Which sustainer system would you chose for your sailplane?

On Thursday, January 14, 2016 at 11:06:50 PM UTC, kirk.stant wrote:
On Thursday, January 14, 2016 at 4:19:13 PM UTC-6, J. Nieuwenhuize wrote:
IMHO, this plus a small 4-stroke generator of 10-20 hp is the perfect system:
https://www.facebook.com/gpgliders/v...5333550523888/

No noticeable drag if it fails to start, electric reliability and extreme range due to the generator.

Looks nice, but could the drag caused by all those doors (even closed) not equal the drag of a closed FES prop?

Speaking of FES, why not have a single blade? Counterweight in the spinner (it's been around for a long time), fold the prop into a recess under the nose of the plane, cover with a door if you want to be really Gucci...

Kirk
66

There would have to be something far wrong with the fit of aft fuselage engine doors before they caused the same drag as a FES prop. The flight test of the Lak FES that has from time to time been cited as showing minimal drag actually shows around 4-8 kph difference for the same glide angle with the vents open (as would be normal during most gliding) - about one generation of design difference. Diagram on page 7:

http://www.front-electric-sustainer....A%20FES_en.pdf