Air France 447 - On topic only!

[ca787546]

For how long, I wonder, might they have been stalled and falling and not even realized it?

At a V/S of 10000+ft/min.... my guess is not very long unfortunately....

[Evan]

A reminder about the Airbus procedure, which says that if the safety of the flight is directly affected, such procedure is to be followed. I know some people may think that "hey, I'm in partial panel, the safety of the flight is directly affected" Truth is, if you're at FL350, over the atlantic, and the aircraft is still flying safely, perhaps it could be better to leave the thrust at the current condition (if it's not at idle and was maintaining speed at the moment of autothrust disconnection), and leave the pitch at the current angle, as well as maintain the wings level.

In the post-AF447 world, I'm really hoping the gravity of the situation is more apparent, the hidden dangers are more clear and the memory items are taught as a requirement whenever UAS occurs at altitude.

Finally, let's remember that there's also a note in that specifies that only the ISIS and PFD1 information is available from the recorder, and that the PF was flying with the information from PFD2, so in reality, we're not sure what he was actually observing during the last minutes of the flight.

I didn't realize that. Has that been confirmed? I was assuming the PF was the senior F/O. The junior officer had only 807 hours on type.

[ca787546]

Evan, this is the thing, had the PF not pulled up, mostly left the aircraft "as is" it would've very likely remained in a more stable flight path. I am not saying they should've done or not done something, that's for the professional accident investigators to decide, but I am just explaining why airbus mentions "If the safe conduct of the flight is impacted:" right before listing the UAS memory items part of the procedure. The reason for such memory items are to stabilize the aircraft in a climb when close to terrain so as to clear the terrain and consequently level the aircraft off for troubleshooting. If the aircraft is already clear of terrain, and levelled off, then we are potentially better off leaving it more or less in that stable condition and while still flying the aircraft with partial panel, troubleshoot the failure. Now, to this situation, add the fact that you're in the middle of the atlantic, dark in the middle of the night, in IMC conditions, with weather and turbulence around you, and a few other ECAMs going on in relation to the failure. Also, imagine that they had just switched seats not long before for the captain to go take his rest. The flight ahead is long, and the rush of the departure has past, now they are more likely settling for the long hours of cruise ahead through the night. I imagine that even for a trained and experienced pilot, you would have a startling factor, even if a minor one when suddenly your airspeed tape on the PFD drops to 60 knots or so... I'm not sure what your experience is with aviation Evan, but if you're a pilot I'm sure you'd understand what I'm talking about. Experience sure helps you to keep cooler than the inexperienced pilot, but it doesn't make you infallible.

Also, about the FO being the PF, that's what I understood from reading the note sent out by the BEA. The FO was the PF from the beginning, and he remained so until about 1 minute prior to impact when he transferred the controls to the other FO which was seating on the left seat. The Captain was on the left seat until he was relieved for his rest by the other FO, which would then take his seat and have continued acting as PNF until the last minute of the flight when he finally took controls.

[Fear_of_Flying]

Evan, this is the thing, had the PF not pulled up, mostly left the aircraft "as is" it would've very likely remained in a more stable flight path. I am not saying they should've done or not done something, that's for the professional accident investigators to decide, but I am just explaining why airbus mentions "If the safe conduct of the flight is impacted:" right before listing the UAS memory items part of the procedure. The reason for such memory items are to stabilize the aircraft in a climb when close to terrain so as to clear the terrain and consequently level the aircraft off for troubleshooting. If the aircraft is already clear of terrain, and levelled off, then we are potentially better off leaving it more or less in that stable condition and while still flying the aircraft with partial panel, troubleshoot the failure. Now, to this situation, add the fact that you're in the middle of the atlantic, dark in the middle of the night, in IMC conditions, with weather and turbulence around you, and a few other ECAMs going on in relation to the failure. Also, imagine that they had just switched seats not long before for the captain to go take his rest. The flight ahead is long, and the rush of the departure has past, now they are more likely settling for the long hours of cruise ahead through the night. I imagine that even for a trained and experienced pilot, you would have a startling factor, even if a minor one when suddenly your airspeed tape on the PFD drops to 60 knots or so... I'm not sure what your experience is with aviation Evan, but if you're a pilot I'm sure you'd understand what I'm talking about. Experience sure helps you to keep cooler than the inexperienced pilot, but it doesn't make you infallible.

You've lost me a little bit here, CA - remember I'm a non-expert on all things aviation.

I get that the environment would have been harrowing, and that can explain someone making mistakes.

I get that using the memory items is to some extent a judgment call - to be used when the safety of the flight is jeopardized. Further, I understand your point that in this instance, maintaining thrust, attitude, and keeping the wings level may have been a prudent course of action.

But the pilot didn't do that. He pushed the nose up 10 degrees with no thrust, and stalled the aircraft with stall warnings blaring.

You suggest that perhaps he was partially following the memory items by using nose-up inputs, albeit far in excess of what was needed. But with no thrust? I would hope those memory items would be as familiar as the 6x tables to the pilots, stressed out or not.

On the other hand, if he was attempting to keep the aircraft in safe flight, he again did so with disastrous results, as he did not maintain the conditions that so far had kept the aircraft flying. So which was it? Personally, I can't see how one could infer very easily that he was doing either one of those things.

Then, once the plane was stalled, and you suggest that would have been apparent quickly to the pilots, do you see much indication that they performed actions that would have taken the aircraft out of the stall?

Thanks for your patience.

[Fear_of_Flying]

I guess the other comment I would make is with respect to your point that the pilots had just changed seats and were hunkering down for a long lazy flight across the ocean. It seems to me that flying through a massive cell of thunderstorms should have been enough to perk them up a little bit, and if not, well, isn't the ability of a pilot to respond immediately and effectively to adverse circumstances probably the most important job he has? Not just setting the flaps for take-off. Otherwise, we might as well get to the fully automated aircraft sooner rather than later.

Again, my apologies for the naive perspective.

[Theoddkiwi]

I didn't realize that. Has that been confirmed? I was assuming the PF was the senior F/O. The junior officer had only 807 hours on type.

Yes i picked that out of the info to. The PF was looking at the PFD2 that was not recorded by the FDR. So there is quite a good possibility that his indications were very different from the PFD1 and ISIS indications such is the nature of ice affected Pitot tubes. This will make analysis of his actions a bit harder.

I find it quite odd that the FDR only takes data from the Capt PFD and ISIS.

[ca787546]

Hey guys, I cannot defend nor attack the actions of the pilots at this time, nor do I intend to do either of those things. What I am trying to do is try to explain the situation they found themselves in, the tools, procedures and information they may have had available as resources, and try to figure out where things went wrong. I am not sure why the PF pulled back on the stick after losing his airspeed information. I pointed out that he perhaps tried to initiate the memory items, but that's not certain to me. He didn't stall the aircraft until much later. You have to realize that the aircraft climbed from 35000' to 38000' at around 7000'/min according to the note (stalled aircraft don't really climb well!!!). Let's remember that the "STALL STALL" aural warning come on before the aircraft stalls. The STALL aural warning is triggered in base to the angle of attack. Mind you, at high altitudes such as the ones the A330 was flying at, even a small pitch up command may give stall warnings under heavy weights in level flight compared to lighter weights at around sea level. The intuitive action in case of an impending stall is to reduce the angle of attack, either by easing on the back pressure on the sidestick, or even gently pushing the sidestick forward until the aircraft regains enough lift, then apply power accordingly. During the climb towards 38000 feet the PF did make nose down pitch inputs on the sidestick. This nose down inputs reduced the climb rate to 700'/min. At this time, the speed came back, showing 215 knots indicated, which is quite low for the conditions, and another stall aural warning came on. At this time, the PF applied TOGA thrust, and he put nose-up commands on the sidestick once more. This is when I believe the aircraft must've nosed up quite a bit. The application of TOGA thrust creates a strong pitch up momentum on this kind of aircraft. Add to this the nose-up command on the sidestick, and the auto-trim function trimming nose-up to compensate for the loss of airspeed; as well as the heavy aircraft, with slightly aft CG (although within operational limits), and the fact that they were at a very high altitude for that weight by now (38000') meant they ended up in a stall situation. Soon afterwards, the STALL warnings STOPPED! So imagine you just put full TOGA thrust, and the aircraft stall warnings stopped sounding... what would you think? I would likely think that the stall situation is no longer. Truth is, the aircraft was still stalled, it was even in a deeper stall than before, but because the speed indications dropped below 60 knots the AOA indications became invalid for the system, and thus the stall warning stopped. The aircraft was falling from the sky in a stall, but then both the pilots said that they didn't have any more "indications." What did they mean by that, I am not certain, but during this time, they had been fighting to keep the wings level (due to the stall, one wing or the other may suddenly fall due to even the smallest amount of yaw or disturbance in the airflow). Because of the lack of a stall warning, they eventually reduced the thrust to idle. Then, with no more indications, the PF put some nose-down pressure on the sidestick (pushed the sidestick down) and with this reduced the angle of attack, and also increased the airspeed of the aircraft to the point where the AOA indications became valid again, triggering again the stall aural warning. By now, the aircraft was in a deep stall, falling from the sky, close to 10000' when both of them applied commands to their sidestick, and this is when they noticed they were about to reach 10'000 feet, and the Left seat FO transferred controls to the right seat FO. It is unclear from the note what actions the Left Seat FO took after this, but less than a minute later they had crashed into the ocean. That is what I gather from the BEA note. The initial drop in airspeed was likely due to unreliable airspeed due to the pitot tubes in the given aircraft being more prone to icing, but the later drops of airspeed may have been real indications, but perhaps the pilots were still thinking the speed was no longer reliable.

Now, Fear Of Flying, to your comment. I just took a considerable amount of time writing this post, analyzing the 4 page note from the BEA, and looking through some of my Airbus manuals while doing this. These pilots had 4 minutes from the moment they first had the UAS indications until they impacted into the sea. This occurred to them 4 hours after the engine start up. The flight started at 22:10 Rio time, and the accident occurred at 02:14 Rio time. I agree, pilots should be able to react immediately and effectively during all portions of the flight, but they are also humans. Few people know what it is like to fly from Paris-Rio-Paris, have 1 or 2 days layover there working with the jetlag of the timezone changes, then get up at 19:30 or so local time (remember, have to sleep before your flight, even if it's daylight!), then head to the airport, go through the briefing, security, immigration and so on. Then do a complete cockpit preparation and walk around. Then take-off, do the departure, do the communications and preparations for the atlantic crossing, and finally settle into the cruise. By now, it's 2AM local time in Rio, but it's actually 7AM in Paris where your base is at. So, do you think you may be a bit tired by then? I would say so, because your circadian rythm has been thrown into a blender and the puree button been pushed. This is a long haul pilot's every day life. Somehow we manage to keep the skies mostly safe, safer than drivers do on the road that is, at least if we are to believe those people making the statistical data. It takes very focused and motivated individuals to keep up with the lifestyle, and pilots love flying, that's why we put up with the crazy schedules. Unfortunately, we're humans and we make errors, some are non-consequential, and some have consequences. We have training, information, references, technology, forecasting, etc etc etc at our disposal to try to mitigate those errors, or try to correct them, or try to stop them from developing into an accident, but it's difficult to completely eradicate the chances of an air disaster occurring.... we learn from every accident in the aviation industry. That's what I can say, I will keep on learning, that's what I do. Like they tell you when you get your private license: "this is a license to learn"
So I apologize on behalf of the pilots of AF447 for making a mistake that cost them their lives, I know in no way it would be of any consolation to the relatives of the victims, but trust me, I am 100% certain they were doing their absolute best with what they had right there and then, unfortunately it didn't cut it right there and then. There have been many corrections and recommendations put in motion since these accident, even before the CVR and FDR were recovered.

[Fear_of_Flying]

Hey guys, I cannot defend nor attack the actions of the pilots at this time, nor do I intend to do either of those things. What I am trying to do is try to explain the situation they found themselves in, the tools, procedures and information they may have had available as resources, and try to figure out where things went wrong. I am not sure why the PF pulled back on the stick after losing his airspeed information. I pointed out that he perhaps tried to initiate the memory items, but that's not certain to me. He didn't stall the aircraft until much later. You have to realize that the aircraft climbed from 35000' to 38000' at around 7000'/min according to the note (stalled aircraft don't really climb well!!!). Let's remember that the "STALL STALL" aural warning come on before the aircraft stalls. The STALL aural warning is triggered in base to the angle of attack. Mind you, at high altitudes such as the ones the A330 was flying at, even a small pitch up command may give stall warnings under heavy weights in level flight compared to lighter weights at around sea level. The intuitive action in case of an impending stall is to reduce the angle of attack, either by easing on the back pressure on the sidestick, or even gently pushing the sidestick forward until the aircraft regains enough lift, then apply power accordingly. During the climb towards 38000 feet the PF did make nose down pitch inputs on the sidestick. This nose down inputs reduced the climb rate to 700'/min. At this time, the speed came back, showing 215 knots indicated, which is quite low for the conditions, and another stall aural warning came on. At this time, the PF applied TOGA thrust, and he put nose-up commands on the sidestick once more. This is when I believe the aircraft must've nosed up quite a bit. The application of TOGA thrust creates a strong pitch up momentum on this kind of aircraft. Add to this the nose-up command on the sidestick, and the auto-trim function trimming nose-up to compensate for the loss of airspeed; as well as the heavy aircraft, with slightly aft CG (although within operational limits), and the fact that they were at a very high altitude for that weight by now (38000') meant they ended up in a stall situation. Soon afterwards, the STALL warnings STOPPED! So imagine you just put full TOGA thrust, and the aircraft stall warnings stopped sounding... what would you think? I would likely think that the stall situation is no longer. Truth is, the aircraft was still stalled, it was even in a deeper stall than before, but because the speed indications dropped below 60 knots the AOA indications became invalid for the system, and thus the stall warning stopped. The aircraft was falling from the sky in a stall, but then both the pilots said that they didn't have any more "indications." What did they mean by that, I am not certain, but during this time, they had been fighting to keep the wings level (due to the stall, one wing or the other may suddenly fall due to even the smallest amount of yaw or disturbance in the airflow). Because of the lack of a stall warning, they eventually reduced the thrust to idle. Then, with no more indications, the PF put some nose-down pressure on the sidestick (pushed the sidestick down) and with this reduced the angle of attack, and also increased the airspeed of the aircraft to the point where the AOA indications became valid again, triggering again the stall aural warning. By now, the aircraft was in a deep stall, falling from the sky, close to 10000' when both of them applied commands to their sidestick, and this is when they noticed they were about to reach 10'000 feet, and the Left seat FO transferred controls to the right seat FO. It is unclear from the note what actions the Left Seat FO took after this, but less than a minute later they had crashed into the ocean. That is what I gather from the BEA note. The initial drop in airspeed was likely due to unreliable airspeed due to the pitot tubes in the given aircraft being more prone to icing, but the later drops of airspeed may have been real indications, but perhaps the pilots were still thinking the speed was no longer reliable.

Now, Fear Of Flying, to your comment. I just took a considerable amount of time writing this post, analyzing the 4 page note from the BEA, and looking through some of my Airbus manuals while doing this. These pilots had 4 minutes from the moment they first had the UAS indications until they impacted into the sea. This occurred to them 4 hours after the engine start up. The flight started at 22:10 Rio time, and the accident occurred at 02:14 Rio time. I agree, pilots should be able to react immediately and effectively during all portions of the flight, but they are also humans. Few people know what it is like to fly from Paris-Rio-Paris, have 1 or 2 days layover there working with the jetlag of the timezone changes, then get up at 19:30 or so local time (remember, have to sleep before your flight, even if it's daylight!), then head to the airport, go through the briefing, security, immigration and so on. Then do a complete cockpit preparation and walk around. Then take-off, do the departure, do the communications and preparations for the atlantic crossing, and finally settle into the cruise. By now, it's 2AM local time in Rio, but it's actually 7AM in Paris where your base is at. So, do you think you may be a bit tired by then? I would say so, because your circadian rythm has been thrown into a blender and the puree button been pushed. This is a long haul pilot's every day life. Somehow we manage to keep the skies mostly safe, safer than drivers do on the road that is, at least if we are to believe those people making the statistical data. It takes very focused and motivated individuals to keep up with the lifestyle, and pilots love flying, that's why we put up with the crazy schedules. Unfortunately, we're humans and we make errors, some are non-consequential, and some have consequences. We have training, information, references, technology, forecasting, etc etc etc at our disposal to try to mitigate those errors, or try to correct them, or try to stop them from developing into an accident, but it's difficult to completely eradicate the chances of an air disaster occurring.... we learn from every accident in the aviation industry. That's what I can say, I will keep on learning, that's what I do. Like they tell you when you get your private license: "this is a license to learn"
So I apologize on behalf of the pilots of AF447 for making a mistake that cost them their lives, I know in no way it would be of any consolation to the relatives of the victims, but trust me, I am 100% certain they were doing their absolute best with what they had right there and then, unfortunately it didn't cut it right there and then. There have been many corrections and recommendations put in motion since these accident, even before the CVR and FDR were recovered.

Thank you for your honest and thoughtful posts. I'm sure no one thinks this was anything other than a tragic accident, and "pilot error", insofar as it may have played a role, is an unfortunate term, in that it should not be taken in a pejorative sense.

The sequence of events is, however, still unclear to me, including when the pilots realized they had stalled the aircraft. That is why I asked how long they might have been stalled and not even realized it. You seem to be suggesting that they fell for some time not understanding their condition.

I'm still leaning towards deer-in-the-headlights as a leading theory. Even the fact that the PNF called for the senior pilot repeatedly seems a bit odd to me. How did he find the time to do that? And does it not speak to the possibility that he felt he was in over his head?

I am, however, amongst the great unwashed.

In any event, as Evan said, the "note" seems to raise more questions than it does answers, and hopefully the next report will clarify further the chain of events.

Thanks again.

[Harding]

Hey Guys.
My dad is not into aviation in any way - but he is quite intrested in this accident, and he made me summarize the information i had. He actually had a great question for being a "non-aviation person".

As we recall, in the very beginning when the tail fin was found, people suggested that it perhaps was torn apart mid flight - and its now known to us that the vertical speed of the stall was ~10900ft/m.

Would this airplane withstand the force of this stall?
Is there any possibilities that the tail fin actually was ripped off during this stall - and by result, the airplane was no longer controllable?

The last recorded values were a pitch attitude of 16.2 degrees nose-up, a roll angle of 5.3 degrees left and a vertical speed of -10,912 ft/min.

Does some of this information indicate this?

[Evan]

Evan, this is the thing, had the PF not pulled up, mostly left the aircraft "as is" it would've very likely remained in a more stable flight path. I am not saying they should've done or not done something, that's for the professional accident investigators to decide, but I am just explaining why airbus mentions "If the safe conduct of the flight is impacted:" right before listing the UAS memory items part of the procedure. The reason for such memory items are to stabilize the aircraft in a climb when close to terrain so as to clear the terrain and consequently level the aircraft off for troubleshooting. If the aircraft is already clear of terrain, and levelled off, then we are potentially better off leaving it more or less in that stable condition and while still flying the aircraft with partial panel, troubleshoot the failure.

This is very interesting. We (including the investigation team) have been very interested to know why the memory items have not been performed in the past. Your statement here is not what is stated in the FCOM of the FCTM, but perhaps had become conventional wisdom among Airbus pilots. The Airbus lit is ambiguous enough to allow for that. The question is this: how do you know, instantly, in a moment like this, what the A/THR setting is? You can't get a visual cue from the TLA. What if the A/THR is slowing for turbulence penetration? The FMA will tell you 'THR LK' mode. The only way to quickly unsure adequate thrust is to move the levers, right? And 5° pitch is a nice, conservative amount of drag to allow for it. If you are already at 2-3°, it's a minor adjustment, so there is no risk of overcontrol like we are seeing here. This is why I am hoping the new policy is to ALWAYS execute the memory items above FL100, regardless of terrain issues.

Few people know what it is like to fly from Paris-Rio-Paris, have 1 or 2 days layover there working with the jetlag of the timezone changes, then get up at 19:30 or so local time (remember, have to sleep before your flight, even if it's daylight!), then head to the airport, go through the briefing, security, immigration and so on.

I'm sure you are right about that, but there are some people who understand this very well and they write the procedures that must be followed. If pilots have memory items memorized, and do these instinctively, they don't need to really think the situation through to stabilize the aircraft. Once the initial shock factor passes, they can go to the QRH and sort things out.

[opa-opa]

Too many unknowns

Hi this is my first post in this thread.

So far all we know is HOW the plane crashed. But what we don't know is the WHY. Why did the co-pilot ignore the stall warnings? Why did he not try to recover from the stall? I feel like there is a lot of info the BEA is purposely not telling us, and much of it is stuff from the CVR. I'm sure there were many, many frantic things said between the 3 people in that cockpit, but for some reason the BEA only chose to reveal 3-4 sentences to us. Why? Is there some troubling, controversial information in their conversations that they don't want to reveal (unless it's in a courtroom?) IMHO we already know all the mechanical, aerodynamic details involved in the crash. But the human, behavorial details still have barely been released to the public. We've all been making theories about lack of training, confusion, etc, but maybe the real answer is even simpler than that? And why is Air France insisting so strongly that the pilots' behavior wasn't anything but "professional" while in the cockpit? Do they know something?

[ca787546]

Hey guys, like I said, not an investigator here, and definitely don't have all the data. How long were the pilots aware or unaware of the stall, I am not certain. What information did the pilot have at his disposal isn't certain either. Also, like with most failures, troubleshooting may be required. You're trying to figure out what information is reliable and which is not. Is the speed reliable or no longer reliable? Did it come back or is it still unreliably telling them that they're flying 215 knots? Since the pitots iced up, could the static information be unreliable as well (Vertical speed/Altitude information)?
By the way, the FCOM and FCTM do state CLEARLY that if the safety of the flight is impacted one should follow the memory items for UAS... if the aircraft is in level flight and clear of terrain I would not follow them, as the safety of the flight is not impacted. If I was heavy and flying at 41000 feet in the A330, and my airspeed drops to 60 knots, I am going to try to not touch anything unless required if the aircraft is stable. At heavy weights and high altitudes close to the maximum recommended altitude an aircraft is finely trimmed and without much margin below or above speedwise. This is not the first case of an A330 losing airspeed indication, and most of the other cases that I've heard from fellow pilots and my own case of UAS, we left the aircraft as is, and luckily we regained airspeed indication soon thereafter while going for the QRH unreliable speed indication checklist. Had there been impending danger to the safety of the flight, we may have followed the memory items.

When the Autothrust is disconnected without the pilot's command, it goes into thrust-lock mode. The thrust levers remain in their position, but looking at the EPR or N1 indications on the Engine/Warning display will quickly tell you the thrust they are locked at and you may move the Thrust Levers to match the TLA indication to that of the thrust being produced.
Now, as of why the PNF repeatedly tried to call the captain to the flight deck? I think that is obvious. First of all, I am 99.99% sure that it is part of their procedures to call the captain to the flight deck in case of any abnormal or emergency procedure. Second of all, imagine yourself as the Senior First Officer of the flight acting as PNF, would you consider calling the Captain forward or would you leave the experience and input he may have resting in the back? Now, put yourself in the Captain's shoes and ask yourself if you'd like to be woken up from your rest in case of UAS? Also, it doesn't take long to push a button on the pedestal and say "captain to the flight deck." Ok, I think I don't have to go over that point any further.
To the point of the tail withstanding the airflow. 10900 ft per minute is just slightly above 100 knots. Those 100 knots is a true airspeed, which means that due to the changes in temperature and air density at higher altitudes would become a lower indicated airspeed if you were to measure it. This airspeed is measured vertically, so it would be equal to just exactly the vertical vector of the movement of the aircraft. I'm not an expert in this matter, but my opinion is that the tail would've been able to stand this aerodynamic forces (but don't take my word for it!).

Evan, the procedures are written by people that have a deep understanding of the commercial aviation business. They are usually drafted by teams. These teams may include engineers, pilots, aviation lawyers, and other consultants. You have to understand that aviation is a multi-million dollar business, and people will always try to cover themselves and all the bases.
The reason the FCTM and FCOM specify that you may not always fly the memory items in case of UAS is for a reason. Imagine the case stated above, where the aircraft is heavy and close to its maximum ceiling, with protections lost due to a loss of airspeed indications. I pull gently on the sidestick but end up increasing the nose slightly more than I needed, as I try to correct this, I increase the thrust to climb power, which creates a further pitch-up momentum. Now my nose is at 7.5 or 10 degrees nose up. Guess what, the aircraft was not in a low energy level and it of course climbs. And it climbs fast past its maximum recommended ceiling. I am now in a potential of overspeeding and stalling the aircraft at the same time. I have a lot of work on my hands to recover from the situation I put myself in. Now imagine, at the same time, 1 mile to my right, the exact same aircraft type, in the exact same conditions goes through the same problems, but they choose to not follow the memory items as they feel the aircraft is still flying safely, even though they've lost their airspeed indications. The aircraft remains flying, perhaps losing a couple hundred feed, or maybe gaining a couple hundred feet, losing a few knots, or gaining a few knots, as it was trimmed, and the thrust set to maintain level flight. The one that remains level starts going through the QRH to get the unreliable speed indication checklist and troubleshoot. 30 seconds later, both aircraft's pitot tubes became unclogged, and airspeed indication is regained. Which one is in a favourable condition?
Now, let's examing a different scenario. Both aircraft are in descent into Geneva Airport in Switzerland in instrument meteorological conditions at night through 20000 feet at a rate of 2000'/minute. Both aircraft lose the Airspeed indications. One of them decides to not follow the memory items and continue the descent, while looking for the UAS checklist in the QRH. The second aircraft decides to follow the memory items, and increases the pitch and thrust to reach 5 degrees nose up and climb thrust. The aircraft here are at a high level of energy, far away from their aerodynamic limitations, and closing in on mountainous terrain. The 1st aircraft that continued the descent now gets a ground proximity warning system alert advising them of terrain ahead and soon after they get the "pull up" alarm. They now increase the thrust to TOGA, and pull back on the sidestick, creating a very powerful nose up momentum and the pitch of the aircraft increases to perhaps 20-25 degrees nose up. The 2nd aircraft doesn't get a GPWS warning, and once they are above the Minimum Obstacle altitudes for their area get the tables off the QRH and level the aircraft off to troubleshoot the problem. As you can see, that is why the FCOM, QRH and FCTM say "if the safety of the flight is impacted" before listing the memory items for UAS.
Finally, there is a reason why the BEA is not releasing all information and transcripts right away. I'm not certain, but I figure it is likely so that it may be analyzed by professionals and experts in their fields before the media and other people without the proper qualifications start misreading the information and drawing wrong and erroneous conclusions. That is never healthy for any investigation, let it be an aviation accident or a criminal investigation.
I think it is obvious why AF would continuously say that their pilots were completely professional while in the cockpit. Now, I want you question when was the last time you made a mistake at work? Now, think about everything you said to your co-workers throughout that whole day before you made that mistake at work. Now, I ask you, would you like a transcript of that day's conversation posted on the CNN website? I'm not talking just business related conversations, I'm talking ALL conversations, including the joke by the water cooler, or anything you may have said to your best buddy on the desk next to yours. that's a cockpit voice recorder!

[guamainiac]

Let me ask a question about the shape and dynamics of the system they were flying in and how that may affect the way the "stick" was handled.

The conventional logic is that we view the storm as an "updraft" and that is the profile most are familiar with.

Depending on the maturity of the cell there can also be associated downdrafts that are as severe as the updrafts. It is possible they went from that part of the system that (perhaps), contributed to the gain in altitude that took them to 38,000 feet and then into a shear or downdraft that sealed their fate?

Many times the thermal system is more like a mushroom with decay along the edges?

[ca787546]

Let me ask a question about the shape and dynamics of the system they were flying in and how that may affect the way the "stick" was handled.

The conventional logic is that we view the storm as an "updraft" and that is the profile most are familiar with.

Depending on the maturity of the cell there can also be associated downdrafts that are as severe as the updrafts. It is possible they went from that part of the system that (perhaps), contributed to the gain in altitude that took them to 38,000 feet and then into a shear or downdraft that sealed their fate?

Many times the thermal system is more like a mushroom with decay along the edges?

That is a completely possible contributing factor. Strong up and down drafts are common in thunderstorm cells.

[opa-opa]

Well

Finally, there is a reason why the BEA is not releasing all information and transcripts right away. I'm not certain, but I figure it is likely so that it may be analyzed by professionals and experts in their fields before the media and other people without the proper qualifications start misreading the information and drawing wrong and erroneous conclusions. That is never healthy for any investigation, let it be an aviation accident or a criminal investigation.

I think it is obvious why AF would continuously say that their pilots were completely professional while in the cockpit. Now, I want you question when was the last time you made a mistake at work? Now, think about everything you said to your co-workers throughout that whole day before you made that mistake at work. Now, I ask you, would you like a transcript of that day's conversation posted on the CNN website? I'm not talking just business related conversations, I'm talking ALL conversations, including the joke by the water cooler, or anything you may have said to your best buddy on the desk next to yours. that's a cockpit voice recorder!

What I find strange is not the fact they haven't released the whole transcript, but why they selected to release just those few particular quotes uttered by the pilots out of the whole critical 4 minutes. For example whatever instructions the senior captain gave after he returned to the cockpit would be quite important; why was nothing he said mentioned?

And although Air France's response isn't all unexpected, it's a little off-putting that they would circle the wagons so soon, before all the information is made public. Are they worried about something that might come out when all the truth is known?

BTW here's a pretty good timeline of the events:

http://www.spiegel.de/international/world/bild-765764-220365.html

According to this, the senior captain entered the cabin just after the stall occurred and according to the article, he gave instructions to push the nose down. However, the co-pilot didn't do so until 2:12:17, almost 30 secs later. What happened in that half minute between 2:11:40 and 2:12:17? And why was nothing in the CVR transcript released from 2:12:40 to 2:13:32?