Originally Posted by
boofhead
I've been criticized for blaming the pilots …...
Sure Boeing has made errors but the airline that employed these pilots and did not give them the required training/checking to handle a trim runaway was the start of the problem, not the MCAS/Boeing input. A runaway trim can happen from many causes/failures and MCAS is only one. The problem presented was the trim moving without pilot command.
B737 require that the runaway is handled way before the trim stop is reached, or way before the maximum speed is exceeded.
My understanding of CS 25.671/25.672 is that, either:
- A trim runaway must be “extremely improbable”, this can not be claimed with the present DAL C architecture.
- Be capable of continued safe flight and landing following runaway of a flight control to an adverse position, without requiring exceptional piloting skill or strength.
To me the B737 seem to have a certification gab..
There is a factor 10000 between “extremely improbable” (DAL A), and what DAL C can deliver.
This means that pilots must be able to recover 10000 times, before one failure, in order to be as good as a DAL A flight control system capable of preventing runaway.