Originally Posted by
RdKetchup
On the A300, the physical switch actuates 2 switches on the electrical circuit.
From the FCOM:
"Each electric trim rocking lever actuates two switches. If switches provide contradictory orders both pitch trim systems disengage."
Now why was this approach not used on other aircraft design? Maybe for fear of a condition where the physical switch is actually jammed in one direction or the other. A double jam is probably a lot less likely.
what was the point of this though? Couldn’t they just have the 2 separate switches side by side instead of placing them under 1 large switch?