No I haven't but I don't think it would be a lot different to the stalls I have done at 22,000'. It would be a little more sensitive perhaps and i would need to be careful not to over control but the principles of stall recognition and recovery defined by Airbus in their FCTM and QRH would be the same:-

1/ reduce AOA

2/ increase energy.

Since accident investigations are carried out to primarily prevent future similar occurences, and since to me it is clear that the crew knew the aircaft was in a stall, but based on control input evidence failed to recover from it, IMHO the effort should next focus on why they failed to initiate recovery.
Here comes to play a major role of Airbus system design, like it or not. With substantial personal experience in both own circumstances and other's, there must follow-on a drastic system redesign:
a. A human is unlikely to adapt well to changing control laws. Why is someone, used to not trimming, start trimming all of a sudden while he is already task-overloaded.
b. Why would anyone have an autoflight system obstructing/ overruling pilot control inputs and decisions, in a stable transport aircraft. Believe me I have likely much more experience than most of you flying variable stability aircraft and rotorcraft. There is no need to override a pilot control motion, just to properly design the flight control system such that there is almost no likelihood of the pilot damaging the aircraft to become unflyable. This must be coupled with proper pilot selection and training. Too expensive for the airline? choose another.

The CSS (Control Stick Steering) Boeing design, an arrangement I flew as example on the Douglas A-4H Skyhawk, enables autopilot flight during which the pilot can make desired changes, small or substantial, by synchronizing autopilot feedback signal (nullifying it) in the channel the pilot has applied force onto, such that it recognizes the new desired attitude upon pilot control pressure release. Simple and natural for the human in flight, during blue skies and in emergencies.

I would never pilot an aircraft with not only a mind of its own, such as trimming, but also limiting my AOA command, whether within the flight envelope or out of it. As captain it is my call, I know how to fly it better than any lead system engineer, fill reports later, in 36 years of flying they were few but all very well accepted and approved.

The current modern pilot flight displays are overly saturated such that no regular apt and trained human can quickly build in his mind a dynamic aerial situation. 60 year old captains would need at least double the time for that. In research simulator flights, 18 out of 19 seasoned and young pilots alike, failed to recognize and act upon erroneous FMA readings and below glidepath approaches. To me this is more than obvious, and leads to e.g. a Boeing 737-800 flying an auto-ILS with 1:50 of idle throttles just to stall it before the threshold, without pilot reaction, till it was too late. You guys fly them and should be well aware of this.

?somatogravic disorientation - pitch down illusion?
 

Sounds like the common sense immediate response to the stall warning was ignored, but the deceleration could have created a somatogravic illusion ,shared by all, for false nose down pitch sensation, hence the repeated and probably confused "pitch up" commands.

If thats the case, everyone would have had to be ignoring the AI, the stall warning, and the angle of attack indicator....very very strange....

A worst case scenario would combine it with a tail heavy loading configuation but that doesnt appear to be the case.

Sadly, they just couldn't work out out how to fly a stalled aircraft, no ASI, albeit in very bad weather which was avoidable...

Ask21,
good thoughts, especially about the trim effect on aoa of the stab. I fly only small planes, but I guess the report is simply not providing enough information for a sound judgement.
I would not be surprised if the final conclusion will be that this stall, fully developed, was unrecoverable. I doubt if such a scenario was ever flight tested during certification. Certainly not without a drag chute installed.

Never the computer will prevent you from recovering from a stall
 

Human factor is the only cause of the stall.

Whatever is the configuration of the computer, when stall warning : nose down.

Never a computer will prevent you from recovering from a stall if you nose down.

Both american and european authorities says that 80% of the crews earing a stall warning don't nose down at first bacause of a human factor.

The challenge is to train the crews to react like a top gun and not like a civil servant.

Dropping a wing is taught in unusual attitude recoveries on Boeings if you find yourself with a very high nose attitude and the speed rapidly heading south. ( and at the same time reducing thrust to help to help the nose down pitching moment )

There could have been a deceleration somatogravic pitch down illusion causing the erroneous pitch up commands. But 3 minutes or so is a long time to keep that up - I'd be surprised if the artificial horizon and the angle of attack indicator were not functioning, and even more surprised if they werent referenced automatically in the stall.

To recover a stall, forward sidestick control motion is required. It was recovered once then the pilot longitudinal control moved aft and stayed there. The rest about such things like anti-spin chute, recoverability etc... may be important but irrelevant to the specific stall recovery.

Cricky do any of you fellas read previous posts?

Yes all the Attitude indicators where fully functioning.

The problem was with the Air Data Modules receiving crap info from the iced up Pitot tubes....

Some Aircraft have AOA displayed on the Primary Flight Display but in this case I don't think AF do. Certainly my Airline and many others do not on any of our Aircraft types.

I'm sorry, I'm losing the overview.
Can somebody please remind me, what the margins were in the given conditions?
Obviously, the air was relatively warm yet below dew point. How can we interpret that they couldn't climb higher because of the temperature gradient being shallower than expected? Was that just referring to the tops of the cb being above their ceiling at that time?
What's the speed margin between Vmmo and Vs?
What's the AoA in normal flight at that altitude and what's the Stall AoA? (did I see it's only 6°?)

What triggered the 13° nose up trim on the THS? What impact would that setting have, along with fuel trim aft, on their chances of recovering from a stall if they had positively identified it in the first place?

With so many indicators being unreliable or not available, what "direct", that is aerodynamic or "seat of the pants" feedback would you have in a machine of that size with FBW controls? Obviously, there's no feedback from the control surfaces, there's no stick force to overcome (or rather to soften when the control surfaces get into turbulent air from the stalled wings)
Can the turbulent flow be felt through the airframe?
I honestly have no idea if those guys would have had any primary means of identifying the stall, given that the secondary means (read: instruments) were unreliable.

Also, I've read a lot about "law changes" in this thread, how does an AB pilot stay aware of what law what control axis is in at any given point? I'm sure there's nice flow charts in the documentation, but I wonder how many distinct states of flight law degradations there are and how often the system is allowed to change between them.

If, and it might, this turns out to be a case of "loss of situational awareness" (or rather: they never gained awareness of the situation they were in), it begs the question how complex the situation was when it was presented to them. A simple AoA indicator might have made all the difference to them.

The interface between the automation systems and the pilots seem to be the most difficult part of any design these days. How does the system present all the relevant information while not overwhelm the pilots? And this in a situation where the system is forced to give up since it's parameters are outside what it knows to handle. We could interpret such situations as the design engineers saying "this is a situation we have not considered / thought possible, over to you, pilots". This almost necessarily also means that it's hard or even impossible to say what information is relevant and what can be withheld. As a system designer, you are faced with the decision to possibly withhold information that might be meaningful to interpret the situation or to present information overload which doesn't help either.

I don't envy you guys who poke around at the levels >300.

ps: the system "knows" the AoA. If getting AoA display is an optional item on the aircraft order and AoA is not automatically displayed when the stall warning goes off because the feature wasn't ordered, that would seem sickening to me.

Well this is a discussion forum after all, and just as Nitpicker has pointed out is anyone reading previous posts at all??!! I am no authority at all, but having just done a shiney new Airbus rating I just practised Unreliable Airpeed last week(!), all the alerts are going off left right and centre, with 3 different airspeed indications in the cockpit, so putting TOGA on and pitching up 15deg (sounding familiar yet anyone?!!) you have a manouver which gives you an airspeed that should be at least what you get on initial climbout, then its time to see which speed tape has what you think it should have and compare with the G/S for at least ball park ideal.

Opherben
 

With all due respect, we basicly agree on the fundamentals: more training, more situation awareness.
Systems redesign? Very unlikely.
I cannot envisage a better scenario for this ill fated plunge into the ocean than the described.
I have some good thousands of hours on both designs: Boeing and Airbus.
Both have their virtues and flaws.
It's very unlikely that systems control design have anything to do with the outcome.
The lack of 'aviate' certainlly have...
If they ever trained high altitude stall recognizing and recovering everybody would be probably at thome at this time.

Thanks bud and congrats on the conversion.

But please don't pitch up to 15 deg other than on TO below acceleration height!!:ok: Remember there a 3 different phases mentioned:ok:

Hi Delta!
 

No offense: are you sure you're Bus rated?
Were in the earth you're taught to TOGA and rotate to 15 degrees, upon a loss of speed indication and stall warning at 35.000'??
Please, go back to your FS.

You know what I think is that a lot of Pilots don't know the normal performance to expect on their Aircraft. ie normal CLB pitch and N1, Normal CRZ pitch and N1 and normal DES pitch and N1 ( yeah yeah idle !! )

If don't really know what's normal how could you know what to set when the !!!! hits the fan? Like in Iced Pitots or Volcanic ash flameouts etc...

I've asked FO's in the past what pitch attitude and N1 should we have in cruise now, don't look ( cheater := ) Quite a few got it wrong by quite a bit.....

Anybody of YOU ...
 

anybody of you fellow pilots out there have been through this
(or something similar)?

1. approaching CB killer cell without seeing it (why?, wx radar fault?, too-fast buildup?)
2. entering the outer downdraft surprisingly (cpt woke up?), (ice)
3. entering low-pressure inner updraft (water)
4. back in the outer zone (N.E.) with new massive downdraft

aside from the overwhelming (and distracting) body of
technicalities, can (has it been shown somewhere else)
a large A/C survive this encounter? With what probability?

I remember a similar encounter: Pulkovo 612 which
came out of a large CB in a flat spin (is this still valid?),
where the PF tried to "fly over" the mess and failed.

Would AF447 PF try to "overfly" the "turbulence" that
he (obviously) didn't know what it really was (otherwise,
he wouldn't be heading straight into it).

This is a question of a layperson, so please pardon
any wrong assumptions.

Thanks & regards

Been following this and my amateur .02 is:
who has not fallen victim to the tyranny of the urgent at some time or other? - but tres dangerous in a cockpit..:suspect:

Oh another one........

To save you from reading previous posts that have addressed your question I'll answer it for you again.

Yes, this has happened before in much the same circumstances as AF 447.
Other Airbus and Boeing types have entered CB's by mistake and lived to tell the tail. CB's large enough to injure Pax and freeze the pitot tubes with super cooled water......

Re: Oh another one.....
 

nitpicker330:

I read the posts, a lot of them, but not all 850+, so
sorry for missing some important parts.

I read many of your posts too and I'd like to ask
you as an AB driver: can you understand, why the
PF pulled with N1 100%? Did he try to get out?
Sometimes, subjective assessments by the right
people are more instructive than loads of technical
detail.

But: maybe I'm completely on the wrong track.

Hi Graybeard
 

We can assure you: they didn't tried to pass over the CB.
One explanation why they pulled back an already stalled airplane is confusion, lack of proper training, panicking, etc.

@Flyerbob

As I noted earlier, the core difficulty faced by the crew was that the standard practice of using pitch + power to maintain safe flight without air data didn't seem to be working, and the problem is that it won't if the aircraft is already stalled. With the airbus' FBW [fly by wire] system and passive stick, the crew would have none of the force or buffet cues through the side-stick that might have told them this. Thus, once they stalled, with no instrumentation or VH, this was for all practical purposes unrecoverable in an Airbus. Under the circumstances, at night with no visible horizon, even an exceptionally well trained and experienced professional pilot would have lost situational awareness and would not have been able to discern the pitch attitude of the aircraft. I don't see how they can be blamed for their actions in the cockpit once the problems developed in an Airbus.

maynardGkeynes, so what about the pitch displayed on the attitude indicators?

well this pax is adding AirFrantic to its no fly list
BrutishAir has been on there for a while...
and I am thankfully never going to India
j

As far as can be determined, all three ADIs (Attitude Direction Indicators, or artificial horizons in layman's terms) was FULLY FUNCTIONAL.

As for pitching to +16 degrees of pitch at TOGA at FL380 (above optimum cruise alt for the weight and conditions)...

To quote the report:

I'm not very good at English :} but this is telling me that the PITCH ATTITUDE WAS +16 DEGREES.

Anyone care to explain why this could possibly be considered a safe pitch attitude at FL380?

I can understand lots of alerts confusing the crew, but seriously, does anyone actually think that +16 degrees of pitch at high altitude is going to enable the aircraft to maintain a healthy airspeed?

As a simple-minded Twotter driver there is one factor here which seems critical to me. If the stall warning sounds I know to get the nose down in a hurry then grab for the apehangers to add power.

In this case the stall warning only sounded (twice?) briefly which was probably the critical misleading clue which convinced the crew that they were not stalled.

If the stall warning had behaved as expected by any sane pilot and sounded continually during the stall then any sane pilot would have realised that the aircraft was indeed stalled and applied the correct recovery.

Why the hell did the stupid automation silence the stall horn ?
THIS SHOULD NOT HAPPEN :ugh::ugh::ugh:.

A great question. The systems silenced it because the IAS fell below 60 kts for a time. This caused the FWC (Flight Warning Computer) to silence the STALL warning.

It should be that any time stall AoA is sensed with the aircraft in the air mode that the stall warning sounds. Airbus must have assumed that if the IAS is < 60 kts then the aircraft is on the ground even if the weight on wheels switches say it is in the air. There is no logical explanation for it silencing the stall warning based apparently on IAS alone. :eek:

I'd love to know why display of AoA on the PFD is a very expensive paid-for option. IMHO knowing the AoA is at least as important as knowing IAS, if not more so, and should be a mandatory instrument/display.

If you think about what could have been done to prevent this accident, rather than about whether the crew were competent/incompetent or whatever, it seems as though if they had had available the information that we have from the FDR, ie alpha, airspeed and descent angle, they would have recognized the problem immediately and recovered. But that info was not provided evidently because the system designers considered this scenario impossible. But three identical pitots known to be able to be overwhelmed by ice are not triply redundant; they are a single point of failure. The airplane -- any airplane whose systems rely so heavily on airspeed -- needs a truly alternate airspeed source, a full-time angle of attack indicator, and a stall warning that does not go to sleep and then wake up at inopportune moments.

So you've decided to spend the rest of your life hiding under your bed, since the riskiest part of a flight is the drive to and from the airport, rather than fly on some the safest international airlines? British Airways hasn't seen a fatal accident that could be attributed to the airline since it was formed. It's been something like 45 years since its predecessor companies had a fatal accident. They've seen millions of safe takeoffs and landings in the meantime.

In short, you're thinking irrationally.

Thanks, Garrison
 

To the point, fellow poster. Thank you.

BTW, don't forget a FBW control scheme that may have contributed to the humans reacting to the situation in the manner they seemed to.

The Wright Flyer had only one instrument....An ANGLE OF ATTACK METER.

( In this case a piece of string attached to a stick in advance of the wing leading edge out of updraft if I remember correctly). No need to remember power attiude values for various weights / density altitudes.

Totally infallible..probably not
Pretty damn close to infallible..I think so.

Well, here's a guy who thinks the pilots were at first presented with information that the plane was flying too fast. This is the first I've heard this take on the situation, but read what he says:

Black Boxes Tell What Happened To Air France 447 - National Fear of Flying | Examiner.com Black Boxes Tell What Happened To Air France 447 - National Fear of Flying | Examiner.com

Any comments on this theory? I hadn't heard myself that the pilots were at first presented with information that they were flying too fast. Could this be the reason for the nose up inputs? They thought they were in an overspeed condition?

Back to BASICS
 

Let's return to Basics:

When I started flying a long time ago, the very first thing my FI taught me was 'in any abnormal situation: FLY THE AIRCRAFT'.

When I see the altimeter winding down real fast and the VSI confirming that with a high neg reading, first thing I ask myself why I'm going down and the only answer can be

> I'm in a severe ND attitude (which they were not, as they could see on
the artificial horizon with a glance).
> a severe downdraft by meteorolical cause (but NOT several thousand
ft./ min!)
> no or nearly no lift (which was the cause, as we now know).

How can I create lift? By building up speed, so NOSE DOWN.
Really quite simple.

If the AF pilots didn't do that, they EITHER
> paniced (not so far away; I've seen it happen) OR
> reacted by the book: Nose up and GA pwr (Standard procedure, as
written in several postings).

I wouldn't blame the pilots for either reaction, the first is normal (panic is caused by simple overstress in an abnormal situation and cannot be 'trained away', only the level of entry into the panic state can be hightened) and the second leads to the question if the system OVER-trains todays pilots. Could it be that the system presents a so specific solution to every situation, that the simple basics of flying disappear behind the 'DO THAT, WHEN THAT HAPPENS'?

Does the system train away common (flying-) sense?

Please don't hang the subject up to high into technical terms, try to put yourselves into the pilots and stick to basics.

Leaves two questions:
> The captain arrived quite fast after the beginning of the situation. He
was not fighting the situation (as was the PF), and not trying to assist
(as was the PNF). What would he do? My guess is, he'd try to get an
overview of the situation the aircraft is in first thing. He should have
recognized the stall and ordered a ND attitude. Did he and the PF didn't
comply (panic?). Or did he not, than why not.
I hope the CVR script will reveal that.
> Could the crew break the stall, even if they had recognized it? With an
AOA of more than 40° that wouldn't have been to easy: With practically
no clean airflow over the elevators (close to a flat spin), those may not
have responded to a ND input, even if it had be given. Would they have
had the time to throw out the LG or even deploy the thrust reversers in
order to get a ND momentum? And would the FBW systems have let
them?

The whole story focuses onto one simple subject: The technocrats are over-stressing the pilots. It over-emphasizes specific reactions to specific situations (which computers can comply to much better and faster).

We know of enough incidents (that the pilots were able to walk away from), where cpmpletely unorthodox reactions saved the day.

The solution? Have airplanes be flown be computers (only) or ... return to basics and focus onto what we were trained for in the firt place:
FLY THE AIRCRAFT!
　

@ fireflybob
 

@ fireflybob

You are correct: attitude, derived from a combination of rate and attitude gyros should still have been reliable. At the same time, if the attitude of the aircraft is nominal [normal], power is nominal, but vertical speed is indicating -10,000ft per minute, the most likely cause is that the airplane is stalled. The problem the crew faced is that using the standard practice of pitch + power to maintain safe flight does not work if the aircraft is ALREADY stalled, which was the case here. With the airbus' FBW [fly by wire] system and passive stick, the crew had none of the force or buffet cues through the side-stick that would have told them that were in a stall, which would also have explained why the pitch + power response, which seemed not to be working for them, was to no avail. I believe that under the circumstances, the stall was effectively unrecoverable.

Here's an idea: have secondary pitot tubes in the airframe that can be deployed like a RAT should the primaries be lost. At least it might provide sufficient time to recover and apply the correct pitch/power settings.

@182flyer

You need to read the transcript properly. Approx 37 seconds after the Captain entered the cockpit the PF made pitch-down inputs. Apart from the aircraft speeding up and the stall warning re-sounding we know little about what happened next.

As others have said the stall warning coming back on may have led a confused crew into thinking they were making matters worse. It seems unbelievable that there is not a warning to warn the the plane is currently in a stall.

I wonder if there will be three recommendations out of this...

1) A warning that the plan has stalled and is falling
2) AOA indicator
3) A more robust (manual or automated) way of allowing the pilot to return to the previously good settings (attitude and power).

At the beginning of this mess the a/c was not stalled. A stalled plane won't climb 7000 ft/min. The question that can't be answered so far is why didn't or couldn't they maintain pitch and thrust at this point.

I believe that should be true for approach to stall. When already stalled I suppose even Airbus procedures would call for nose down?

> Could the crew break the stall, even if they had recognized it? With an
AOA of more than 40° that wouldn't have been to easy: With practically
no clean airflow over the elevators (close to a flat spin), those may not
have responded to a ND input, even if it had be given.


I have talked with several aerodynamicists who were generally in agreement (just theoretically -- no first-hand knowledge) that the A330 probably does not have an unrecoverable deep stall mode and that the airplane would have responded to a nose-down pitch command. In fact there was a brief moment during which an AND command was given, the airplane began to pitch down, and then lo and behold the stall warning came to life and discouraged the pilot from continuing the experiment. It would have been necessary, if I understand the control laws correctly, to manually trim out of the full ANU stabilizer setting of -13 deg. An important point is that the flight path was 25-30 degrees down, and so a stall recovery by reference to the PFD would have required putting the nose 20 degrees or more below the horizon.

ECAM, how would you prevent the secondary pitots from icing up?

Better to have pitot probe heat robust enough not to allow icing up.

Then educate the autopilot to go into pitch and power hold mode at loss of airspeed, and remain, engaged, in Normal.

I am not a pilot, I am not a technician or aviation specialist. I am your average passenger who flies constantly around the world.
Gentlemen, most of you are professionals, paid to do a job. I could care less about your problems or issues with such and such aircraft. I am paying you to fly me from A to B fast and safe.
Reading through the comments on this web site, it appears that 3 pilots made wrong decisions. They chose to fly through a storm when many airlines had deviated their course by miles. The Captain went for a nap knowing there was a storm ahead. The two copilots appeared to be poorly trained and unable to cope with issues.
I hope Air France will be punished and the families compensated for what appears to be recklessness, arrogance and a total lack of professionalism from the pilots.
228 people died as a result.
As far as I am concerned I will never fly Air France again and I will tell as many people as possible to do the same.

I think I have read all the contributions. There is no mention of coffin corner in the thread.

Does the AB 330 not have such a problem? Could someone with practical knowledge of the aircraft estimate whether at the assumed weight and altitude what margins there would be at the cruising altitude. Also would the climb to FL380 have put them into coffin corner? Once there of course (if it exists for the AB) the aircraft would be buffeting with an increase or decrease of speed (Mach No.)