Craig Reinholt wrote on 3/16/2021 7:57 AM:
One issue not discussed is the duration / altitude of the launch. At Ely, and other sites (Williams is one), the launch may run well over 20 minutes and altitude gain over 3000 feet hunting for lift. The numbers supplied by the manufacturers are for a 1500' gain under 10 minutes. That difference will put a severe dent on the retrieve distances.
Craig

That hasn't been my experience at Ely, where a 2000' launch has almost always done the job, but
maybe I'm just lucky :^) Williams is a special case, and some FES will undoubtedly have to
take tows just to get to the soaring. It shouldn't be a problem for electrics with 50+ mile
range. Note that "the numbers" vary greatly between electric gliders, with some older FES
gliders having very limited climbs, and the newer mast-mounted motor systems by Schleicher,
Jonkers, and others offering 9,000'-13,000' climbs.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1