I'm quoting Wikipedia's summary of the Report: * The stall warning deactivates by design when the angle of attack measurements are considered invalid and

I'm quoting Wikipedia's summary of the Report: * The stall warning deactivates by design when the angle of attack measurements are considered invalid and this is the case when the airspeed drops below a certain limit. * In consequence, the stall warning stopped and came back on several times during the stall; in particular, it came on whenever the pilot pushed forward on the stick and then stopped when he pulled back; this may have confused the pilots. * Despite the fact that they were aware that altitude was declining rapidly, the pilots were unable to determine which instruments to trust: it may have appeared to them that all values were incoherent. Personally, I'm not sure whether to believe that the copilot simply made an amateur mistake .