Hybrid Engines??

The acceleration is still limited by the available power vs the total mass
of the glider and tow plane.


Possibly a better approach is to look carefully at propeller
efficiency in the initial acceleration. *In the ground roll where the
prop efficiency unlikely to be more than 25%.

Hmm, perhaps a better idea for a hybrid towplane than these hybrid
engines would be a tug with electric motors in it's wheels to quickly
get the party started... say up to 30mph or so before the prop is
providing primary thrust.

-Paul

PS. Noel, I definitely agree that battery/energy storage technology
needs to improve vastly (including $$$) for these to be truly viable
(read revolutionary) alternatives...