Jack Cook wrote:
Quote:
A runaway prop is caused by a failed prop governor. That will cause the engine to overspeed, eventually leading to failure.
A few things to remember and will helps make it more understandable.
1. You want the engine to drive the prop.
2. You DON"T want the prop driving the engine.
3. adding power increase prop rpm first
4. reducing power decrease manifold pressure first
Over to the experts!
A runaway prop is a failure of some part of the system to control pitch angle of the prop blades.
Blade angle is used to load the engine based on any power setting setup by the pilot. That is set by the prop gov adjusting blade angle (pitch) to maintain a set rpm of the engine.
I've heard a Merlin sound like a T-6 when the prop oversped.
I've also heard aircraft overspeed a bit on application of throttle during takeoff.
In an overspeed situation you reduce throttle to control the overspeed. Since the prop control is whacko the only thing left to reduce the runaway situation is the throttle.
The problem is that low pitch angle = flat blades=high drag. Since you also are reducing the power of the engine combined with the high drag you can have a problem keeping aloft.