On Jan 5, 8:46 am, flyingmr2 wrote:
The limiting factor is not the winch, but the rope length which in turn
is related to the available runway length. A rough estimate is that the
height with no wind is about half the rope length.

Super cool video with an awesome launch. The hydrowinch site says
they have enough room on the spool for 10K of Spectra rope. I guess
if you have a 10k runway available,. you could get launched into
space! Well, not quite, but it would sure seem high compared to a
regular 2k launch.

The question of just how high a winch launch could go has come up
several times. There is a small group of extreme kite flyers who have
flown L/D ~4 kites up to 30,000 feet using the same Spectra rope used
by glider winches. That suggests that launching a glider to the floor
of Class A airspace would be possible given enough runway and wind. I
expect that someone will do that fairly soon.

If the glider can be launched into a 50 knot wind layer, a tension
controlled winch would automatically reverse the drum rotation
direction and pay out rope - the glider would in effect be a high L/D
kite. The possible release height would then depend on the length of
the rope, not the length of the runway.