Tony, I sent a couple of replies to your emails recently, but as they didn't
surface
on my screen or provoke replies I suspect they went down a black hole. I
am copying them both directly to you. I was also persuaded to check engine idle
glide angles for my plane which is a mono XS with 914, Kremen prop and speed
kit. I did it over the Severn Estuary in a large blue space with the surrounding
land giving rise to good thermals, ie in what I would expect to be slowly
sinking air. With fully fine prop I got the following: 70kt- 700fpm,75kt-700fpm,
80kt-800fpm. When fully coarse:70kt-590fpm, 75kt-660fpm, 80kt-670fpm This
gives best glide angles of 1 in 10.7 at 75kt, fully fine and 1 in 11.9 at 80kt
fully coarse, neither figure dramatically worse than your feathered figure of
1 in 13.5, but very much at odds with your engine idling rate of 1 in 6.4 Also
the old fixed gear, fixed prop Robin I learned on managed 1 in 7 with engine
idling. Did you have the gear down? Regards, David
|