You call the two needles “requested” and “current collective”, but how do you know this is how they actually work? Honest question, is it mentioned in some documentation or the manual of the real thing?
I don’t think this is what the two needles mean. I think the small blue needle is what is the required Power for the current pitch angle (collective position) and current RPM is, I guess?
The big white needle, which is laggy and nonlinear, I think shows the current power output of the helictoper engine. It says “PWR” on top of the dial. Power is torque times angular velocity (RPM).
I might be completely wrong here because I don’t know much about helicopter physics, but I have never heard the terms “current” and “requested collective” and I don’t think that’s what the needles are supposed to represent.
I guess what I am trying to say is, as long as you RPM are kept stable by the governor, the change in pitch angle induced by moving the collective will have an immidiate effect. The engine’s power output required to maintain this is secondary, you shouldn’t worry about it at all as long as it is not in the red zone.
Concentrate on what you can control directly in the helictoper, which is the pitch angle of the rotor bladed via the collective. You do not control the throttle/power output directly, so don’t concentrate on the indicated values too much, they will not help you.
This is in contrast to fixed wing aircraft, where you directly control the throttle/power and the blade pitch is automatically adjusted for you to keep a certain RPM (in constant speed propellers).
In a helictoper, you control the blade pitch directly, and the throttle is automatically adjusted to keep a certain RPM.