Dear itsmoked,
The s/sheet attached in my first post show my workings-out.
There are several parts to a launch -
a) the initial acceleration and rotation into full climb. This is taken at max power.
b)The first half to two thirds is at near max power.
c)The last third is under reduced power...
Thanks for the responses, Greg.
Cessnas have 150 and 180 hp engines, and take 2 or 3 minutes to get to 2000' from rest. A glider makes 2000' in 30 seconds. Raising the dead weight of a 600kg glider by 2000' requires quite a bit of effort. And dead weight does not take into account induced drag)...
(It's probably too difficult/expensive, but what the heck. I'll ask the questions anyway)
I'm doing some research into the possibility of launching a glider using an electric winch. Currently winches consist of a 400ci V8 coupled to an auto, coupled to a heavy truck diff driving a 1metre...