Afriqiyah Airbus 330 Crash [Archive] - Page 7

737Jock

20th Mar 2013, 15:22

Lederhosen... The Perpignan was a return to lessor flight. Not a test flight as such. The aircraft was certainly considered ready for line operations.
Anyway it is not something that could not happen on an aircraft in line operations, mistakes are made in engineering.

We haven't even touched the subject of engines spooling up at a different rate during a stall recovery, which could also happen. Not sure how controllable that would be during a stall. Even with features such as approach idle.

The certifying authorities haven't covered every single mishap that may happen. Tails of modern aircraft are optimized to reduce drag as much as possible. They don't leave a lot of control margin outside their design.

That the current training on jets is abysmal is correct, checking the trim during a stall recovery on an airbus because you might just have reverted into direct law. Never heard of it until I read the Perpignan accident report!

But to suggest that there is 1 recipe for every stall situation? The initial action to lower the nose maybe. But from there on... closing the thrust might be step 2 if needed.
I strongly doubt lawyers will have their ass covered as you can see from the airbus QRH.

I imagine the AF pilots have had quite a bit of stall traing since AF447, which is why I could see this as a reason for these guys closing the thrust levers. Not saying that it was correct. Which is the point where blind pew started to declare his superiority in all things aviation.

Frankly I don't care who many books blind pew wrote on aircraft that have been out of service for years. It hardly relates to the issues pilots face in modern jets that they are supposed to fly on automatics, but save with superior handling skills, they never get to practice, when those automatics give up.

blind pew

20th Mar 2013, 19:04

During my 45 years in aviation I have had the dubious pleasure of a lot of changes in philosophy - mostly after an accident or a promotion of a new boy.
With hindsight many of these wonderful ideas were eventually binned and generally replaced by something that other pilots had been doing for aeons.
Good ones included the wind shear at low level, being nice to cabin crew and staying on the runway to evaluate the situation - this was six years before Airtours Man. disaster - flying with a track offset over Africa and listening to ATC.
Not forgetting the old pneumonic FTFAS.....

Bad ones - which I still find difficult to believe are cross feeding using the jettison pumps, splitting the manufactures on ground emergency checklist so that the tank fuel shut offs don't close, braking as late as possible to save pad wear and having a stall procedure to cater for the "I have got this completely wrong because I don't understand the aircraft and I am stupid" which leads to the enevitable question is how do you judge what is a reasonable amount of thrust if you are in unknown territory?
The answer which jock will no doubt pooh pooh is as much as I can and still retain control of the aircraft.
And for jock - how do I find this levels quickly as possible? Open the taps fully and slowly close them if the beast doesnt do what you want it to.
Hopefully you don't fly for one of the LoCo carriers as I use them often.
(and if you are perhaps you was the first officer who had verbal diarrhoea into EGSS last week then did the classic death grip over controlling once the autopilot had been taken out followed by a tent peg landing).
Been there and got the tea shirt :ok:

Clandestino

20th Mar 2013, 21:58

but perhaps the expert clandestino can tell us exactly what happens to the lobes? They get used as diversion device in PPRuNe discussion of the crew that was utterly lost and had very chivalrous attitude towards low vis approaches.

It seems that this crew has been into a wild territory where Airbus has never been before. Whose responsibility is that no Airbus was tested in capturing the glideslope at 2500 ft QFE, two miles from the threshold?!? People have the right to know! :E

That possibility for such an aggressive pitch up at G/S* was probably unknown from Airbus.My back of the fag pack calc shows they were slightly above 10° glide towards gp transmitter when they pitched up so it wasn't mundane 3° path autoflight was chasing. Despite some ideas false glidepaths are spread at even 3° intervals, this is actually true just for some installations and some locations. There is no requirement for false lobe to be set at such-and-such angle and be straight. Calibrators confirm they don't impede on normal ILS operations and that's about it.

I would like to know what would come next if the pilots are in a VERY bad day ... ?Smoking hole. Point is?

No reference unfortunately. So all hearsay really, anybody heard something like this?Nope, but I'll be glad to add it to my collection of Airbus myths.

the Airbus way of flying can lead to the pilot being that much further outside the loop.Not the official one but the one oft found in cockpits surely can.

But due to the aerodynamic build of the aircraft the horizontal tail of the aircraft is actually a bit too small. So that's why 737 sucks in strafing circuit. Well, if it's not useful ground pounder we might need to relegate it to purely transport duties.

The Perpignan was a return to lessor flight. Not a test flight as such. The aircraft was certainly considered ready for line operations.Absolutely not! It was test flight to confirm whether it would be returned to lessor as sound as leased out. That it was severely improvised with stall protection system being tested on base leg was the final link in accident chain.

Lonewolf_50

20th Mar 2013, 22:28

lederhosen:
the Airbus way of flying can lead to the pilot being that much further outside the loop.
clandestino
Not the official one but the one oft found in cockpits surely can.
Isn't that the issue at hand in a number of these incidents?

"that" = pilot - machine interface

CONF iture

20th Mar 2013, 22:31

Smoking hole. Point is?
little pilot guy is best protected when he knows and understands his aeroplane and medium he is traveling through. Failure to do so more often causes his demise than anything else.

737Jock

20th Mar 2013, 23:33

And for jock - how do I find this levels quickly as possible? Open the taps fully and slowly close them if the beast doesnt do what you want it to.
Hopefully you don't fly for one of the LoCo carriers as I use them often.

Did I ask you something? Don't believe I did. Levels? Taps? Can you please teach us oh god of aviation...:ugh:

Take it up with the manufacturers if you are so passionate about stalls. Until that time the authorities, manufacturers and pilot bodies are quite clear on the topic.

Oh and you better stop flying loco... and I'm not an FO either...
In the meantime I will just avoid stalling alltogether. Such a change...

737Jock

21st Mar 2013, 00:03

[QUOTE][Absolutely not! It was test flight to confirm whether it would be returned to lessor as sound as leased out. That it was severely improvised with stall protection system being tested on base leg was the final link in accident chain./QUOTE]

Sure but maintenance considered the aircraft fit for passenger flights. The defects that were present could be present on an aicraft carrying passengers, with a stall leading to a similar result.

It's not a test flight in terms of certifying an aircraft through the authorities.

DozyWannabe

21st Mar 2013, 01:29

...the Airbus way of flying can lead to the pilot being that much further outside the loop.

Could you define what you mean by the "Airbus way of flying"? Airbus's procedures are no more automation-dependent than those of any other manufacturer.

The stall my mate got killed in had many causes - the principal was suppressing previous events, followed by incorrect stall recovery teachings, lack of understanding, general incompetence, fear of the aircraft and bullying.

Among other things. As you said in your book (and no less an authority than the late D.P. Davies refers to in his), there was a feeling among the Trident crews that the stick pusher was prone to false engagement, whereas a proper analysis of the data actually showed that the engagements were worryingly correct!

We haven't even touched the subject of engines spooling up at a different rate during a stall recovery, which could also happen. Not sure how controllable that would be during a stall.

If my reading is correct, it shouldn't be a problem as long as neither of the engines suffers a compressor stall (which was what kicked the Birgenair 757 into a spin).

checking the trim during a stall recovery on an airbus because you might just have reverted into direct law. Never heard of it until I read the Perpignan accident report!

Damn the control laws - that check should be done regardless!

Frankly I don't care who many books blind pew wrote on aircraft that have been out of service for years. It hardly relates to the issues pilots face in modern jets that they are supposed to fly on automatics...

It is often said that those who do not learn from history are doomed to repeat it.

Would it tamp down your ire somewhat to understand that the aircraft he is referring to was probably the most advanced jetliner (in avionics terms) of its day? It was the in-service pioneer of autoland, had the most comprehensive navigation equipment available (almost a decade ahead of what the US were offering) and the airline that was the primary customer used that as an excuse to put inexperienced pilots in the right-hand seat. This was in the early '70s.

Look - this accident seems fairly straightforward in terms of explanation. If people must ride their hobby horses this isn't the one to get involved in.

lederhosen

21st Mar 2013, 08:50

Dozy I see from your profile that you are not a pilot. But from your posts you obviously know a lot about aviation. I am a Boeing pilot, so it could be argued that my hands on experience of Airbus flying is also limited. But I will try and answer your question as best I can. Although your statement that Airbus procedures are no more automation dependent than any other manufacturer suggests you already have pretty firm views.

I know a lot of Airbus pilots and most are extremely positive. What they say is that their aircraft are on a day to day basis very agreeable to fly. However when something abnormal happens they can be more complicated than a Boeing. The sheer amount of information available and the different levels of automation, for example control laws makes them that much more complex. A sim session involves endless reading. On a 737 you can switch off all the automatics and mostly you know what you have. On an Airbus in normal operation manual flight is actually still through the computer with auto trim and with the autothrottle engaged. It does not have to be that way. But it is often so.

The Airbus guys will jump up and down and say that they often fly autothrottle off and practice real raw data flying all the time. The fact is that it seems that there are some long haul guys at least, who have very little opportunity and possibly inclination to practice. If you get one or two landings a month often at five in the morning are you really going to be as current as an Easyjet captain doing ten times as many landings a month?

The man machine interface is the critical issue here. There is no doubt what Airbus intended and there are doubtless countless lives saved we will never know about because of all the safety features that Airbus have built in. However the issue of manual flying currency is one that Airbus is aware of as other threads such as the one about the A350 demonstrate.

So in summary what I mean by way of flying is not just the manufacturer's procedures. Individual companies can significantly further influence what really happens on the line, for example by discouraging autothrottle off flying or manual flight over flight level 100. The end result is a risk of automation dependancy. The Air France captain's desire to reengage the automatics so soon after an unusual attitude recovery could certainly be interpreted that way. The Afriqiyah crew flying a serviceable aeroplane into the ground clearly demonstrates they were not fully in control or as I put it in my earlier post they were outside the loop.

Capn Bloggs

21st Mar 2013, 09:09

Airbus's procedures are no more automation-dependent than those of any other manufacturer.

Codswallop. What don't you understand about:

the automatic trim system, which relieves the pilot of any actions to trim the aeroplane, was no longer available. In the absence of preparation and anticipation of the phenomenon, the habit of having the automatic trim system available made it difficult to return to flying with manual trimming of the aeroplane.
Just when you need it most, the aeroplane behaves totally differently to normal.

Clandestino

21st Mar 2013, 12:57

Isn't that the issue at hand in a number of these incidents?

"that" = pilot - machine interface Yup, but it is oft neglected there are two members in "pilot-machine interface". There are definite limits to dumbing down the machine interface to make it more pilot friendly.

Sure but maintenance considered the aircraft fit for passenger flights. The defects that were present could be present on an aicraft carrying passengers, with a stall leading to a similar result.Absolutely did not! Maintenance cleared the aeroplane for test flight which needed to confirm it is fit for passenger service. Post mortem revealed due to unapproved maintenance practice, it absolutely wasn't. If the flight was better planned and executed, such a conclusion could be made timely, without losing the crew and the aeroplane.

It's not a test flight in terms of certifying an aircraft through the authorities. That is not the only type of the test flights there is in the real life.

Although your statement that Airbus procedures are no more automation dependent than any other manufacturer suggests you already have pretty firm views.I'd say his firm views are at least partly stemming from his ability to positively differentiate flight controls and autoflight. Lack of such facility is otherwise very prominent in PPRuNe Airbus discussions, often making them unintentionally hilarious.

Just when you need it most, the aeroplane behaves totally differently to normal. I'd be hard pressed to find better example of misleading quote out of context. Capn bloggs, would you be kind to provide the context of your quote or would you rather prefer me to do the honours?

Capn Bloggs

21st Mar 2013, 13:56

Capn bloggs, would you be kind to provide the context of your quote or would you rather prefer me to do the honours?
Go for it.

Lonewolf_50

21st Mar 2013, 14:04

In the meantime I will just avoid stalling alltogether. Such a change...
Sir, I wish to subscribe to your newsletter. :cool:

Since the Air Afriqiyah flight in question in this thread does not appear to have stalled on its way to the crash, it's been interesting to watch the thread drift, beginning in about page 74, into discussions of stall, engine influence on stall, trim, trim rates, and pilot response to aircraft inputs from the systems designed to help the pilot fly.

What appears to be going on in the crash this thread was initially covering strikes me as germane to a fairly recent post about Flight Directors. (Handy tools when used, though there is some thought that the man flying the go around wan't using his ... )

The very nature of flight directors require the pilot to concentrate squarely on the FD needles and normal flight instrument scan becomes practically non-existent. It is no wonder pilots instrument scan on the airspeed indicator and other flight instruments are "disorganised" when 99 percent of an airline pilot's flying in his career will be with reference to the flight director. That is dictated by company policy and recommended by the manufacturer.
http://www.pprune.org/tech-log/510755-flight-directors-may-cause-more-problems-than-they-designed-solve.html

A few pages ago, before the great drift, we got an anecdote from someone who knows the fellow who failed this crew on a check ride of some sort. Not sure if the results of that will mesh with the post on FD's but what appears to be evident in this crash is the problem of establishing good instrument scan, good VFR scan, and good "inside outside" scans when in the approach and landing phase.

One of the things I used to teach in our CRM flights in multi crewed aircraft, as part of our CRM baseline, was that of one pilot scanning inside and one outside when on final for an instrument approach. However, you could argue that if you aren't in IMC conditions, that isn't as hard a requrement as when one guy is on the gages and the other is looking for the runway.

This brings us to restricted visibility of other sorts, causing me to ponder the numerous observations in this thread about flying into bright sunrise. If your visual scan is interfered with, and you go from approach to go around, do you do it on the gages or visually, and why? Do you report rates of climb?

Worth discussing in crew rooms as an element of CRM.

Put another way, regardless of how professional or sloppy this crew might have been, was this crash a "there but for the grace of God go I" depending on how well honed your team skills are for the approach/landing phase of your mission?

PJ2

21st Mar 2013, 22:39

PPMFJI, Lonewolf_50 but re your question, "was this crash a "there but for the grace of God go I" depending on how well honed your team skills are for the approach/landing phase of your mission?", while there are CRM aspects to the Afrikiyah accident, I think that once again this is a performance-based accident.

In other words, if at least one pilot was competent at both his instrument scan and handling / flying the airplane as well as knowing both the A330 systems and specifically how to do a non-precision approach in the A330, the accident (assuming that pilot took over control and kept it), would likely not have occurred. CRM is a foundational safety tool and required kit but as we all know, at some point the airplane just has to be flown. Why and how this state of affairs occurred both in the short term and overall, was up to the Report to determine.

BTW, I concur with Clandestino's views on Perpignan.

thermostat

26th Mar 2013, 20:39

I will never understand how some people just don't understand the concept of "Auto Trim". Why not learn about it? I found it to be very helpful when I piloted the A320. Never had a problem with it. Is that because I understood how it worked? I think so. Knowledge is power.

DozyWannabe

26th Mar 2013, 21:44

The sheer amount of information available and the different levels of automation, for example control laws makes them that much more complex.

As others have said, FBW and automation (i.e. FMC/FMS) are totally different animals, and control laws relate only to the FBW implementation. Being aware of this, and being aware of what each of them is and does, is crucial.

FBW is essentially the electronic equivalent of the electro-mechanical linkages between the controls and the flight surfaces on non-FBW aircraft, and like those linkages, is in operation whether the aircraft is flown manually or under automation. Conversely, automation implementations are by-and-large the same whether an aircraft is FBW or not. For example, both Airbus and Boeing buy their modern FMS/FMC systems from Honeywell.

FMS/autopilot systems are by their very nature complex whereas FBW systems are designed to be as simple and transparent as possible in order to keep the risk of error to a minimum. So whenever you hear about a "What's it doing now?" situation, it's almost always in reference to a misunderstanding with the FMS/autopilot.

The only thing one needs to keep in mind regarding the Airbus control laws is that outside of Normal Law the aircraft is no longer subject to the hard protections, and the systems will follow the inputs they are given even if those inputs are dangerous (i.e. you can stall it and put it into a spiral dive as with aircraft without the protections).

Autotrim is a very simple aspect of the Airbus FBW system in technical terms. A good layman's analogy would be an automatic gearbox on a car. Just as with an automatic gearbox, the driver or pilot does not need to manually select the setting appropriate for the conditions, however this does not mean that the driver or pilot should not pay attention to what the device is doing, nor does it mean they should not be prepared to assess the situation and take over manually should it be required. Autotrim is *not* automation in the traditional sense of aviation terminology because it does not in and of itself make and effect flightpath decisions.

jcjeant

26th Mar 2013, 22:41

The little (but important) difference between "moderns" and "old" aircraft is the amount of surface of the elevators and trims movable surfaces
Before the trim surface was small .. now it's big .. it's just the inverse of the "old" system
I see there not really a technical reason .. but a economic reason ..
I can be wrong :)

DozyWannabe

26th Mar 2013, 23:04

What economical reason can you see? A trimmable stabiliser is a much more involved engineering proposition than a trim tab!

To my mind the advantage of a trimmable stabiliser over tabs in a technical sense has to do with command authority - a trimmable flight surface can potentially have a far greater degree of pitch authority in the event of an elevator system failure or jam than a trim tab on the elevator itself. I don't think any airliner has used tabs over surfaces for trim since the days of the B707 and DC-8.

jcjeant

26th Mar 2013, 23:09

What economical reason can you see?
One a aerodynamic way .. which system of the two causes greater drag ?

DozyWannabe

26th Mar 2013, 23:22

You'd have to ask an aerodynamicist to be sure, but I'm confident that the difference would be negligible - to say the very least!

Capn Bloggs

26th Mar 2013, 23:49

To my mind the advantage of a trimmable stabiliser over tabs in a technical sense has to do with command authority - a trimmable flight surface can potentially have a far greater degree of pitch authority in the event of an elevator system failure or jam than a trim tab on the elevator itself. I don't think any airliner has used tabs over surfaces for trim since the days of the B707 and DC-8.
It's got nothing to do with pitch authority. One cannot "fly" an aeroplane, in the normal sense of the word, using the horizontal stabiliser alone. It doesn't react fast enough (unless it's an all-flying stab like a fighter). That's why there is an elevator surface hanging off the back of it, connected to the stick.

You'd have to ask an aerodynamicist to be sure, but I'm confident that the difference would be negligible - to say the very least!
Negligible? How about massive? Good aerodynamics equals good economics, Dozy. When I take off, my stab trim is around 5°. In the cruise it is zero. If I had a fixed stab, the drag would be huge. The compromise, setting a fixed stab at 2.5°, would be crazily draggy in the cruise and would require a massive elevator for takeoff and landing.

DozyWannabe

26th Mar 2013, 23:56

It's got nothing to do with pitch authority. One cannot "fly" an aeroplane, in the normal sense of the word, using the horizontal stabiliser alone. It doesn't react fast enough (unless it's an all-flying stab like a fighter).

Most trimmable horizontal stabs on modern airliners are all-flying, though. In fact the last-ditch control law on the Airbus FBW types is MAN PITCH TRIM ONLY, in which the pitch and rudder trim are the only way (other than differential thrust) to control the aircraft.

I've asked my friendly local aerodynamicist about the drag question - hopefully I'll get an answer shortly. :ok:

Capn Bloggs

27th Mar 2013, 04:26

Most trimmable horizontal stabs on modern airliners are all-flying, though.
No they are not. I did say "in the normal sense of the word". That does not mean pitch-trim-only pitch control. The pilots cannot control the stab as if it were an elevator. My understanding of the "emergency" pitch control on the earlier Airbus is pitch TRIM, not "pull back on stick and nose goes up". In other words, manually spin the pitch trim wheel (just like you'd have to do if it trimmed full nose up and then you stalled/lost normal law). :cool:

PJ2

27th Mar 2013, 07:14

The term "all-flying" refers to a stabilator, like the L1011 design. The entire horizontal stabilizer moves with the control column and also independently trims the aircraft either by manual or autoflight control. AFAIK, the Lockheed was the only transport type with this design.

The term "all-flying" means nothing because horizontal stabilizers have been trimmable since the dawn of the jet age.

Clandestino

27th Mar 2013, 10:56

Codswallop. What don't you understand about:

the automatic trim system, which relieves the pilot of any actions to trim the aeroplane, was no longer available. In the absence of preparation and anticipation of the phenomenon, the habit of having the automatic trim system available made it difficult to return to flying with manual trimming of the aeroplane.

Just when you need it most, the aeroplane behaves totally differently to normal.

This excerpt was taken from BEA's report on fatal accident of A320-232 D-AXLA near Canet-Plage on Nov 27 2008. Aeroplane was on post maintenance test flight, during which it was planned to test high AoA protections. Due to ATC restrictions, test could not be made at high altitude so the crew decided to perform it as they were returning to airport. No calculation of speeds at which protections would become active was performed so as the aeroplane decelarated at 3000 ft, no one noticed that displayed low speed cues on PFD were unrealistically low or that FMGS displayed "CHECK GW" - indication that there is discrepancy between speed , AoA and FMGS inputed weight. Protections did not activate because 2 out of 3 Aoa probes froze and gave constant and false AoA output. They froze because someone pressure washed the aeroplane without using protective covers.

So yes, badly maintained aeroplane behaves totally differently to normal, it's not something every Airbus does and I expect furious denial that such a thing was even remotely suggested. Freezing of AoA probes was something properly conceived and executed flight test should have caught.

Owain Glyndwr

27th Mar 2013, 11:31

Dozy,

Not sure what you mean by friendly local aerodynamicist, but since I qualify on two out of the three I'll stick my oar in :)

You are wrong I'm afraid -well half wrong anyway. Trimming using the whole HS (to a smaller deflection) is going to be more efficient than just using elevators on a fixed HS. That said, there is a side benefit from having a trimmable HS in that it leaves the whole range of elevator deflection available for manoeuvre.

I'm afraid that using trim tabs on the elevators (or other control surfaces) is before even my time :ouch:.
But as I understand it, their use was to trim out the hinge moments associated with the elevator deflection needed to trim the aircraft. This removed any standing trim load on the stick so the aircraft could be flown hands off. The trimmed drag would then be much the same as that from deflected elevators on a fixed HS.

lederhosen

27th Mar 2013, 15:40

I originally raised the similarities between the Air France incident and the Afriqiyah crash: early morning arrival, dangerously bad approach and mishandled go-around on an airbus widebody. I also used the phrase Airbus way of flying.

Dozy asked me what I meant by this and linked it to Airbus procedures, which was not what I was talking about, as I pointed out in my response. Clandestino then picked up on the word automation which he equated to autoflight, which is not correct.

Automation is the technique of making an apparatus, process or system operate automatically (to take a widely available definition). The autotrim system is clearly therefore an example of automation. As has been pointed out in direct law it stops working. So there is a link between control laws and level of automation. Dozy's definition that automation only applies at the level of FMC/FMS is twisting things to back up his view of the world. The fact that Honeywell produce FMCs for both Airbus and Boeing is also hardly evidence that the aircraft are operated the same way.

Pprune discussions regularly split into Airbus versus Boeing camps. People are often quick to rubbish the views of anyone who disagrees. Things that were never said are misattributed and used as evidence that those with different views do not know what they are talking about. I will be astonished if there is any kind of grudging acceptance of this very plain fact.

Nevertheless it is still a valid question as to whether this type of incident or accident occurs more frequently on the Airbus. I am not aware of any crashes for instance on the 777 caused by this kind of thing.

DozyWannabe

27th Mar 2013, 17:29

All - Regarding my mistake in terminology ("all-flying") and drag - thanks for the heads-up!

Automation is the technique of making an apparatus, process or system operate automatically (to take a widely available definition). The autotrim system is clearly therefore an example of automation. As has been pointed out in direct law it stops working. So there is a link between control laws and level of automation. Dozy's definition that automation only applies at the level of FMC/FMS is twisting things to back up his view of the world.

I was actually very careful to qualify my statement, which was "Autotrim is *not* automation in the traditional sense of aviation terminology because it does not in and of itself make and effect flightpath decisions". Put another way, I choose - based on what I've read and been taught - that the distinction between the two is whether one is hand-flying or under autopilot/autothrust control.

In the FBW Airbus types, a hand-flying pilot is still hand-flying if the autotrim is active (which will be the case for almost all line pilots flying the types for the duration of their careers). Sure, autotrim is a form of automation in the fundamental sense of the term, but so is the yaw damper system which has been around for much longer. Yaw dampers have failed, in some cases leading to the loss of aircraft - but I can't think of a case where such an incident was considered an example of encroaching automation dependency.

Clandestino

27th Mar 2013, 20:20

whether this type of incident or accident occurs more frequently on the Airbus.Compared to Boeing FBWs, it does. I know you won't be able to resist this bait.

DozyWannabe

27th Mar 2013, 20:27

With the caveat that there are fewer T7s than A330/A340s even before one takes into account the number of A320 variants, and that Airbus sold their types in more territories with a marginal safety record than Boeing did the T7. This makes comparison of raw hull-loss statistics a misleading metric.

This isn't an A vs. B issue for me - I only engage on more Airbus threads because I know the technology better than I do that of the T7.

lederhosen

27th Mar 2013, 21:12

I cannot disagree with anything in the last two posts. Although the difference in numbers between 777 and A330/340 is not orders of magnitude, around about 1100 versus 1300 delivered.

I like Airbus and what they are trying to do. The irony is that when basic flying skills are most required they seem less in evidence after a while of the Airbus way of flying.

DozyWannabe

27th Mar 2013, 22:12

Honest question - what is your definition of "the Airbus way of flying"?

Judging by the evidence at hand, I'd say that accidents resulting from loss-of-control seem to be very much type-agnostic.

lederhosen

28th Mar 2013, 14:20

I refer you back to to post 1521 where I attempted to convey some of the issues. At the man machine interface level the Airbus is more than just a little different from conventional jets. If you are not convinced by my words let me quote from the Airbus Flight crew operating manual.

Direct law

The sidestick is directly coupled to the controls via the computers, but without any of the stabilization feedbacks. In effect this law turns the aircraft into a conventional aircraft.....

So Airbus themselves are pointing out that their aircraft are different from conventional aircraft and go on to warn pilots about the consequances of missing protections etc.

The aim of the technocrats to deskill flying was clear, paraphrasing one of them, it was to design an aircraft his doorman could fly. However what they also did was create a machine that can be extremely complicated in abnormal situations and where apparently experienced pilots seem to do inexplicable things.

DozyWannabe

28th Mar 2013, 15:00

The aim of the technocrats to deskill flying was clear, paraphrasing one of them, it was to design an aircraft his doorman could fly.

If you believe that, it's because you've only heard one side of the story. There was a pilot engineer group included at every stage of design and development (including, and later headed by D.P. Davies' successor), and nothing passed muster without their approval. The intent was never to deskill flying, it was simply to provide an extra layer of safety using technology that had been used in the space programme and military aircraft for over a decade before the A320 was even proposed.

BZ's infamous "concierge" comment was nothing more than an off-the-cuff remark - his role in terms of leading the project was largely managerial and later sales-related.

However what they also did was create a machine that can be extremely complicated in abnormal situations and where apparently experienced pilots seem to do inexplicable things.

That's true of any aircraft though, no matter the level of technology and/or automation available.

Clandestino

28th Mar 2013, 22:04

I know a lot of Airbus pilots and most are extremely positive. What they say is that their aircraft are on a day to day basis very agreeable to fly. However when something abnormal happens they can be more complicated than a Boeing. So say anonymous friends of anonymous poster. AS these are anonymous forums...

The sheer amount of information available and the different levels of automation, for example control laws makes them that much more complex.Unsubstantiated claim. T7 also has FBW degradation modes; they don't call it alternate and direct law but rather secondary and direct mode. It is simple and straightforward, just like in the Airbus. For pilots, that is.

A sim session involves endless reading.No different from other modern airliners.

On a 737 you can switch off all the automatics and mostly you know what you have. Same as on the bus but then you have to know your aeroplane and for that you need to read and understand FCOM, not just complain "oh, it's sooo complicated!".

It does not have to be that way.Now it's certified that way, it does.

The fact is that it seems that there are some long haul guys at least, who have very little opportunity and possibly inclination to practice.Same as on the other long haul aeroplanes.

If you get one or two landings a month often at five in the morning are you really going to be as current as an Easyjet captain doing ten times as many landings a month?
If you get one or two landings a month, you certainly won't be doing Easyjet's captain job. Since we have no crashes of long haul widebodies on daily basis, point is moot.

There is no doubt what Airbus intended and there are doubtless countless lives saved we will never know about because of all the safety features that Airbus have built in. Those who want and need to know, have the way to find out. Incident reports. Safety bulletins.

However the issue of manual flying currency is one that Airbus is aware of as other threads such as the one about the A350 demonstrate. Same as on the other aeroplanes.

The end result is a risk of automation dependancySame as on the other aeroplanes.

The Air France captain's desire to reengage the automatics so soon after an unusual attitude recovery could certainly be interpreted that way. The Afriqiyah crew flying a serviceable aeroplane into the ground clearly demonstrates they were not fully in control or as I put it in my earlier post they were outside the loop. And we are to believe that since both occurences happened to 330, well then it must be Airbus fault?

Although the difference in numbers between 777 and A330/340 is not orders of magnitude, around about 1100 versus 1300 delivered. That's not complete argument that was made. Let me help you:

there are fewer T7s than A330/A340s even before one takes into account the number of A320 variants, and that Airbus sold their types in more territories with a marginal safety record than Boeing did the T7. This makes comparison of raw hull-loss statistics a misleading metric.

I refer you back to to post 1521 where I attempted to convey some of the issues.Though issues were successfully conveyed, I find them somewhat lacking in plausibility.

Alternate law

The sidestick is directly coupled to the controls via the computers, but without any of the stabilization feedbacks. In effect this law turns the aircraft into a conventional aircraft.....Alternate law is still flightpath stable on any Airbus, it is definitively not direct coupling of stick to controls. This quote is stupendously wrong.

So Airbus themselves are pointing out that their aircraft are different from conventional aircraft and go on to warn pilots about the consequances of missing protections etc.In your post, that is.

The aim of the technocrats to deskill flying was clear, paraphrasing one of them, it was to design an aircraft his doorman could flySales hype contradicting the introduction of every Airbus FCOM but don't let the facts ruin the good libel.

However what they also did was create a machine that can be extremely complicated in abnormal situations and where apparently experienced pilots seem to do inexplicable things. Same as the other passenger transport aeroplanes.

Capn Bloggs

29th Mar 2013, 00:17

Bit of trolling going on here.

lederhosen

29th Mar 2013, 14:12

I agree with you Cpt Bloggs. Clandestino your over the top effort to persuade us that you are right and anyone who has a different opinion is talking rubbish reminds me of the time you attempted to argue in favour of the MD11.

Just to make it clear I am no way anti Airbus. I have merely raised the issue that the combination of long haul, back of the clock flying and the Airbus man machine interface seem to have occured in some notable recent incidents and accidents.

I did however make a typo (which I have corrected) in my previous post, when I wrote Alternate law instead of Direct law. If you are an Airbus pilot you can find the paragraph in FCOM3 Flight Operations, supplementary techniques, flight controls, abnormal control laws, general (with acknowledgement to Airbus).

I am not saying that Airbus overall are any more dangerous than comparable aircraft (unlike the MD11...cue incoming from Clandestino), just hypothesising about some issues obvious in the Afriqiyah accident and elsewhere, which seem to offer further opportunity for improvement. I do not expect everyone to agree, but lets discuss this reasonably.

Turbine D

29th Mar 2013, 22:52

Originally Posted by lederhosen
I agree with you Cpt Bloggs. Clandestino your over the top effort to persuade us that you are right and anyone who has a different opinion is talking rubbish reminds me of the time you attempted to argue in favour of the MD11.

IMO, the problem is some people post personal opinions as if they were absolutely factual information, supported by published data, when in fact, they are often not supportable or factual. It is not a matter of over the top persuasion at all.
Originally Posted by Capn Bloggs
Bit of trolling going on here.
Definition of "trolling": Submit a posting with the intent of inciting an angry response. I would suggest this is not the case at all, it is simply pointing out fact from fiction (opinion) to the original poster who portrayed fiction (opinion) as fact.

DozyWannabe

30th Mar 2013, 16:23

IMO, the problem is some people post personal opinions as if they were absolutely factual information, supported by published data, when in fact, they are often not supportable or factual. It is not a matter of over the top persuasion at all.

Indeed. In fact I'd say that a far bigger issue is elements of both sides of an argument being unwilling to listen to and appreciate the arguments of the other side when it comes to opinion, then becoming so entrenched in defending that position that they hold it tenaciously and willing to give no quarter even when presented with hard evidence.

Definition of "trolling": Submit a posting with the intent of inciting an angry response.

To be more precise in terms of the original definition, it's about inciting as many angry responses as possible, then drawing those who make said responses into an off-topic argument that can continue for pages and pages. It's about attention-seeking, and in fact the term is based on the verb "to troll" (as in fishing terminology) more than it is the noun "troll" (meaning an aggressive, ignorant mythical creature). :ok:

lederhosen

30th Mar 2013, 19:41

Lets just agree to differ. As a current jet captain (who gets to jumpseat on the bus from time to time and has a smattering of experience in workplace design) I believe I have an informed opinion. This is after all a professional pilots rumour network. Most of what is posted is opinion. What the last two gentlemen posted is their opinion (to which they are entitled).

I attempted to answer a question from Dozy in good faith. Clandestino deconstructed it in a way that made me smile. Not all he says is unreasonable. But I think most people would accept that it is a bit over the top.

Boiling it down to essentials, as a professional pilot I consider the man machine interface in the Airbus to be different from conventional aircraft (fact). Airbus say it is so and and frankly it is hardly a blinding insight. I have hypothesized about the role this played in some recent incidents/accidents (opinion).

I would be delighted if we could move on.

Clandestino

31st Mar 2013, 08:15

I believe I have an informed opinionYou might as well be right, but the rest of us will find it easier to believe you if you provide information on which your informed opinion is based. Plausible, if possible.

Most of what is posted is opinion.True. Some substantiated, some not.

as a professional pilot I consider the man machine interface in the Airbus to be different from conventional aircraft (fact)Fact is that you consider it to be so. Fact is the manual mentions difference between Airbus and "conventional" aircraft very seldom and then emphasizes difference is not radical. Fact is the pilot who fly their buses IAW manuals tend to perform successful flights so while it might be issue for unduly biased, so far no articulated and well supported argument that it represents safety issue has been made.

BTW, since my A319/20 FCOM hasn't been updated since NOV 2008, only thing I could find about direct law in it bears only insignificant resemblance to what you posted. It is entirely possible things have changed radically since I departed the bus.

Airbus say it is so and and frankly it is hardly a blinding insight.Quote?

I have hypothesized about the role this played in some recent incidents/accidents (opinion).I appreciate that.