I was surprised to learn recently that the Hartzell propeller governor (S Series) cannot adjust the blade pitch with an engine speed below about 1800 rpm.  Seems like that could be a problem in an engine out glide scenario, where the prop stays at flat pitch, high drag.

I talked to a guy at Hartzell Technical Support and he confirmed that’s how their S series governors work.  He said it’s not a problem and that they are on all the Cirrus airplanes.  But, with the Cirrus’ single lever control linkage, I don’t think Cirrus pilots can adjust the blade pitch in an engine out scenario anyway.

For the Legacy flyers out there flying with the Hartzell governor, when you’re at best glide speed of 120 KIAS, are you able to get enough engine rpm to get maximum blade pitch (low drag) or not…?

Thanks,

Valin Thorn

Legacy Project

Boulder, Colorado USA