seat belts and restraints

[Bill Daniels]

I know there has been long threads about belts, 4-point, 5-point etc... I
still think there is more that needs to be discussed.

I am nursing a stiff neck from repeatedly banging my head against the canopy
on a particularly violent encounter with wave rotor yesterday. The tow
pilot is also nursing bruises from banging around in the Pawnee cockpit.
After release, I got rolled and pitched past the vertical several times - it
was that rough. I started to think that I might get knocked out if my head
hit the canopy any harder. To make things worse, I still didn't contact the
wave.

My 4-point belts were as tight as I could get them but they still didn't do
enough to keep my head from hitting the canopy. 5-point belts would have
helped, but probably not enough.

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.

Bill Daniels

[Vaughn Simon]

"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?

Vaughn


>
> Bill Daniels
>

[Bill Daniels]

"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

[[email protected]]

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

[Jim Vincent]

>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

Another trick is to just put a piece of foam in your hat.

Jim Vincent
N483SZ

[Bill Daniels]

OK, how does this save your neck or avoid breaking the canopy? Isn't it
better to avoid hitting the canopy in the first place?

Bill Daniels


"Jim Vincent" > wrote in message
...
>
> >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
>
> Another trick is to just put a piece of foam in your hat.
>
> Jim Vincent
> N483SZ
>

[Jim Vincent]

Bill,

It'll reduce the chances of breaking the canopy since the foam softens the
impact. As far as saving your neck, have you tried scootching down in the seat
or getting a thinner chute?


Jim Vincent
N483SZ

[BTIZ]

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

BT

"Bill Daniels" > wrote in message
news:rKGtd.730764$8_6.17288@attbi_s04...
>I know there has been long threads about belts, 4-point, 5-point etc... I
> still think there is more that needs to be discussed.
>
> I am nursing a stiff neck from repeatedly banging my head against the
> canopy
> on a particularly violent encounter with wave rotor yesterday. The tow
> pilot is also nursing bruises from banging around in the Pawnee cockpit.
> After release, I got rolled and pitched past the vertical several times -
> it
> was that rough. I started to think that I might get knocked out if my
> head
> hit the canopy any harder. To make things worse, I still didn't contact
> the
> wave.
>
> My 4-point belts were as tight as I could get them but they still didn't
> do
> enough to keep my head from hitting the canopy. 5-point belts would have
> helped, but probably not enough.
>
> 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.
>
> Bill Daniels
>

[Bill Daniels]

"Jim Vincent" > wrote in message
...
> Bill,
>
> It'll reduce the chances of breaking the canopy since the foam softens the
> impact. As far as saving your neck, have you tried scootching down in the
seat
> or getting a thinner chute?
>
>
> Jim Vincent
> N483SZ
>

Even cushioned blow will break a canopy if it flexes the plastic enough. I
have a thin 'chute and I had reached my scrootchability limit.

Bill Daniels

[Stefan]

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

.... at the price of your virility.

Stefan

[Eric Greenwell]

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

[Mark Zivley]

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.

[Bill Daniels]

"Eric Greenwell" > wrote in message
...
> 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

[Eric Greenwell]

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

[Bob Salvo]

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.
>

[Nyal Williams]

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!

[David R.]

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!
>
>
>

[Bob Korves]

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

[Jim Vincent]

>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

[Charles Petersen]

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
>

[Marian Aldenhövel]

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."

[OscarCVox]

Speaking as someone who has never flown is severe rotor I would be somewhat
worried about the structural integraty of the glider if you are being thrown
about so severely. How rough is rough?
Since gliders tend to be more strongly constructed that light aircraft I would
also be worried for the poor pilot in the tug.

[Bill Daniels]

"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

[Steve B]

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 James Boyd]

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

[Bill Daniels]

"OscarCVox" > wrote in message
...
> Speaking as someone who has never flown is severe rotor I would be
somewhat
> worried about the structural integraty of the glider if you are being
thrown
> about so severely. How rough is rough?
> Since gliders tend to be more strongly constructed that light aircraft I
would
> also be worried for the poor pilot in the tug.

As long as the aircraft is flown below the Va (Maneuvering) and Vb
(Turbulence Penetration)airspeeds it should be able to withstand a sharp
edged gust load of, I think, 30 FPS. (32FPS?) There may be no practical
distinction between Va and Vb in this case since the controls are likely to
be continuously hitting the stops in this kind of turbulence as the pilot
tries to maintain control.

There is no doubt that wave rotors (and thunderstorms) can produce gusts
that exceed that value since there is a history of severe damage to
airplanes and gliders.

The key is keeping the airspeed well below the Va - Vb speeds particularly
when flying downwind since the rotor is stationary with respect to the
terrain. The glider will traverse the gust edges faster so the "bang" is
sharper. If an unlucky pilot encounters a series of gusts at an airspeed
that produces a frequency that equals the natural resonance of an aircraft
structure, damage may result at a lower airspeed.

In these incidents there is always the question of whether the pilot was
incapacitated before or after a catastrophic structural failure. My
experience suggests that getting knocked out first is a real possibility.

Slightly off topic now. There used to be a slickly produced poster using
FAA-like language on the wall of the airplane FBO at Boulder, CO. It
purported to describe light, moderate and severe turbulence. In fact, it
was a practical joke on visiting flatland pilots who were encountering
mountain turbulence for the first time.

It described "light" turbulence as causing "occasional negative G".
"Moderate" turbulence was described as causing "occasional loss of control
of the aircraft". "Severe" turbulence was described as "total loss of
control for extended periods of time." Locals tried to keep a straight
face as wide-eyed flatlanders read the poster. Glider pilots didn't laugh.

Bill Daniels

[Bruce]

Bob Korves wrote:
> 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
>
>
>
Not true about not hurting if your head can't move.

With my chute and 1/2" of dyna-foam behind me, my head is in contact with the
hoop of my Std Cirrus on launch. To stop banging against the canopy I tend to
push my head back against the frame in turbulence. Despite not being able to
move much the vibrations and variations in force still give me a nice clearly
marked bruise on the crown. The price we pay for being 186cm. I wonder about the
tall guys though.

For what it is worth, and for those who have not had the privilege of flying
one, the Cirrus has wings like a steel truss, very little flex so you notice any
turbulence. Makes finding thermals easy though...

[tango4]

"OscarCVox" > wrote in message
...
> Speaking as someone who has never flown is severe rotor I would be
> somewhat
> worried about the structural integraty of the glider if you are being
> thrown
> about so severely. How rough is rough?
> Since gliders tend to be more strongly constructed that light aircraft I
> would
> also be worried for the poor pilot in the tug.

Rough can be bloody rough. I have ...

Been rolled past the vertical in spite of full opposite controls,

had the ASI fluctuating from 40kph to 120kph almost instantly,

experienced vibrations like driving on a corrugated dirt road.

And, as Bill has intimated had big 'pushes' both positive and negative. At
least +- 2G. Some people have had worse.

I have never turned back or landed because rotor but I have been airborne
whilst older and wiser pilots ( not necessarily less brave ) have.

Rotor is sometimes 'the price you have to pay' for the magic of the wave.

Ian

[John Galloway]

At 18:30 09 December 2004, 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?
>
>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 can't quote chapter and verse from memory but there
was quite a bit of discussion in the late 70s that
floppy wings (as in the ASW 20 and 17) could gain energy
in wing up flex from positive g gusts and then release
it in the down flex as lift/thrust. I always wondered
why it wasn't also discussed whether they would lose
a similar amount of energy in negative g gusts.

John Galloway

[Ray Lovinggood]

Back around 1992 or so, I saw an old, odd looking Cezzna
at a local airport. It was either an old 182 or an
even older 210 with the strutted wings. (This was
at Triple W airport on the south side of Raleigh, North
Carolina, USA)

The very odd thing I noticed was a small, round pressure
gauge mounted near the lower end of the each wing strut.
Then, I noticed some type of gas damper mechanism
between the lower wing strut attachment and the fuselage.

What the heck?

I was told this STC mod also put 'hinges' of some type
at the wing roots and allowed the wings to flex in
turbulence, to give a better ride. The person said
it looked VERY ODD when the wings stalled and flexed
upward (or the fuselage fell downwards.)

Ray Lovinggood
Carrboro, North Carolina, USA

[Ralph Jones]

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

[Tim Ward]

"Steve B" > wrote in message
...
> 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
>
<snip some stuff>

Okay, how about this:
Below the adjusters on each of the shoulder straps, sew an extra strap.
They should be long enough to go over your shoulders and Y together
somewhere in the vicinity of the small of your back.
A single strap continues down from there, through a slot in the seatpan, to
a low anchor point. It continues through the rear low anchor point to a
front low anchor point, where it becomes the crotch strap.
Now tightening the crotch strap will also pull down on your shoulders. The
low anchor point shouldn't compress your spine, because the rear low anchor
point should be in front of your shoulders.
Because the additional straps pull your shoulders down and forward, you
can't slide up and back along the normal shoulder straps to bump your head.
Because it's adjustable, it should fit more than one pilot. There's extra
strap, but the same number of adjusters, so it shouldn't be too expensive.

Obviously, a similar scheme could be used with two straps under the seat pan
in a 6-point harness arrangement.

Tim Ward

[Eric Greenwell]

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

[Bill Daniels]

"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

[tango4]

"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 )

[Roger Worden]

> My 4-point belts were as tight as I could get them but they still didn't
do
enough to keep my head from hitting the canopy.

Is it a matter of having no further travel in the adjuster, i.e. the
adjuster stopping against a fold or stitch? Are the belts simply too long?
I've had that problem (in regular turbulence... I've never been in rotor)
after a bigger person had used the ship. Fortunately in the Blanik L13, the
other end of the belt is also adjustable for length - don't know about
yours.

Or are they sufficiently short, i.e. stopping your shoulders from moving
upward at all, but your head and neck are able to stretch upward to the
point that your head hits? If that's the case, it seems to me that solid
shoulder bars would not perform any better than straps.

[Michel Talon]

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

[Ian Johnston]

On Fri, 10 Dec 2004 08:44:36 UTC, (Michel
Talon) wrote:

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

I had great fun flying one of Brian Spreckley's Pegases is France few
years back, and this energy storage in the wing was very obvious. When
you hit a thermal you could see the tips move up, then catapult the
glider a little later.

It's also important in, for example, rowing eights. Having the boat
slightly flexible means that some of the initial thrust from each
stroke is stored in the hull, then released as the rower pull more
gently towards the end of the stroke. One reason that the early
carbon-fibre eights weren't terribly successful, and were replaced by
more flexible moulded wooden ones.

Ian


--

[Don Johnstone]

At 05:30 10 December 2004, Tango4 wrote:
>
>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 )

Now that is impressive :-)

Don (20 metres)

[Stefan]

Don Johnstone wrote:

>>Ian ( 25.5 metres )

> Now that is impressive :-)
>
> Don (20 metres)

I always believed that size didn't matter?

Stefan (23 cm)

[Don Johnstone]

When it comes to wings I can assure it does

At 13:00 10 December 2004, Stefan wrote:
>Don Johnstone wrote:
>
>>>Ian ( 25.5 metres )
>
>> Now that is impressive :-)
>>
>> Don (20 metres)
>
>I always believed that size didn't matter?
>
>Stefan (23 cm)
>

[Nyal Williams]

>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.


Kinda give a new meaning to the phrase 'Put a sock
in it,' doesn't it.

[[email protected]]

Michel Talon wrote:
> Or a Pegase of the first series, which had soft wings. This is indeed
> comfortable in gusty air.
>
> --
>
> Michel TALON

While physically comfortble, I did not find it comforting. In strong
turbulence, whenever I looked out at the Pegasus' wings flapping
around, I felt compelled to review the bailout procedure. Eventually, I
stopped looking.

These flexible wings can also be a problem on field landings. If they
flex down and catch on a furrow, or in the crop, you are in for a wild
ride.

[COLIN LAMB]

For those who adventurous and like to fly rotors, look at:

http://www.nasm.si.edu/galleries/lae/images/LE600L17.jpg

for why you should wear all the protection you can find - plus something to
read on the way down.

Colin N12HS


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.783 / Virus Database: 529 - Release Date: 10/25/04

[J.A.M.]

Better your virility than your life. IMHO.
And even that is not really proven...

"Stefan" > escribió en el mensaje
...
> 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
>
> ... at the price of your virility.
>
> Stefan