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Air Asia Pilot Response Leads To Plane Crashing (wsj.com)
hcs_$reboot writes: The investigation took a year, but we finally know why Air Asia Flight QZ8501, en route to Singapore from the Indonesian city of Surabaya on December 28 last year, crashed into the Java Sea, killing all 162 people on board. The crash was caused by a combination of system malfunctions and improper pilot responses to cascading electrical and rudder-system problems. A cracked solder joint on the Airbus A320 resulted in an electrical interruption that caused computer-generated warnings of a rudder malfunction. The problem occurred four times during the flight. The first three times, the flight crew responded according to standard procedure, investigators said. The fourth time, however, the flight-data recorder indicated actions similar to those of circuit breakers being reset. That led the autopilot to disengage. Investigators said the crew was unable to react appropriately to "a prolonged stall condition," ending in the crash. The investigation points to weaknesses in pilot training in dealing with upsets, or when an aircraft is angled greater than 45 degrees.
Air France certainly does train for it now. They didn't use to (and neither did other Airbus operators) because Airbus did not include it in the curriculum. They said their airplanes couldn't stall so it was pointless to train for it. The most we did was an "approach to stall" and recovery without actually stalling.
I'm sure Air Asia must have trained for it as well since Airbus has updated the curriculum after AF 447 and included stall recovery as a mandatory exercise, sending lots of communications about it to Airbus operators and requiring those exercises to be performed asap during recurrent training or even in separate, dedicated extra sessions.
But there's something weird going on here. The first officer apparently pulled his stick all the way back and made the plane climb at a rate of more than 10,000 ft/min before it stalled. That's a pretty insane maneuver and I can't find a rational explanation for it no matter what his training was. It's not an "inappropriate response" but rather a completely unprovoked action for no good reason whatsoever.
It might have been a technical malfunction in the flight control computers. There have been a few cases where Airbus pilots were accused of incorrect inputs in certain incidents where they luckily did live to tell, and where the pilots involved were adamant they did not give those inputs. Maybe there's a bug when the FAC circuit breakers are pulled. I remember one procedure that's sometimes performed on the ground, where such a reset also resets the stabilizer trim so it's vitally important to set the correct trim again. Maybe something like that goes on in the flight control computers during flight as well. Maybe the flight recorder confuses a flight control input with a trim input resulting from a FAC reset? Or maybe some integer overflowed?