Originally Posted by
Centaurus
Couldn't agree more. Seen that in 80% of simulator sessions in the 737. Just as illogiocal are those who overshoot the approximately 40% N1 advice during the rolling start, then hurriedly reduce power back to approx 40% N1 when they realise what has happend and then shove open to takeoff power hitting TOGA on the way, oblivious to the fact that they are eating up runway distance and invalidating V1 in some cases.
40%....
that is a natural response to the way we do an evaluation of crew performance. it is a measurable "error" that an instructor or examiner can comment on, so commentary on that and a consequential irrational emphasis can result. The problem of being human. Institutional training devolves over time towards a firm grasp on the trivial, unless an independent review of system behavior occurs.
As you describe, the outcome from an excessive concentration on a specific value rather than the underlying reason for a value, (achieving near symmetric acceleration of the engines results in a loss of SA on the equally serious matter of achieving takeoff performance. it's a good example of consequences, as was the overemphasis on automation use which led to loss of skills and more importantly, loss of SA of many crews reliant on automation.
Originally Posted by
Centaurus
We also see PM's who "back up" the thrust levers as they move under TOGA and then for some reaon keep their hand behind the thrust levers while the PF has his hand on the thust levers. Old Wives Tales again from DC3 era about throttles and dodgy friction nuts. if the PF suddenyly chops the throttles to abort, the PM is in danger of severely damaging his hand caught between the aft edge of the throttles and the start levers in the 737.
Probably only do it once unless they grow new fingers.