@rudderrudderrat:
Whose FCTM is this? Stating that
The effectiveness of fly-by-wire architecture, and the existence of control laws, eliminate the need for upset recovery maneuvers to be trained on protected Airbus aircraft.
is IMHO criminally negligent. FBW has known degradation and failure modes, insisting that they will always work properly when proverbial hits the fan is ignorant at the best. Chances of having to perform GPWS maneuvre in direct law are so small they can be ignored but Airbus pilot must absolutely know when to rely on protection and when it is not available.
Originally Posted by Old Carthusian
This links into what I believe are relevant cultural issues at Air France particularly in the area of crew training.
Could be but it's not necessarily so as a few AF crews have previously successfully negotiated temporary loss of all airspeeds. Question is what made crew act so differently form every other crew facing the same problem. That HF group report will be a bomb is quite safe bet.
Originally Posted by jcjeant
We certainly will have more knowledge about this accident when (if ever) the FDR DATA will be published ... instead of those graphics from the BEA belonging more to cartoons than technical graphics
(...)
I repeat ...
You have no datas in the BEA report .. only cartoon graphics ...
(...)
BEA chalkboard graphics less FDR data is partial and inaccurate information
Graphic presentation of AF447 DFDR readout is accurate, consistent and informative enough for anyone able to read it. Airline pilots of sub-average grade and above should be able to understand what is drawn. Of course, there are lot of PPRuNers who are either unable to understand BEA data or insist on misunderstanding it as graphs contravene their pet notion of Airbus being intrinsically evil. "Why" is good question.
Originally Posted by gums
From the data traces I see no extraordinary efforts by the crew to recover from a stall such as using flaps, spoilers, etc. In other words, I do not think the crew knew that the plane was fully stalled, and the control inputs do not reflect appropriate stall recovery techniques/procedures.
You are correct but it's even worse; CM2's reaction to stall warning was surprisingly consistent and fatally wrong; first time stall warning goes off as the nose is jerked up, he just keeps pulling, second time, as the energy bled off, he pulls inanely. Third and fourth times as he released the stick, AoA decreased and air data became valid again, he pulled again, sealing the flight's fate, never commenting what and why he was doing.
Originally Posted by gums
So a stall may not be easy to recognize, especially if the crew is trained that "you can't stall this airplane". FBW and "protections" for another time, another thread, IMHO.
If that's indeed so, it's a good thing there's synthetic voice shouting "STALL STALL" at A330 pilots. Cricket too.
That A330 or any other FBW Airbi cannot be stalled is severe misunderstanding and if the crew were really officially told so, then their trainers should be taken off duty until retrained. There's not magical about FBW alpha protection, it's just a mechanical-electronical device which limits pitch control in order to keep alpha below critical. Just like on 'Vark or Viper. It needs valid sensory input, computer and output to elevator. Something gets banged up in the chain - it doesn't work and it's easy to promptly see if it dropped offline, if one pays attention to his artificial horizon, that is. Nothing startrekkish about it.
Originally Posted by ChrisN
There is now much more on approach to stall/buffet (but not into stall), and emphasis on recovering controlled flight including nose down if that is what it takes, and not on minimum height loss only as it used to be.
I sincerely hope this is not the whole story.
IMHO it won't hurt to repeat what must be readily understandable to any pilot at any time of day or night: there is a whole world of difference between low and high level aerodynamic and engine performance. People who keep insisting that maybe CM2 was trying to replicate extremely low level manuever at FL330 are maybe onto something but usually go tangential when they go on blaming the training for it. For Finnegan's sake, any pilot must be fully and correctly aware at any time of what his aeroplane is capable of doing - if not, he has no business being at the controls. What was so far trained was avoidance of stall at low level because final turn stall was quite common killer and still is in the general aviation. What is commonly misunderstood in PPRuNe discussions is that airliner pilots are trained to recover from approach to stall, not fully blown stall recovery. That's because the only thing that can extract any aeroplane from low level, low energy stall is excavator.
High altitude stalls were never of concern because it was assumed that pilot would readily understand that they need to keep the speed up to avoid stall and trade altitude (of which there's abundance at typical cruise level) for speed if they got on the back of the power curve. Real life with lack of high altitude stalls seemed to confirm the notion. Than we had Pinnacle 3701. That accident was quickly forgotten as it was ferry flight, so no public outrage over passengers' deaths, and ascribed to cowboyishness of the deceased pilots. Heck, on PPRUNe there was ever-present "blame it on the technology" brigade who insisted that core-lock phenomenon was main culprit in the crash. It is correct that pilots undid themselves but they were not suicidal, they were just ignorant and that killed them. Did the powers to be push for better pilot selection and training post Pinnacle and Colgan? No. Just more hours that should serve as panacea for all the holes in the pilots' knowledge. Learn as you go.
IMHO, no amount of unusual attitude or high altitude full stall recovery training is going to prevent AF447-like (or Colgan, Armavia, Gulf Air, Ethiopian, Kenyan....) accident form recurring! We are not discussing about aeroplane being thrown form the sky with crew failing to recover, we are dealing with disoriented and confused crew that kills itself and everyone on board by doing the exactly wrong thing while believing it is right! It is not about recovery, it is about recognizing one is confused and getting to grips with reality ASAP. If this is dealt with soon enough, no radical recovery actions are needed, if not, it might be too late for airframe strength or altitude available anyway.
Originally Posted by gums
I was not aware of the small AoA margin that the 'bus has between cruise and stall. I have to admit that I was shocked at the low AoA values I saw, as my experience in bent wing jets exhibited much higher AoA values before getting into trouble, the VooDoo being the big exception ( ask me about that beast offline, heh heh).
...and yet no airliner falls from the sky because of it. There are a lot of things common to all aeroplanes but some fine details are either applicable to subsonic, stable transport, some to supersonic, maneuverable interceptor bot not to both.
there's no "protections" concerning overspeed.
Normally, there is high speed protection which, very unsurprisingly, doesn't work without valid airspeed.
But seems like the jet has this auto-throttle feature, and I am not sure when the pilot can tell the "system" that throttle position commanded by the human in the cockpit should be obeyed.
To be pedantic: it's called autothrust and unlike autothrottle doesn't have servos that physically move the trust levers. It dropped off as speed become unreliable and anyway it can be disconnected by using the red button on either thrust lever. With ATHR off, it acts just as you wrote:
our PLA ( power lever angle) command was just that. It commanded a level of power that we mortal pilots desired/commanded.