seat belts and restraints

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

Hi,

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.

Minus the force your neck exerts on your head, right? Which brings
us back to restraining systems.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"Flying an An-2 is like making love to a fat lady who's had too much to drink:
there's a lot to work with, it's unresponsive, you're never quite sure when
you're there, and it's big-time ugly."

"Marian Aldenhövel" wrote in message
...
Hi,

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.

Minus the force your neck exerts on your head, right? Which brings
us back to restraining systems.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"Flying an An-2 is like making love to a fat lady who's had too much to
drink:
there's a lot to work with, it's unresponsive, you're never quite sure
when
you're there, and it's big-time ugly."

Many Eastern European gliders have toe straps for the rudder pedals which do
a good job of keeping your shins from banging the underside of the
instrument panel. The seat belt does a great job of keeping your butt in
the seat. The problem is with the shoulder straps.

Since pilots sit reclining, shoulder straps are usually angled 45 degrees to
the longitudinal axis so they are only effective in preventing the upper
torso from bending up and forward at the hip joint in a crash. They are
much less effective in preventing the upper torso, neck and head from moving
vertically in turbulence.

What if the shoulder belts crossed over the chest like bandoleers and
attached to the seat belt anchors somewhat like double automotive shoulder
straps? That seems like it would secure the upper body well but I don't
know how a quick release would work.

The idea of shoulder restraints as part of the canopy frame would work great
with front and rear hinging canopies. I can't see it working with side
hinging canopies.

Thinking about this has made me realize that what I really fear about
turbulence is a head or neck injury. I'm not really concerned about an
upset since I know I can fly out of it safely. Getting knocked out by a
blow to the head is a real concern for me.

Knowing for certain that my head couldn't touch any part of the glider in
severe turbulence would be a real comfort.

Bill Daniels

I believe that the shoulder restraints are recommended to be anchored
no more than 5 degrees below the shoulder and 30 degrees above the
shoulder in a vehicle IIRC.

In a glider I would think that the reclined position would change the
dynamics of the restraint. Because of the reclined position I would
think that there would be less of a tendency to compress the spine
when the shoulder straps are under a load. Is the 5th strap and
submerging the issue?

Would a low anchor point help with the upward motion of the pilot? How
would a low anchor point respond with a reclined seating position in a
crash?

Sounds like keeping your head intact is a primary concern and spine is
secondary?

So I am thinking 2nd set of straps with a low anchor point (for head
to canopy interference) and the standard straps to keep from
submerging (family jewels to 5th strap interference).

Steve





On Thu, 09 Dec 2004 15:34:37 GMT, "Bill Daniels"
wrote:


"Marian Aldenhövel" wrote in message
...
Hi,

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.

Minus the force your neck exerts on your head, right? Which brings
us back to restraining systems.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"Flying an An-2 is like making love to a fat lady who's had too much to
drink:
there's a lot to work with, it's unresponsive, you're never quite sure
when
you're there, and it's big-time ugly."

Many Eastern European gliders have toe straps for the rudder pedals which do
a good job of keeping your shins from banging the underside of the
instrument panel. The seat belt does a great job of keeping your butt in
the seat. The problem is with the shoulder straps.

Since pilots sit reclining, shoulder straps are usually angled 45 degrees to
the longitudinal axis so they are only effective in preventing the upper
torso from bending up and forward at the hip joint in a crash. They are
much less effective in preventing the upper torso, neck and head from moving
vertically in turbulence.

What if the shoulder belts crossed over the chest like bandoleers and
attached to the seat belt anchors somewhat like double automotive shoulder
straps? That seems like it would secure the upper body well but I don't
know how a quick release would work.

The idea of shoulder restraints as part of the canopy frame would work great
with front and rear hinging canopies. I can't see it working with side
hinging canopies.

Thinking about this has made me realize that what I really fear about
turbulence is a head or neck injury. I'm not really concerned about an
upset since I know I can fly out of it safely. Getting knocked out by a
blow to the head is a real concern for me.

Knowing for certain that my head couldn't touch any part of the glider in
severe turbulence would be a real comfort.

Bill Daniels

Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

This does NOT seem to be the same kind of thing Gary
Osaba does in the Sparrowhawk or Carbon Dragon (with super stiff
wings), but it seems related...

Any long-wingers care to comment?

In article ,
Steve B wrote:
I believe that the shoulder restraints are recommended to be anchored
no more than 5 degrees below the shoulder and 30 degrees above the
shoulder in a vehicle IIRC.

In a glider I would think that the reclined position would change the
dynamics of the restraint. Because of the reclined position I would
think that there would be less of a tendency to compress the spine
when the shoulder straps are under a load. Is the 5th strap and
submerging the issue?

Would a low anchor point help with the upward motion of the pilot? How
would a low anchor point respond with a reclined seating position in a
crash?

Sounds like keeping your head intact is a primary concern and spine is
secondary?

So I am thinking 2nd set of straps with a low anchor point (for head
to canopy interference) and the standard straps to keep from
submerging (family jewels to 5th strap interference).

Steve





On Thu, 09 Dec 2004 15:34:37 GMT, "Bill Daniels"
wrote:


"Marian Aldenhövel" wrote in message
...
Hi,

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.

Minus the force your neck exerts on your head, right? Which brings
us back to restraining systems.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"Flying an An-2 is like making love to a fat lady who's had too much to
drink:
there's a lot to work with, it's unresponsive, you're never quite sure
when
you're there, and it's big-time ugly."

Many Eastern European gliders have toe straps for the rudder pedals which do
a good job of keeping your shins from banging the underside of the
instrument panel. The seat belt does a great job of keeping your butt in
the seat. The problem is with the shoulder straps.

Since pilots sit reclining, shoulder straps are usually angled 45 degrees to
the longitudinal axis so they are only effective in preventing the upper
torso from bending up and forward at the hip joint in a crash. They are
much less effective in preventing the upper torso, neck and head from moving
vertically in turbulence.

What if the shoulder belts crossed over the chest like bandoleers and
attached to the seat belt anchors somewhat like double automotive shoulder
straps? That seems like it would secure the upper body well but I don't
know how a quick release would work.

The idea of shoulder restraints as part of the canopy frame would work great
with front and rear hinging canopies. I can't see it working with side
hinging canopies.

Thinking about this has made me realize that what I really fear about
turbulence is a head or neck injury. I'm not really concerned about an
upset since I know I can fly out of it safely. Getting knocked out by a
blow to the head is a real concern for me.

Knowing for certain that my head couldn't touch any part of the glider in
severe turbulence would be a real comfort.

Bill Daniels



--

------------+
Mark J. Boyd

On 9 Dec 2004 09:58:52 -0700, (Mark James Boyd)
wrote:

Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

In principle, it's possible to extract energy from fluid flow that
varies over a scale smaller than the size of the vehicle -- in other
words, if THIS part of the aircraft and THAT part are in measurably
different airflow.

There's a gadget sometimes demonstrated on model boats called a "wave
motor," that demonstrates this. You equip the boat with a lightweight
frame sticking down from the hull, and mount some hinged vanes on it.
The vertical motion of waves gets smaller with increasing depth, so
the vanes are alternately dragged up and pushed down with respect to
the deeper water, and they propel the boat.

So all we have to do is figure out the transition from "in principle"
to "in fiberglass"...;-)

rj

Mark James Boyd wrote:
Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

You don't have to go to long wings to enjoy this effect, but just buy an
ASW20 ("A" or C model, though the B was relatively flexible, too)!

A lot of 20 owners thought/think that the 20 did well in dolphin flight
because of this, compared to the stiff winged Ventus, but it might be
the Ventus just had separation problems near the root, unrelated to wing
stiffness.
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

"Eric Greenwell" wrote in message
...
Mark James Boyd wrote:
Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

You don't have to go to long wings to enjoy this effect, but just buy an
ASW20 ("A" or C model, though the B was relatively flexible, too)!

A lot of 20 owners thought/think that the 20 did well in dolphin flight
because of this, compared to the stiff winged Ventus, but it might be
the Ventus just had separation problems near the root, unrelated to wing
stiffness.
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Now THAT's interesting. My stiff carbon winged Nimbus 2C isn't worth a damn
at dolphin flight. I've wondered why.

BTW, I wasn't flying the Nimbus when I got hammered by the wave rotor. I'm
afraid to fly it in rotor conditions with empty wing tanks as I would have
to do for high wave flight.

Bill Daniels

Eric Greenwell wrote:
Mark James Boyd wrote:
Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

You don't have to go to long wings to enjoy this effect, but just buy an
ASW20 ("A" or C model, though the B was relatively flexible, too)!

Or a Pegase of the first series, which had soft wings. This is indeed
comfortable in gusty air.

--

Michel TALON

"Mark James Boyd" wrote in message
news:41b8925c$1@darkstar...
Here's a wierd idea:

Get longer wings. If the wings hit an updraft, they will
go up, and flex, but the fuselage won't go up right away,
kind of a "shock absorber." Then the wings will reflex,
giving extra thrust, and dissipating the G's. A few oscillations
later and you'll feel real queasy, but you'll have more glide
and less G's. Better all around, right?

OK, a bit off thread, but has anyone modeled this (dynamic)
interaction? Sure sure, we know about best glide, but what
about the effect of long wings flapping like a seagull in turbulence?

This does NOT seem to be the same kind of thing Gary
Osaba does in the Sparrowhawk or Carbon Dragon (with super stiff
wings), but it seems related...

Any long-wingers care to comment?


I thought you guys with short stiff ones already knew that us blokes with
long floppy ones got all that extra go from the flapping motion.

:-)

Ian ( 25.5 metres )