Pépé le Pilot
Well-Known Member
I also have the FDR transcript but it's pretty big to translate and I don't have that much time right now...
Air France pilots and high altitude stall training
- Thread starter jtrain609
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seagull
Well-Known Member
Without the FDR in English, I am not sure what the pitch angle was. I took a quick look but did not see the FDR in French either, but my French is not great. What is the link for that, is it in tab form or charts? It is not normally a "transcript". However, what were the max pitch attitudes?
One thing about the high altitude stall (or any stall for that matter) is that 40 degrees of AoA may easily happen at even slightly negative pitch attitudes.
One thing about the high altitude stall (or any stall for that matter) is that 40 degrees of AoA may easily happen at even slightly negative pitch attitudes.
Pépé le Pilot
Well-Known Member
I'm with the iPhone so bear with me. Pitch angle was at 40 to 41 deg nose up. Here's the doc : http://www.lepoint2.com/sons/pdf/AF447enregistrements.pdf
The AF Crash is quite a big topic right now on this side of the pond. If you're interested you can read the corresponding threads in the pprune forum. Just google it. I don't know if linking to other forums is actually allowed. There are 2 of them. One can be found in the "Tech Log" section and concentrates on, you guessed it, the technical issues of the crash.
No offense Pepe, but your translation is "not perfect". There is a better one on pprune. At the beginnig for example the PNF was actually commanding the PF to descend. The PF was climbing with 7k fpm right after he assumed command.
I also don't want to judge those guys, but CRM was non-existent most of the time. The Stall Warning stopped right before the Cpt entered the cockpit. The PF and PNF didn't say a word about what happened up until the moment he entered the flightdeck. He had to figure it out on his own but he was lacking important information how they actually got into the situation.
The PF didn't had the feeling that they were climbing. He thought that they were too fast. On the CVR you can hear an increase in loudness, which is accredited to ice crystals above the thunderstorm cell. The PF misinterpreted that increase in loudness and thought that they were accelerating. Shortly after that the pitots froze and speed indications were lost followed by the AP/AT disconnection. He even deployed the spoiler. That's the "no, stop don't touch them" part in the CVR transcript.
Attitude information was never lost. Only the speed indication was lost on all instruments including the ISIS.
BEA announced that they will publish the official English translation this Wednesday. Till then you have to live with the French version.
It's very hard to read because the guys up front never had a chance to recover from the situation they were in. They weren't trained to handle that situation. It's sad to see how everything lines up perfectly against them.
No offense Pepe, but your translation is "not perfect". There is a better one on pprune. At the beginnig for example the PNF was actually commanding the PF to descend. The PF was climbing with 7k fpm right after he assumed command.
I also don't want to judge those guys, but CRM was non-existent most of the time. The Stall Warning stopped right before the Cpt entered the cockpit. The PF and PNF didn't say a word about what happened up until the moment he entered the flightdeck. He had to figure it out on his own but he was lacking important information how they actually got into the situation.
The PF didn't had the feeling that they were climbing. He thought that they were too fast. On the CVR you can hear an increase in loudness, which is accredited to ice crystals above the thunderstorm cell. The PF misinterpreted that increase in loudness and thought that they were accelerating. Shortly after that the pitots froze and speed indications were lost followed by the AP/AT disconnection. He even deployed the spoiler. That's the "no, stop don't touch them" part in the CVR transcript.
Attitude information was never lost. Only the speed indication was lost on all instruments including the ISIS.
BEA announced that they will publish the official English translation this Wednesday. Till then you have to live with the French version.
It's very hard to read because the guys up front never had a chance to recover from the situation they were in. They weren't trained to handle that situation. It's sad to see how everything lines up perfectly against them.
seagull
Well-Known Member
Are you positive that is not AoA, because that's what it looks like to me?
Pépé le Pilot
Well-Known Member
Let me look it up tonight. As for the translation, it's straight from the link I gave. Sorry it's not as great as the one on pprune, I have a job, flying, and it was a quick translation.
Edit : incidence is AoA !
Bernoulli Fan
Controller
My French is ok; I believe you are correct: the AoA remains near 40 degrees on the way down. The pitch initially goes to 12 degrees nose up when they climb to FL380, then varies between 2 and 8 degrees on the way down.
Sorry Pepe, I didn't want to criticize you. It honors you that you actually provided a quick translation. Nevertheless there are crucial parts which aren't reflected correctly by your translation.
The Cpt wasn't thinking that they were climbing. He actually said:
PNF: Alors donne-moi les commandes à moi les commandes
So give the me controls. I have control
that's when the PNF took over the controls
PF: Vas-y tu as les commandes on est en TOGA toujours hein
Go on, you have control. We're still in TOGA.
CAP: Attention tu cabres là
Watch it, you're pitching up
PNF: Je cabre ?
I'm pitching up?
Some people think that the Cpt was an the right way to realize that they were stalling all the time. But sadly every time when the PF pitched down the Airspeed Data became valid again (>60 kts) and the stall warning started again. So the PF pulled the SS back and they slowed down below 60 kts, the data was rendered invalid and the stall warning stopped.
The AOA was around 38° all the time.
The complete French report can be found here:
http://media.webcastor.fr/web/bea/f-cp090601e3.pdf
The 3D flight path is on page 11.
FDR Data can be found in chart form on pages 109 and following.
The CVR transcripts (in French) are on pages 91 and following.
More "refined" FDR Data can be found on pages 31 and following.
You should pay attention to the fact that this is an interim report (a 117 pages interim report...) and not the final report of the investigation. BEA hasn't released all of the information yet.
And like I said earlier, the translated version should be published on Wednesday.
wheelsup
Well-Known Member
So wait, with no stall indication, bad a/s indications, and a pitch attitude of around 8-10*, I can see how you can get into this situation. I wonder if they'd had an AOA indicator in the cockpit, they would've pitched down instead. Scary stuff.
Speed Pilot
Brain Damaged
From what I've read, there is no Angle of Attack indicator. I can see it being hard to wrap your mind around that you are in a stall at only 10 degrees nose up and TOGA power.
wheelsup
Well-Known Member
Especially when the stall warning goes away when you pitch up to that. No stall warning combined with TOGA power and 8* pitch up sounds like exactly what we practice here when we get into a stall.
Speed Pilot
Brain Damaged
Yeah, it sounds more and more like they did everything the way they were trained to do it. Alternate Law of the Airbus seems to have been what did them in. They acknowledged that mode switch but were they already so busy at that point that they didn't have time to comprehend everything that it entailed?
drunkenbeagle
Gang Member
Even a yaw string taped to the window would have done fine - they would have noticed it standing straight up.
wheelsup
Well-Known Member
At night, in the clouds, turbulence, lightning, strobes, and beacon going? While not even knowing what was happening at that time? HAHAHAHAHA
wheelsup
Well-Known Member
It's funny, all that technology and a simple C172 or Piper Warrior stall warning system with the tab would've kept them in the loop, at least the way I look at it. Crazy. From the sounds of it, they were past the stall phase and basically falling practically straight down like a dropped piece of paper.
I must've missed it but how did they get into that situation to begin with? Why did they pitch up so much at the beginning? Is that what bled their airspeed off to below 60 knots indicated?
Speed Pilot
Brain Damaged
If I remember right when they lost all data and everything disconnected, they pitched up, in alternate law with all protections gone, it let them stall the airplane. I am going to lunch, I'll try to find those passages in the data when I get back.
seagull
Well-Known Member
Like I said it all began when the pitot tubes froze.
Autopilot and Autothrottle disconnected followed by the change to alternate law. Alternate law was announced by the SFO (PNF) and the FO (PF) acknowledged. He took the controls and it went downhill from here. He pitched up (he thought that they were accelerating, at least that's the theory right now). The increase in pitch resulted in a climb with an initial climbrate of 7000 fpm from FL350 up to around FL370. At the end of that climb the aircraft of course lost its speed and stalled. Up to this point the situation was actually salvageable.
But then the stall warning started and he actually did the wrong thing in that situation. He selected TOGA and started to pitch up again. Maybe he didn't want to lose altitude, I don't know. Nevertheless from this point on they were doomed. There were several factors which worked against them. Like the "not really optimal" stall warning logic built in by Airbus. On the other hand that aircraft was never designed to fly slower than 60 kts. I mean, nobody really wants a stall warning every time they are below 60 kts.
And there was the lack of good CRM. The Cpt didn't know that they climbed to FL370 and actually had an active stall warning. Like I said the stall warning stopped moments before he reached the flightdeck. The FO said several times that he felt like they were flying too fast, even during the stall. But they somehow ignored him and didn't address his concern.
And there was also the lack of good training. Hand flying at high altitudes didn't belong to the training syllabus. Alternate Law in high altitudes wasn't trained either. And so on.
They pilots weren't trained to handle a high altitude stall. At least not a full stall. They only received the standard approach to stall training. Of course there is the problem that you actually don't have realistic flight data (from test flights) to feed a simulator in order to depict a full stall in simulator. Nobody would risk a real A330 for the collection of data. The models used are AFAIK computed and not 100% accurate.
Airbus released a new stall recovery procedure in the wake of the investigations: http://www.flightglobal.com/article...procedures-centre-on-angle-of-attack-not.html .
I'm not judging the crew. I'm sure that I would have reacted the same way with the same training as they had...maybe. It's easy to analyze all the things they did wrong from my comfy couch.
I rather would like to show, that the AF crash is going to change a lot of things because of the many factors (CRM, training, Human-Machine Interface) involved.
BeRich
Very Special Agent
Especially with the warning horn going only when you pitch down. Definitely a crappy situation to be in.
