Airbus Industrie Flight 129

Investigation

The crash was investigated by a commission of enquiry within the Direction Générale de l'Armement (DGA), the French Government Defense procurement and technology agency responsible for investigating flight test accidents. The commission found the crash was due to "a combination of several factors, no one of which, in isolation, would have caused the crash." These included:

Captain Warner's fatigue after a "punishingly busy day" which had included an A321 demonstration flight, supervision of a simulator session, and two meetings, including a press briefing;

Lack of a complete pre-flight briefing, caused by Warner's schedule, and possible complacency caused by success of the testing through the previous takeoff;

Choice of maximum takeoff/go-around (TOGA) thrust rather than the slightly lower "Flex 49" setting, which caused higher than planned thrust asymmetry during the simulated left engine failure;

Choice of trim setting at 2.2° nose-up; although within acceptable limits, this was inappropriate for the extreme aft CG configuration flown.

Autopilot inadvertently left set at 2000 ft altitude capture from the previous test;

Absence of attitude protection in the autopilot's altitude capture mode;

Uncertainty in allocation of tasks between the captain and co-pilot; the co-pilot rotated the aircraft "firmly and very fast" to a takeoff attitude of more than 25°, compared with the usual 14.5° used for the first, successful takeoff;

The captain simulated an engine failure immediately after takeoff: autopilot engage, throttling back the left engine, and tripping the hydraulic circuit breaker; this took him temporarily "out of the piloting loop."

Lack of visual indication of autopilot mode, obscured by the extreme pitch attitude;

Crew overconfidence in expected aircraft response;

Delayed reaction of the test engineer to changes in flight parameters, particularly airspeed;

Captain's slowness in reacting to the development of an abnormal situation.