The aircraft is a B412SP with PT6T-3B engines. When making a power change engine 1 hunts high and low (torque, ITT and N1) about four times before settling down; engine 2 settles down after only one cycle.
Is there a prescribed minimum (either in seconds or number of cycles) before which the engine should be in a stable state? If so, where can I find it? I’ve looked through both the B412 and PT6T Maintenance Manuals and failed to find any hard data.
Thanks for any pointers.