On 28 Mar 2004 22:53:07 GMT, John Galloway
wrote:

Through the contributions to the avoiding VNE thread
runs the theme of the difficulty of avoiding overspeeding
and/or overstressing some modern designs in accidental
spin recovery. This is made more difficult than in
older composite gliders because they had a little more
drag and a little more (fortuitous) margin in the g
limits.

Is it not blindingly obvious that there is a need for
an emergency drag device that does not reduce the G
limits of gliders? Clearly if we all handled the recovery
from inadvertent spins etc perfectly all would be well
but equally clearly that does not always happen and
it is a shame to lose pilots in this situation.

Well, I have to admit that as fine as your solution sounds - it will
only be the cure for an extremely small part of all glider accidents.

How big is the fraction of overspeed/overG accidents after a spin
recovery that went wrong? 0.1 percent? 0.2 percent?

Certainly not higher - the only inflight breakups in such a situation
I ever heard of were the ASW-22 prototype (1981), the eta and the US
Nimbus, the first two being test flights of prototypes.

In the 22 case it was clear that the airframe would break up before
the flight beacuse it was not designed for the load factors that were
created by extreme asymmetrical water ballast load.

Bert Willing also exceeded the design limits of a 26 meter glider, but
his glider survived the incident without damage.


Investing a very small part of the costs for such a device in, say,
three spin-training flights per year, is probably going to make things
a lot safer.

I think the money is far better invested in a rescue system, be it
NOAH, bei it Soteira (which I prefer), or be it a BRS. A rescue system
will be able to safe the pilot in a lot more cases than a strong
airbrake.



Bye
Andreas