MS804

[kraznyi_oktjabr]

Originally Posted by Catfish

There was that Air France Flight from South America. Ice had rendered all tachometer devices useless, and the autopilot tried to counter with the data it received. When the jet lost altitude it gave positive elevator control and the nose went up until stalling.
The pilots did not know what was going on and were not able to switch from automatic to manual steering. A stall, drop and circling could be a hint for a similar technical failure.
Just saying.

There are three major errors in your narrative:
1) When autopilot does not get sufficient data to fly safely it disconnects. That happened on Air France Flight 447.

2) Change between flight control laws is automated process not manual one. However ff person knows what he or she is doing it can be intentionally triggered by shutting down some of flight control computers.

3) At time of the accident plane's captain was off duty. First officer was in captain's seat with second officer in FO's. When troubles started first officer tried to correct situation. However second officer was applying constant nost up command in his side stick which caused the orignal stall situation and as it overrode all first officer's control inputs also ensured first officer could not correct situation. However I do not know if first officer's intended actions were appropriate or not.

Air France Flight 447 crash was due pilot error with mechanical malfunction (frozen pitot tubes) and user interface design (presentation of information and lack of feedback via side stick controllers) playing secondary role. Procedures exist for flying aircraft without accurate speed information but those were not followed.

(Air France 447 and Air Transat 236 were used as examples in user interface design course when speaking about user interface design in safety critical applications.)