Originally Posted by
Uplinker
No, because the aircraft will warn of a pitch trim problem if one of the switches underneath the rocker fails either mechanically or electrically.
It cannot detect a mechanical failure. If the toggle cannot be moved, the control system cannot detect it. If the toggle becomes mechanically disconnected from the switches, it cannot be detected.
It can detect a differential electrical connection, but not a failure that has not reached the point of a differential electrical connection. It can certainly not detect that one switch is not responding with the same amount of reaction force when joined with a single toggle that would be detected in comparing two separate toggles.
The point you are making is that after the failure has occurred and it is too late to do anything about that failure, the system can notice some aspects of that.
The point I am making is that with two separate toggles the pilot has the chance to detect that the switches need to be replaced before there is an in-flight failure.