PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Tech Log (https://www.pprune.org/tech-log-15/)
-   -   AF447 final crew conversation - Thread No. 1 (https://www.pprune.org/tech-log/466259-af447-final-crew-conversation-thread-no-1-a.html)

seafuryfan 13th Oct 2011 22:58

AF447 final crew conversation - Thread No. 1
 
'Damn it, we're going to crash, it can't be true!': Terrified final words of pilot on doomed Air France jet | Mail Online

The crew sound pretty confused about how to deal with the situation.

Very sad.

Loose rivets 13th Oct 2011 23:33


France's air accident investigation unit, the BEA, reacted angrily to the publication of the book, with a spokesman saying printing the conversation showed a 'lack of respect to the memory of the crew who died'.
It may be hard for the ones left behind, but transparency is the only course to take in accidents like these. Providing of course, that 'facts' are facts.


There's an valid comment in the thread below the article. The translation would need some latitude in interpretation to have the real feel of what he meant.

TheShadow 14th Oct 2011 00:01

disbelief is the thief of time
 
You really cannot blame the crew.
They experienced (i.e. quietly slipped into) a pitch-up (and thrust-) induced, and very insidious, deep-stall entry at high altitude - a straight unapparent and unremarkable entry into a very high descent rate, featuring a quite misleading and almost normal pitch attitude.
It's a bizarre phenomenon that's unique to the environment and only possible due to automation (especially the auto-trimming of the horizontal stabilizer) – but perhaps also due to the pitch-up effect of applying full power to underslung wing-mounted engines…... an Air France SOP (as with many other airlines).
In the deep stall:

a. the stall warning trigger threshold "cooks off" at a LOWER AoA and remains silent at deep-stall AoA's (i.e. any attempt to stick fwd [and thus lower the nose] triggers a quite deterrent aural stall warning – so any prudent pilot unstalling actions are thwarted).
.
b. All the normal audible and airframe vibrational cues of a stall are absent (i.e. wing-induced turbulence does not impinge upon the tail surfaces) - so the ensuing stalled flight condition is quite uncharacteristically "smooth" (for a stalled state).

c. prior training is irrelevant to the point of being misleading (including the aural exhortations to "Pull UP")

d. time is simply not available to resolve what's happening, particularly against a background cacophony of aural alarms and visual alerts.

e. auto-rotational wing-drop trends are "managed" by the flight control system - so there is no "give the game away" tendency towards spin entry. Once any bank component becomes part of the attitude presentation, a pilot may be inspired to take an Unusual Attitude (i.e. “upset”) recovery action. However in this case the bank remained well within limits and the pitch attitude was around what one would expect. One tends to think of that soubriquet “sucked in” when considering the AF crew’s dilemma once in deep-stall territory, i.e. a propos automation “set-ups” and confidence tricks.

f. pilot sidestick inputs are always hidden from the other pilot and any unseated observer

g. engine thrust increases tend to induce (or sustain) the pitch-up into the high AoA stall attitude (around 40 degrees AoA) and helps "mask" the stall by approximating a level flight attitude.

h. disbelief is the thief of time

It is just one of the "late to the party" Achilles Heels of automation.


THE FINAL MOMENTS
Marc Dubois (captain): 'Get your wings horizontal.'
David Robert (pilot): 'Level your wings.'
Pierre-Cedric Bonin (pilot): 'That's what I'm trying to do... What the... how is it we are going down like this?'
Robert: 'See what you can do with the commands up there, the primaries and so on…Climb climb, climb, climb.'
Bonin: 'But I have been pulling back on the stick all the way for a while.'
Dubois: 'No, no, no, don't climb.'
Robert: 'Ok give me control, give me control.'
Dubois: 'Watch out you are pulling up.'
Robert: 'Am I?'
Bonin: 'Well you should, we are at 4,000.'
As they approach the water, the on-board computer is heard to announce: 'Sink rate. Pull up, pull up, pull up.'
To which Captain Dubois reacts with the words: 'Go on: pull.'
Bonin: 'We're pulling, pulling, pulling, pulling.'
The crew never discuss the possibility that they are about to crash, instead concentrating on trying to right the plane throughout the final four minutes.
Dubois: 'Ten degrees pitch.'
Robert: 'Go back up!…Go back up!…Go back up!… Go back up!'
Bonin: 'But I’ve been going down at maximum level for a while.'
Dubois: 'No, No, No!… Don’t go up !… No, No!'
Bonin: 'Go down, then!' (a poorly expressed exhortation to lower the nose?)
Robert: 'Damn it! We’re going to crash. It can’t be true!'
Bonin: 'But what’s happening?!'

The recording stops.


Read more: 'Damn it, we're going to crash, it can't be true!': Terrified final words of pilot on doomed Air France jet | Mail Online

AlphaZuluRomeo 14th Oct 2011 00:42

Gentlemen, there already is an AF447 thread in the tech log. ;)
Mods, if you merge topics, feel free to erase this as well :ok:

bubbers44 14th Oct 2011 01:13

I know they were new pilots but why couldn't they figure out what was happening to them? pulling back for 3 and a half minutes goes against all of our survival instincts.

Burnswannabe 14th Oct 2011 01:24

Gentlemen, as a former military pilot who has had the benefit of a surfeit of sim instructors who love to play the “he’s doing ok, but how would he cope with this…..” game, I can only stand back and be glad I did not experience these confusing events for real. However, I find it difficult to understand the misidentification of the stall, I can remember trying to setup many a stalling sequence only to have the first indication of the stall being the high rate of descent with no other definite signs other than my own expectation due to control inputs.

I admit I am lucky, I have only flown older aircraft that do not have modern automation, I have not had to sacrifice physical feedback to the demands of efficiency, but perhaps, even given erroneous readouts, the pilots should have had enough overall awareness of there situation that a stall should have been self evident. If the throttles are back and you are losing height then who cares if the system says pull up, it is nose forward and power on time …..

I know that I speak from a legacy viewpoint but the current fear that manual flying skills will atrophy as systems take more of a role appears to be valid. Until recently I would have been of the opinion that that the perseverance of inclusion of human fallibility in the flying system was detrimental to overall safety, now I sit confused; there is now doubt that increased automation has improved safety but the major accidents I can think of recently, in the western world, have been in spite of automation or directly/indirectly caused by it.

Perhaps we need, as an industry and as a fraternity, to invest more in operator input at the design stage. Perhaps all pilots under training should make themselves available for 2 weeks of simulator testing at industry expense, not for the benefits of the pilots but for the benefit of the designers, let them see what an inexperienced pilot will do, not a 20,000 hr test pilot would. It is oh so easy to sit in the sim expecting trouble but it is rare in life to find ourselves outside of the norms. I am not criticising modern training techniques, I am certainly not suggesting we go back to fully manual control systems, rather, I suggest that we all need to spend more time in the sim being surprised as opposed to just knocking out the stats, even if this means more expense. Longer scenarios and more insidious errors combined with long scenarios with sudden error would be useful although I would never suggest a reduction in the current training, this would be as well as not instead of.

Thoughts?

Intruder 14th Oct 2011 02:09


You really cannot blame the crew.
They experienced (i.e. quietly slipped into) a pitch-up (and thrust-) induced, and very insidious, deep-stall entry at high altitude - a straight unapparent and unremarkable entry into a very high descent rate, featuring a quite misleading and almost normal pitch attitude.
Sorry, but that response may be valid for the first 15 seconds, but not the last 3 minutes. The pitch attitude was definitely NOT normal or even "almost normal" with 10+ deg nose up at 30,000'+!

The Airbus software may have contributed to the confusion with the on-again, off-again stall warnings, but an experienced pilot should have recognized the reality within a minute or less by the attitude and [lack of] airspeed.


Another thought just came to me...

What would have happened if the pilots just took their hands off the stick altogether. What would the computer have done? Has anyone tried this in a [lab] simulator?

Lyman 14th Oct 2011 02:11

Confusion came from entering an unknown land, a regime of which there was no knowledge, least of all experience. The accident began when the autopilot stopped. Perhaps some several seconds earlier. The Shadow, as is his wont, has laid it out explicitly.

The only aircraft system that may have had a part to play in the Stall was the THS, and it is completely unknown if the crew could have recovered with the Trim Back at 3. I think they could have, but they should not have climbed at the outset, and that climb is not well understood.

I am sorry this has leaked out, after the apex of the climb, nothing of value is to be captured by reading their last few comments.

If under some circumstances an aircraft can STALL whilst carrying passengers, it needs to be trained, not ignored, at the altar of self serving "mastery" of the craft. We are all buffoons, some more culpable than others, but it is an industry abdication of responsibilty that this happened.

dlcmdrx 14th Oct 2011 04:59

So there was an aurall warning of pull up during the descent??

Locked door 14th Oct 2011 06:47

Of course there was, from the GPWS as they closed in on the sea. Nothing to do with Fly By Wire and probably too low to recover from a stall by then anyway.

BOAC 14th Oct 2011 07:24


Originally Posted by TheShadow
e. autorotational wing-drop trends are "managed" by the flight control system - so there is no "give the game away" tendency towards spin entry.

- I am puzzled by this - do you know that for sure? I cannot believe the software was designed to REVERSE aileron response OR apply rudder in a fully stalled condition? I would have expected the 'managed' response (if there was one) to worsen the wing drop.

Croqueteer 14th Oct 2011 09:00

:confused:n
Now retired and never having flown fly by wire, I still wonder if the mode of operation of the side-stick contributed. With a traditional column if it is back past a certain point the wing is stalled, and it is pretty obvious that the a/c is being held in a stall, ie the stick position gives a idea of attitude.

4468 14th Oct 2011 09:40

These words should never have been made public. What on earth is the point??

Just so ghouls and idiots like amos can pontificate in the luxury of utter ignorance?? In all my years of flying, I have learned that people like amos are EXACTLY the kind of person you never want to be at the controls. Whether you are sitting next to them, or down the back! (He doesn't even know it's possible to stall an A320 in normal law. The type he claims to fly!!:rolleyes:)

Deepest sympathies to all affected.

windytoo 14th Oct 2011 09:44

Burnswannabe, possibly the most erudite and sensible post on this subject. Unfortunately due to cost it will never be implemented. Pax will not pay realistic prices for a ticket and a huge proportion of modern pilots would never reach the required standard to leave the simulator, leading to massive pilot shortages. Even with the current recruiting and training systems too many people with genuine natural flying ability and enthusiasm never get near an aeroplane.

in my last airline 14th Oct 2011 10:12

I believe that self regulation in the Training dept is not the way forward. It's too self serving. Some depts are ineffective due to an old boys club feel where checkers are 'looking after' their buddies regardless of their output. Others are quite happy to accept minimum standards with no wish to spend any extra cash on more education, whilst other depts are simply inept and are run by politicians that were never any good in the right seat never mind the main training management positions. The way forward is for an externally delivered LPC (regulator) every 3 yrs covering all the normal items plus any number of potential items. Let's get back to 'hard, firm and fair' training and checking.

Skipskatta 14th Oct 2011 10:16

Burnswannabe: "If the throttles are back and you are losing height then who cares if the system says pull up, it is nose forward and power on time ….."


Is it that simple?

BOAC 14th Oct 2011 10:31

Indeed - it is a strange quote and could confuse some Flt Sim folk:hmm:

wet vee two 14th Oct 2011 10:38

Ok children, back to the topic with one question for all?
How often have you all practiced unusual attitude/unreliable airspeed scenarios?

Please go on right now and without looking it up, answer to yourself with honesty, at what indications you will have during climb or any flight regime due to a blocked pitot tube, or static port or a combination of both.
How would you recognise it and how would you manage it?The size of a modern flight deck, the eyes have a long distance to travel across all instruments and make the right right diagnosis in such a pressured situation with coupled with the vast data available.

So its easy to sit in your comfy chair and slate the actions of others forgetting that we are all human and often enough react just the same!

(except for amos2 and mates of course 'cause they are super humans)

Recognising one's own deficiencies(or telling the truth) are the most difficult of all demands that face adult humans.

Loose rivets 14th Oct 2011 10:44


Gentlemen, there already is an AF447 thread in the tech log.
Mods, if you merge topics, feel free to erase this as well

I fell this thread started out very well. It's very specific to one aspect and time-band of the accident. There have been two superb posts - some points I didn't agree with, but they had me thinking, which is what it's all about. However, other points really were thought-provoking.

My comment about transparency. It would be ideal to let concerned professionals know those last words, while not allowing them to stab at the sensibilities of families and friends. It really is important we know - those words reveal so much.

I've mentioned this before, but there must have been an absence, or at least a major reduction, of white noise. Ten degrees or more nose up would have had me feeling uneasy, but had been coupled with the kind if silence they must have been in, I would like to think I'd have taken that into account as a major factor. Remember, by now they must have known much of their normal information was suspect, and should have been looking outside the box for other clues. The cockpit noise from way back on the drag-curve, to a good flying speed is chalk and cheese.

BOAC 14th Oct 2011 10:52

The 'new' quoted 'lines' add nothing to the pot over the 4000' quote except to confirm that even the Captain did not appear to recognise a stalled situation which should be another cause for concern in AF.

Loose rivets 14th Oct 2011 10:54

w v t I was being checked by a very experienced Viscount captain, when we suddenly got a crazy airspeed indication. His reaction was to pitch down so hard passengers touched the ceiling. Hard-wired brains can be as dangerous as badly written software.


BOAC. I'm not at all sure about that. Getting into the minds of aircrew is something not really covered by ordinary training and so-called CRM. Trying to feel what they felt, and then understand why they didn't react in the way we'd expect, is a vital part of learning. It may well not alter the facts, but will hopefully aid enlightenment.

Huck 14th Oct 2011 11:16

We do practice erroneous air data indications.

The solution is to manage the triangle of Pitch / Power / Airspeed. Power can be obtained by charts in the QRH. Or you can just set it somewhere in the middle.

But I have found, the best solution to unreliable indications is to use the flight path vector. Just put it on the horizon, set a normal power setting and you're golden. When it is time for the approach just put it 3 degrees below the horizon. No idea why this isn't taught.

BOAC 14th Oct 2011 12:03


Originally Posted by LR
Getting into the minds of aircrew

- there's no need for 'psychology' here - it is plain as the nose on your face that at 4000' the Captain had not absorbed from the clues that they were fully stalled. THAT is the area of concern I am expressing here.

Huck - without trawling through the immense quantity of pages on all the threads, are you sure the FPV was available and visible? No-one should have to rely on a computer generated FPV symbol in order to fly an aircraft with working 3 x attitude indications.

rudderrudderrat 14th Oct 2011 13:26

Hi BOAC,

I cannot believe the software was designed to REVERSE aileron response OR apply rudder in a fully stalled condition? I would have expected the 'managed' response (if there was one) to worsen the wing drop.
You are correct. There is no software control reversal.

Once the wing was stalled, any aileron deflection downwards would have increased drag and yawed the aircraft, causing a roll the wrong way (due sweep). Fortunately the secondary effect of dihedral levelled the wings.

Gums explained it from his experience in Viper days.


are you sure the FPV was available and visible?
When the FPV (Bird) was turned on, the 10,000 ft/min rate of descent probably caused it to be out of view below the visible part of the PFD.

The training philosophy of manual flying on the AB is either with the FDs on or FDs off & Bird on. There is very little exposure to basic raw data flying - because it's expected to have both of those aids available.

I agree with your final comment and I hope it will be a recommendation to practice basic flying skills again (without the use of FD or Bird) - like it used to be in the old days.

punkalouver 14th Oct 2011 15:04

Can someone post the entire transcript please.

oldchina 14th Oct 2011 15:07

Only the BEA has the entire transcript.

punkalouver 14th Oct 2011 15:17

Not anymore it would seem.

Diamond Bob 14th Oct 2011 15:25

What did the other crews do when their pitots were blocked? Supposedly this occurred 32 times on A330s and A340s before AF 447, but I've never seen any accounts as to how this was handled in those situations.

Northbeach 14th Oct 2011 15:42

Wishful thinking.................
 

Can someone post the entire transcript please.
No, not for years-decades maybe. "Entire transcript" maybe never.

The lawyers prevent that, (accident investigation protocol, past practice and "agreements", all the usual important sounding terms, that tell most of the rest of us to get lost) powerful corporations and even nations have a vested interest in the outcome. It doesn't matter whether it is Boeing or Airbus; European Union or the United States.

I have no inside knowledge or opinion regarding AF447. As far as I am concerned Airbus makes a wonderful airplane and AF pilots are among the best in the world.

If one controls the information one can control or greatly influence the decision or opinion held by others. Few entities want the TRUTH, most want a favorable outcome (from their prospective); after all so much is at risk. The TRUTH can be embarrassing, painful, awkward and horrendously expensive. (This is not the position I advocate, just my "take" on how the world of business, commerce, religion and politics works.)

The accident investigation will run its course over time. The professional pilot community will have to learn what we can from it. Is it a perfect system; no far from it. From a transparency and a honest effort to learn perspective, what we have in aviation is probably better than what is available in many other industries .

No; none of us here on PPRuNe are going to get the entire transcript released for our reading, entertainment and pontification benefit.

DozyWannabe 14th Oct 2011 15:52

Read the other thread guys - this is *not* the complete transcript. The BEA transcript contains the flight-relevant conversation on the CVR only. This publication apparently adds some non-relevant words (for the sake of sensationalism) and actually leaves out some of the flight-relevant conversation, the better to push the side of the story being argued.

Come on, this is a Daily Mail article - sensationalism at the expense of accuracy is their stock-in-trade.

ATC Watcher 14th Oct 2011 16:12

Northbeach. While I do not disagree with you on your brillant analysis of the world we live in , there is a new factor coming in : the small black thing everyone now carries in his pocket that can not only take photos , but also record anything discretely and e-mail it to the outside in seconds. That is changing drastically the picture and keeping somethiing confidential today is becoming a serious challenge.

On this perticular topic a few days ago, a book ( in French ) by JP Otelli ( a well known French Aviation author) has released the (almost) AF447 full CVR . I suspect the UK article linked in this thread is based on that book.
The transcript in the book has also the audio warnings added, and that is interesting.

One Outsider 14th Oct 2011 16:20

Once a CVR was a tool for investigators. Now it is a source for entertainment and pandering to rubberneckers.

It stinks.

Mr Optimistic 14th Oct 2011 16:46

Anyone know how this sort of information stands with respect to the Freedom of Information act and its kin ?

jackharr 14th Oct 2011 16:53

I am sure this has been covered before but it’s been a very long thread (threads).

Had the deep stall been recognised at say 30,000 feet, was recovery possible? Or was the situation akin to the BAC 1-11 deep stall crash or the Gloster Javelin fighter when recovery was just not possible from a stall?

Jack

DozyWannabe 14th Oct 2011 17:01


Originally Posted by Burnswannabe (Post 6749877)
If the throttles are back and you are losing height then who cares if the system says pull up, it is nose forward and power on time …..

With the important caveat that in jets with a podded and wing-mounted engine design, increasing thrust will cause a pitch-up that must be monitored and corrected if necessary.


I know that I speak from a legacy viewpoint but the current fear that manual flying skills will atrophy as systems take more of a role appears to be valid.
What bothers me is that this was not the intent of the designers, but something that has been assumed by airline management over the last 20 years.


Perhaps we need, as an industry and as a fraternity, to invest more in operator input at the design stage. Perhaps all pilots under training should make themselves available for 2 weeks of simulator testing at industry expense, not for the benefits of the pilots but for the benefit of the designers, let them see what an inexperienced pilot will do, not a 20,000 hr test pilot would.
Both Airbus and Boeing did just that when they developed their more recent ranges - contrary to what appears to be received wisdom, the A320 was not developed in a vacuum with management and engineers making all the decisions. The problem here is that the PF in this case appears to have done something that would be anathema to any pilot that had undergone stall training, which was to pull up and hold the stick back both prior and during the stall warning.

@jackharr - No one is willing to state it definitively, but the consensus on the threads seems to be that all the crew had to do at 30,000 feet was push the stick forward and recovery was in all likelihood possible.

Mr Optimistic 14th Oct 2011 17:08

Jack, yes it has been on the other thread. Helluva job finding it though. Opinions differed, some , I think, optimistic to 10k feet. Others doubtful through 30.

Clandestino 14th Oct 2011 19:32

Is mr. Otelli's latest book available in hardcover? :hmm:

Ashling 14th Oct 2011 19:58

Remember they were in alternate law so roll was in "Direct Law" therefore no aircraft induced correction of wing drop.

The crew failed to recover the aircraft because they failed to diagnose why they were out of control. They died not knowing what had gone wrong. To me its surreal that they could not recognise the stall but it would seem that the situation was beyond their training, experience and competence. How could they be allowed to be in command of a commercial jet in that environment when they didn't possess the skills required to cope when it all went wrong?

Automation has allowed corners to be cut in pilot experience, training and supervision. The more sophisticated the automation the more streamlined the training becomes. The crew may well be found culpable but they were products of a system and it is that system that is at fault every bit as much if not more than the crew.

Lonewolf_50 14th Oct 2011 20:20


Robert: 'Damn it! We’re going to crash. It can’t be true!'
Bonin: 'But what’s happening?!'
If those are indeed the last two things spoken in the cockpit, Bonin's frustrated question needs to be trace back to its root cause. Until that is done, thoroughly, this crash teaches the industry nothing.
(Besides the already known axiom that pitch and power results in performance ... which the industry would hopefully already know.)

DC-ATE 14th Oct 2011 20:33


jackharr-
Had the deep stall been recognised at say 30,000 feet, was recovery possible?
Don't know about this particular type of aircraft, but recovery from a deep stall is possible [from 10000 feet above ground] in a 737-200. Been there, done that !! No problem.


All times are GMT. The time now is 22:14.


Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.