Originally Posted by
alf5071h
DaveReidUK, #3647, Icarus2001, quentinc
“… no evidence that it's the case for electric trim.”
Indications in the EASA reference ‘Equivalent Safety Case’ suggest otherwise.
“Simulation has demonstrated that the thumb switch trim does not have enough authority to completely trim the aircraft longitudinally in certain corners of the flight envelope, e.g. gear up/flaps up, aft center of gravity, near Vmo/Mmo corner, and gear down/flaps up, at speeds above 230 kts.”
Now why would a manufacturer limit the thumb switch trim range to even less than the autopilot trim authority, particularly when it could no longer be shown to trim throughtout the required envelope?
How about non compliance with the out of trim dive requirement as mentioned in said equivalent safety determination?
Perhaps the easiest solution was to use the 30lbf out of trim with the wheel rather than redesign the system to be compliant when 3 seconds of no load electric trim operation is applied?