Constant torque on take-off (CTOT) assists a pilot in setting takeoff power by electronically adjusting fuel to maintain a pre-selected torque. Power levers can override the CTOT system and add additional fuel. The CTOT system will come on when the power levers are above the 60 degree switch and the CTOT switch is on. Switch position: OFF, ON, APR (automatic power reserve)
References
Constant torque on take-off Wikipedia(Text) CC BY-SA