That's why they have weak links.

3,500 fpm is just the vertical component of a 45 degree
climb angle at about 50 knots.


At 06:12 30 October 2006, Eric Greenwell wrote:
Bill Daniels wrote:
Good show!

Dyneema/Spectra winch cable allows for launches to
approximately 50% of the
original cable length. Calculations show that there
is really no upper
limit to the amount of Dyneema that can be used.

90 seconds to 5200 feet AGL on a winch beats the hell
out of 20 minutes on
aero tow. That's especially true when the typical
cost is $10 for the
launch.

That sounds a bit frightening - 3500 fpm! What are
the stresses on the
glider to get that kind of climb rate? How far away
is disaster if the
pilot twitches a bit on the controls or hits some wind
shear or a thermal?

--
Eric Greenwell - Washington State, USA
Change 'netto' to 'net' to email me directly

'Transponders in Sailplanes' on the Soaring Safety
Foundation website
www.soaringsafety.org/prevention/articles.html

'A Guide to Self-launching Sailplane Operation' at
www.motorglider.org