2G wrote on 4/16/2020 8:34 PM:
On Thursday, April 16, 2020 at 8:20:37 PM UTC-7, Eric Greenwell wrote:

This discussion about the performance of electric gliders was based mostly on the
manufacturers numbers. NOBODY suggested these numbers can be trusted to be so
accurate you can discard the normal glider pilot cautions about the uncertainties
in what we do. Still, they are accurate enough to make useful comparisons for the
purposes of the discussion. Case in point: You said none of the electric gliders
could run for more than 30 minutes, and I responded with examples of electric
gliders that clearly can exceed that. That's just factual disagreement, not a
recommendation you fly the glider until the motor stops.

Please Read my "A Guide to Self-Launching Sailplane Operation" (link below) for a
better understanding of what I think are good practices for being safe in a
motorglider.


The 30 minutes was at full power, not a low power cruise setting.

Your original reference was to 30 minute VFR fuel reserves, which are at cruise
power, not full power, so I assumed your 30 minute remark about electric gliders
duration was also about cruising.

Practically speaking, full power duration is not a useful number when talking
about motorgliders; instead, it's climb rate for the launch, and range using the
motor, that are the important numbers. You and I are accustomed to using the "saw
tooth" method for achieving maximum range in our gas powered gliders, but for FES
gliders (and I thin also for the GP15), steady cruising is the way to achieve
maximum range.

--
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