Air France 447 - On topic only!

[BoeingBobby]

I rode in the crew bus a couple of days ago with a Jet Blue Airbus pilot and we discussed this for a few minutes. He told me that there is NO WAY to get control of the flight controls manually on the Airbus. An ex F-18 Navy pilot so he is used to the FBW systems. Airbus goes on the assumptions that with the redundancy built into these systems, the possibility of all of them failing is very unlikely. oooops!

[BoeingBobby]

I was thinking today about the plane's captain, and how he was at a significant disadvantage in terms of understanding what was going on.

He was absent when the autopilot went off and the PF pulled up. He didn't witness the first stall alarm go off, and then see the PF pull up again. Then he missed the critical 20 seconds, when the plane went from a climb to a steep descent, in essence, when it went from flying to not flying. This is when I imagine there would have been a notable shift in how the aircraft was behaving, the noise that it made, and the accompanying sensation. It was also shortly after that that the PF said he had lost control. This entire sequence of events might have informed the captain more clearly as to what was transpiring.

As it was, he entered the cockpit when the aircraft was already stalled. He had no idea of what to look for in a stall, as to the best of my knowledge "stall recognition" is not taught, nor of course would he know what a stall "feels" or "sounds" like. While we may say that he still should have been able to put together the fact that the plane was falling precipitously along with the other stall symptoms, it certainly would not have been as straightforward a task as it would have been had he been present when the plane was put into the stall in the first place.

To some extent, then, perhaps his mind-numbingly catatonic behavior is understandable.

The other thought that occurred to me today was just how pathetic it was that this plane was falling like a boulder from the sky while the pilots were entering these completely pointless and irrelevant inputs to keep the wings level and control the roll. Such a non sequitur, really the opposite of pilots fighting valiantly to keep the plane flying.

We train in the simulator every six months. Stall recognition and recovery is done in take-off, landing and cruise flight conditions. So I am afraid your knowledge is flawed a bit here.

[seahawk]

If the machine could not tell the pilots what is wrong in a clear and understandable way, the machine is to blame and I think that the man-to-machine interface is wrong. I think such planes must be considered unsafe to fly, especially as the computer never allows manual control of the airplane.

[mawheatley]

Please excuse me if this is a dumb question, but even when stalled, and falling rapidly, would there not be some clue in that walking towards the flight deck you're walking uphill? I know you're not pulling positive g's - in fact you're probably in negative territory here, but wouldn't the front at least look higher than the back? In that case the captain is surely at an advantage, rather than a disadvantage, in that by the time he got there he'd at least had the opportunity to experience that, if only for a few yards. The two pilots flying would only have had the sensation of the back dropping away behind them? (Maybe I'm wrong.)

[yeti]

If the machine could not tell the pilots what is wrong in a clear and understandable way, the machine is to blame and I think that the man-to-machine interface is wrong. I think such planes must be considered unsafe to fly, especially as the computer never allows manual control of the airplane.

The reason the "Machines" still have pilots is that they are not infallible and do not yet have the ability to apply human logic to complex problems with an infinite amount of variables. Pilots should be and are trained to asses the information presented to them and form a logical conclusion and then act on it. There WAS enough reliable information in this situation for them to recover the airplane, they appeared to have ignored the information and panicked. This could have been a failure in crew training or some other human factor but it was avoidable. No machine in existence today can reliably tell a human exactly what is wrong with it. (because half the time the thing that monitors what is wrong, is wrong)

[Fear_of_Flying]

You may notice that I try not to make categorical black-and-white statements. My point was that the captain may have had less information to go on in assessing the problem than he would have had he been on hand during the whole sequence that led to the stall (not that he had insufficient information). I believe the suggestion had been at least hinted at earlier that he was in a more advantageous position, and I would dispute that.

If someone can point out anything in the transcript or FDR info that is consistent with pilots attempting stall recovery, please advise.

As absurd as it may seem, I tend to agree with Evan's point that an additional message alerting the crew to the fact that they were fully stalled might have made a difference here. (And by the way, this doesn't mean I believe the interface is inadequate, but it was inadequate for these particular pilots.)

[Evan]

I rode in the crew bus a couple of days ago with a Jet Blue Airbus pilot and we discussed this for a few minutes. He told me that there is NO WAY to get control of the flight controls manually on the Airbus. An ex F-18 Navy pilot so he is used to the FBW systems. Airbus goes on the assumptions that with the redundancy built into these systems, the possibility of all of them failing is very unlikely. oooops!

A few facts for you BoeingBobby (we get our facts from the FDR, you see, so we don't need some guy in a bus to fill us with scarebus nonsense).

They WERE controlling the flight manually. The plane gave them control the moment it detected a problem. It WAS responding correctly to their control inputs. In terms of manual flight control, it performed exactly as it was designed to. Simulator recreations produced almost identical control reactions, including the THS movements. READ THE REPORT.

FYI, Boeing also goes on the assumptions that with the redundancy built into these systems, the possibility of all of them failing is very unlikely.

Perhaps what your Airbus pilot meant was that ONCE IN A FULLY DEVELOPED STALL there is no way to regain control manually in either an Airbus or Boeing aircraft UNLESS you can first take appropriate stall recovery measures.

Either that of he's another Airbus pilot in need of serious education.

[Evan]

You may notice that I try not to make categorical black-and-white statements. My point was that the captain may have had less information to go on in assessing the problem than he would have had he been on hand during the whole sequence that led to the stall (not that he had insufficient information).

It comes down to this:

Once stalled and falling through, either A) the captain with 11,000 hrs and the crew with thousands between them had absolutely no idea what to do in a stall situation, or B) they had a flawed situation awareness.

I'm going with B. But only because of prior breakdowns in CRM and certification and recurring training programs that didn't adequately train (and retrain) for stall recognition and recovery.

You notice that the word "stall" is never mentioned. A stall warning does not mean they are already in a stall.

I would like to see both an AoA indication appear on the PFD whenever AoA reaches Alpha Prot, and a red flashing message on the PFD indicating something like WING STALL / PITCH DOWN / TOGA whenever AoA exceeds critical angle. Not because we should need this, but because we obviously do need this.

[BoeingBobby]

A few facts for you BoeingBobby (we get our facts from the FDR, you see, so we don't need some guy in a bus to fill us with scarebus nonsense).

They WERE controlling the flight manually. The plane gave them control the moment it detected a problem. It WAS responding correctly to their control inputs. In terms of manual flight control, it performed exactly as it was designed to. Simulator recreations produced almost identical control reactions, including the THS movements. READ THE REPORT.

FYI, Boeing also goes on the assumptions that with the redundancy built into these systems, the possibility of all of them failing is very unlikely.

Perhaps what your Airbus pilot meant was that ONCE IN A FULLY DEVELOPED STALL there is no way to regain control manually in either an Airbus or Boeing aircraft UNLESS you can first take appropriate stall recovery measures.

Either that of he's another Airbus pilot in need of serious education.

The point I was trying to make here is that there IS NO way to manually control the rudder, elevators or ailerons. No manual reversion or cables going to them from the joy stick what so ever. I have read all of the reports put out by the BEA. My company has released them to our crews as they have been released to the public. Until I had the conversation with the Jet Blue pilot the other day, I was not aware that there is no way in the world to get manual control of that airplane. After all I am just an old Boeing driver and have no experience with the Airbus systems. As our 747-8's start being delivered in a couple of months, I guess I will have to start learning some of the next generation technology that I have been avoiding for years.

Evan, You are an Airbus pilot right? So I guess your system knowledge is up to speed. After all you do proficiency training in the simulator at six month intervals and yearly ground school and a proficiency check six months after that at the airline you work for?

[Evan]

The point I was trying to make here is that there IS NO way to manually control the rudder, elevators or ailerons. No manual reversion or cables going to them from the joy stick what so ever. I have read all of the reports put out by the BEA. My company has released them to our crews as they have been released to the public. Until I had the conversation with the Jet Blue pilot the other day, I was not aware that there is no way in the world to get manual control of that airplane. After all I am just an old Boeing driver and have no experience with the Airbus systems. As our 747-8's start being delivered in a couple of months, I guess I will have to start learning some of the next generation technology that I have been avoiding for years.

BoeingBobby, if you happen to see that pilot again, PLEASE tell him to refer to something called the "FCOM". Tell him to read it carefully this time. The rudder IS mechanically linked to the rudder pedals. The horizontal stabilizer IS mechanically linked to the THS pitch wheel. The Airbus IS capable of being manually controlled with complete electrical buss failures. It wouldn't be easy, but then with the RAT and a battery powered essential buss, it will never happen either.

Not that this should be an issue, because even in direct law, the flight surfaces are proportionately following the stick movements without computer interpretation (that's right, no HAL). At this point it's just a matter of wires or cables. Both are vulnerable to failure. But so far I'm only aware of airliners (DC-10's for instance) that have crashed from cable failure, with great loss of life, not servo-loop wire failure. This is because FBW is safer.

Evan, You are an Airbus pilot right? So I guess your system knowledge is up to speed. After all you do proficiency training in the simulator at a six month intervals and yearly ground school and a proficiency check six months after that at the airline you work for?

That's a brilliant retort BoeingBobby, and yet... so familiar...

[BoeingBobby]

[quote=Evan;583318]BoeingBobby, if you happen to see that pilot again, PLEASE tell him to refer to something called the "FCOM". Tell him to read it carefully this time. The rudder IS mechanically linked to the rudder pedals. The horizontal stabilizer IS mechanically linked to the THS pitch wheel. The Airbus IS capable of being manually controlled with complete electrical buss failures. It wouldn't be easy, but then with the RAT and a battery powered essential buss, it will never happen either.

Not that this should be an issue, because even in direct law, the flight surfaces are proportionately following the stick movements without computer interpretation (that's right, no HAL). At this point it's just a matter of wires or cables. Both are vulnerable to failure. But so far I'm only aware of airliners (DC-10's for instance) that have crashed from cable failure, with great loss of life, not servo-loop wire failure. This is because FBW is safer.



That's a brilliant retort BoeingBobby, and yet... so familiar...

Was a serious question not a retort! You have how many hours as PIC of a heavy jet? or SIC for that matter?

[Highkeas]

Please excuse me if this is a dumb question, but even when stalled, and falling rapidly, would there not be some clue in that walking towards the flight deck you're walking uphill? I know you're not pulling positive g's - in fact you're probably in negative territory here, but wouldn't the front at least look higher than the back? In that case the captain is surely at an advantage, rather than a disadvantage, in that by the time he got there he'd at least had the opportunity to experience that, if only for a few yards. The two pilots flying would only have had the sensation of the back dropping away behind them? (Maybe I'm wrong.)

It is the angle of attack that matters in a stall - an aircraft could have positive, negative, or zero pitch angle and still be in a stall.

It is possible that there was minimum g effects during the descent - for example in an elevator no g effects are felt except during initial acceleration and final deceleration. However for AF447 the altimeter told them they were dropping at high rate of speed.

[mawheatley]

It is the angle of attack that matters in a stall - an aircraft could have positive, negative, or zero pitch angle and still be in a stall.

It is possible that there was minimum g effects during the descent - for example in an elevator no g effects are felt except during initial acceleration and final deceleration. However for AF447 the altimeter told them they were dropping at high rate of speed.

Yes, I get that. But the report says the aeroplane was nose up. The PF pulled back on the sidestick. I understand it can be nose up and descending, I understand that relying on "perceived g forces" is irrelevant, but my point is that as the captain walked from the crew rest area to the flight deck door, before he even got to see the altimeter spinning wildly, it must have occurred to him that the "front was higher than the back!" Perhaps?

[Evan]

Yes, I get that. But the report says the aeroplane was nose up.

The report says that the pitch was all over the place, including nose down at times. I think the Captain asked same question I would ask when he entered the cockpit, which was basically "What the hell are you doing!". I also think he should have been able to divine very quickly from the vertical speed vs the attitude that the plane was stalled. I think it's just so incredible that anyone could stall an A330 that he suspended disbelief a bit longer than time allowed.

[BoeingBobby]

The report says that the pitch was all over the place, including nose down at times. I think the Captain asked same question I would ask when he entered the cockpit, which was basically "What the hell are you doing!". I also think he should have been able to divine very quickly from the vertical speed vs the attitude that the plane was stalled. I think it's just so incredible that anyone could stall an A330 that he suspended disbelief a bit longer than time allowed.

And this is because you have such extensive experience in the cockpit of a heavy jet correct?