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Old February 15th 18, 11:58 PM posted to rec.aviation.soaring
Kiwi User
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Default New Glider Dream Elon Musk Flow

On Thu, 15 Feb 2018 13:38:45 -0800, ND wrote:

On Thursday, February 15, 2018 at 3:18:37 PM UTC-5, Kiwi User wrote:
On Thu, 15 Feb 2018 05:36:39 -0800, ND wrote:

On Wednesday, February 14, 2018 at 6:19:48 PM UTC-5, WB wrote:
On Wednesday, February 14, 2018 at 2:01:41 PM UTC-6, Kiwi User
wrote:
On Wed, 14 Feb 2018 11:06:11 -0800, ND wrote:

speaking of cars... this is a little nuts, but, airbags? i've
always thought that during a crash, you probably smack the ****
out of your head.

Airbags shouldn't be necessary provided that your straps are tight
and the anchor points don't pop off the hull, though your chin may
hit your chest quite hard. The stick is be short enough that your
head won't hit it and the shoulder + lap straps will stop your
head hitting the panel



--
Martin | martin at Gregorie | gregorie dot org

That's assuming a straight ahead impact. A friend was killed when
his glider impacted in a yawed orientating (spin). The side of his
head hit the canopy rail hard enough to kill him. It would have
taken side airbags to have protected him, or a helmet.

side airbags is basically what i was thinking, to protect your head
during a yawing or side impact. like if you were going into a ridge,
caught a wingtip first, and impacted sideways.


I'd have thought that the tip would catch, causing the glider to pivot
round it through almost 90 degrees, putting the fuselage into the ridge
nose-first. Have I got that wrong?


--
Martin | martin at Gregorie | gregorie dot org


yeah, it's not going to pivot on the wingtip and hit nose first. it IS
going to pivot. but would probably pivot, stall, and begin to fall all
while travelling sideways. the nose may be the first to touch the ground
but i think the major force of the impact would be in a sideways
direction, relative to the pilot.

i think you'll agree that it wouldn't be a horrible thing to have
airbags deploy around the pilots head in this situation (i realize its
not him catching a wingtip) :
https://www.youtube.com/watch?v=4nsXL72S9OA


I don't think you can tell a lot from that: it looks more like low speed
stall-spin onto the top of a wide spur. I can just about read the ASI,
which looks to be reading in the low 30s and the yaw string also appears
to show low speed judging by the way it first flaps about, followed by a
slip toward the low wing as the spin develops.

In the ridge-running scenario we were talking about the glider should be
flying a lot faster to keep the glider responsive. I don't go near the
hill at less than 55kts in my Libelle. Catching a tip would whip the
glider round pretty fast and, if the slope is covered in scrubby stuff
the tip isn't going to pull free. Of course, if your tip touches smooth
rock, then things are rather different but thats a situation I've never
flown in. My ridge running experience, apart from one flight in a DG-1000
at Omarama, has been under 3000 ft along grass or heather-covered ridges.

In the conditions I think I understand airbags might help, but then
again, they might not. Further, consider that a glider cockpit is a very
small volume to trigger and explosive inflation in, so that could be very
harmful by itself. Think of eardrums getting ruptured.


--
Martin | martin at
Gregorie | gregorie dot org