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AF447 final crew conversation - Thread No. 1

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AF447 final crew conversation - Thread No. 1

Old 8th Feb 2012, 19:15
  #1261 (permalink)  
 
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J.O.... I don't have an aunt Sally so I'm not sure what you mean.
Just think of it as a 'dig' along the lines that "maybe the solution reached was logically flawed".

Comes from a maths mnemonic "Please Excuse My Dear Aunt Sally"; Parentheses, Exponents, Multiplication, Division, Addition (and) Subtraction.

Put another way, it could be said that those who remember it have been around too long!
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Old 8th Feb 2012, 20:40
  #1262 (permalink)  
 
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at easy we are practicing what we think happened in our simulator check. Having had it explained on the white board, demo'd in slow time, knowing what was about to happen, I have to say that it is the most confusing set of indications I have ever seen.

How many of us Airbus pilots realised that the STALL STALL STALL silenced below 60kts? (and why would we).

I understand the theory of what happened now, but there is no way I could of comprehended it happening in real time the way it did to the poor souls on 447.

The understanding is coming out, but of course a lot is best guess.
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Old 9th Feb 2012, 01:09
  #1263 (permalink)  
 
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Who would think any pilots could find a way to put an Airbus below 60 knots airborn? I don't think any aircraft is idiot proof.
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Old 9th Feb 2012, 01:22
  #1264 (permalink)  
 
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Originally Posted by Lord Bracken
Secondly, Sully's A320 remained in Normal Law (powered by the APU and RAT) throughout the ditching, with all flight control protections active until splashdown.
Great piloting yes, but he had some help.
Nothing indicates the RAT was deployed during the flight, either automatically or manually, and had no reason to be.

Do you think that experienced pilot needed help to not stall ?
Remaining in Normal Law prevented that experienced pilot to manage the flare at his convenience.

But maybe better to go there A320 and the Miracle on the Hudson to discuss further.
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Old 9th Feb 2012, 02:01
  #1265 (permalink)  
 
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The RAT doesn't deploy unless you lose both engine generators in all aircraft I have flown and the APU would not have been on for that short flight because they could bleed air off the engines. I didn't bother to respond because I knew most people knew.

Also the autopilot being worthless meant how could it have had anything to do with the outcome of the Hudson landing. He was a highly skilled pilot and the autopilot did nothing to help him. He didn't need stall protection with his skill landing in the Hudson. None of us in any Boeing would have stalled so why did it help him? It didn't. Why do Airbus pilots always think the only way to fly is by automation? I don't understand it. Now I read an article about letting automation rotate the airplanes to prevent tail strikes. Have you ever had a tail strike? 23,000 hrs and zero.
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Old 9th Feb 2012, 02:59
  #1266 (permalink)  
 
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The RAT doesn't deploy unless you lose both engine generators in all aircraft I have flown and the APU would not have been on for that short flight because they could bleed air off the engines. I didn't bother to respond because I knew most people knew.
You obviously "don't know" because the NTSB report very clearly states that the APU was started soon after the bird strike. Section 2.3, [Analysis of] Flight Crew Performance, 2.3.1 Decision to Use Engine Dual Failure Checklist:

Although the flight crew was only able to complete about one-third of the Engine Dual Failure checklist, immediately after the bird strike, the captain did accomplish one critical item that the flight crew did not reach in the checklist: starting the APU. Starting the APU early in the accident sequence proved to be critical because it improved the outcome of the ditching by ensuring that electrical power was available to the airplane. Further, if the captain had not started the APU, the airplane would not have remained in normal law mode. This critical step would not have been completed if the flight crew had simply followed the order of the items in the checklist.
The NTSB concludes that, despite being unable to complete the Engine Dual Failure checklist, the captain started the APU, which improved the outcome of the ditching by ensuring that a primary source of electrical power was available to the airplane and that the airplane remained in normal law and maintained the flight envelope protections, one of which protects against a stall.
My point is that "the automation that day was worthless because it couldn't handle it" is not a correct statement - the autopilot was never engaged, obviously, but the 'automation' in the sense of the flight control laws, remained active and assisted a superior pilot in handling the aircraft in a superior way (as is how an Airbus should be operated: by excellent pilots who know their aircraft...not without pilots, or by pilots without excellence.)
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Old 9th Feb 2012, 03:29
  #1267 (permalink)  
 
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I recall them starting the APU but since the engine generators never went off line it never came on line but it was a good back up. The engines never totally failed, they just couldn't produce thrust, the engine generators were the only power supplying electrical power when they ditched. The APU would have picked it up if they had failed however. It was a good decision.
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Old 9th Feb 2012, 14:04
  #1268 (permalink)  
 
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Who would think any pilots could find a way to put an Airbus below 60 knots airborn?
The aircraft (Airbus 330) itself dynamically never got 'below 60 knots', only the sensors associated with the air data system.

With minimal 'handling' demarcation between stalled & un-stalled other than the turbulence masked buffet, the speed at which it 'gently' mushed into the stalled condition was somewhere around 185KIAS, at a point in time where the KIAS on one or more displays may very well have been temporarily available to them, as valid air data was intermittently recovered at numerous points.

Without re-reading Interim #3, I believe it settled in somewhere around what would have been equivalent to 150KIAS on the displays had the air data sensors not been corrupted essentially by actual flight path versus body angle.

This is the reason for pages & pages of discussion about full time stand alone AOA availability, not connected to the ADR's and their 60 knot threshold for validity.

(Correct me if I've stated something in error here.)
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Old 9th Feb 2012, 16:19
  #1269 (permalink)  
 
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Originally Posted by OK465
the speed at which it 'gently' mushed into the stalled condition was somewhere around 185KIAS, at a point in time where the KIAS on one or more displays may very well have been temporarily available to them,
The a/c stalled when AoA exceeded 10° at 2h10m57s. At that time the F/O was seeing IAS from ADR3 which was still UAS, while the Captain PFD was on ADR1 which had returned to normal some 20s earlier and was showing 207 kCAS at 2h10m58s.
Without re-reading Interim #3, I believe it settled in somewhere around what would have been equivalent to 150KIAS
That's not in Interim #3, but is probably based on a graph I posted some time ago that showed CAS calculated from the recorded groundspeed.
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Old 9th Feb 2012, 17:10
  #1270 (permalink)  
 
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What can be changed assist in avoiding this kind of accident?

This is a very long thread now. I am perhaps foolish to add to it further, but here goes...

It is clear that the pilots on the day (or night) were indeed idiots. However, I think it is fair to say that we are all capable of being idiots on our day also. It is desirable but impossible to assure that every person has the complete skill set or training to deal with every eventuallity.

Therefore, I think that even though working on better training and weeding out bad pilots is of some assistance it will never be able to ensure all pilots are adequate, properly trained, or will not have lapses in there handling of situations.

Notwithstanding the above, I think there are two things that could and should be changed that may well have given the crew assistance.

First, when the autopilot disengaged there should have been an explicit message that it did so because of air speed indication anomalies.

Second, clearly the stall warning should continue regardless of airspeed except in specific circumstances ie if you are airborn at significant altitude there really is no reason for the stall warning to be discontinued...

These matters are easily corrected and are clear failures in logic. No one will ever know if these changes would have saved the fateful flight but I am sure that they would have been of some assistance in overcoming the confused state that the pilots had fallen into.

In addition, "Pull up...Pull up" was perhaps not as helpfull as it could have been in that it was exorting the pilots to do exactly the opposite to that which they needed to do. It was in the event less helpful than "don't crash...don't crash" would have been. What it was really trying to say was that they were loosing altitude and getting close to the ground.

A careful review of the messaging that pilot get is needed in order to at least avoid ones that are not helpful and ensure that helpful ones are not disabled.
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Old 9th Feb 2012, 17:25
  #1271 (permalink)  
 
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HN39: Thanks for the correction. I personally believe your graphs are probably very close to the event as it unfolded.

edit: BTW on page 92, it shows max altitude of 37,924 reached at 2:11:10 with ISIS CAS of 184 recovered 3 seconds earlier, so they were still climbing, at least ballistically, from 207 down to 184. The benign 'mush' started at this time??

Last edited by OK465; 9th Feb 2012 at 18:02. Reason: review of interim #3
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Old 9th Feb 2012, 18:52
  #1272 (permalink)  
 
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Report: Cobham B712 at Kalgoorlie on Oct 13th 2010, stick shaker on two approaches

Humans behind the plane instead of ahead.

Cheers.
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Old 10th Feb 2012, 08:17
  #1273 (permalink)  
 
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Originally Posted by OK465
BTW on page 92, it shows max altitude of 37,924 reached at 2:11:10 with ISIS CAS of 184 recovered 3 seconds earlier, so they were still climbing, at least ballistically, from 207 down to 184. The benign 'mush' started at this time??
Yes, at 2:11:10 the AoA is well past the maximum lift and the LF has dropped to 0.75 g. One could say the "mush" starts as early as 02:10:52. Up to this time the normal load factor (=lift, essentially) rises commensurately with AoA (page 43), then starts to flatten off while AoA continues to increase.
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Old 10th Feb 2012, 10:15
  #1274 (permalink)  
 
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AF 447

I find it very disturbing that so much reliance is placed on computerised flight systems which apparently are not fully capable of informing the ‘human’ pilots of the aircrafts actual status in flight.

Yes, there were audio stall warnings on the flight deck of AF 447, but did any of these warnings advise the pilots to decrease AOA?

No.

Why not?

Multiple audio warnings and multiple ECAM messages on the flight deck only serve to distract the pilots from the job in hand. Passenger aircraft should be designed to give the pilots the option of disabling all automated systems and of taking full manual control when required.

Pilots should be trained and tested to ensure that they are skilled enough to do this.

As I understand it, this is not currently the case..

When I and my family fly as pax, I want to be confident that the flight crew can actually fly the aircraft manually and are not totally reliant on it’s automated systems.

Can anyone assure me that this is the case?
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Old 10th Feb 2012, 11:52
  #1275 (permalink)  
 
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Carjockey

Yes, there were audio stall warnings on the flight deck of AF 447, but did any of these warnings advise the pilots to decrease AOA?

No.

Why not?
That is what the STALL STALL audio warning is for telling the "pilot", reduce the AOA NOW!!!!! Why the "pilot" in AF did not do so we will never know.

Multiple audio warnings and multiple ECAM messages on the flight deck only serve to distract the pilots from the job in hand. Passenger aircraft should be designed to give the pilots the option of disabling all automated systems and of taking full manual control when required.
We are able to do so! Why do you think there are two pilots, one is pilot flying and one is pilot monitoring who runs the ECAM. The PF only has to crosscheck Thrust lever / Fuel Cut off switch / Fire switch and any guarded switch that the PM has to operate. So there should be NO major distraction. As PF you have to FLY the A/C first and unfortunately the PF in this case did not appear to do so!

Pilots should be trained and tested to ensure that they are skilled enough to do this.

As I understand it, this is not currently the case..
Most pilots are and most airlines ensure this is so, again we will never KNOW why the PF did what he did and why the PM never took control!!!

My only concern is the MPL, which is a whole new topic, this "training" will be fine and dandy for box ticking, but does not instill the life preservation skills that each pilot needs.
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Old 10th Feb 2012, 13:12
  #1276 (permalink)  
 
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Originally Posted by VGCM66 View Post
Thanks. And to quote that report:
The operator’s recurrent training programs did not address the recovery from a stall or stickshaker activation such that the ongoing competency of their flight crew was not assured. [Minor safety issue]
Birgenair, Colgan, AF 447, Ethiopian at Beirut, Perpignan.... and more and it'll carry on until someone figures out that it is not a "minor safety issue".

[ and it's not a sidestick vs. yoke or control feedback issue either ].
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Old 10th Feb 2012, 13:25
  #1277 (permalink)  
 
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infrequentflyer789-
and it's not a sidestick vs. yoke or control feedback issue either
Maybe not so much sidestick vs yoke, but FBW vs Direct Control. This FBW CR*P is nothing but an "arcade" game instead of having FULL control of your aircraft. Yes.....cable-operated. Old-fashioned...yes...but 99.9% reliable.
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Old 10th Feb 2012, 14:26
  #1278 (permalink)  
 
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Birgenair was "direct control", as was Colgan Air, Aero Peru, Ethiopian and many more. But let's not allow the facts to get in the way of a good rant.
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Old 10th Feb 2012, 14:44
  #1279 (permalink)  
 
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Yes.....BUT.....in this particular situation, I think they would have survived with Direct Control of their aircraft rather than some computer.
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Old 10th Feb 2012, 15:46
  #1280 (permalink)  
 
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Yes.....BUT.....in this particular situation, I think they would have survived with Direct Control of their aircraft rather than some computer.
Let me agree with this particularly with regard to the aircraft pitch trim system.
An aircraft that keeps trimming the force off the stick/wheel as you slow might be convenient, but it loses natural speed stability and requires increased attentiveness/awareness in manual flight-or an automatic speed control system.

Any aircraft that keeps automatically trimming nose up after the stall AOA is reached has a fouled up design.
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