AF447 wreckage found

[maynardGkeynes]

@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.

[fireflybob]

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.

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

[John James]

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

[ECAM_Actions]

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:

The airplane’s altitude reached its maximum of about 38,000 ft, its pitch attitude and angle of attack being 16 degrees.

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?

[The Ancient Geek]

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 .

[ECAM_Actions]

Why the hell did the stupid automation silence the stall horn ?

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.

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.

[Garrison]

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.

[ST27]

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

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.

[gums]

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.

[RansS9]

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.

[Diamond Bob]

Originally Posted by ECAM_Actions

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?

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:

First, an erroneous speed indication showed the plane was flying too fast. The pilots, believing the erroneous speed to be genuine, slowed the plane. As they did, the speed suddenly indicated the speed was too slow. But this speed indication, only 60 nautical miles-per-hour, was obviously incorrect.
Without accurate speed information, the pilots slowed the plane too much for the wing to provide adequate lift.

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?

[182flyer]

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!
　

[maynardGkeynes]

@ fireflybob

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

@ 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.

[ECAM_Actions]

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.

[pmansion]

@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).

[Zorin_75]

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.

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.

> reacted by the book: Nose up and GA pwr (Standard procedure, as
written in several postings).

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

[Garrison]

> 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.

[Graybeard]

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.

[torquemada60]

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.

[Mornington Crescent]

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.)