Originally Posted by
HarryMann
That's fine efatnas, providing you know that those airplane fundamentals have changed... aren't we being told that communication and documentation from Boeing on MCAS was lacking or certainly insufficient .. considering this system messed in a previously unheard of way with the stabiliser trim ?
It would appear that consideration was given to this area and that the people involved believed that a qualified 737 pilot would disconnect Stab Trim if it was persistently trimming the aircraft in an unwelcome way. They certainly didn't expect pilots with trim repeatedly going more nose down to just fight it when the Stab trim Cut Out switches have been in the same place and are known by all qualified pilots. From the thread above pilots seem to have been trained that the _only_ time the Stab Trim Cut Out switches are used is for a runaway trim defined
and demonstrated in simulators as a continual trimming in one direction. This appears to have been totally unexpected. Luckily for one set of pax a Batik jump seater did not have this limited view of the Cut Out switches utility. So perhaps it is only a subset of qualified 737 pilots that would let the aircraft trim them into the ground.
Just think if Boeing had suggested with the launch of the max that the NNC for 'Runaway Trim' was altered to 'Runaway or Repeated Trim'. The semantic specialists would have use the Cut Out switches and this thread would not be here.