Engine manufacturers will establish operating parameters for their product, but once put into an aircraft, the airframe manufacturer may establish additional limitations which will be more conservative than those of the engine manufacturer. When mated with a particular propeller (in the case of a turboprop), additional limitations may apply, which are typically either torque or RPM limits (or caution bands), and wind limits during ground operations. Operators frequently place additional limitations on the way the aircraft will be used or operated.

When I'm running a PT6A-67, I'm usually carrying 800 ITT continuously during takeoff and climb, and sometimes for a good portion of the flight, and I'll return to it frequently when maneuvering. In cruise I back off if able, but there I run torque and fuel flow.