A Scenario for an insidious A/T knock-out?
Auto-throttle can conventionally and generically be knocked out (disconnected) in a number of ways:
.
e.g. (and typically)
.
ATS OFF/ON button pushed,
A/T DISC on left throttle pressed,
AP disengaged,
ALL INTERRUPT button on yoke pressed, and.........
.
Pilot manually pushes throttle lever and actual position and autothrottle position differ by >10 degrees for 3s. (a Turkish trainee's typical ab initio error?)
.
Is it within the realm of possibility that a trainee (that's not used to auto-throttle) should sight unseen (by the other pilots) make such a singular inadvertent input and then realising his mistake, thereafter cease making throttle inputs, thinking that the auto-throttle was still doing its thing?
.
Plausible on a 738?