Two were on low level nav missions. Each hit something, which was not part of the plan for that mission.

I lost another friend in an A-6 that Stalled low over the ocean when he overcorrected a high closure rate on his lead, low altitude rendezvous. :{ Not CFIT either. Ejection not in time.

Typical CFIT scenario is an unstalled aircraft hitting the ground due to any number of errors that get it there unintentionally. The Escape maneuver you refer to, robot assisting or not, has as its purpose to FLY away from the terrain using the best performance the aircraft can give you.

A stall ends your flying and begins your plummeting.

It may also end up with aircraft meeting terrain, unintentionally, but the C part is no longer in application, as you are no longer in Controlled Flight when stalled. You could call it OCFIT (Out of Control Flight into Terrain) or simply a crash. Dead no matter what you call it, absent an ejection seat.

Thus, if you are WARNED that you are approaching a stall, you FLY your plane at an AoA and attitude and power setting that both
a) avoids a stall (because as soon as you stall you begin to fall, more or less, and are not really flying)
b) gets you away from the ground (which you wish to encounter under more frienly circumstances a bit later on)

Are we clear on the difference? :) I didn't drag CFIT into this, and would like it to stay out. Plenty of post for that over in the thread regarding the Islamabad crash recently.

Turbine D

19th Jul 2012, 01:46

@Lyman,

You are asking questions that are part of training for Airbus pilots as well as how the aircraft (A330) performs and is controlled. Perhaps this Airbus A330/340 Flight Crew Training Manual will help you understand more and answer many of your questions:

http://www.dream-air.ru/new/pilotam/FCTM_ENV_LR-1-.pdf

Lyman

19th Jul 2012, 03:00

Thank you TD, that's very kind of you...

DozyWannabe

19th Jul 2012, 09:51

They did. Local police did. Nothing to do with Asseline's lawyers.

What did they do?

You do know that the "switching /altering flight recorders" accusation was a lie, don't you?

jcjeant

19th Jul 2012, 11:56

What did they do?Nothing ...
But ... the DGAC take the recorders (with no judicial seals) and keep them 1 week :* and this was outlaw
After that .. they were requested by a judge ... :ok:
That's a good point for launch any "conspiracy theory" :)

You do know that the "switching /altering flight recorders" accusation was a lie, don't you?
Myself .. to today .. I don't know ..

DozyWannabe

19th Jul 2012, 12:04

@jcj:

It seems to be a truism that when regulators get themselves involved in accident investigation and resolution, things go wrong (e.g. UK CAA with the BA 747 approach incident, US FAA several times - but notably with the DC-10 'Gentlemen's Agreement' post-Windsor).

The point is that because journalists frequently can't be bothered to learn the difference between the investigatory body and the regulator, on that occasion the BEA were unfairly tarnished.

Re: that incident, the apparent "time discrepancy" that the retired AAIB investigator noted turned out ot be a misreading of the data. The photo sent to the Swiss for analysis proved nothing, as the only person to suggest that the boxes in the photo and the ones from the crashed aircraft should have been one and the same was a journalist. Generally when you've got non-technical people searching for something, you have another example around to show them what it looks like.

jcjeant

19th Jul 2012, 12:08

It seems to be a truism that when regulators get themselves involved in accident investigation and resolution, things go wrong And things can go more wrong when those regulators make illegal actions :)
And things can go wrong when those regulators are not punished in any way for those actions ....

The Ancient Geek

19th Jul 2012, 12:46

Black helicopter, grassy knoll, moon landing was the Mojave, YAWN.
Please take your stupid conspiracy theories to an appropriate forum.
:=

jcjeant

19th Jul 2012, 13:51

Please take your stupid conspiracy theories to an appropriate forum.Not talking of "stupid conspiracy theory" here .. :=
Just talking about the fact (not theory) that DGAC detained (illegally) the recorders (and under no supervision of any) during one week (no judicial seal on ... as required by the law)
Normally the recorders had to be detained by the BEA (the lone official body in France, allowed to make investigations) .. and had to be sealed by judicial supervisor (like in the AF447 case)

Zionstrat2

20th Jul 2012, 17:33

Hello all-
Long time lurker, GA type who has learned so much from this thread and everything else on PPRune- Thanks so much for an excellent forum.

Of course full stalls are never trained in the real world, but I can't imagine why there isn't a requirement for commercial pilots to have regular sim experience? I understand that current sims can't model stalls because no one ever spins and stalls commercial AC in testing, but whey don't they?

In a FBW environment, wouldn't it be easy to wire up a prototype and remotely pilot it beyond the envelope? This should generate data for design and efficiency that didn't exist before and give sims accurate data for stalls and spins?

Test pilots increase the odds of total failure incrementally, so I would imagine that a lot of data could be collected before the airframe is lost and planning on loosing the airframe would be the same as wing bending and pressure testing- You just factor the loss into the total cost of the program.

Perhaps the AC will provide great data in approach to stall and recovery after a spin or two. Maybe great data can be obtained falling off the high and low ends of the coffin corner- It might have the opportunity to be recovered after a high altitude stall, and if it makes it this far, the holy grail would be attempted recovery from a deep stall (assuming the AC can be deep stalled)-

If you get good data from that, maybe a high speed dive until the wings come off, but if I understand modeling correctly, everyone of these data points should allow better sim modeling for unusual attitudes.

Am I missing something? Is the cost of an aircraft the only thing stopping an approach that seems like common sense from the outside?

Much appreciated, and sorry if this was an insane question.

Mr Optimistic

20th Jul 2012, 18:28

The perseverance of the French authorities in the location and examination of the wreckage is to be applauded though I expected nothing less.

jcjeant

20th Jul 2012, 19:18

The perseverance of the French authorities in the location and examination of the wreckage is to be applauded though I expected nothing less. My idea is that the authorities were certainly driven specially by Airbus for further research
In fact ... by analyzing ACARS report and preliminary reports before discovery ... Airbus certainly had the certainty that (exept pitot tubes) .. his plane was not implicated technically
This required that the wreck (and recorders) was discovered at any price that leaves no room for doubt or speculation about the quality of their product

bonernow

21st Jul 2012, 15:08

To quote a paragraph on Page 187:

However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to it's point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the side stick. It appears that this absence of positive static stability could have contributed to the PF not identifying the approach to stall.

If I were a lawyer looking to blame Airbus I believe this would be my "smoking gun" so to speak. However also in the report the paragraph prior states:

When there are no protections left, the aeroplanee no longer possesses positive longitudinal static stability on approach to stall. This absence specifically results in the fact that it is not necessary to make or increase a nose up input to compensate for a loss of speed while maintaining aeroplane attitude. This behaviour, even if it may appear contrary to some provisions in the basic regulations, was judged to be acceptable by the certification authorities by taking into account special conditions and interpretation material. Indeed, the presence of flight envelope protections makes neutral longitudinal stability acceptable.

So the certification authorities have allowed a "relaxation" of certification standards. Airbus themselves designed a flight control system that contributed to this accident.

Again if I were a lawyer, I would love to examine the "special conditions and interpretation material".

The certifying authorities and Airbus still have many questions to answer. This final report has no doubt marked the beginning of some serious legal process

DozyWannabe

21st Jul 2012, 17:26

@bonernow

The stability question is being bounced around quite a lot in the most recent Tech Log thread on the subject. I'd suggest having a peek in there to get a better idea of what those paragraphs state.

The idea that standards were "relax[ed]" is a contentious one - they were simply changed to accommodate changes in technology, as they have been for every iteration of airliner design from the beginning.

While the design removes the traditional signs of feeling approach to stall through the primary flight controls, the other signs (including buffet) can definitely still be felt, and because thet's not enough, there's a very loud aural "STALLSTALL" warning. What the design made obsolete with one aspect was replaced with others - the change in design did not make it harder to recognise approach to stall in real terms.

svhar

22nd Jul 2012, 01:19

- no. I suspect the 'put down' referred to was under another of svhar's usernames.

What other usernames?

Only today you have managed to insult a few posters with your attitude. On various threads. Go play golf or something.

deSitter

22nd Jul 2012, 01:35

DW, it always seems you are making excuses for a bad design. This is a travesty of engineering - an airplane that can't be felt, only interpreted.

Turbine D

22nd Jul 2012, 01:55

@ svhar,

Your quote: What other usernames?

This is a legitimate question. Although you show only 23 posting, you are actually credited with a total of 466. Most coming on JB, "Where in the world?"

Suggest you log on, click on your name on one of your posts and then click on "See more posts by svhar", and see for yourself. Are you the only one or is there another? Who is the real svhar? :confused:

RR_NDB

22nd Jul 2012, 06:14

The report suggests
Diagnosis : the pilots never diagnosed "unreliable air speed". Analysis of the dozen or so similar incidents where pitot tubes froze suggest that most of those crews did not diagnose it either.
Stall warning: did they comprehend it? The report provides references suggesting that in a confusing environment, humans can be cognitively deaf to aural stimuli, and tend to prefer and respond to visual stimuli much better.
(http://www.pprune.org/rumours-news/489790-af-447-report-out-4.html#post7280354)

Technically it is VERY EASY to detect and report IMMEDIATELY and PRECISELY to the crew the UAS. Airbus SAS prefer delegate it to the crew. :} (A paper from Airbus SAS designers, etc. shows that):E

A big part of this was the human-machine interface, which did an extremely poor job of letting the pilots know what was actually going on.

It seems Airbus SAS don't consider important the GIGO concept. The non trained crew were presented with ABSURD data mixed with consistent data.

IMO F-GZCP had a ridiculous design (WRT to Air Speed) AND An ABSURD man machine interface.

So, from a cognitive perspective, the accident makes sense.

This accident was "designed" by Airbus SAS. No redundancy at all (AS probing) and misleading indications presented to crew.

In earlier posts i wrote on AS ridiculous design. After final report i include ABSURD man machine interface. (http://www.pprune.org/tech-log/481350-man-machine-interface-anomalies.html)

Are they entirely, or even primarily to blame? Far from it.

Who can tell the truth? BEA? Airbus SAS? :)

glad rag

22nd Jul 2012, 08:40

DW, it always seems you are making excuses for a bad design. This is a travesty of engineering - an airplane that can't be felt, only interpreted.

Do you pilot at all? And if so what experience of Airbus fbw do you have?

RetiredF4

22nd Jul 2012, 09:02

@glad rag
Let me ask another provocative question:
How much "piloting" is there in "airbus FBW expierience", not to mention on a long range job?

Lyman

22nd Jul 2012, 15:35

Most of us abandoned the concept of aviation as terminally unique ages ago. For the simple reason that those who wished high profit could claim "complexity" to hide their greed and demands for special treatment from regulators and the public.

Airbus and BEA insult all of us who are capable of understanding not only flight, but controls and failures, with this entirely unsatisfactory report.

Concierge? Thus started the patronizing and fallacious nonsense....

BOAC

22nd Jul 2012, 16:17

Turbine - I assume he/she is still going on about it. As I said, I don't see his/her posts. I did exactly what you posted a while back but could find no post where I had put 'svhar down' (oh to be a vet:)). I have a vague memory that some way back he/she claimed exclusive evidence that AF447 had been struck by lightning to which I replied (I think I may have mentioned the 'O' bird, but got away with it), but I assume a mod sensibly deleted the post. Hey ho. Time to move on, I think. Bigger fish to fry.

HazelNuts39

22nd Jul 2012, 18:18

From the FAA Regulatory and Guidance Library (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/Frameset?OpenPage): A Special Condition is a rulemaking action that is specific to an aircraft make and often concerns the use of new technology that the Code of Federal Regulations do not yet address. Special Conditions are an integral part of the Certification Basis and give the manufacturer permission to build the aircraft, engine or propeller with additional capabilities not referred to in the regulations.Special conditions are often a precursor to later general rulemaking proposals. Although originally specific to an airplane make, other manufacturers in a similar situation may elect to use them for their projects.

Interpretative material is published by the regulatory authority to illustrate one or several ways to meet a requirement that have been found acceptable in past certifications, for example FAA Advisory Circulars or EASA ACJ/AMJ material.

jcjeant

24th Jul 2012, 22:32

Breaking Story:
Below is Roger Rapoport's latest response to Air France 447 developments making headlines around the world.
The Rio Paris Crash: Air France 447 (http://www.airfrance447crash.com/index.html)
And:
Pilot briefing 'could have prevented Air France tragedy' - World news, News - Belfasttelegraph.co.uk (http://www.belfasttelegraph.co.uk/news/world-news/pilot-briefing-could-have-prevented-air-france-tragedy-16186379.html)

stepwilk

24th Jul 2012, 22:37

I read the first line of the first paragraph of the first chapter (the introduction, actually) of the book, and it alone is such buehlchit that I went no farther. Totally misinterprets what fly-by-wire means.

jcjeant

24th Jul 2012, 23:16

stepwilk

24th Jul 2012, 23:20

Ya think? As a literary "criticism"--which I actually do for a living, thank you, since you can read my reviews at Air & Space Smithsonian and Aviation History Magazines--it saves me a lot of time.

PJ2

24th Jul 2012, 23:43

jcj;

In the available text, (Introduction), the author seems confused and even misinformed about technical fly-by-wire control solutions, the notion of "automation" and the concept of "protections", (or as gums puts it, "limits").

I think that that is a major fault in a book claiming to present to readers an informed discussion on this accident specifically, and an explanation regarding these very different ideas generally. From the introduction alone, I couldn't take the book seriously as a technical explication.

Whether the author is able to clarify the differences between these three things for his readers in the rest of the book is unclear from what is available.

jcjeant

25th Jul 2012, 01:54

In the available text, (Introduction), the author seems confused and even misinformed about technical fly-by-wire control solutions, the notion of "automation" and the concept of "protections", (or as gums puts it, "limits"). I agree but ....
If you read the article by the author (on the blog) you have to wonder if the purpose of his book is to be an explanation of what the FBW is .. or another subject
Personally I do not believe that his book have aimed to explain what is the FBW .. but rather to highlight deficiencies (from many parties) that would have made the AF447 accident happen

Lonewolf_50

25th Jul 2012, 13:35

A couple of thoughts

Roger is an aviation expert?

Except for the fact that they were flying during daylight, the pilots of the August 2008 Paris-Madagascar Airbus 340 faced identical problems to those that later confronted flight 447 to Paris.
When the captain lost reliable airspeed due to pitot tube icing, he did not set power and pitch according to flight procedures or maintain level flight as prescribed by the Air France emergency procedure checklist.

OK, so both crews had trouble implementing procedures, or recognizing what the malfunction was.

In the midst of heavy turbulence, he immediately descended 4,000 feet, ignoring both the flight director and a brief stall warning.
“Because he could see the horizon he had a major advantage over the Air France pilots who were blindsided in a storm at night,” says a technical expert who has read the investigator’s summary of the previously undisclosed Madagascar flight report.
Sorry, but I find this to be deliberate ignorance.
Professional pilots know how to fly on instruments, using reference to attitude indications displayed on their primary flight instruments.
You can refer to the artificial horizon and fly with reference to it, just as the captain on the other flight flew with reference to the real horizon.

According to an online update to a book on the crash, Air France and Airbus failed to notify pilots about a crisis aboard a Paris to Madagascar flight on August 16, 2008, that bore striking resemblances to the calamities which befell flight AF447 over the south Atlantic nine months later.
The other link has the above.

Sorry, a malfunction is not by definition a crisis.

For people who write for a living, they sure go out of their way to get words and meanings wrong ... if they are selling themselves as aviation experts. :p

PJ2

25th Jul 2012, 14:13

Personally I do not believe that his book have aimed to explain what is the FBW .. but rather to highlight deficiencies (from many parties) that would have made the AF447 accident happen
I read the blog. He writes inaccurately and argues poorly. His is not a work I would go to for any explanations regarding anything aviation. The credibility just isn't there. He's selling, even in his explaining and those who take this stuff seriously know the difference.

Lonewolf_50;

Good examples. The research and the writing is Reader's Digest quality.

rogerg

26th Jul 2012, 18:08

I have read most of the posts with regard to this accident. Many people pontificating about this law or that law etc etc. Does the AB have standby instruments? If so are the crew trained to use these in times of uncertanty.
If not why not?
They have been a big help to me in times past. Maybe the whole accident is down to poor training.

BOAC

26th Jul 2012, 18:10

I think you need to read the whole thread(s), and the report?

jcjeant

26th Jul 2012, 20:01

Airline pilots are trained professionals, and the planes are safe machines.
This is what is pounding in public for years .. as an advertising slogan
Is that this slogan has to undergo some corrections after the accident of AF447?

Lyman

26th Jul 2012, 20:08

Neither statement is a lie. However, not being 'wrong' does not make them adequate...

Lonewolf_50

27th Jul 2012, 15:57

As an adjunct to your post, Lyman, the statistical probability of you or I getting on to a commercial air transport and arriving safely at our chosen destination is in the 99% + range.

That doesn't make 100% a valid expectation, or reality, nor does it make the tragic exception, like AF 447, any easier to swallow.

BOAC: to be fair, rogerg cuts to the meat of the matter, in terms of what one would expect as a standard means to deal with an instrument problem during IFR flight. Yes, it may be a bit reductionist in scope. :cool:

That said, when all of the Airspeed indications are Tangu Uniform, one is forced to use cross check and secondary scan for performance, getting out the checklists, and follow that with a methodical and sound crew response ... gee, we are back to a core point of his, that of training.

A well trained crew does these things.

BOAC

27th Jul 2012, 16:34

BOAC: to be fair, rogerg cuts to the meat of the matter, - no, he/she does not! It is plain the report and thread has not been looked at

1) There was no need for 'Standby Instruments' for attitude.- unless you or Rogerg know differently to the BEA, the primaries were fully functional.

2) There were no 'standby' ASIs fitted

..and as for "Maybe the whole accident is down to poor training.?"

Oozlum time?

Lyman

27th Jul 2012, 21:48

Lonewolf50, BOAC

If the primary displays were reputed fully functional, why are video recorders the new clamor? Displayed information is not recorded? Puzzle...

rogerg

27th Jul 2012, 22:11

the primaries were fully functional.

With all that was going on I would like some basic indications that did not involve the normal systems. Like some "standby instruments" it seems that the AB is lacking.
Flying should not be that complicated.

jcjeant

27th Jul 2012, 22:54

Lonewolf50, BOAC
If the primary displays were reputed fully functional, why are video recorders the new clamor? Displayed information is not recorded? Puzzle... That's a good one ..
Another ..
I read in the TV programs that on PpruneTV was programed the documentary "the whole truth about the crash of AF447" on Tuesday 7:45 p.m.
When I looked PpruneTV at 7:45 p.m. ... I saw an ad for a flying school ... and after .. apologies for the delay for the documentary
Sometimes .. what is written in the book is not what one sees on the screen :)

Lyman

27th Jul 2012, 23:37

What we have is no proof of what pilots were seeing on the panel. I have seen. "What the ECAM would have looked like...." but we do have proof from the CVR: "we have no indications..."

Let's say Bonin survived, bloody but alive, 227 dead, and he is up for manslaughter. Is the jury PPRuNe? Do we ignore his protests of "We had no indications..." in that case, his testimony would have to be allowed, why is the CVR being ignored?

Way back, because the displays are not saved on DFDR, new guidelines are in place to record the PFD.

Other Airbus wide bodies have had incidents of loss of displays with loss of speeds.

Read the CVR with a synthetic bias toward pilots who were flying an upset jet without instrumentation, and see if the story starts to answer more questions....

Why did Dubois not intervene? If the screens were black, everybody's experience is at par; replacing either pilot in a seat would be bad, they were at the start, Dubois had no clue.

With even a minimum of trust in these three guys, one has got to allow for some mitigating evidence that actually is available, but disregarded?

" I have no vario..." " I don't even have vario?"

Further, it explains the lack of comment, with black screens, what's to discuss?

What could Dubois have been after, "Wait, Autopilot ! ....click....."

I've heard the standard reply, what else could he be wanting from auto?

Mod: this is written by a pilot, to pilots, about pilots, and the report; what say you let this one remain?

bubbers44

28th Jul 2012, 03:11

We know that the PF kept pulling back on the SS. He was approaching a stall and forced the aircraft to continue to go into a full stall. Then he continued back pressure for about 39,000 ft to impact. End of story.

Lyman

28th Jul 2012, 03:17

Except the part about THS. Take the THS out of the equation, and the a/c Stalls earlier, with both warnings, due higher a/s at break.

End of chapter

DozyWannabe

28th Jul 2012, 05:20

Like some "standby instruments" it seems that the AB is lacking.

The Airbus does have standby instruments in the form of ISIS - in fact the Captain refers to them on the CVR.

What we have is no proof of what pilots were seeing on the panel.

Actually we have precise proof of what the PNF in the LHS saw on his panel.

I have seen. "What the ECAM would have looked like...." but we do have proof from the CVR: "we have no indications..."

There's a lot of room for interpretation in the latter statement - at no point does the PF or PNF clarify - but the Captain does make a reference to all three ADIs (l'horizon) functioning. This pours a lot of cold water on the idea that all MFDs may have been blank.

Way back, because the displays are not saved on DFDR

The LHS DFDR *is* recorded.

Other Airbus wide bodies have had incidents of loss of displays with loss of speeds.

Not this Airbus widebody.

Why did Dubois not intervene?

This is not the only occasion where a pilot who had a better handle on the situation did not intervene - I'd bet money on it being purely HF.

With even a minimum of trust in these three guys, one has got to allow for some mitigating evidence that actually is available, but disregarded?

" I have no vario..." " I don't even have vario?"

Equally possible that the VSI (vario) was pegged against the bottom and was difficult to read due to vibration.

Further, it explains the lack of comment, with black screens, what's to discuss?

Were it not for the fact that the DFDR does record the displays on the LHS, you might have a point. Instead all I see is another attempt to make excuses.

What could Dubois have been after, "Wait, Autopilot ! ....click....."

I've heard the standard reply, what else could he be wanting from auto?

Given that AP was OFF when he said it, and still off after the button was recorded onto the CVR, I'd say that's a red herring - he was probably just making 100% sure it was OFF.

jcjeant

28th Jul 2012, 13:33

to read due to vibrationFrom the BEA report I understand it was a smooth ride to the sea .... and event the cabin crew and passengers (and pilots ?) were not aware ...
Have vibrations that prevent reading instruments is not what I would call a smooth descent

Linktrained

28th Jul 2012, 15:02

" 10,000 Ft."

Just how was that announced?

In cold print it is not easy to work out whether this was just routine, something one has anticipated... Or was it a surprise?

In my words, it would have been a shock, an impossibility for a 330 to descend so far and so rapidly...

( Although the noise had been a bit unusual for the last few minutes.)

Mr Optimistic

28th Jul 2012, 20:25

JCJ: there were several instances of the cc calling....and going unanswered. The unusual air flow noise and dynamics would surely be causing cc alarm, even if the pax were bemused and anxious rather than panicked. However, in the absence of any comments on the cvr, agree on vibration.

Clandestino

29th Jul 2012, 00:26

The unusual air flow noise and dynamics would surely be causing cc alarmOr wrong CALL button was pressed as CM1 tried to get to captain, so CC picked up the phone and hang it up after receiving no response to hallos. Misdirected calls happen in normal operations, no reason why it shouldn't happen when tension was high.

The Airbus does have standby instruments in the form of ISISCorrect, but seems that rogerg is blissfully unaware that "standby instruments" have very discrete meaning in the aviation world and is actually trying to give it a whole new meaning.

Not this Airbus widebody.Correct, phrase "loss of display" is used by the original poster with astonishing ignorance about what it denotes. Or agenda. Whatever.

Except the part about THS. Take the THS out of the equation, and the a/c Stalls earlier, with both warnings, due higher a/s at break.Untrimmed aeroplane stalls at higher speed... how do you figure?

Read the CVR with a synthetic bias toward pilots who were flying an upset jet without instrumentationWhat upset jet? We're discussing AF447 here.

With even a minimum of trust in these three guys, one has got to allow for some mitigating evidence that actually is available, but disregarded?Looking just for the evidence that confirms the already established notion, eh?

jcjeant

29th Jul 2012, 04:36

Or wrong CALL button was pressed as CM1 tried to get to captain, so CC picked up the phone and hang it up after receiving no response to hallos. Misdirected calls happen in normal operations, no reason why it shouldn't happen when tension was high.That we will never know
This will be one of the many mysteries concerning this accident
Indeed page 60 final Report:

ˆ A first cabin crew or flight rest facility call (high-low chime) was heard at
2 h 10 min 53.5;
ˆ Vibration noises were heard in the cockpit from 2 h 10 min 54 until 2 h 12 min 57;
ˆ Five call signals were transmitted to the crew rest facility between 2 h 11 min 09.8
and 2 h 11 min 27;
ˆ The Captain returned to the cockpit at 2 h 11 min 42.5.

For the first call .. BEA has been written that it is bound for the cabin crew or to flight rest facility
For subsequent calls (5) .. BEA has been written that they are bound for the flight rest facility
How the BEA is not sure of the destination of the first call but certainly the destination of the other calls remains a mystery to me ..
And this is not a transcription error for that is exactly the same words used in the report in French

Lyman

29th Jul 2012, 10:15

There is a serious incident report that refers to cabin comm. disruption following an electrical short circuit in another AB wide body. Perhaps since it occurred in a separate incident makes it less impossible to know in 447?

This is a problem with this report, it leaves possible areas of concern completely unaddressed....

Mr Optimistic

29th Jul 2012, 15:15

Nothing would now surprise me. Perhaps they were blind and couldn't see the attitude and altitude, dumb and couldn't ask the pf what he was doing and remind him they were in alternate, so makes sense they were also deaf to the cc and stall warner......

Clandestino

29th Jul 2012, 15:58

There is a serious incident report that refers to cabin comm. disruption following an electrical short circuit in another AB wide body.Where? At least give us date, registration, company, whatever so we can look it up since you can't be bothered to link to it.

That we will never knowLest we keep on readin your post, which says...

For the first call .. BEA has been written that it is bound for the cabin crew or to flight rest facility
For subsequent calls (5) .. BEA has been written that they are bound for the flight rest facility

There.

How the BEA is not sure of the destination of the first call but certainly the destination of the other calls remains a mystery to me ..They know something about the A330 you don't.

jcjeant

29th Jul 2012, 17:02

They know something about the A330 you don't.
Seem's to me that they don't know more than me about those calls ...
For the first .. they don't know precisely .. for the 5 other they know (or suppose know ?)
Where is the difference between first and the 5 other ?

Lyman

29th Jul 2012, 19:50

"Where? At least give us date, registration, company, whatever so we can look it up since you can't be bothered to link to it."

G-EZAC. Serious incident. EI-EAT 7/1/2002.

This has much in common, but should not be considered as foundational. I cite it because it has commonalities with 447 in re: potable water plumbing ( see ACARS, early), cabin Comms issues, possible loss of ECAM, etc.

Clandestino, a good investigation is thorough, especially so in regards tech issues. I am not terribly impressed with HF, but airframe architecture, plumbing, EE bay, heating, avionics, radios, etc. must be exhaustively researched to find possibilities. In the biz, "nothing happens for the first time..."

I doubt this incident has value for most posters, but it interests me, and there are two more I have reviewed that show some merit in discovering possible mechanical issues. The value they contain is up to you, but believe me, BEA have looked at all the records and logs, and I have some disappointment in that the report is too succinct.

Lyman

29th Jul 2012, 19:54

jcjeant

In the above incident, cabin communications were lost, affected along with NAV loss, ECAM blank, autopilot loss, etc.

Clandestino

29th Jul 2012, 21:56

I doubt this incident has value for most posters

It does for me.

There is a serious incident report that refers to cabin comm. disruption following an electrical short circuit in another AB wide body.

A sister ship to the 330 had an electrical short circuit in flight, and the crew lost half of their ECAM, lost Navigation, had cockpit cabin communication failure, and lost effective control of the stick, along with autopilot.

G-EZAC. Serious incident. EI-EAT 7/1/2002.

Here: 1. report on EI-EAT, A300 freighter (http://hclj.dk/da/luftfart/havarirapporter/havarirapporter+1999+-+2007/kopi+af+motorfly+2005+2/~/media/Files/Havarikommissionen/Havarirapporter/Luftfart%202002/02-02-ei-eat.ashx), 2. report on G-EZAC, Airbus 319. (http://www.aaib.gov.uk/cms_resources.cfm?file=/4-2009_G-EZAC.pdf)

So you are unable to tell the difference between A319 and A330. You are not even aware that 319 is not widebody. You have presented the false notion the stick control was lost as a fact.

I cite it because it has commonalities with 447 in re: potable water plumbingThis is complete fabrication. All the received ACARS messages were consistent with blockade of all three pitots, except cabin rate which was consequence of extreme rate of descent.
Clandestino, a good investigation is thorough, especially so in regards tech issuesIt was a good investigation. All tech issues were covered. No failures except those stemming from blocked pitots were found.

I wonder what kicks does one get from contaminating the discussions?

Seem's to me that they don't know more than me about those calls ...Correct. Seems to you. Investigators do know exactly how the particular aeroplane's comm pane was configured. Did it ever occur to you that phrase " A first cabin crew or flight rest facility call" might actually be lousily translated reference to chime sounding at both areas and not that investigators are uncertain about which area was called on INT.

Lyman

29th Jul 2012, 23:01

How soon we forget.

Clandestino

Quote:
Originally Posted by Lyman
"I cite it because it has commonalities with 447 in re: potable water plumbing"

This is complete fabrication. All the received ACARS messages were consistent with blockade of all three pitots, except cabin rate which was consequence of extreme rate of descent.

Not fabricated, unless ACARS was faked. The aircraft had one lav inop, and also an audio panel inop....The lav issue is similar in that a tee valve leak caused a flooded EEbay, (in the freighter) which destroyed some electrical circuits, causing loss of autopilot, NAV, loss of ECAM, etc. The radio is interesting because both 447 (may have had) and freighter audio issues re: cabin Comms.

Show me the lav location?

I am sure you are incapable of confusion, so you must be impatient, there are two references.

EI-EAT is a wide body, a 300.

Clandestino

29th Jul 2012, 23:10

Not fabricated, unless ACARS was fakedWhoa there... you have your sources contradicting the BEA?
The aircraft had one lav inop, and also an audio panel inop....
Report makes the reference only that RMP3 was MELed. Page 31

Quousque tandem abutere, Lyman, patientia nostra?

EDIT:

EI-EAT is a wide body, a 300. So? Did it have problems with sidesticks? Were there problems with communication to cabin? :E

Lyman

29th Jul 2012, 23:22

Read the report.

jcjeant

29th Jul 2012, 23:31

Did it ever occur to you that phrase " A first cabin crew or flight rest facility call" might actually be lousily translated reference to chime sounding at both areas and not that investigators are uncertain about which area was called on INT. As you know in this kind of report (who is the result of meticulous investigation) each word have his weight .. some more than other I agree ...
If this is in both areas .. you don't use the word OR ( ou in french . .. like in the french report).. instead you will use the word AND ( et in french)
Or = choice (you can't have both)
And = addition (you can have both)
This word "or" (not used for the 5 other calls) still a mystery for me and you explanation don't help ..

RR_NDB

30th Jul 2012, 00:02

This could be as a source of concern in the cabin ? (http://www.pprune.org/rumours-news/489790-af-447-report-out-16.html#post7288766)

Could, but

Very probably tunnel effect could explain this.

Lonewolf_50

30th Jul 2012, 14:04

BOAC:
Let's watch this one on video taped replay.
I have read most of the posts with regard to this accident.
Many people pontificating about this law or that law etc etc.
Does the AB have standby instruments?
If so are the crew trained to use these in times of uncertanty.
If not why not?
They have been a big help to me in times past.
Maybe the whole accident is down to poor training.
I note that this is perhaps a reductionist approach, and wish to clarify a few things in re your response to my response, yours here.
http://www.pprune.org/rumours-news/489790-af-447-report-out-24.html#post7317776

We may be talking past one another.

There is a primary display in front of the First Officer's station (RH Seat) and a Primary Display in front of the Captain's Station (LH Seat).

There is a third array of flight instruments more toward the middle of the cockpit display area, offset to the left slightly (lefft of the E/WD screen) to favor the captain's position.
I note the names of those instruments involving flying here:
ASI and Altimeter(Which sure look like an airspeed indicator and an altimeter, hence Flight Instruments)
STBY Horizon(Sure look like an attitude indicator, or Artificial Horizon)
Nav/Compass/Needles
Clock

I would call these -- perhaps using archaic language -- a standby or back up display. Why?
You don't normally use that, since it isn't right in front of you and most of the time you use the instruments that are right in front of you.
I note from the information I have available that those instruments are differently shaped than the primary displays. (THough they are of a shape familiar to any pilot who was not born and raised on glass cockpit displays).

If that isn't what rogerg was referring to -- in re standby instruments -- then I misunderstand rogerg.

I also pointed out, in my response, that with all three airspeed indications unreliable (our best information is that this was the case initially as a trigger to the entire event), that a flying pilot's scan has to change to check performance by using cross checks. (Trends from VSI, trends from altitude, pitch attitude, power, etcetera). If he looks over at the standby instruments to see if his are the only instruments acting up, he'd either see a confirmation, or not, of what his problem is. Seems he looked a more than one instrument, as the remark had to do with "losing the speeds." But something may have been lost in translation there.

Standard Flying On Instruments. If you want to dispute that, I'd be stunned.

BUt TRAINING is an issue, whether or not we agree on what is or isn't a back up instrument.
It is to my thinking an issue of central importance since passengers are left wondering just how well Air France pilots can be expected to respond to a malfunction. (I hear the voices of the Pitch and Power chorus warming up ...) since an industry standard means of addressing malfunctions as a team in the cockpit, which more pilots are trained to do (or are they?) was not in evidence. (Declare, do immediate action items, get out the check list/ECAMS, go through the procedure step by step ... )

TRAINING issue. Air France appears to need to answer to that. That is where I feel rogerg hit on a core problem, even if that isn't what he/she meant. That doesn't render the other issues neglibible. And it may be that the entire industry, and not just Air France, have some issues to address in re training.

The matter of updating pitot tubes was in progress at Air France.

jcjeant

30th Jul 2012, 14:18

The matter of updating pitot tubes was in progress at Air France. That's exact ... but it was a very delayed updating (not entire fault of Air France) when you know that:
In December 1995, Airbus had made the finding of a lack of certification for the pitot probe
In January 1999 the German BFU had recommended the amendment of the certification standards of the Pitot probes
What were the actions - responses of EASA .. DGAC .. FAA ... BEA .. NTSB .. etc .. ?
Findings had been made .. there was taken into account? much too late or not at all .. and now .. in 2012 .. BEA has made recommendations about Pitot tubes ... (they discover the problem in 2012 .. really ?)
2012 - 1995 = 17 years !

BOAC

30th Jul 2012, 14:19

LW - my main point was There was no need for 'Standby Instruments' for attitude.-. Re The s/by ASI, I should have said
"There were no 'standby' ASIs fitted that were of any use". My mistake.

Lonewolf_50

30th Jul 2012, 14:39

OK. With scan breakdown, a whole host of instruments, unused, can't help a crew.

jc: I understand your point on delay in pitot tube recall.

DozyWannabe

30th Jul 2012, 20:23

jc: I understand your point on delay in pitot tube recall.

In all fairness he's conflating problems during different periods. The problems found by Airbus in 1995 were in Rosemount model pitot tubes, and in 1996 Airbus mandated that these models be replaced with Goodrich models. But the DGAC did not make that mandate a legal requirement until 2001. The BFU's recommendation was likely in response to this issue, as it reported the issues in 1998.

The saga of the Thales pitot tubes was a separate issue which raised its head in the mid-2000s. Thales pitot tubes were always an optional fit, with Goodrich being the default.

Read the report.

Clandestino was pointing out that while the A300 is a widebody, it is of a different generation to the A330 - no FBW, no sidesticks and the systems implementation is totally different.

With all due respect, this is getting very tiresome.

Lonewolf_50

30th Jul 2012, 22:11

Dozy, I appreciate what jc is doing. What I see jc presenting is the kind of argumentation that a lawyer will use on an ignorant jury to get a large settlement.

I expect that AF's defense will be a reasonable one, as their counsel will show that they had begun to replace the Thales probes, and that this hull wasn't one of the ones YET refitted.

How the jury is played will influence how harshly the jury will perceive AF's schedule and intention to comply with the formal directive ...

NeoFit

30th Jul 2012, 23:07

Quote:
Originally Posted by Lyman
Read the report.
Clandestino was pointing out that while the A300 is a widebody, it is of a different generation to the A330 - no FBW, no sidesticks and the systems implementation is totally different.

With all due respect, this is getting very tiresome.
Why?
The problem is not A300 or A332.

The subject was Kapton (R) insulated wires.
Actually, this insulating product is nowaday not used. But since how many time?

Regards

DozyWannabe

30th Jul 2012, 23:15

The subject was Kapton (R) insulated wires.

I didn't see a reference to Kapton in the linked report - are you sure?

I'm aware there was convern over the use of Kapton over a decade ago, but to my mind the only civil incident where it was an issue was Swissair 111. Even then the cause of this was improper installation of the IFE equipment, causing high-voltage electricity to travel where it was never supposed to go. If installed properly, Kapton shouldn't be an issue.

OK465

30th Jul 2012, 23:19

...the kind of argumentation that a lawyer will use on an ignorant jury...

How does one know when a jury is ignorant?

Would one present something different to an intelligent jury?

DozyWannabe

30th Jul 2012, 23:37

Ignorance does not mean lack of intelligence - it refers simply to informedness. Most members of the public are not well-informed in aviation matters.

I like to think I'm not amazingly dumb, but on the subject of - say - the ins-and-outs of accountancy, I am certainly woefully ignorant!

jcjeant

31st Jul 2012, 02:27

Would one present something different to an informed jury, if one knew they were informed?A jury of idiots or very intelligent people does not matter (likely not) in the case of AF447
The judgment of the case is not in a criminal court (court d'assises) so .. it will be no jury
If at the end of the trial .. the judge (s) determines that an individual or individuals are personally directly responsible for the deaths of others ( a premeditated or voluntary murder ) .. he will request immediate arrest and they can be trialed by a criminal court (with idiots and intelligent people in the jury :8 )
IMHO ...

goldfish85

31st Jul 2012, 04:26

I've been following the discussion. When reading the interim reports, I had a great deal of difficulty in understanding what was going on in the pilots' minds. After reading the final report, I would classify the accident as initiated by spatial disorientation and exacerbated by mode confusion. The ultimate factor was a stall with a botched recovery.

This wasn't just an Airbus problem or a sidestick problem. Look at the Northwest B-727 in December 1974. When I read the report on that one, all I could think was "how dumb could he be?" A few months later, I found out just how dumb I could be. The only difference was I flew out of the cloud before losing the airplane.

In all three cases, there were multiple indications caused by a single common cause. The problem is that human pilots are not very good at working back from multiple indications to a common cause. If you had asked all three pilots what the effect would be of iced pitot tubes, I'm sure that they could have told you. I think that given multiple indications, first on A/S, then a second, then autopilot disconnect, then ... and so on, it would be much more difficult.

There have been a number of studies of multiple failures in transports and in light aircraft. Look at Gideon Singer's doctoral dissertation for example. We should all remember that we've had thirty seven months to study the cause. The crew had a couple of minutes.

Clandestino

31st Jul 2012, 12:22

I was pointing out that absolutely no faults were recorded during the flight of AF447 that were not either the consequence of 1. losing the actual total pressure in pitot installation 2. loss of control. Aeroplane was perfectly sound until the moment she hit the water. Oblique hints that AF447 could have been afflicted with loss of control due to electrical failure as there were similar cases, on closer inspection turned out to be complete fabrication put together from details of other completely unrelated incidents.

Now, falsification needs not to be deliberate, as people quite often do misunderstand or misremember some details, but PPRuNe is full of "thank you for correcting me", which is very normal when one is interested in facts. When our esteemed colleague was warned his story was quite fairytalish, his reaction was curt "Read the report" without further explanation why would it be beneficial or reference to what needs to be corrected. Therefore I am unable to give him the benefit of doubt that he invented the story unintentionally and without some purpose incompatible with open and honest discussion.

Lonewolf_50

31st Jul 2012, 12:30

Goldfish85
The ultimate factor was a stall with a botched recovery.

While "mode confusion" may be a sound analysis, I will point out to you that, based on available evidence, there was no attempt at stall recovery, therefore one cannot have been botched. Why do I conclude that? There was, based on available evidence, not recognition of stall from which to recover, even though one was in progress.

There was a botched response to a malfunction, that led to a stall.

After that, I think you can argue that mode confusion was the modus operandi until impact with the ocean. :(

gleaf

31st Jul 2012, 13:30

Smart cows eat the grass and spit out the sticks. I have been grazing the AF447 thread long term, read the reports in detail and many of the references. I am a computer test lab rat not a pilot, This is likely sticks.

There is no human ability to mentally muti-task.
The mind must move from one problem to the next, and if returning
to a previous step in a long problem, must recover the previous point in progress and then advance.

My particular sicky spot is that as the airspeed data returned to a computer valid number the stall warning was activated. And that happend three times if memory serves me.

I start to correct my nose up input. I get stall warning....
and it happens three times.
Has the timing and the sequence convinced me that nose down is an error no matter what else the computer is telling me?

Facing a tremendous display of data and alarms.
We know the plane was not flying. It seems they never grasped that
crucial single element. Their view was 'flying with problems'. What does it take to mentally unlock from 'its flying' to 'its not flying'?

Some years in the future we may see a human factors disection of the FDR and CVR data coupled to pilot grade scan and process the information speeds. (much above average street smarts)
As a member of the computer programmming clan, how was it that 'its not flying' was not made obvious? And for you who sit in the seats, do you now know how to glean 'its not flying' from the data they faced?

Lonewolf_50

31st Jul 2012, 14:33

gleaf, I do not totally agree with your analysis, though I appreciate your thought process since you have to model the behaviors in serial. (Or so it appears).

Tasks and skills unique to instrument flying are suceptible to clumping and grouping, typically in most easily clumped or grouped aggregates of 3 to 5. Once you get over five, you can typically clump or group the greater number in to 2 heirarchies of three, and so on. I'll suggest to you that it is indeed multitasking when you are actually flying. When you are watching the plane fly, maybe not so much.

That disagreement aside, you are on to something in terms of serial prioritization, which we list as the holy triumvirate in aviation:

Aviate
Navigate
Communicate

Inside "aviate" are a lot of sub tasks, some of which you do in parallel when flying, some in series. You can talk and fly at the same time, that need not be done in serial, and you can also navigate and fly at the same time: many of us have done so. The reason we fall back to that holy triumvirate is to make sure that as we encounter changing conditions or changing requirements, we take care of first priority when task loading increases. Malfunctions and emergencies are typically a period of increased task loading. Responses are typically organized around the prioritization logic of the holy triumvirate.

Things get a bit more complex when dealing with change while operating under instrument conditions. (It's easier to do when VFR, since you peripheral senses help you with flying references ...)

As far as multi tasking, breaking down an instrument scan would appear to be a serial exercise, as you alluded to. One typically trains an "in order" priority of condition and task decisions by going from your primary instrument, the attitude gyro/artificial horizon/whatevertheycallitnow and then cross check your various performance parameters: airspeed, altitude, vertical speed (if any), heading, power, ball in, time, fuel, etcetera. The core conditions to consider are pitch, roll, and power, by which your aircraft's performance (flying) is governed.

Ab initio instrument training typically brings you back to the vertical gyro's display between each cross checked instrument, however, there are other effective instrument scans (NASA had a circular scan that better followed muscle movement in the eyeball) that for my money is more effective.

An instrument scan is "a rinse and repeat until conditions or performance changes," repetitive task. You switch to a tailored scan pattern suited to your task should your task be other than flying straight and level:
climbing turn, navigational problem, speed and heading change, configuration change, and so on.

You do this while dealing with all other matters within the aircraft in parallel, and are frequently (particularly when flying as a single pilot) multi tasking: doing several things at once.