Wide open throttle vs stopping the prop during glide

[Steve Kleiman]

I read "The Engine-Out Glide" article in the last August issue of Aviation Safety magazine. There was a sidebar in the article about stopping the prop bringing an 8% 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 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 sucking air against a barrier when the throttle is closed. This is why "compression braking" works in non-diesel cars. I’m not going to do the experiment, but I wonder whether most or all of that 8% advantage can be had (for fixed-pitch props I think) by simply opening the throttle fully without having to attempt to stop the prop. This advice would hold for constant-speed props as well if oil pressure loss positioned the prop in fine pitch. Even in coarse pitch, the engine is still windmilling.

Steve

 

[Ogie_ogelthorpe]

 

[Steve Kleiman]

 

[NorthernAviation]

 

[datorres88]

 

[NorthernAviation]

 

[Warriorgreg]

 

[Ed Dartford]