Is the current CS 25 paragraph 671 valid for the B737, or are there grandfathering rights?
And how is paragraph 671 to be understood:
The aeroplane must be shown by analysis, test, or both, to be capable of continued safe flight and landing after any of the following failures or jamming in the flight control system and surfaces (including trim, lift, drag, and feel systems) within the normal flight envelope, without requiring exceptional piloting skill or strength.
A runaway of a flight control to an adverse position and jam must be accounted for if such runaway and subsequent jamming is not ‘extremely improbable’.
Is it required for the manual trim to be functional in the full flight envelope, after runaway to full ANU or AND?
Are other non FWB able to manually trim in the full envelope?
ManaAdaSystem was of the opinion that most aircraft could not be trimmed in this situation.
MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Does the B737 have the cut-out switches since a runaway is not ‘extremely improbable’, or is the switches an extra layer of safety?.
Some modern FBW aircraft does not have trim wheels, can they document that a runaway is ‘extremely improbable’?.