[expatpat]

They have GPS navigation. The confusion was not re climbing or descending, they knew they were descending. The confusion was over the airspeed. Were they descending because the nose was down (and the speed thence rising), or were they descending because they were in a stall situation (low speed)?

The flight control computer thought they were stalling, but that was because the airspeed data was erroneous (they might have been stalling, as it thought, or they might have been diving, but how can you tell without some kind of speed information - no noise from the wires you'd hear in a biplane!)

[steve86]

expatpat: "The confusion was not re climbing or descending, they knew they were descending"

transcript: "What's the altitude?" "What do you mean what altitude?" "Yeah, yeah, yeah, I'm descending right?"

Steve86: Sounds like confusion over descent/ascent to me. Then once they got that out of the way the reason for the descent needed to be determined.

expatpat: "but how can you tell without some kind of speed information"

Steve86: Well, one way is to monitor the speed and altitude information available from the GPS system.