Originally Posted by
EDML
Elevator feel / feedback is a simple mechanical system. It is not possible to simply extend that to cover special parts of the flight envelope.
CORRECTION: Do you mean that what Boeing calls a "
Elevator Feel Computer" is actually a mechanical computer ???
This is correct for the Elevator Feel Shift (EFS) module which simply increase by a factor 4 the system A pressure fed into the Elevator Feel & Centering Unit.
It is also true for the Elevator Feel & Centering Unit which transforms differential pressure into feel forces.
But the pressure normally fed into the Elevator Feel & Centering Unit is controlled by a computer unit, the Elevator Feel Computer, which uses airspeed and stab position inputs for computing how much hydraulic pressure it should transfer downstream.
I reckon that the AoA is NOT documented as an input data received by the Elevator Feel Computer ; AoA is only available to the EFS (in this area).
But an upgrade of the Elevator Feel Computer by adding AoA input and modifying its algorithms should not be more considerable than fixing the MCAS logic with dual AoA input.
The advantage of acting through the Elevator Feel System is obvious : no effect on the pilot pitch authority if the AoA probe goes mad in normal flight.