I don’t think these guys had a clue what their airspeed was/ Doesn't seem like it...and
a wall of ice particles that blocked the aircraft speed sensors.
My Air Force instrument systems guess: Pitot tube heater failure led to eractic airspeed inputs that confused the hell out of the computers and the pilots.
No, they didn't, thanks to the lousy flight data that was coming from the computerized flight-control/air-data system. However, they should have realized (and probably did?) that they were descending, since the altimeter is a simple and fairly reliable instrument. However, they faced a huge dilemma:
was the actual, real air-speed low or high? If low, they needed to lower the nose. However, if it was really high, lowering the nose could easily put them past not-to-exceed airspeed and the wings could break off. Certain death.
If they raised the nose, the speed would go down, accentuating the stall.
The computerized flight-control system certainly thought the plane was stalling, even if it wasn't, and it perhaps wasn't letting the pilots raise the nose to pull out of a dive, which they may have needed to do to maintain alitude.