Originally Posted by
Luc Lion
No.
I am a bit too lazy to look for the link to the wiring diagram, but I remember that the cut-off switches remove power from the whole system early in the diagram and undoubtedly before the wiring bundles carry the command to the tail section.
The hazard involved with the bundle is similar to the MCAS hazard : the pilots must cut-off the faulty command early if they want to save the day.
Not what the leak above suggests, which implies that I guess a permanent live for another part of the system runs in close proximity to the stab trim after the cutout switch - so if the two chafe and short, you get an uncontrolled runaway that you can't stop.
"
In one instance, engineers found a hot power wire that was too close to two command wires running to the jet’s moveable horizontal tail, or stabilizer, one for commanding the tail to swivel to move the jet nose-up, the other to move it nose-down. The danger is a short that causes arcing of electricity from the hot wire to the command wire.
“If a hot short occurs between the power wire and either the up or down command wire, the stabilizer can go to the full nose-up or nose-down position,” the engineer said.
Furthermore, the electrical power in that wire could circumvent the cutoff switches in the cockpit that, in the event of such a stabilizer runaway, are used to kill electrical power to the tail. Theoretically, the pilots could be unable to shut it off."