seat belts and restraints

BTIZ wrote:

I remember an article somewhere.. can't find it.. the 5 point in a glider
really only keeps you from submarining under the lap belt in case of a
landing accident as you rush forward from a rapid stop..

although there is some credence that the 5th strap will help keep the center
of the seat belt low on your waist/hips.. and hold your hips down, but it's
the shoulder straps that keep your head off the canopy.. your body still
articulates around your waist when you hit that bump that puts your head on
(or into) the canopy

Since the 5th belt holds the buckle in the proper position, you are able
to tighten the shoulder belts much more, and this reduces the severity
of "canopy encounters". Even tight shoulder harnesses won't eliminate
the problem, because they aren't designed to hold you down, but more to
keep you from going forward. If the belts angled down behind you,
instead of going straight back, a crash would likely lead to severe
compression of the spine.

A "work around" I use is to press my body up against the belts. This
tends to reduce the "overshooting" that occurs when you are thrown
against the belts by negative G's, and reduces or eliminates the impact
with the canopy.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

How about a "Hans" device?

Short of that what you probably want is some sort of neck brace, the
drag racers and dirt track racers wear that horse shoe looking spacer,
but that probably gets most of it's benefit when used w/ a helmet.

"Eric Greenwell" wrote in message
news
BTIZ wrote:

I remember an article somewhere.. can't find it.. the 5 point in a
glider
really only keeps you from submarining under the lap belt in case of a
landing accident as you rush forward from a rapid stop..

although there is some credence that the 5th strap will help keep the
center
of the seat belt low on your waist/hips.. and hold your hips down, but
it's
the shoulder straps that keep your head off the canopy.. your body still
articulates around your waist when you hit that bump that puts your head
on
(or into) the canopy

Since the 5th belt holds the buckle in the proper position, you are able
to tighten the shoulder belts much more, and this reduces the severity
of "canopy encounters". Even tight shoulder harnesses won't eliminate
the problem, because they aren't designed to hold you down, but more to
keep you from going forward. If the belts angled down behind you,
instead of going straight back, a crash would likely lead to severe
compression of the spine.

A "work around" I use is to press my body up against the belts. This
tends to reduce the "overshooting" that occurs when you are thrown
against the belts by negative G's, and reduces or eliminates the impact
with the canopy.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

So, what about the idea of a pair of short, say 8", padded arms that rotate
down over each shoulder and latch in place? That would prevent the upper
body from rising and the head from snapping sideways. The latches would
release and the arms spring back when the canopy was opened.

Bill Daniels

Bill Daniels wrote:

"Eric Greenwell" wrote in message

A "work around" I use is to press my body up against the belts. This
tends to reduce the "overshooting" that occurs when you are thrown
against the belts by negative G's, and reduces or eliminates the impact
with the canopy.


So, what about the idea of a pair of short, say 8", padded arms that rotate
down over each shoulder and latch in place? That would prevent the upper
body from rising and the head from snapping sideways. The latches would
release and the arms spring back when the canopy was opened.

Perhaps fixed arms could be on the canopy frame, so they would rise with
the canopy without any complications.

Another possibility would be a modified or removed seat back that would
give you more distance from your head to the canopy.

Any of these things would need careful design to ensure they don't make
other situations, like a crash, much worse.

Or maybe it's time for a different glider with a larger cockpit, or more
flexible wings!

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

How about wearing a set of football shoulder pads? I would think more
downward force would be available from the shoulder harness since they would
have to go up over the shoulder pads.


"Mark Zivley" wrote in message
. com...
How about a "Hans" device?

Short of that what you probably want is some sort of neck brace, the
drag racers and dirt track racers wear that horse shoe looking spacer,
but that probably gets most of it's benefit when used w/ a helmet.

At 03:00 09 December 2004, Bill Daniels wrote:

snip

So, what about the idea of a pair of short, say 8',
padded arms that rotate
down over each shoulder and latch in place? That would
prevent the upper
body from rising and the head from snapping sideways.
The latches would
release and the arms spring back when the canopy was
opened.

Bill Daniels

You make 'em. Tim Mara will sell them!

With all this talk about padded arms dropping over my shoulders, I keep
thinking about the "you must be this tall in order to ride" sign that would
have to be nearby. Of course, a "you must be this short in order to ride"
sign would actually do a better job of solving the problem.


"Nyal Williams" wrote in message
...
At 03:00 09 December 2004, Bill Daniels wrote:

snip

So, what about the idea of a pair of short, say 8',
padded arms that rotate
down over each shoulder and latch in place? That would
prevent the upper
body from rising and the head from snapping sideways.
The latches would
release and the arms spring back when the canopy was
opened.

Bill Daniels

You make 'em. Tim Mara will sell them!

If you have your head touching the canopy it cannot accelerate into the
canopy and hurt you.
-Bob

"Eric Greenwell" wrote in message
...
Bill Daniels wrote:

"Eric Greenwell" wrote in message

A "work around" I use is to press my body up against the belts. This
tends to reduce the "overshooting" that occurs when you are thrown
against the belts by negative G's, and reduces or eliminates the impact
with the canopy.


So, what about the idea of a pair of short, say 8", padded arms that
rotate
down over each shoulder and latch in place? That would prevent the
upper
body from rising and the head from snapping sideways. The latches would
release and the arms spring back when the canopy was opened.

Perhaps fixed arms could be on the canopy frame, so they would rise with
the canopy without any complications.

Another possibility would be a modified or removed seat back that would
give you more distance from your head to the canopy.

Any of these things would need careful design to ensure they don't make
other situations, like a crash, much worse.

Or maybe it's time for a different glider with a larger cockpit, or more
flexible wings!

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

If you have your head touching the canopy it cannot accelerate into the
canopy and hurt you.

Sure it can. If you hit a 3 G negative acceleration, not uncommon in heavy
ridge lift, the glider is accelerating down at 3G. Your head is trying to stay
where in one postion spatially, so the result is a force against the canopy
equal to the mass of your head times the G forces. The more dense your head,
the higher the force!

Jim Vincent
N483SZ
illspam

Tilly will happily give you, at no charge, additional cut-to-size foam
inserts. I have three in my hat, but I've met another pilot who flies with
a pair of socks in his hat in rough air.

wrote in message
ups.com...
Hi,
I use a Tilley Hat. It has a 1/8" dense foam on top. IT help some but I
dont know about rotor turbulence. Tom Knauff sell them.
S6



Bill Daniels wrote:
"Vaughn Simon" wrote in message
...

"Bill Daniels" wrote in message
news:rKGtd.730764$8_6.17288@attbi_s04...

I'm starting to think about a pair of short arms that swing down
over
the
pilots shoulders and lock in that position. The idea is to
provide an
additional, robust restraint to prevent the pilots head from
hitting the
canopy. Opening the canopy would release the locks so the arms
would
spring
up and back out of the way.

Wouldn't a bicycle helmet be much simpler and lighter?

I've never seen one that was small enough to fit under the canopy.
Anyway,
that doesn't protect your neck.

Bill Daniels