Engine RPMs after stall turn.

[Screamadelica]

I've noticed when coming out of a stall turn with the throttle cut back that as the aircraft is diving out of the turn after a short time the engine RPMs suddenly go into overdrive, exceeding 3000 RPM before returning to normal operation. You have to be careful not to apply throttle until after it settles back to normal after it has had it's dummy spit.

Curious as to why it does this, is it correct for the engine to behave like that in those circumstances?

Only ever happens after performing a vertical stall turn.

Cheers, Scream.

[grafspee]

Constant speed prop, rpm governor always keeps set rpm, when you cut throttle prop blades are twisting that way that wind drives prop. Even with engine shut off when enough airspeed is present system will be able to keep engine rpm set by cockpit lever. Chage of speed or  throttle closing or opening require that constant speed unit will adjust blades angle to keep set rpm, that actuation speed is limited so when air speed rapidly increasing or throttle is advanced very fast system lagg will result in engine over rev. Afaik you can saffely over rev to 3250rpm in Spitfire, P-51.

That is how this system works and that behavior is expected, we could only argue about that prop blade pitch actuation rate is it spot on or is it slower or faster then in real plane.

Edited October 31, 2024 by grafspee

[Screamadelica]

 

And that explains why perfectly!

Thanks grafspee.