Bob Kuykendall wrote:

Furthermore, virtually everything you can do to improve crashworthiness
increases weight, And everything you do to increase weight increases
speed and impact energy. It's all a bunch of trade-offs.

Let me quibble with Bob a bit: a "safety cockpit" is more than just more
structure to make it stronger, but includes things like

* a steeply sloped seat pan under the thighs to reduce the chance of
submarining
* locating the seat belt anchor points so the belt stays on the hips and
does not ride up to the abdomen
* locating the shoulder harness so it doesn't compress the spine during
a crash
* making the instrument panel frangible, so it doesn't injure the pilots
legs
* making the instrument panel swivel upwards, so a pilot can bail out
more easily
* using a form of "Roeger hook" to ensure quick and clean jettisoning of
the canopy when the pilot wants to bail out

The items above involve little, if any, additional weight, yet can make
a major difference to the pilot's injuries. Older gliders might not have
any of these features; newer ones will have most of them.

Some features of the newer cockpits will add weight, but I don't think
it's a given that the speed will increase. Don't the JARs require
certain stall or landing speeds, for example? A designer can compensate
for weight with more wing area or a different airfoil to keep the speeds
the same.

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Eric Greenwell
Washington State
USA