On 3/16/21 12:05 PM, Eric Greenwell wrote:
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 :^)Â* 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.


Well the Antares was supposed to have 10K feet climb capability, but in
reality it was a whole lot less. That shows the danger of comparing
real life performance of existing products with spec sheets of future
products. Don't suppose you went to Poland to verify the performance
numbers?