"Ron Wanttaja" wrote in message
...
On Sun, 5 Oct 2008 09:18:21 -0600, "Bill Daniels" bildan@comcast-dot-net
wrote:

I would claim they are directly related. A glider carefully engineered
for
great handling and occupant protection will also have a good L/D.

Bill, I don't have a dog in this hunt, but: Unless you're using a
different
definition of "occupant protection" than I am, I disagree. Adding a steel
crash
cage to a glider cockpit will increase occupant protection, but has a
negative
effect on the aircraft weight without improving the aerodynamic
performance.

If your intent was more along the lines "occupant encapsulation" (e.g.,
enclosing the pilot to minimize aerodynamic drag), then we're in
agreement. but
it would be possible to put the pilot in an eggshell that would achieve
the
aerodynamics without significantly improving the crash protection....

Ron Wanttaja

I think steel tube structures are way overrated for "occupant protection" as
compared to carbon/Kevlar cockpits on modern composite gliders. Race car
builders abandoned steel tube "birdcages" for carbon/kevlar tubs a long time
ago for safety reasons. You'll never look at steel tube structure the same
way after you've seen a folded tube sever a leg artery.

For the most part, steel tube cages are limited to wing attachment/landing
gear structures in modern gliders.

Bill D