Ramen,
The Chinook (A-B-C) models had an ineresting engine trim system.
The Primary Engine Trim was an AC system which provided inputs to a DC powered actuator.
The Emergency System was a set of momentary switches on the lower center console just ahead of the Engine Condition Levers which allowed for direct input to the DC Acutators.
The procedure was to pull the Overhead Circuit Breakers to the AC Trim and revert to the Emergency Trim Switches which had no memory and had to be adjusted for any collective movement.
Thus one could balance engine output by means of the Emergency Trim Switches.
The one draw back was pulling the overhead CB's....the field mod was a couple of Hand Grenade Pin Rings safety wired to the CB's and left dangling for easy reach.
It beats rolling throttles and throwing switches as well as allowing one to control high side failures by pulling the affected engine down by use of the momentary switch while getting the overhead CB pulled to disable the Normal Engine Trim.