wrote:
i know that BRS systems have been pretty common in
ultralights for a while. and used successfully. I would think that
sailplanes would have similar descent rates but still not as much
energy absorption as them.

That is one of the challenges for the glider rescue designer. The
descent rate must be limited to what the fuselage can provide in pilot
protection. Older gliders (say, before the ASW 24) had "weak" fuselages
and would require a relatively large parachute, compared to modern
gliders. A large parachute is heavier, takes up more space, and makes it
harder to deploy slowly enough to avoid huge forces on the glider
structure and pilot. Another problem is ensuring the fuselage and
remaining bits descend without a lot of oscillating, so the cockpit hits
the ground at the right attitude to absorb enough energy to protect the
pilot.

All things considered, it is much easier and cheaper to retrofit a NOAH
system, even though it doesn't provide exactly the same function. The
problem is much easier to solve in an ultralight, because of their
slower speeds and lighter weights.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org