Originally Posted by
NSEU
You understand that yoke trim switches have an "power button" button and a "direction" button? It's unlikely both switches would fail. Also, faulty yoke switch inputs can be immediately overridden by pulling/pushing on the stick in the opposite direction, then the cutout switches can be used.
Avionics maintenance engineer (40 years)
Somehow, this forum is leaking valuable postings, something I have noticed more and more, especially over the past 5-10 years.
Of course, the trim switches are as you describe, though that does not imply, a trim-runaway is impossible. Hence, the presence of the double trim cut-off switches. These are there, because these are regulatory and technically needed.