I believe there is something really
insidious in this auto thrust philosophy.
After spending hours forgetting about those frozen thrust levers, but still brilliantly managing any thrust variation between idle and climb thrust, we can tend to unconsciously obliterate their function and keep them out of the process.
Anytime there was an auto thrust adjustment on the 757, I can remember placing my hand on the levers, almost by reflex, just to feel them moving, and moving
together, sometimes even to initiate that movement or also to delay it in other circumstances ...
There was a physical materialization of any thrust change, a kind of complete cycle :
- Instruments
- Brain
- Arm Hand
- Thrust levers
- Instruments
Nothing like it on the Bus unless you decide to get rid of the automatic process.
The Arm Hand Thrust levers are useless elements of an automatic thrust adjustment.
But on three
known occasions, crews forgot to fully reconstitute that physical link and failed to retard one of both thrust levers, which lead to very serious consequences.
Blaming the TAM accident on Airbus shoulders is over simplistic, but thinking that Airbus auto thrust conception has nothing to do with it is all that much.