To those that have had the unfortunate privilege of an in-flight rotary
engine failure, has the prop windmilled the engine?  I'm wondering because
the engine would be turned at between two and three times the engine rpm,
which seems fast for windmilling.

Also, because of the ratios, the prop's torque is diminished by the gear
ratio on the engine.  Making it easy for the engine to turn the prop, but
not the other way around.

As a tangent thought, I would be tempted to put a prop/engine brake on
certain light twins. Rather than a feathering constant speed prop.  Stop the
windmilling to lower the drag.  Save weight, complexity, and cost.  The
brake could be very simple and light.



Matt-


During flight testing, I would turn off the engine to test exactly
this.  For me, the prop would windmill above about 80kts.  During an
actual engine failure (due to lost coolant and subsequent lost
compression),  the engine windmilled until after touchdown.