Originally Posted by
MurphyWasRight
Others have posted that the runaway trim procedure was changed from first using the right switch only to using both a few years ago for unknown reasons.
No one has posted a rational sounding reason why the switch functions were changed.
I did my 737-3/400 initial course in 1998 and have no recollection at all of ever using just one of STAB TRIM CUTOUT switches. They were always, unless seniity has completely overtaken me, used together. Seems rather more than 'a few years ago' to me.