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AF 447 Thread No. 9

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AF 447 Thread No. 9

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Old 24th Jul 2012, 11:24
  #681 (permalink)  
 
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TTex600:

You want to know why the aircraft failed to pass along information that it's logic knew? I'll say this, then duck for incoming from certain persons who take years to design something that I the pilot have seconds to deal with.
Thanks.

The aircraft doesn't tell everything because there would be liability in doing so.
I was expecting this, but as liability goes, it is very volatile matter. Incredible to think that better diagnosis by the plane would get the manufacturers even in deeper trouble.

Every part of this Godforsaken industry hides behind the pilot. No matter what, the pilot is legally responsible, which leads to manufacturers making statements to the effect that pilots are expected to follow procedure and understand situation before they act.
What I have read, I cannot but agree.
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Old 24th Jul 2012, 11:28
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1// It was not only one pitot, it were all 3 and not at the same value and duration. If it had been only 1 this one was isolated and that would have been clear to both A/C as pilots.
You are right. My mistake after remembering the page 96 of the final report.

2// Due to the difference in both values as in duration the automation could not set the ADR disagree message in the initial phase.
Agreed. But in 40 seconds period it could have, generating a better diagnostics. As the final report says on page 176: "the ECAM displays no information that is likely to point to a speed indication problem". But the AP disconnected exactly because of this.." .. "It should be noted that the reconfiguration to alternate law occurred because of the triggering of specific monitoring that is designed to react to events like icing of several Pitot probes, However, no explicit indication that could allow a rapid and accurate disgnosis was presented to the crew".
The plane knew something it did not "bother" to say.

3// The messages are not cryptic (at least NOT to airbii insiders) they are brief and if any crew action is required it will be displayed in a cyan color and idented to distinct it from the message itself.
I am sure they are quite familiar to AB pilots. Still I think that the briefness of the messages can add to the congnitive stress situations more than ease it. Many times acronyms can speed up reading, but under stress it can be deteriorating.

"Between 2 h 10 min 18 and 2 h 10 min 25, the PNF read out the ECAM messages in a disorganized manner"

Surely there could be a better way to get the messages out and understood.


f.i. there was no ECAM action to select RH PFD to ADR 3, with this action they extended the duration of unreliable airspeed indication on his display.
Maybe a step to identify the problem by exclusion. They had the info at that point, at 2.11.06.


Still I cannot help to think that there was something, in the displays, indicators or anywhere that made quite experienced pilots to start moving the plane before understanding the situation.
And even when it seems they started to get the understanding, they did not apply anymore.

Thanks!
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Old 24th Jul 2012, 16:27
  #683 (permalink)  
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Still I think that the briefness of the messages can add to the congnitive stress situations more than ease it. Many times acronyms can speed up reading, but under stress it can be deteriorating.

"Between 2 h 10 min 18 and 2 h 10 min 25, the PNF read out the ECAM messages in a disorganized manner"

Surely there could be a better way to get the messages out and understood.
Under stress perceptions do change but that's what training, training, training, (and continuous study and learning as part of one's profession) is for. Such responses cannot be eliminated but they can be reduced by familiarity.

The QANTAS A380 event shows how complex the ECAM can be but that system is extremely well designed and works providing it is followed to completion.

The "better way" is in how the response was made right from the start of the event. The SOPs do not change significantly from type to type. The trained crew response to an emergency or an abnormality is, with minor variations throughout the industry, very clear and very specific:

- Take control of the aircraft, (usually the PF) and ensure stable flight and navigation;
- Communicate: PF announces the emergency/abnormality so the other crew member, (PM), is aware and shifts thinking and priorites to the emergency/abnormality, (where applicable, PF takes radio communications responsibilities);
- PF calls for the "ECAM Actions" first, then the QRH checklist where applicable;
- PM executes/completes ECAM actions, clearing messages as they are completed;
- When finished, PM calls "ECAM Actions Complete" and calls up the Status Page for aircraft and system condition review;
- When aircraft/system Status is reviewed, PF calls for any applicable QRH checklists. For example, sometimes landing data requires modification;
- Secure the aircraft for continued flight or diversion;
- Communicate with ATC, F/A's (through their leader) and company dispatch;
- Passenger announcement, if required;
- Monitor changes in aircraft performance, fuel situation etc, as required.

The popular notion of "startle effect" has some place in this discussion because responses are always going to be influenced by the immediacy of an event. However, these trained responses are absolutely standard and what recurrent simulator sessions are all about and are intended in part to reduce the effects of surprise.

You might google "CRM" as that is the way cockpit communications are conducted when an emergency/abnormality occurs, ensuring a) all crew members are aware of the problem, b) everyone is prepared for what's next and c) awareness is followed by a plan of action and resolution of the problem. The process is about "what, not who", so anyone who senses/sees a problem speaks up and the matter must be resolved to everyone's satisfaction. It isn't a democracy, it is a way of communicating information so that everyone is aware. The captain always has the final word.
Still I cannot help to think that there was something, in the displays, indicators or anywhere that made quite experienced pilots to start moving the plane before understanding the situation.
The barometric altitude reduced slightly and it has been theorized that this was a reason for the immediate, strong pull-up by the PF.

While that may be an explanation for the instant pull on the stick, it does not explain the continued pitch-up and climb in which SOPs and cockpit discipline were entirely absent. As I have said many times, even given the pull to stop what may have been perceived as a descent, the airplane settled down quickly and if the PF had done nothing but maintained pitch and power while calling for ECAM Actions while ensuring stable flight, (and 10 to 12deg pitch is NOT stable flight at cruise altitudes!), we wouldnt' be discussing an accident here.
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Old 24th Jul 2012, 18:14
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Suspension of Disbelief

For Zeroninesevenone:

Tex's response makes sense to me, but I'd like to restate something that has been a point of discussion over the past three years: The aircraft senses AoA, but does not display it on the instrument panel. IIRC, it takes six or seven key strokes (based on what I've been told, I've never done this in an A330, so I don't know) to get to the page that displays AoA.

Would an AoA gage, or an AoA reading imbedded in a corner of the display have given the crew a better sense of what they were looking at, what their wing was doing, or make the stall warning alarm more compelling to them?

We don't know. Based on what is available to analyze, the scan breakdown (possibly due to training? Possibly due to over reliance on the bird? Possibly due to few reps in sims? We don't know) was a critical part of the upset, and a CRM breakdown contributed no small amount.

We don't know what we don't know,

I understand why some do not think an AoA gage is needed, in the idea of a pound of prevention being worth a pound of cure.

You typically take steps to NOT fly near the edge of stall, as a matter of policy, good airmanship, and for the sake of your passengers.

That doesn't change the fact that the aircraft has AoA probes, you fly the wing, and if you don't know what your aircraft is doing you can make a fundemantal mistake.

AoA is a critical metric that tells you whether or not you are flying, or falling.

I conrfess, I learned to fly on small aircraft with no AoA gage.

Varga 2150a Kachina Aircraft history performance and specifications

I also knew well enough not to stall, but that little plane had a very easy to recognize buffet. Also, where I flew that little plane, icing up the pitot tubes wasn't an issue: I didn't fly in bad weather.

I later taught flying in the Navy in a trainer that had AoA gage. My cockpit awareness, once I learned how to use it, increased significantly.

What I had to do versus what professional pilots, who fly pax each day, have to do differs considerably. I realize the arguments against, but the data is already being fed into the cockpit.

How about making it available? Yes, 99.99 percent of the time, you don't need it. Upon that 0.01% occurrence, it might help save your chili.
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Old 24th Jul 2012, 19:15
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My friend John flew the A320 for ten years before he flew the T7. He loved the Bus, and he was in Normal Law his entire ten years, the aircraft did not even hiccup, not once. I asked him about 447, he allowed that he felt for the crew, saying they got in over their head, and weren't able to find their way out.

Now John is a premier pilot, respected by all, and I listen to him. I asked what he thought his chances would be had he been flying the Sister, 330, that fateful night. He said: "Bill, not good. We get complacent, skills deteriorate, and I could not say I would do better. I like to think I would, but there was a great deal going on for those guys."

I venture to say that training is important, even paramount, but there are other things that work against success when confronted with the dicey realities of life.

Staying cool under pressure comes to mind, and having the ability to clear one's mind in the face of real danger is critical. As the possibility of danger retreats into the land of near impossibility, there, there be dragons.

Since teaching flying has deteriorated into the state it is in, and standards are almost non existent re skill, why not start looking for the psychologically prepared candidate first and foremost? The other boxes have been checked.....

Courage? Grace, under pressure.

Last edited by Lyman; 24th Jul 2012 at 19:18.
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Old 24th Jul 2012, 20:27
  #686 (permalink)  
 
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Between 2 h 10 min 18 and 2 h 10 min 25, the PNF read out the ECAM messages in a disorganized manner
That is a critical statement from the BEA, but somehow they have decided that what the PNF conveyed by speech to the PF in respect of the ECAM messages had no bearing on the conduct of the flight. That could be right, but in the circumstances, how those messages were conveyed is important in trying to understand their reception by the PF.

The "eagles" will be circling over that omission.
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Old 24th Jul 2012, 20:55
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I think the report alludes to the less than optimum task load for the PNF, to the point of being difficult and frustrating to function as a dedicated, ECAM actions deciphering PNF, when you're trying to get your buddy to push the nose down.
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Old 24th Jul 2012, 21:25
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So you suspect that the disorganized relay of the ECAM messages was due to the PNF's other preoccupation - keeping an eye on the PF. Strikes me that it may have been useful to know just what was said and when, and if the PF ever acknowledged any of it.

Last edited by mm43; 24th Jul 2012 at 21:27.
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Old 24th Jul 2012, 21:48
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It's like the FD thing, educated conjecture on the surface, but certainly ringing true in the context of what goes on in crewed aircraft when the PNF's confidence level is impacted.

When I flew as an instructor during type rating training in the aircraft, it was also my job to provide all the necessary support to the trainee that he could expect to receive from a dedicated, disciplined first officer.

As the instructor, however, I was a terrible co-pilot when I could see a potential compromise of aircraft control.
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Old 24th Jul 2012, 21:50
  #690 (permalink)  
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So you suspect that the disorganized relay of the ECAM messages was due to the PNF's other preoccupation - keeping an eye on the PF.
Yes, that certainly makes sense to me. The PNF was left without leadership but knew something had to be done regarding the ECAM and so tried to do his job but the PF had already launched on his own course of action which left the PNF in a position of not knowing how the PF was receiving the communication. The effort would be halting and interrupted by what the PF was doing with the airplane, leaving the PNF in the lurch about how, where and when to pick up the ECAM discipline and get the operation on the proper track. He had about 40 seconds to do so before the more serious problems occurred and there was no turning back after that point in terms of SOPs.

The appropriate intervention by the PNF in the face of such non-standard actions on the part of the PF would be to hold his own Takeover Priority button down longer than 30 to 40 seconds, (forgotten exactly how long) which locks out the right sidestick in order to fly the airplane uninterrupted and maintain stable flight. Surely some sense of how unstable the airplane was going to get must have entered the PNF's mind.

The PNF then becomes the PF so he could recover the airplane. Once things had calmed down he and the captain could settle the disagreement, but he likely didn't know where it was going until it was too late.
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Old 24th Jul 2012, 23:22
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OK465, PJ2;

Thanks to both of you for your feedback.
Surely some sense of how unstable the airplane was going to get must have entered the PNF's mind.
Demonstrated by the PNF's desire to get the Captain back, and yet apparently too timid to be assertive and take control.

The BEA's HF group must have reviewed the missing part of the CVR we are discussing and considered the relevance of the exchange, or lack of, and could draw nothing of significance from it. I am left wondering if others would.

No doubt it will be "picked over" further down the track.
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Old 25th Jul 2012, 03:43
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No doubt the questionable CRM is critical to this accident. Then there's a FBW system that could be improved, but that comes later in the post.

I was struck by the "brief" briefing when the aircraft commander left for a break. I heard no clear assignment of who was really in charge and who was simply flying at the time. Could be an AF standard procedure and such, I don't know. But I would prefer to have the duties and such clearly briefed.

I also heard/read on the CVR transcript the PNF say something to the effect that he had three indications of a climb and advise the PF to stop climbing. Did I get that wrong?

As most here know, I am disappointed in the lack of AoA inputs to the system when airspeed is unreliable. I shall not debate the issue of an AoA display any longer if the rank and file of the transport pilots here can't handle it or don't want it or don't think it would have helped.

OTOH, a FBW system advertising all the "protections" should certainly rank AoA very high. Airspeed inputs play a large role on the "gains" ( control surface deflections to achieve the commanded Nz or roll rate), but body rates are there by default and help a lot.

If the system designers do not use AoA sensor inputs ( cones or vanes) once speed is deemed unreliable, then why not use the obvious AoA available from the inertial system and attitude reference ( derived from inertial or a separate gyro)?

Subtract inertial flight path vector from pitch attitude and you get AoA - voila!. Then use that for stall warning, but mainly to provide the "protections" the drivers are expecting. Of all the "protections", the two that seem to be paramount are total Nz and AoA. The others in the myriad of laws/ reversions seem nice, but not as critical to basic aircraft control.

From the crew reactions, including the aircraft commander's, I cannot help but think they thot that the AoA "protections" were still in effect. "You can't stall this airplane".

that's all I'll say for now, and may comment about corporate mentality and such later.
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Old 25th Jul 2012, 04:13
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Surely some sense of how unstable the airplane was going to get must have entered the PNF's mind.

Demonstrated by the PNF's desire to get the Captain back, and yet apparently too timid to be assertive and take control.

The BEA's HF group must have reviewed the missing part of the CVR we are discussing and considered the relevance of the exchange, or lack of, and could draw nothing of significance from it. I am left wondering if others would.

No doubt it will be "picked over" further down the track.



This is very hard to understand. He knew the PF was out of control but elected to call the captain back instead of assuming control. When the captain got back to the cockpit it was too late.
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Old 25th Jul 2012, 04:58
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Originally Posted by bubbers
This is very hard to understand. He knew the PF was out of control but elected to call the captain back instead of assuming control. When the captain got back to the cockpit it was too late.
IMO, PM (Robert) was still suffering some effects of sleep inertia and he knew it. He just didn't trust himself. He had been awakened only a few minutes before. If he had been fully alert, it might well have been different.
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Old 25th Jul 2012, 05:44
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Displaying Alpha

Displaying alpha is only truly useful when the applicable limits are also displayed. Stall alpha at altitude is much less than at sea level, best seen by observing the slow march of the "feet" (low and high speed buffet boundaries) towards each other as you climb.

The MD 11 (and the B717) displayed a useful alpha indication by virtue of the permanent display of PLIs (pitch limit indicators) on the PFD. At all times during flight, the pilots had a clear indication of how much alpha was available - I say alpha rather than pitch, because the PLIs tended to 'float away' from the pitch attitude at low level more so than at high level. That came about for two reasons: first, the difference in the alpha envelope and, second, reflecting the difference in dynamic predictions and steady state alpha with altitude.

I can no longer remember whether there were circumstances such that the PLIs may have been inaccurate, although clearly it is possible. Certainly it would be affected by the altitude (static) input, but I don't think it was influenced by the speed (pitot) input.

But to use it, you had to look at the PFD and see the attitude - something that unfortunately seems to have disappeared from the skill set of our younger pilots, to be replaced by "magenta fixation" - whether it is the FD or the track display!
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Old 25th Jul 2012, 06:00
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I was struck by the "brief" briefing when the aircraft commander left for a break. I heard no clear assignment of who was really in charge and who was simply flying at the time. Could be an AF standard procedure and such, I don't know. But I would prefer to have the duties and such clearly briefed.
Thanks Gums. I had wondered about that before. A 40 second handover (between PNF entering and Captain leaving) seemed extraordinarily brief. Especially in view of weather and recent discussion about max altitude.

I am also curious about this extract from the CVR
0 h 58 min 07
Captain Try maybe to sleep twenty minutes when he comes back or before if you want

PF Yeah ok that’s kind, for the moment I don’t feel like it but if I do feel like it yeah
Is Dubois really saying he was happy for PF to have a doze while Dubois was having his rest period? Surely I am misunderstanding this.
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Old 25th Jul 2012, 06:03
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IMO, PM (Robert) was still suffering some effects of sleep inertia and he knew it. He just didn't trust himself. He had been awakened only a few minutes before. If he had been fully alert, it might well have been different.
He had left the deck just 10 or so minutes earlier. Barely time to lie down. Let alone get into the deeper stages of sleep associated with sleep inertia.
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Old 25th Jul 2012, 07:20
  #698 (permalink)  
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slats - you are confusing PM with the Captain?

While 'sleep inertia' (ie 'waking up') is a known event, I would wager that adrenalin would be a great stimulant.
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Old 25th Jul 2012, 07:35
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Sorry BOAC. You are right.

Robert claimed he had not really slept well (his words were "so so"), and so was unlikely to be suffering sleep inertia.Even if he had been, he should have been coming good 15 minutes later.

The Captain had only been absent for 10 or so minutes, and so sleep inertia was unlikely the explanation for his actions when he returned.
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Old 25th Jul 2012, 09:35
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bubbers44;
This is very hard to understand. He knew the PF was out of control but elected to call the captain back instead of assuming control. When the captain got back to the cockpit it was too late.
Poor CRM? I don't doubt for a moment. The real question is why a relatively simple loss of air data lead to such a monumental "cock up".

Is the "startle factor" excuse a cop out for poor training endemic throughout the airline, or is this event a "one out of the box" horror story? The average soul could be forgiven for believing it is the latter.

Strange as it may seem, I have a suspicion that the same event could have happened in a similar fashion to more than 10% of rostered crews, but the odds have luckily worked against it happening.

The industry deserves better than a lottery style "chance" draw.

Last edited by mm43; 25th Jul 2012 at 09:36.
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