On Sunday, 7 February 2021 at 21:00:17 UTC, David Scott wrote:
This is all just food for thought. ... I have a few questions.
Let us use a 500lb 15 meter glider as the reference.
(a) Any idea on how much thrust is need to sustain altitude?
(b) How much thrust is needed to climb at 200 fpm? 300 fpm?

(a) 11lbs (just the drag) and
(b) 28lbs for 200fpm, or 36lbs for 300fpm (drag + gravity)

Why? Working with sensible accuracy: glide ratio of 45:1 at 60kt:
Drag = 11 lbs at 60kt (500/45)
sin(gradient) = 2/60 for 200fpm, or 3/60 for 300fpm, so...
Force to overcome gravity @ 200fpm: 16.66lbs (500/30)
Force to overcome gravity @ 300fpm: 25lbs (500/20)
J.
(This was posted elsewhere, but has not shown up. Apologies in advance should this end up in a duplication!)