News French plane lost over Atlantic

[garyw]

What I don't understand about this is how experienced pilots can forget/not review the 'loss of airspeed' procedure which is simplicity itself. Nose up to 5 degress pitch and N1 to 85%. This maintains a fairly constant speed until the bad weather has passed.

I know the weather was rough but these guys were experienced.

This BBC documentary is fascinating and shows one of the stranger high altitude phenomena called 'super cooled liquid water;.

 

[RGClark]

Popular Mechanics article, 6/12: What Really Happened Aboard Air France 447

An interesting article. Some pretty alarming statements were made it in. The article seemed to want to put most of the blame on the pilot with the least experience who was at the controls at the time. But based on what's in the article there were some serious failings in regards to Airbus and Air France as well.
First, it's extraordinary that the Airbus plane doesn't give any indication to the pilots if different inputs are being applied by the pilots. According to the article, the plane just averages the inputs. So in this instance if one pilot is applying inputs for full nose up which is causing the plane to stall, and the other pilot is applying slight nose down inputs trying to recover from the stall, the plane just averages the inputs which still results in nose up and a stall. And neither pilot understands why the plane is not responding as he expects it to.
As for Air France, the article implies that pilots were not aware that the Airbus plane could stall. They apparently were given the impression that the fly-by-wire, computer controlled system prevented pilots from applying inputs that can cause a stall.
If this were true then that would be an unconscionable error on Air France's part. However, I don't know about this conclusion in the article. This conclusion is based on the article claims that the pilots made no reference to the usual computer protections on the allowable pilot inputs being released. But I remember in earlier descriptions of the transcripts that the pilots did make reference to their no longer being in "natural law", meaning having the computer protections, and being instead in "alternate law", meaning no computer protections.
So this conclusion I'm unsure about. But another fact might suggest it was true. In those other articles I read describing the transcript from the cockpit, I don't recall the pilots specifically discussing the stall warnings. If they believed the plane couldn't stall then they may have dismissed them as being false readings. In that case, that would be serious fault on the part of Air France by not making the pilots fully aware under the conditions that a stall could occur for these fly-by-wire planes.


Bob Clark

 

[Quick_Nick]

Based on the video, it seems that they may have been flooded by computer messages and possibly either did not notice messages telling them that the computer had switched flight modes or they were busy focussing on other messages.
I agree with the article in thinking that it's a lack of communication, combined with lack of experience and the captain being absent. But of course, the article is my source of information.

 

[Notebook]

The BEA (Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile) is the French authority responsible for carrying out safety investigations relating to accidents or serious incidents in civil aviation.

Flight AF 447 on 1st June 2009 A330-203, registered F-GZCP

http://www.bea.aero/en/enquetes/flight.af.447/flight.af.447.php

http://www.bbc.co.uk/news/world-europe-18720915

N.

 

[kamaz]

Animation of the accident:

[ame="http://www.youtube.com/watch?v=vSz-UeEGbUw"]Air France A332 June 1st 2009 . French BEA animation of the accident - YouTube[/ame]

 

[C3PO]

Watching that right stick makes me cringe. Horrible!

 

[MaverickSawyer]

Jesus... That really shows how poorly things were being coordinated in the cockpit.

 

[kamaz]

After watching it, I have even more trouble understanding what happened.

At the age of 12-13, while playing with an F-15 sim on a monochrome monitor, I have learned that stall warning - throttle up and nose down. Otherwise, the plane will start to "slide" backwards after a few seconds.

Here, the crew responds to a stall warning by throttle down and nose up.

I simply can't understand why a trained pilot would do that.

 

[Proximus]

After watching it, I have even more trouble understanding what happened.

At the age of 12-13, while playing with an F-15 sim on a monochrome monitor, I have learned that stall warning - throttle up and nose down. Otherwise, the plane will start to "slide" backwards after a few seconds.

Here, the crew responds to a stall warning by throttle down and nose up.

I simply can't understand why a trained pilot would do that.

Indeed, perhaps the fear of a greater loss of altitude or the hope engine power would return.
Scary stuff indeed

 

[Urwumpe]

More likely problem: What did the pilots actually see on their displays, when the pitot tubes failed. Yes, coordination was likely terrible, but you also have to understand that the instruments likely also displayed wrong and diverging values. If you only have left or right side available, which side is the correct one?

AFAIR, two out of three pitot tubes failed in that flight.

 

[Artlav]

Well, it might be obvious with a god's view we have, but in the darkness of the night (and middle of a storm?), inside the cockpit with only the (assumed failed?) instruments the perspective can be quite different.

Then again, they were falling for 4 minutes or so.
Plenty of time to stop and think for 5 seconds - that doing the same thing over and over again and expect different results is, in most cases, a bad idea.

Or, perhaps, it was this:

it's extraordinary that the Airbus plane doesn't give any indication to the pilots if different inputs are being applied by the pilots. According to the article, the plane just averages the inputs. So in this instance if one pilot is applying inputs for full nose up which is causing the plane to stall, and the other pilot is applying slight nose down inputs trying to recover from the stall, the plane just averages the inputs which still results in nose up and a stall. And neither pilot understands why the plane is not responding as he expects it to.

Under what circumstances would it be a good idea to average the inputs?

 

[Urwumpe]

Under what circumstances would it be a good idea to average the inputs?

when both pilots do more or less the same. Also, Boeing aircraft are not much different there, but both sticks there are also mechanically connected (instead of electrically averaging the inputs, you would average mechanically... with feedback).

Also, there is a "Dual input" warning in most airbus aircraft, the A330-200 of Air France is one of them, should both pilots press the priority buttons at the same time.

 

[ADSWNJ]

After watching it, I have even more trouble understanding what happened.

At the age of 12-13, while playing with an F-15 sim on a monochrome monitor, I have learned that stall warning - throttle up and nose down. Otherwise, the plane will start to "slide" backwards after a few seconds.

Here, the crew responds to a stall warning by throttle down and nose up.

I simply can't understand why a trained pilot would do that.

Human computer interaction, blind faith in automation, and failure to think about basic aviating is how this happens.

I'm convinced that none of these three pilots would have had any difficulty recovering a stall in a little basic 2-seater Cessna at night, in a storm, at the edge of the respective flight envelope. The difference is direct tactile feedback on the stick and a simple set of instruments including AoA.

Their reaction of pulling back on the stick and giving it full throttle was IMHO a perfect example of training to the automations, against the natural reaction of a pilot flying himself. The idea, presumably, was to tell the plane you want to go up, and assuming the automation system was configured to respond. In the degraded mode they were in though (iced pitots), this was not the case.

It's just tragic to see the plane held in a death-stall for 35,000 feet, right into the ocean. RIP to all those who perished, and let's hope that aviation has become safer from the memory of this incident (better training regimes, more manual flight hours, specific simulator tests for this situation, etc.).

 

[garyw]

After watching it, I have even more trouble understanding what happened.

At the age of 12-13, while playing with an F-15 sim on a monochrome monitor, I have learned that stall warning - throttle up and nose down. Otherwise, the plane will start to "slide" backwards after a few seconds.

Here, the crew responds to a stall warning by throttle down and nose up.

I simply can't understand why a trained pilot would do that.

Sitting at home in front of a computer, you never get scared when something goes wrong. Fear can and will do terrible things, it'll interfere and remove all that training you've had and lead you to do the worst things possible, as happened here.

The pilots did wrong. The Captain realised what was going on but it was too late. Bonnin made the fatal mistake and never corrected it or communicated it for two reasons:

1. Airbus aircraft cannot stall (except when they are not in normal law, of course).

2. Fear acted a block on all that training, especially the part about what happens when an airbus is in alternate law.

 

[N_Molson]

Yes, commercial airlines crews are very skilled, sometimes are retired military pilots, but they are not Neil Armstrong either and have stress limits. Stress, when over a certain thresold (aka fear or panic) lead people to take wrong decisions and often forget basic concepts, being focused on the part of their training that they remember during the critical moment.

 

[Urwumpe]

The pilots did wrong. The Captain realised what was going on but it was too late. Bonnin made the fatal mistake and never corrected it or communicated it for two reasons:

1. Airbus aircraft cannot stall (except when they are not in normal law, of course).

2. Fear acted a block on all that training, especially the part about what happens when an airbus is in alternate law.

Especially:

1.5.: Confusing and contradicting displays in high altitude without reliable visible cues on aircraft attitude left the pilots to wonder in which situation they actually are - stall or overspeed? Which indication is the wrong one in the end?

It is all easy in Orbiter, when you can rely surface MFD to display the truth all the time. But what if Surface MFD could "lie" to you? We are all used to take Orbit MFD with a grain of salt. But could you imagine Orbit MFD to display complete bollocks?

 

[RisingFury]

Well, it might be obvious with a god's view we have, but in the darkness of the night (and middle of a storm?), inside the cockpit with only the (assumed failed?) instruments the perspective can be quite different.

Trouble started at 37 000 feet, which was likely above the weather. As for darkness, that's what the artificial horizon and stars are for...

Then again, they were falling for 4 minutes or so.
Plenty of time to stop and think for 5 seconds - that doing the same thing over and over again and expect different results is, in most cases, a bad idea.

Right, I have no idea why they reduced power and throttled back up several times. Were they experiencing engine problems and hoping that would fix it? But I still don't understand why they didn't pitch nose down. For the most part, they're trying to pull nose up.

Under what circumstances would it be a good idea to average the inputs?

No. It's best one person is in direct control. Once you give an input and the plane - or even car - responds counter to your input, you get VERY confused.

In the third driving lesson I took, the instructor pressed the gas pedal all the way in while I was holding the clutch and shifting. I heard the engine go to full power and I completely lost all sense of what was going on with the car. Thought it was a malfunction.

 

[garyw]

Yes, commercial airlines crews are very skilled, sometimes are retired military pilots, but they are not Neil Armstrong either and have stress limits. Stress, when over a certain thresold (aka fear or panic) lead people to take wrong decisions and often forget basic concepts, being focused on the part of their training that they remember during the critical moment.

SOMETIMES, yes, but today many commercial pilots are being taught the WRONG way about flying a plane. There is little sick n rudder flying.

I've posted this before but it's worth posting again.

https://www.youtube.com/watch?v=fbQB72-4WQ0

 

[kamaz]

Fear can and will do terrible things,

But that's why you have training. The whole point of training is to drill automatic response to signals -- i.e., if you get a stall signal, you initiate stall recovery.

I get that a pilot can (incorrectly) believe that the stall signal is spurious and do nothing. (Though he should still realize that his altitude is dropping while the nose is up.)

What I don't get is that the pilot gets a stall signal and does the exact opposite of what he is supposed to do to recover.

Thinking about it, it appears that the two other pilots in the cockpit did not get it either -- i.e. they did not imagine that the guy at controls would respond to the stall warning by pulling the stick back.

 

[garyw]

But that's why you have training. The whole point of training is to drill automatic response to signals -- i.e., if you get a stall signal, you initiate stall recovery.

No, not with the psychology in play that night. The training states that Airbus cannot stall, this is something that is told to pilots, something that is drilled in and it's wrong. Airbus cannot stall WHEN IN NORMAL LAW. In that situation, it's easy to get confused. Remember that Bonnin was the PIC at that point an the most junior.

What I don't get is that the pilot gets a stall signal and does the exact opposite of what he is supposed to do to recover.

Thinking about it, it appears that the two other pilots in the cockpit did not get it either -- i.e. they did not imagine that the guy at controls would respond to the stall warning by pulling the stick back.

He didn't though, He pulled the stick BACK and expected the Airbus fly by wire to save the situation. In Normal Law you can do this and the plane will go nose up and slow down but it won't fall out of the sky.

The other two pilots got it. Listen to the voice tapes, David Robert, sitting in the left seat got it and tried to fix the situation but Bonin, seated in the Right didn't let go of the stick.

The major error that Bonin and Robert committed was very poor CRM. That is what killed everyone.

The Captain is blameless, he wasn't on the flight deck and made it back just in time for the end.