JaredJames said:I think caution is certainly required, otherwise the media may turn it into a fly-by-wire witch hunt. The beginnings of which you can see at the end of that article.
It is worked at all, GPS would only give you ground speed. If you were flying through a thunderstorm, the difference between that and airspeed could quite easily be 100 knots.What about GPS for approximate air speed?
AlephZero said:Before we start speculating about pilot error
‘The inputs made by the (pilot flying) were mainly nose-up,’ the report notes, indicating a potential pilot error. Generally, pilots would push the nose down to recover from a stall.
Granted, but assuming the article is accurate in the statements about the control inputs (as noted above, yes, control inputs are recorded), the actions of the pilot couldn't have been more backwards:AlephZero said:Before we start speculating about pilot error, the first question is whether the aircraft type was designed to be recoverable from a full stall even with all systems working properly (which clearly they were not). Recovering from a stick-shaker or audible stall warning is a very different situation from the full monte.
Based on that, my previous post wasn't quite accurate: this is basically saying that the pilot caused the stall. Except for doing it on purpose, the only thing I can think of that would make a pilot make such control inputs is for the instruments to tell him he was going too fast. Still, he was apparently acting against his training.USA Today said:Two minutes after that, the emergency began abruptly when the autopilot shut itself off. "I have the controls," one of the co-pilots said.
Almost immediately, the pilot pulled the jet into a climb, rising from a cruising altitude of 35,000 feet to 38,000 feet.
If pilots lose accurate speed information, they are taught to fly level and maintain the same power setting until they can diagnose the problem.
However, at some point the pilot reduced the jet engine power to idle. Even as the jet's forward speed slowed and it entered a dangerous stall, the pilot continued to try to pull the nose up, the BEA said.
russ_watters said:Granted, but assuming the article is accurate in the statements about the control inputs (as noted above, yes, control inputs are recorded), the actions of the pilot couldn't have been more backwards: Based on that, my previous post wasn't quite accurate: this is basically saying that the pilot caused the stall. Except for doing it on purpose, the only thing I can think of that would make a pilot make such control inputs is for the instruments to tell him he was going too fast. Still, he was apparently acting against his training.
JaredJames said:They report the engines were throttled back to idle, that is recorded is it not? So a pilot obviously interacted there to do that much (wrong action in a stall).
AlephZero said:... At the first stall warning (which may have been wrongly triggered by the incorrect speed indication) ...
If the flight recorders survived as well as the press reports claimed, there will be much more raw data than was published in that 4-page report.Andre said:It occurs to me that the descriptions here, reflecting what is actually known, are too fragmented to judge the cause of the accident.
From the small amount of data in the report, one of the first unanswered question is: from flying level at a normal cruisng speed and making a gentle turn, how did the aircraft get into a 7,000 ft/min climb for 3000 ft after the first stall warnings? My best guess would be the first par of stall warnings were both false, and the plane had just flown into the top of a thunderstorm with a wind speed of at least 80 to 100 mph upwards.But in the end, I would not be surprised if the root cause would be the failure to avoid the thunderstorm after all.
The flight crew do have the artificial horizon and the climb and turn rates displayed, which are logically equivalent to the AOA, and for normal passenger flying more useful to meet the basic operational requirement - don't spill the first class passenger's drinks, especially if they are major shareholders in the airline.I read that the pilots are not presented with a raw angle of attack indication. This is amazing for a fighter pilot, to whom the angle of attack is the most important feedback on the dynamix of the aircraft. Accurate angle of attack information could have prompted the pilots to take the right decisions.
AlephZero said:On the other hand a simplistic "cause: pilot error" doesn't achieve anything. Even if the cause was pilot error, you want to stop the same type of error happening again.
From the small amount of data in the report, one of the first unanswered question is: from flying level at a normal cruisng speed and making a gentle turn, how did the aircraft get into a 7,000 ft/min climb for 3000 ft after the first stall warnings? My best guess would be the first par of stall warnings were both false, and the plane had just flown into the top of a thunderstorm with a wind speed of at least 80 to 100 mph upwards.
The flight crew do have the artificial horizon and the climb and turn rates displayed, which are logically equivalent to the AOA, and for normal passenger flying more useful to meet the basic operational requirement - don't spill the first class passenger's drinks, especially if they are major shareholders in the airline.
So I was wrong: the pilot error was much worse. Greg's article basically says that aside from sporadic and not overly serious airspeed indication faults, there was nothing wrong with the plane: nothing affecting it's flyability. The crash was caused by the one co-pilot applying full back pressure to the stick for nearly the entire event and neither the other copilot nor the captain recognizing it (except for a brief moment during the first stall) until it was too late.russ_watters said:So it sounds like the cause was faulty speed indication leading to a stall, then pilot error in recovering: http://content.usatoday.com/communi...rance-flight-experienced-35-minute-freefall/1
With the report into the tragedy of Air France 447 due next month, Airbus’s 'brilliant’ aircraft design may have contributed to one of the world’s worst aviation disasters and the deaths of all 228 onboard.