In “The Engine-Out Glide” article in your August issue, there was a sidebar about stopping the prop bringing an eight-percent improvement in glide distance. Many years ago, I took the GAMI Advanced Pilot Course. In that course, there was a discussion that it’s best to move the throttle to the wide-open position during an engine-out glide. No one ever mentions this in the press, nor do I see it in piston aircraft emergency procedures.
If you think about it, a windmilling engine is pumping air against a barrier (a.k.a., the misnamed “compression braking”) when the throttle is closed. I’m not going to do the experiment, but I wonder whether most or all of that eight-percent advantage can be had by simply opening the throttle fully without having to lose altitude by slowing to stop the prop. This advice would hold for constant-speed props as well, especially if oil pressure loss positioned the prop in fine pitch.
