The basic ( serious
) speculation semms to point to both engines failing to respond to Autothrottle Command.
We have some technical input on the forum into the fact that both FADEC, are totally independant and with alternate sources.
The Autothrottle will vary power according to some input that is trying to maintain a specified flight path from some parameter(s). The power is constantly changing to maintain this flight path
2 questions.
1 Where is the source for the A/T and is it duplicated
2.If the A/T fails to command the crew will get a visual indication from F/D that all is not well. How long from when the A/T failed to repond and the aircraft deviates from the prescibed path would the crew realise?