Crouch Strap story

[Ed Byars]

I sent the following to our magazine nine months ago and didn't receive an
acknowledgement or receipt. I guess it was not suitable for them so I
thought I would share it with ras to maybe provoke some safety discussion.

efb10-11-03-rev.6-5-04

You may be interested in my latest crotch strap experience.

I'm still analyzing my June 2003 accident and the cause. More later on this.
The role of the crotch strap is significant and worthy of mention.

The last half dozen gliders I've had I added a crotch strap (usually
available from Wings & Wheels), which easily clicks into the bottom, front
or 5th slot of the standard Gadringer belt hardware. I secure the other end,
which terminates with the belt into a triangular link, with a quarter inch
hole that I bolt to the seat pan with a large "wood" washer behind the seat
pan. My gliders are Experimental category so this is legal.

I always heard that the main purpose of a crotch strap was to keep the lap
belt across the upper thighs and prevent it sliding up to the stomach area.
I have since learned better.

It of course depends on the direction of the accident loads and the
direction of the inertia of the body as to how all restraint straps come
into play.

Many glider accidents involve "dropping in" vertically wherein the tailbone
(in the L-1, L-2 area) or higher are damaged so the belts don't help much.
You seldom see accidents with lap belt overload, but it happens. I have a
sad memory of helping remove a dead friend from an inverted Ventus cockpit
where the lap belts on both sides had pulled lose from the seat pan.
Fortunately rare but it happens.

In my "incident" the nose of the glider hit hard ground at about a 60 plus
degree angle. The "load" was about along the longitudinal axis of the
glider. Since in our modern gliders (ASW-28 in my case) we recline (sit
supine), the inertia of my body was toward the nose with only the crotch
strap to resist. Actually Waibel designed the seat pan to take some of this
forward load against the bottom of the thighs. In this seating the knees are
bent more upward.

The nose of the glider (along with my feet) was crushed in a calculated
energy-absorbing manner. Thank you Gerhardt Waibel! I think his design and
the crotch strap saved my knees.

I was conscious and lucid until the helicopter dropped me off at the
Medical College of Georgia Trauma Center.

After that I really was not with it for a couple of weeks, but after that
time I suddenly noticed that my groin area was still quite swollen. I
realized that my crotch area had sustained a significant load and that all
things considered had kept my body from moving more forward and no doubt
helped minimize the leg/knee damage. I had no shoulder strap or lap belt
marks or soreness.

Since my guess is that a significant number of glider accidents impose loads
and body reactions similar to mine, I recommend a crotch strap. Trying to
distribute the load to the pelvic area by wearing an athletic "cup" may be
good for some flights, but for some flights there are other disadvantages.
Many contest pilots regularly wear a male external catheter and I don't
think both would work. With just the crotch strap I always had to be
careful that the strap was adjusted somewhat to the right, was not too
tight, and did not interfere with the flow from the catheter that was to the
left.

I suggest reading Chip Bearden's posting which appeared in the
rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more complex
but better seat belt design.

I hope this discussion will create more thought about glider accident
safety.

Ed Byars

[Robertmudd1u]

>You may be interested in my latest crotch strap experience.
>
>I'm still analyzing my June 2003 accident and the cause. More later on this.
>The role of the crotch strap is significant and worthy of mention.

Dr. Byars, thank you for this interesting and important feedback based on real
world experience.

The standard line from the German manufactures is that a crotch strap is not
needed because the submarining hazard has been taken care of through use of the
"H point" when locating the anchoring point of the lap belts. This system
locates the lap belt a bit further forward than in older designs with the aim
being to get the lap belt lower on your hips. This is supposed to prevent it
from being pulled out of place when tightening the shoulder harness. It does,
but I believe the lap belt has to be tightened to an un-necessary degree to get
anywhere near the effect the "H point" is credited with bringing about.

My experience is that the "H point" is not adequate to keep the lap belt from
being pulled up when tightening the shoulder straps. This is especially true
when flying out west in strong lift at high speed. A crotch strap helps keep
you from bouncing around thus providing more comfort and better control. The
difference is security in the cockpit is dramatic. I normally retro fit a
crotch strap to my gliders and feel a lot safer and more comfortable with its
use. This holds true even with my Genesis which used the "H point" system to
locate the lap belt anchor points.

Robert Mudd

[Bill Daniels]

"Robertmudd1u" > wrote in message
...
> >You may be interested in my latest crotch strap experience.
> >
> >I'm still analyzing my June 2003 accident and the cause. More later on
this.
> >The role of the crotch strap is significant and worthy of mention.
>
> Dr. Byars, thank you for this interesting and important feedback based on
real
> world experience.
>
> The standard line from the German manufactures is that a crotch strap is
not
> needed because the submarining hazard has been taken care of through use
of the
> "H point" when locating the anchoring point of the lap belts. This system
> locates the lap belt a bit further forward than in older designs with the
aim
> being to get the lap belt lower on your hips. This is supposed to prevent
it
> from being pulled out of place when tightening the shoulder harness. It
does,
> but I believe the lap belt has to be tightened to an un-necessary degree
to get
> anywhere near the effect the "H point" is credited with bringing about.
>
> My experience is that the "H point" is not adequate to keep the lap belt
from
> being pulled up when tightening the shoulder straps. This is especially
true
> when flying out west in strong lift at high speed. A crotch strap helps
keep
> you from bouncing around thus providing more comfort and better control.
The
> difference is security in the cockpit is dramatic. I normally retro fit a
> crotch strap to my gliders and feel a lot safer and more comfortable with
its
> use. This holds true even with my Genesis which used the "H point" system
to
> locate the lap belt anchor points.
>
> Robert Mudd
>

After reading Ed and Robert's posts, I intend to install a crotch strap in
my Nimbus. At the very least, it will let me get the shoulder straps REALLY
tight without pulling the lap belt up too high.

When you are riding 10 - 15 knot mountain thermals with a stiff carbon wing
you just can't be strapped in too tight.

Bill Daniels

[Bill Daniels]

"Robertmudd1u" > wrote in message
...
> >You may be interested in my latest crotch strap experience.
> >
> >I'm still analyzing my June 2003 accident and the cause. More later on
this.
> >The role of the crotch strap is significant and worthy of mention.
>
> Dr. Byars, thank you for this interesting and important feedback based on
real
> world experience.
>
> The standard line from the German manufactures is that a crotch strap is
not
> needed because the submarining hazard has been taken care of through use
of the
> "H point" when locating the anchoring point of the lap belts. This system
> locates the lap belt a bit further forward than in older designs with the
aim
> being to get the lap belt lower on your hips. This is supposed to prevent
it
> from being pulled out of place when tightening the shoulder harness. It
does,
> but I believe the lap belt has to be tightened to an un-necessary degree
to get
> anywhere near the effect the "H point" is credited with bringing about.
>
> My experience is that the "H point" is not adequate to keep the lap belt
from
> being pulled up when tightening the shoulder straps. This is especially
true
> when flying out west in strong lift at high speed. A crotch strap helps
keep
> you from bouncing around thus providing more comfort and better control.
The
> difference is security in the cockpit is dramatic. I normally retro fit a
> crotch strap to my gliders and feel a lot safer and more comfortable with
its
> use. This holds true even with my Genesis which used the "H point" system
to
> locate the lap belt anchor points.
>
> Robert Mudd
>

After reading Ed and Robert's posts, I intend to install a crotch strap in
my Nimbus. At the very least, it will let me get the shoulder straps REALLY
tight without pulling the lap belt up too high.

When you are riding 10 - 15 knot mountain thermals with a stiff carbon wing
you just can't be strapped in too tight.

Bill Daniels

[plasticguy]

"Ed Byars" wrote a good piece on belting yourself in.

Before you just go and install marginal belts, look at what is available in
the sports car world
and choose the correct parts. Crotch belts or "5 point harnesses"
were developed for upright seated positions. They worked by holding the lap
belt
in the proper position over the hips and weren't designed to take impact
loads
without "stuffing your balls through your throat". As cars became faster
and aero considerations
moved drivers to the supine driving positions used today, "6 point systems"
evolved.
The load path in grontal impacts could no longer be absorbed by the lap
and shoulder belts because the vectors were wrong. What has evolved is a
belting method
that creates a web seat secured to the lap belt attach points. This
prevents the driver from
sliding forward out from under the belting system.

My SCHROTH harness hooks up like this.
Connect lap belt.
left 6 point go's under my leg, around my upper thigh, over to the
left lap belt anchor, thru a loop and back to the buckle.
Same for right side
connect shoulders
done.

What this does is transfer any decelleration loads into the upper
thigh/lower butt
area and is quite comfortable. It virtually eliminates soft tissue bruising
..
I would not fly a 5 point harness as I feel they are unsafe, the risk of
internal injuries to
the soft stuff is too high. BUT the 6 point harness works very very well.
I have
had the unfortunate "experience" of stuffing a formula car and know exactly
what works,
and what doesn't.

I don't have good pictures, but looking at the WILLANS web site gets the
message across.
Look at the way all the sub straps create seats to support you against
sliding forward.


http://www.willansharness.com/

Scott Correa

[Ian Cant]

The 'crotch strap' is what used to be known as a 'negative-G'
strap. Usually it works to keep your skull away from
the canopy during the bumpy bits of sky; rarely, it
helps you in a crash by preventing submarining. However,
a single strap is both inconvenient and potentially
painful. A better design is a double strap, like an
inverted V, but it needs two hard points. Another
variation is an upright V, with one hardpoint and some
secure way to fasten the ends of the V to the lapstraps
rather than the buckle.

The conventional 4-point or 5-point harness shows its
ancestry from the lapstrap by having the primary mounting
[the buckle] on the lapstrap. Would a better design
not have the buckle assembly permanently mounted to
the [adjustable] negative-G strap and the two lap and
two shoulder straps plugging in later ?

Ian




At 15:00 06 June 2004, Bill Daniels wrote:
>
>'Robertmudd1u' wrote in message
...
>> >You may be interested in my latest crotch strap experience.
>> >
>> >I'm still analyzing my June 2003 accident and the
>>>cause. More later on
>this.
>> >The role of the crotch strap is significant and worthy
>>>of mention.
>>
>> Dr. Byars, thank you for this interesting and important
>>feedback based on
>real
>> world experience.
>>
>> The standard line from the German manufactures is
>>that a crotch strap is
>not
>> needed because the submarining hazard has been taken
>>care of through use
>of the
>> 'H point' when locating the anchoring point of the
>>lap belts. This system
>> locates the lap belt a bit further forward than in
>>older designs with the
>aim
>> being to get the lap belt lower on your hips. This
>>is supposed to prevent
>it
>> from being pulled out of place when tightening the
>>shoulder harness. It
>does,
>> but I believe the lap belt has to be tightened to
>>an un-necessary degree
>to get
>> anywhere near the effect the 'H point' is credited
>>with bringing about.
>>
>> My experience is that the 'H point' is not adequate
>>to keep the lap belt
>from
>> being pulled up when tightening the shoulder straps.
>>This is especially
>true
>> when flying out west in strong lift at high speed.
>>A crotch strap helps
>keep
>> you from bouncing around thus providing more comfort
>>and better control.
>The
>> difference is security in the cockpit is dramatic.
>>I normally retro fit a
>> crotch strap to my gliders and feel a lot safer and
>>more comfortable with
>its
>> use. This holds true even with my Genesis which used
>>the 'H point' system
>to
>> locate the lap belt anchor points.
>>
>> Robert Mudd
>>
>
>After reading Ed and Robert's posts, I intend to install
>a crotch strap in
>my Nimbus. At the very least, it will let me get the
>shoulder straps REALLY
>tight without pulling the lap belt up too high.
>
>When you are riding 10 - 15 knot mountain thermals
>with a stiff carbon wing
>you just can't be strapped in too tight.
>
>Bill Daniels
>
>

[Ian Strachan]

In article >, Robertmudd1u
> writes
>>You may be interested in my latest crotch strap experience.
>>
>>I'm still analyzing my June 2003 accident and the cause. More later on this.
>>The role of the crotch strap is significant and worthy of mention.
>
>Dr. Byars, thank you for this interesting and important feedback based on real
>world experience.
>
>The standard line from the German manufactures is that a crotch strap is not
>needed because the submarining hazard has been taken care of through use of the
>"H point" when locating the anchoring point of the lap belts.

>This system
>locates the lap belt a bit further forward than in older designs with the aim
>being to get the lap belt lower on your hips. This is supposed to prevent it
>from being pulled out of place when tightening the shoulder harness. It does,
>but I believe the lap belt has to be tightened to an un-necessary degree to get
>anywhere near the effect the "H point" is credited with bringing about.

Quite. If you could predict exactly when you were going to crash, and
correctly tighten up your straps beforehand, this might work. But with
sometimes hurried field landing decisions the "pre-prepared crash
scenario" is just not realistic. Also, from other postings in this
thread, the four point harness does not seem to be very good in high
turbulence.

>My experience is that the "H point" is not adequate to keep the lap belt from
>being pulled up when tightening the shoulder straps. This is especially true
>when flying out west in strong lift at high speed. A crotch strap helps keep
>you from bouncing around thus providing more comfort and better control. The
>difference is security in the cockpit is dramatic. I normally retro fit a
>crotch strap to my gliders and feel a lot safer and more comfortable with its
>use. This holds true even with my Genesis which used the "H point" system to
>locate the lap belt anchor points.

Robert, I entirely agree with you and Ed Byars that a fifth (crotch, if
you like) strap is invaluable in a number of situations.

In my military flying, a five-point harness was normal and I spent many
hours wearing one, normally as part of Martin Baker ejection seats of
various types.

Turning to gliding, some 10 years ago another pilot at Lasham ordered a
German glider and wanted 5-point harnesses fitted during build. The
maker refused to fit them "because it has been shown that the fifth
strap is dangerous". When pressed, they quoted a report done by a car
(automobile) test organisation in Germany on five-point harnesses that
suggested that some damage might occur to the crotch area in the case of
a severe impact. Possible damage to the male genitals was also
mentioned, and this seems to have had a major impact (no pun intended!)
on people's thoughts about the fifth strap.

However, my view was that in a major crash, if the fifth strap caused
some soreness afterwards but prevented "submarining" of the body under
the lap straps, then it could reduce damage to the legs or even save the
life of the pilot. It is all very well raising emotional points about
sore genitals. The real point IMHO is in a crash in which life is at
stake or there is the possibility of the pilot becoming a paraplegic.
What is the best option to minimise these awful results in a critical
"life-or-death" crash situation?

To put it crudely, would you rather have a sore crutch for a short
while, or be dead, or in a wheelchair for the rest of your life? In any
case, the "sore crutch" effect may not be there after all, see the next
para.

I was supported in my view by Dr Peter Saundby, the medical advisor to
the BGA, a qualified flight surgeon and an RAF jet pilot himself. He
pointed out that an important function of the fifth strap was to keep
the major load-bearing lap straps from riding up too high, even if they
had slackened off during flight. The lap straps then stood a good
chance of taking the large crash loads for which they are designed, and
any tendency to "submarine" under them would be minimised.

Peter and I were able to interest Dr Tony Segal, a UK glider pilot and
graduate of the UK Aero Medical (Flight Surgeon) course with the RAF at
Farnborough. Tony had already made glider crash tests using redundant
cockpit sections. He then managed to interest the UK Defence Evaluation
and Research Agency (DERA) in the crashworthiness of four and five point
harnesses. Tests were carried out at the UK Defence site at Farnborough
using instrumented human dummies seated in mock-ups of glider cockpits
and the impact test track of the Centre for Human Sciences (CHS) at
Farnborough. The glider cockpit was modelled around a Nimbus 3.

An unclassified report was published. This was also presented to the
gliding scientific organisation OSTIV during their meeting at Bayreuth,
Germany, in August 1999 and no doubt will be available in full from
OSTIV (OSTIV = Organisation Scientifique et Technique Internationale de
Vol a Voile).

As far as I know, this paper is probably the most definitive recent work
on the subject and would probably answer most of the points raised in
this thread. Here are some details:

Title:

Four and Five Point Glider Seat Harnesses - Static and Dynamic Tests

Authors

Dr Anthony M Segal, Lasham Gliding Society, UK
Leslie P Neil, Senior Engineer Impact Protection, UK DERA
Graham A Reece, Instrumentation Engineer, UK DERA
Philip G Murtha, Impact Test Track Engineer, UK DERA

The paper is 20 pages long but para 5b is worth quoting in full (QRF =
Quick Release Fastening, that is, the harness release box)::

"5 b) Observations After the Impact Test

When a 5 point harness was being tested, both with the harness tight and
with the harness slack, the lap straps remained in the correct position
over the hip bones. The QRF also stayed in the correct position.

When a 4 point harness was being tested, both with the harness tight and
with the harness lose, the lap straps were seen to have moved up over
the abdomen until they were jammed tightly under the lower rib margin.
The QRF had moved upwards until it was in the epigastrium (the "pit of
the stomach"). This is very serious, because severe, even fatal injury
may be caused to the internal organs in the upper abdomen.

THIS IS CONSIDERED TO BE THE MOST IMPORTANT FINDING OF THE ENTIRE TEST.

Following the impact test, with a 4 point harness, the shoulder straps
were seen to be hanging loosely between the seat back and the pilot
dummy's shoulders. This was due to the upward movement of the lap straps
and the QRF."

Finally, the conclusion includes the following words:

"A 5-point harness is superior to a 4-point harness in an accident
impact situation and also under conditions of negative-g. This is
especially so if the harness is slack."

It also goes on to say: "It is recommended that the 5th strap be
designed to avoid injury to the crotch of the pilot. This design of
strap should be fitted to new gliders and be retro-fitted (where
structurally feasible) to gliders in current use".

-------------------------------

The above seems pretty conclusive to me and in my syndicate glider we
had a fifth (crotch) strap fitted in the rear cockpit. We were told
that in the front cockpit there was not a proper hard point to which a
fifth strap could be fixed. Maybe with some minor structural
strengthening it could be, this thread has reminded me that we ought to
investigate it.

--
Ian Strachan
Lasham Gliding Centre, UK

[Martin Gregorie]

On 6 Jun 2004 16:55:50 GMT, Ian Cant
> wrote:

>The 'crotch strap' is what used to be known as a 'negative-G'
>strap. Usually it works to keep your skull away from
>the canopy during the bumpy bits of sky; rarely, it
>helps you in a crash by preventing submarining. However,
>a single strap is both inconvenient and potentially
>painful. A better design is a double strap, like an
>inverted V, but it needs two hard points. Another
>variation is an upright V, with one hardpoint and some
>secure way to fasten the ends of the V to the lapstraps
>rather than the buckle.
>
I followed the link to Willans Harnesses in "plastic guy's" post and
moused round the site a little. They supply a Y-strap that's designed
to connect to the 5th slot on their quick release fitting, passes
under your legs and attaches to the lap strap hard points. They say
its designed to upgrade their 4-point racing car harnesses to 6-point
standard.

This looks potentially like a quick and easy way to upgrade a 4-point
harness because it requires no extra hard points in the glider.
Presumably the lap strap hard points are already designed to take the
full deceleration loads in a crash so fitting it would not put
additional loads on them.

Does anybody on here know if this upgrade has been done?

If so, how does it compare with a traditional 5-point system with
regard to anti-submarining and negative-G properties?

Are our 5-point rotary action quick-release units the same as the car
racing gang use?


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Dusty]

Dale Thompson and I had an inverted V crotch strap in our 1-35. It served to
keep the lap belt in position. More important was the assurance that the
legs and hips would probably take the stress instead of other more
"important" parts that could not be so easily repaired.

Fortunately, we never had a test of its effectiveness.

The design is very simple and easily made. Our was made by Alan Silver, in
the San Francisco bay area, who repacked our chute. I do not think he is
still in business.


"Martin Gregorie" > wrote in message
...
> On 6 Jun 2004 16:55:50 GMT, Ian Cant
> > wrote:
>
> >The 'crotch strap' is what used to be known as a 'negative-G'
> >strap. Usually it works to keep your skull away from
> >the canopy during the bumpy bits of sky; rarely, it
> >helps you in a crash by preventing submarining. However,
> >a single strap is both inconvenient and potentially
> >painful. A better design is a double strap, like an
> >inverted V, but it needs two hard points. Another
> >variation is an upright V, with one hardpoint and some
> >secure way to fasten the ends of the V to the lapstraps
> >rather than the buckle.
> >
> I followed the link to Willans Harnesses in "plastic guy's" post and
> moused round the site a little. They supply a Y-strap that's designed
> to connect to the 5th slot on their quick release fitting, passes
> under your legs and attaches to the lap strap hard points. They say
> its designed to upgrade their 4-point racing car harnesses to 6-point
> standard.
>
> This looks potentially like a quick and easy way to upgrade a 4-point
> harness because it requires no extra hard points in the glider.
> Presumably the lap strap hard points are already designed to take the
> full deceleration loads in a crash so fitting it would not put
> additional loads on them.
>
> Does anybody on here know if this upgrade has been done?
>
> If so, how does it compare with a traditional 5-point system with
> regard to anti-submarining and negative-G properties?
>
> Are our 5-point rotary action quick-release units the same as the car
> racing gang use?
>
>
> --
> martin@ : Martin Gregorie
> gregorie : Harlow, UK
> demon :
> co : Zappa fan & glider pilot
> uk :
>

[John Galloway]

For me six point harness is far preferable to a five
point one which would simply be impossible for long
flights. The borrowed Std Cirrus I fly at present
has a non-approved 6 point harness designed for race
car use that uses a 4 point buckle and no additional
attachment points. I think it is a little different
from that described in the earlier post.

The shoulder and lap straps are as normal except that
there is a strong metal ring attached to the top of
each lap strap about 3 inches lateral to the buckle.
The 4th and 5 straps are attached by metal clips under
the seat pan to the fuselage (not seat pan) mounted
attachment points also used for the lap straps. The
upper, business, end of the 2 thigh straps is a loop
not a buckle. The straps run forward and medially
under the seat pan for about 8 inches and emerge through
slit shaped cut outs in the seat pan under the inside
of each upper thigh - giving virtual attachment points
there. With only the laps straps buckled the left
thigh strap comes inside and over the thigh to the
metal ring over the top of the thigh, through it and
then turns upwards and inwards towards the top of the
buckle area. Then the metal tongue of the left left
shoulder strap is inserted throught the thigh strap
loop and into the buckle. Same on the right.

This arrangement pulls down on the lap strap assembly
from the top strap's tongue but the extra straps come
in at an angle from the side and do not cover the buckle.
When the buckle is undone the shoulder straps are
instantly free of the 4th and 5th straps which just
fall away through the metal loops on the lap straps.

When we first looked at the glider we did not understand
that the extra straps attached to the shoulder straps
and thought they were suppsed to attach to the lap
straps which would not have been easy to get out of
in a hurry. I only refitted the extra straps today
as a result of thinking about this thread and it seems
to work really well. I feel secured firmly in the
seat pan and can't slide forward. The lap straps are
held well down in place and at last I don't have to
feel squashed down by shoulder straps - which can be
safely left comfortable. I will be able to pee no
problem too.

I recall from attempts to get six point straps fitted
to a new glider about 3 years ago that the manufacturer's
view was that it was impossible for them as there were
no LBA approved 6 point straps. Damn shame.

John Galloway

[Kilo Charlie]

Excellent post Ed....thanks for sharing it with us. I hope that you are
doing well.

I remember Chip showing us his system years ago when flying at Mid Atlantic
Soaring. My only concern is the same that was posted back when this all was
discussed in 1998....that is if the belts will withstand the loads placed
upon them at angles that they were not designed for when using the system
described by Chip. Does anyone have any further info about this? You out
there Chip? I know that he was concerned re the liability issue of
non-approved applications in the past so may not be willing to discuss this
publicly.

I have a crotch strap installed by myself in my experimental certificated
glider (LS-8) but honestly only use it when on a fast final glide to keep my
head from being bruised i.e. most of the flight it is not connected for
relief reasons. It obviously wouldn't be much help laying there in the seat
just prior to impacting something.

Casey Lenox
KC
Phoenix

[HL Falbaum]

ED
Glad you're doing well. I am curious--did the crotch strap attach point
fail, or was it intact after the crash? If it did fail, at what estimated
load did that occur? Pehaps it does not have to hold the entire load to be
effective--your thoughts?
Thanks

Hartley Falbaum


"Ed Byars" > wrote in message
hlink.net...
> I sent the following to our magazine nine months ago and didn't receive an
> acknowledgement or receipt. I guess it was not suitable for them so I
> thought I would share it with ras to maybe provoke some safety discussion.
>
> efb10-11-03-rev.6-5-04
>
> You may be interested in my latest crotch strap experience.
>
> I'm still analyzing my June 2003 accident and the cause. More later on
this.
> The role of the crotch strap is significant and worthy of mention.
>
> The last half dozen gliders I've had I added a crotch strap (usually
> available from Wings & Wheels), which easily clicks into the bottom, front
> or 5th slot of the standard Gadringer belt hardware. I secure the other
end,
> which terminates with the belt into a triangular link, with a quarter inch
> hole that I bolt to the seat pan with a large "wood" washer behind the
seat
> pan. My gliders are Experimental category so this is legal.
>
> I always heard that the main purpose of a crotch strap was to keep the lap
> belt across the upper thighs and prevent it sliding up to the stomach
area.
> I have since learned better.
>
> It of course depends on the direction of the accident loads and the
> direction of the inertia of the body as to how all restraint straps come
> into play.
>
> Many glider accidents involve "dropping in" vertically wherein the
tailbone
> (in the L-1, L-2 area) or higher are damaged so the belts don't help much.
> You seldom see accidents with lap belt overload, but it happens. I have a
> sad memory of helping remove a dead friend from an inverted Ventus cockpit
> where the lap belts on both sides had pulled lose from the seat pan.
> Fortunately rare but it happens.
>
> In my "incident" the nose of the glider hit hard ground at about a 60 plus
> degree angle. The "load" was about along the longitudinal axis of the
> glider. Since in our modern gliders (ASW-28 in my case) we recline (sit
> supine), the inertia of my body was toward the nose with only the crotch
> strap to resist. Actually Waibel designed the seat pan to take some of
this
> forward load against the bottom of the thighs. In this seating the knees
are
> bent more upward.
>
> The nose of the glider (along with my feet) was crushed in a calculated
> energy-absorbing manner. Thank you Gerhardt Waibel! I think his design
and
> the crotch strap saved my knees.
>
> I was conscious and lucid until the helicopter dropped me off at the
> Medical College of Georgia Trauma Center.
>
> After that I really was not with it for a couple of weeks, but after that
> time I suddenly noticed that my groin area was still quite swollen. I
> realized that my crotch area had sustained a significant load and that all
> things considered had kept my body from moving more forward and no doubt
> helped minimize the leg/knee damage. I had no shoulder strap or lap belt
> marks or soreness.
>
> Since my guess is that a significant number of glider accidents impose
loads
> and body reactions similar to mine, I recommend a crotch strap. Trying to
> distribute the load to the pelvic area by wearing an athletic "cup" may be
> good for some flights, but for some flights there are other disadvantages.
> Many contest pilots regularly wear a male external catheter and I don't
> think both would work. With just the crotch strap I always had to be
> careful that the strap was adjusted somewhat to the right, was not too
> tight, and did not interfere with the flow from the catheter that was to
the
> left.
>
> I suggest reading Chip Bearden's posting which appeared in the
> rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more
complex
> but better seat belt design.
>
> I hope this discussion will create more thought about glider accident
> safety.
>
> Ed Byars
>
>

[Bob Korves]

Alan Silver is very much still in business. See http://www.pia.com/silver/
-Bob Korves
LAK-17a "5K
DuoDiscus "5H"

"Dusty" > wrote in message
m...
> Dale Thompson and I had an inverted V crotch strap in our 1-35. It served
to
> keep the lap belt in position. More important was the assurance that the
> legs and hips would probably take the stress instead of other more
> "important" parts that could not be so easily repaired.
>
> Fortunately, we never had a test of its effectiveness.
>
> The design is very simple and easily made. Our was made by Alan Silver, in
> the San Francisco bay area, who repacked our chute. I do not think he is
> still in business.

[Eric Greenwell]

In article >,
says...

>Finally, the conclusion includes the following words:
>
>"A 5-point harness is superior to a 4-point harness in an accident
>impact situation and also under conditions of negative-g. This is
>especially so if the harness is slack."
>
>It also goes on to say: "It is recommended that the 5th strap be
>designed to avoid injury to the crotch of the pilot. This design of
>strap should be fitted to new gliders and be retro-fitted (where
>structurally feasible) to gliders in current use".
>
>-------------------------------
>
>The above seems pretty conclusive to me and in my syndicate glider we
>had a fifth (crotch) strap fitted in the rear cockpit. We were told
>that in the front cockpit there was not a proper hard point to which a
>fifth strap could be fixed. Maybe with some minor structural
>strengthening it could be, this thread has reminded me that we ought to
>investigate it.

Tony Segal published a later article, which concluded six point
harnesses were superior to five point harnesses. It was published in
S&G, but I'm not were I can look at the article for the date.

--
-------
Eric Greenwell USA

[Robertmudd1u]

>Tony Segal published a later article, which concluded six point
>harnesses were superior to five point harnesses.

I'll bet they are but does this not provide two more straps to un-fasten when
the need for a quick egress arises? Or am I missing something?

Robert Mudd

[tango4]

It is possible to make a 6 point harness that simply falls away when
released. Some were trialled in Europe and the UK I believe . The plusses
for a six point harness outweighed the negatives by a long way! I was trying
to get hold of one but they appear to not have been able to get them
certified.
It is very difficult to innovate in the aviation industry without spending
vast amounts of money and I think this vital innovation may have fallen foul
of this.

Perhaps DG offers this as an option? They seem to be the only real
innovaters left on the soaring scene.

Ian


"Robertmudd1u" > wrote in message
...
> >Tony Segal published a later article, which concluded six point
> >harnesses were superior to five point harnesses.
>
> I'll bet they are but does this not provide two more straps to un-fasten
when
> the need for a quick egress arises? Or am I missing something?
>
> Robert Mudd

[Garret]

Alan Silver

http://www.pia.com/silver/

We only send our parachutes to him. He is still repacking and making
belts.

This thread is making me wonder about if it was a good idea to get rid
of that crotch strap.

Garret

[Robertmudd1u]

>Perhaps DG offers this as an option? They seem to be the only real
>innovaters left on the soaring scene.
>
>Ian

Perhaps, but Herr Weber has always been one of the most vocal in skeaking out,
saying that 5th. belt/crotch straps are not needed.

Robert Mudd

[Ed Byars]

Hi Hartley,
The crotch strap remained intact after doing it's job. I'm just lucky that
no serious permanent damage was done to my sensitive genitals.
I like the ideas presented relative to a six point arrangement. This sure
sounds safer, but any sensible arrangement would be virtually impossible to
get by the LBA/FAA.
It's a shame that it's not likely that any competent person or group
would/will develop and offer for sale such a glider system. Our legal system
just would not allow it. Maybe such a system designed for another more
numerous vehicle, auto probably, might be available for Experimental
licensed gliders. From an overall safety standpoint it may be just as
important to assure that any belting system is quickly free of the body with
one quick push or twist. We must not forget that provision for a quick
cockpit egress may be just as important.
I'm pleased that this thread seems to have made a few of us review our
restraint system and think about possible improvement.
Ed Byars


"HL Falbaum" > wrote in message
news:ouPwc.19014$%F2.12354@attbi_s04...
> ED
> Glad you're doing well. I am curious--did the crotch strap attach point
> fail, or was it intact after the crash? If it did fail, at what estimated
> load did that occur? Pehaps it does not have to hold the entire load to be
> effective--your thoughts?
> Thanks
>
> Hartley Falbaum
>
>
> "Ed Byars" > wrote in message
> hlink.net...
> > I sent the following to our magazine nine months ago and didn't receive
an
> > acknowledgement or receipt. I guess it was not suitable for them so I
> > thought I would share it with ras to maybe provoke some safety
discussion.
> >
> > efb10-11-03-rev.6-5-04
> >
> > You may be interested in my latest crotch strap experience.
> >
> > I'm still analyzing my June 2003 accident and the cause. More later on
> this.
> > The role of the crotch strap is significant and worthy of mention.
> >
> > The last half dozen gliders I've had I added a crotch strap (usually
> > available from Wings & Wheels), which easily clicks into the bottom,
front
> > or 5th slot of the standard Gadringer belt hardware. I secure the other
> end,
> > which terminates with the belt into a triangular link, with a quarter
inch
> > hole that I bolt to the seat pan with a large "wood" washer behind the
> seat
> > pan. My gliders are Experimental category so this is legal.
> >
> > I always heard that the main purpose of a crotch strap was to keep the
lap
> > belt across the upper thighs and prevent it sliding up to the stomach
> area.
> > I have since learned better.
> >
> > It of course depends on the direction of the accident loads and the
> > direction of the inertia of the body as to how all restraint straps come
> > into play.
> >
> > Many glider accidents involve "dropping in" vertically wherein the
> tailbone
> > (in the L-1, L-2 area) or higher are damaged so the belts don't help
much.
> > You seldom see accidents with lap belt overload, but it happens. I have
a
> > sad memory of helping remove a dead friend from an inverted Ventus
cockpit
> > where the lap belts on both sides had pulled lose from the seat pan.
> > Fortunately rare but it happens.
> >
> > In my "incident" the nose of the glider hit hard ground at about a 60
plus
> > degree angle. The "load" was about along the longitudinal axis of the
> > glider. Since in our modern gliders (ASW-28 in my case) we recline (sit
> > supine), the inertia of my body was toward the nose with only the crotch
> > strap to resist. Actually Waibel designed the seat pan to take some of
> this
> > forward load against the bottom of the thighs. In this seating the knees
> are
> > bent more upward.
> >
> > The nose of the glider (along with my feet) was crushed in a calculated
> > energy-absorbing manner. Thank you Gerhardt Waibel! I think his design
> and
> > the crotch strap saved my knees.
> >
> > I was conscious and lucid until the helicopter dropped me off at the
> > Medical College of Georgia Trauma Center.
> >
> > After that I really was not with it for a couple of weeks, but after
that
> > time I suddenly noticed that my groin area was still quite swollen. I
> > realized that my crotch area had sustained a significant load and that
all
> > things considered had kept my body from moving more forward and no doubt
> > helped minimize the leg/knee damage. I had no shoulder strap or lap belt
> > marks or soreness.
> >
> > Since my guess is that a significant number of glider accidents impose
> loads
> > and body reactions similar to mine, I recommend a crotch strap. Trying
to
> > distribute the load to the pelvic area by wearing an athletic "cup" may
be
> > good for some flights, but for some flights there are other
disadvantages.
> > Many contest pilots regularly wear a male external catheter and I don't
> > think both would work. With just the crotch strap I always had to be
> > careful that the strap was adjusted somewhat to the right, was not too
> > tight, and did not interfere with the flow from the catheter that was to
> the
> > left.
> >
> > I suggest reading Chip Bearden's posting which appeared in the
> > rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more
> complex
> > but better seat belt design.
> >
> > I hope this discussion will create more thought about glider accident
> > safety.
> >
> > Ed Byars
> >
> >
>
>

[plasticguy]

"Ed Byars" > wrote in message
> Hi Hartley,
> The crotch strap remained intact after doing it's job. I'm just lucky that
> no serious permanent damage was done to my sensitive genitals.
> I like the ideas presented relative to a six point arrangement. This sure
> sounds safer, but any sensible arrangement would be virtually impossible
to
> get by the LBA/FAA.
SNIPPED


Ed.
Installing the belts in a sailplane is an exceptionally simple procedure.
If experimental, just do it.

If certified, file a 337 and get the field approval for the airplane you
stick it in.

Its quite simple to do and I haven't met a MIDO guy that didn't stamp it off
immediately
and wonder why they weren't there to begin with.

Scott.

[Ed Byars]

Hartley, I reread your post and perhaps I did not address your concerns
completely. My installation was simple. One hole in the fiberglass seat pan
as high up as practical. I used a very short large AN bolt (~5/16th). This
size bolt was gross overkill strength and weight wise but I did not have a
suitable bushing. On the back side I used an AN 970 large area washer and a
NA365 nut. On the front was the head of the bolt and the triangular steel
belt fitting. When this is good and tight the shear and bearing load on the
seat pan is spread out to the big washer size area. I'm sure in my case a
good load was transferred to the pan, Not much way to guess the value. Too
many variables.
Months later when the insurance company sold the glider I offered to help
and got a chance to examine the glider. I saw no localized damage at the
strap attach point.
Hope this helps,
Ed Byars





"Ed Byars" > wrote in message
hlink.net...
> Hi Hartley,
> The crotch strap remained intact after doing it's job. I'm just lucky that
> no serious permanent damage was done to my sensitive genitals.
> I like the ideas presented relative to a six point arrangement. This sure
> sounds safer, but any sensible arrangement would be virtually impossible
to
> get by the LBA/FAA.
> It's a shame that it's not likely that any competent person or group
> would/will develop and offer for sale such a glider system. Our legal
system
> just would not allow it. Maybe such a system designed for another more
> numerous vehicle, auto probably, might be available for Experimental
> licensed gliders. From an overall safety standpoint it may be just as
> important to assure that any belting system is quickly free of the body
with
> one quick push or twist. We must not forget that provision for a quick
> cockpit egress may be just as important.
> I'm pleased that this thread seems to have made a few of us review our
> restraint system and think about possible improvement.
> Ed Byars
>
>
> "HL Falbaum" > wrote in message
> news:ouPwc.19014$%F2.12354@attbi_s04...
> > ED
> > Glad you're doing well. I am curious--did the crotch strap attach point
> > fail, or was it intact after the crash? If it did fail, at what
estimated
> > load did that occur? Pehaps it does not have to hold the entire load to
be
> > effective--your thoughts?
> > Thanks
> >
> > Hartley Falbaum
> >
> >
> > "Ed Byars" > wrote in message
> > hlink.net...
> > > I sent the following to our magazine nine months ago and didn't
receive
> an
> > > acknowledgement or receipt. I guess it was not suitable for them so I
> > > thought I would share it with ras to maybe provoke some safety
> discussion.
> > >
> > > efb10-11-03-rev.6-5-04
> > >
> > > You may be interested in my latest crotch strap experience.
> > >
> > > I'm still analyzing my June 2003 accident and the cause. More later on
> > this.
> > > The role of the crotch strap is significant and worthy of mention.
> > >
> > > The last half dozen gliders I've had I added a crotch strap (usually
> > > available from Wings & Wheels), which easily clicks into the bottom,
> front
> > > or 5th slot of the standard Gadringer belt hardware. I secure the
other
> > end,
> > > which terminates with the belt into a triangular link, with a quarter
> inch
> > > hole that I bolt to the seat pan with a large "wood" washer behind the
> > seat
> > > pan. My gliders are Experimental category so this is legal.
> > >
> > > I always heard that the main purpose of a crotch strap was to keep the
> lap
> > > belt across the upper thighs and prevent it sliding up to the stomach
> > area.
> > > I have since learned better.
> > >
> > > It of course depends on the direction of the accident loads and the
> > > direction of the inertia of the body as to how all restraint straps
come
> > > into play.
> > >
> > > Many glider accidents involve "dropping in" vertically wherein the
> > tailbone
> > > (in the L-1, L-2 area) or higher are damaged so the belts don't help
> much.
> > > You seldom see accidents with lap belt overload, but it happens. I
have
> a
> > > sad memory of helping remove a dead friend from an inverted Ventus
> cockpit
> > > where the lap belts on both sides had pulled lose from the seat pan.
> > > Fortunately rare but it happens.
> > >
> > > In my "incident" the nose of the glider hit hard ground at about a 60
> plus
> > > degree angle. The "load" was about along the longitudinal axis of the
> > > glider. Since in our modern gliders (ASW-28 in my case) we recline
(sit
> > > supine), the inertia of my body was toward the nose with only the
crotch
> > > strap to resist. Actually Waibel designed the seat pan to take some of
> > this
> > > forward load against the bottom of the thighs. In this seating the
knees
> > are
> > > bent more upward.
> > >
> > > The nose of the glider (along with my feet) was crushed in a
calculated
> > > energy-absorbing manner. Thank you Gerhardt Waibel! I think his
design
> > and
> > > the crotch strap saved my knees.
> > >
> > > I was conscious and lucid until the helicopter dropped me off at the
> > > Medical College of Georgia Trauma Center.
> > >
> > > After that I really was not with it for a couple of weeks, but after
> that
> > > time I suddenly noticed that my groin area was still quite swollen. I
> > > realized that my crotch area had sustained a significant load and that
> all
> > > things considered had kept my body from moving more forward and no
doubt
> > > helped minimize the leg/knee damage. I had no shoulder strap or lap
belt
> > > marks or soreness.
> > >
> > > Since my guess is that a significant number of glider accidents impose
> > loads
> > > and body reactions similar to mine, I recommend a crotch strap. Trying
> to
> > > distribute the load to the pelvic area by wearing an athletic "cup"
may
> be
> > > good for some flights, but for some flights there are other
> disadvantages.
> > > Many contest pilots regularly wear a male external catheter and I
don't
> > > think both would work. With just the crotch strap I always had to be
> > > careful that the strap was adjusted somewhat to the right, was not too
> > > tight, and did not interfere with the flow from the catheter that was
to
> > the
> > > left.
> > >
> > > I suggest reading Chip Bearden's posting which appeared in the
> > > rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more
> > complex
> > > but better seat belt design.
> > >
> > > I hope this discussion will create more thought about glider accident
> > > safety.
> > >
> > > Ed Byars
> > >
> > >
> >
> >
>
>

[plasticguy]

"Robertmudd1u" > wrote in message
...
> >Tony Segal published a later article, which concluded six point
> >harnesses were superior to five point harnesses.
>
> I'll bet they are but does this not provide two more straps to un-fasten
when
> the need for a quick egress arises? Or am I missing something?
>
> Robert Mudd

Hi Robert....
All the belts on my SCHROTH harness disconnect when the release is
punched on the buckle/latch. The operating mechanism's are very user
friendly and are meant to be operated by excited people wearing gloves
who are probably on fire. I wouldn't be worried in the least about the
possibility
of entanglements. All connections happen at the buckle/latch, one place to
hookup
and/or release. ABSOLUTELY BULLETPROOF and completely reliable. If I were
to hazard a guess, I'd bet that the motorsport standards exceed the TSO for
aircraft
belts by a very wide margin.
Scott Correa

[John Galloway]

Further to my posting yesterday I have identified the
6 point harness in our Std Cirrus as as Luke PRO6F
designed for single seat race cars.

See:

http://www.lukeracing.co.uk/rec.php?cat=17

Flying with it today was the most comfortable I have
ever been in a glider as I felt totally secured with
the lap strap held low and no tendency to slide forward
in the seat pan with the lap strap rising as happens
in so many gliders. Even a deep seat pan like the
front seat of a Duo comes nowhere near in terms to
achieving that feeling.

It may be non approved but I really don't care as the
benefits for comfort and safety are so clear cut.

John Galloway

[JC Cunningham]

John Galloway > wrote:

>Further to my posting yesterday I have identified the
>6 point harness in our Std Cirrus as as Luke PRO6F
>designed for single seat race cars.
>
>See:
>
>http://www.lukeracing.co.uk/rec.php?cat=17
>
>Flying with it today was the most comfortable I have
>ever been in a glider as I felt totally secured with
>the lap strap held low and no tendency to slide forward
>in the seat pan with the lap strap rising as happens
>in so many gliders. Even a deep seat pan like the
>front seat of a Duo comes nowhere near in terms to
>achieving that feeling.
>
>It may be non approved but I really don't care as the
>benefits for comfort and safety are so clear cut.
>
>John Galloway
>

Could you double check and repost the URL. I am getting a blank page
when I try to load the page.

Thank-you.

[John Galloway]

At 18:12 07 June 2004, Jc Cunningham wrote:
>John Galloway wrote:
>
>>Further to my posting yesterday I have identified the
>>6 point harness in our Std Cirrus as as Luke PRO6F
>>designed for single seat race cars.
>>
>>See:
>>
>>http://www.lukeracing.co.uk/rec.php?cat=17
>>
>>Flying with it today was the most comfortable I have
>>ever been in a glider as I felt totally secured with
>>the lap strap held low and no tendency to slide forward
>>in the seat pan with the lap strap rising as happens
>>in so many gliders. Even a deep seat pan like the
>>front seat of a Duo comes nowhere near in terms to
>>achieving that feeling.
>>
>>It may be non approved but I really don't care as the
>>benefits for comfort and safety are so clear cut.
>>
>>John Galloway
>>
>
>Could you double check and repost the URL. I am getting
>a blank page
>when I try to load the page.
>
>Thank-you.

Thats odd because when I click on the link in your
reply I go straight to it. If all else fails go to
www.lukeracing.co.uk main site and click on the main
link for 'race and rally safety harnesses' and then
on 'Recommended' it will take to the page with a list
of their harnesses. At the bottom is the link for
PRO6F which looks identical to what is in our Std Cirrus
except that instead of the bolt clips at the aircraft
attachment end of the lap and shoulder straps we have
normal glider buckles. Also the attachment points
of the 2 thigh straps under our seat pan is a flat
hook/clip instead of the bolt clip. Our central quick
release buckle also looks to be an older less sleek
model (our straps must be 12 years old but hardly used).
Otherwise the picture gives a good idea of how the
straps work - except that in practice the upper ends
of the thigh loops pull at the lowest point of the
shoulder straps and not a few inches higher as shown
in the non-tensioned photographs.

BTW it would be more difficult to attach the straps
to a glider in which the lap straps attach to the seat
pan rather than - as in the Std Cirrus - to a fuselage
mounted metal point with a hole in the seat pan. This
allows access to the mounting point for the lap straps
from above the seat pan and for the thigh straps from
beneath the seat pan. In other gliders I would envisage
extra mounting points being required forward on the
seat pan - perhaps bonded to the bottom of the seat
pan under the upper thighs.

John Galloway

[tango4]

There are quite a few 6 point harness suppliers in the UK. Just google '6
point harness'

Best price I found on the Luke 6 point PRO6F was £103 including VAT and
shipping from www.rallynuts.com

Ian

[Chip Bearden]

"Kilo Charlie" > wrote in message news>
> I remember Chip showing us his system years ago when flying at Mid Atlantic
> Soaring. My only concern is the same that was posted back when this all was
> discussed in 1998....that is if the belts will withstand the loads placed
> upon them at angles that they were not designed for when using the system
> described by Chip. Does anyone have any further info about this? You out
> there Chip? I know that he was concerned re the liability issue of
> non-approved applications in the past so may not be willing to discuss this
> publicly.

I still use my 6-point harness, the details of which I discussed in a
previous posting. Ed Byars' thoughtful email prompted me to look for
it. Cut and paste this URL into your browser window. You may have to
remove any hard carriage returns that have been inserted into the long
address:

http://groups.google.com/groups?q=group:rec.aviation.soaring+insubject:harn esses+author:jnbearden%40aol.com&hl=en&lr=&ie=UTF-8&as_drrb=b&as_mind=12&as_minm=5&as_miny=1995&as_maxd=7&as_maxm=6&as_maxy=2004&selm=19981119203658.26666.00000154%40ngol03.aol.co m&rnum=1

My concern about modifying harnesses in a certified aircraft remains,
not just for regulatory reasons but also because you're touching a
piece of safety-related equipment that can carry high loads and has
the potential to save your life and/or injure you, as Tim Mara has
previously noted on this forum.

As Casey notes, many 6-point installations (including mine) use the
seat belt attach points to anchor the thigh straps, too. I agree this
raises a question about loads being applied with different vectors
than they were designed for. On the other hand, approximately 50% of
the load on the extra harness straps is fed into the central buckle
which has the shoulder harness restraining it, so it's not as bad as
it first seems. I'd welcome any comments from more authoritative
sources.

In one update since I wrote the above email, several pilots have
assured me that their 6-point harnesses work just as well as a 5-point
harness (i.e., with a crotch strap) for turbulent ridge running. I was
a little dubious but, having never used a crotch strap, I have no
first-hand knowledge.

Chip Bearden

[JC Cunningham]

John Galloway > wrote:

>At 18:12 07 June 2004, Jc Cunningham wrote:
>>John Galloway wrote:
>>
>>>Further to my posting yesterday I have identified the
>>>6 point harness in our Std Cirrus as as Luke PRO6F
>>>designed for single seat race cars.
>>>
>>>See:
>>>
>>>http://www.lukeracing.co.uk/rec.php?cat=17
>>>
>>>Flying with it today was the most comfortable I have
>>>ever been in a glider as I felt totally secured with
>>>the lap strap held low and no tendency to slide forward
>>>in the seat pan with the lap strap rising as happens
>>>in so many gliders. Even a deep seat pan like the
>>>front seat of a Duo comes nowhere near in terms to
>>>achieving that feeling.
>>>
>>>It may be non approved but I really don't care as the
>>>benefits for comfort and safety are so clear cut.
>>>
>>>John Galloway
>>>
>>
>>Could you double check and repost the URL. I am getting
>>a blank page
>>when I try to load the page.
>>
>>Thank-you.
>
>Thats odd because when I click on the link in your
>reply I go straight to it. If all else fails go to
>www.lukeracing.co.uk main site and click on the main
>link for 'race and rally safety harnesses' and then
>on 'Recommended' it will take to the page with a list
>of their harnesses. At the bottom is the link for
>PRO6F which looks identical to what is in our Std Cirrus
>except that instead of the bolt clips at the aircraft
>attachment end of the lap and shoulder straps we have
>normal glider buckles. Also the attachment points
>of the 2 thigh straps under our seat pan is a flat
>hook/clip instead of the bolt clip. Our central quick
>release buckle also looks to be an older less sleek
>model (our straps must be 12 years old but hardly used).
> Otherwise the picture gives a good idea of how the
>straps work - except that in practice the upper ends
>of the thigh loops pull at the lowest point of the
>shoulder straps and not a few inches higher as shown
>in the non-tensioned photographs.
>
>BTW it would be more difficult to attach the straps
>to a glider in which the lap straps attach to the seat
>pan rather than - as in the Std Cirrus - to a fuselage
>mounted metal point with a hole in the seat pan. This
>allows access to the mounting point for the lap straps
>from above the seat pan and for the thigh straps from
>beneath the seat pan. In other gliders I would envisage
>extra mounting points being required forward on the
>seat pan - perhaps bonded to the bottom of the seat
>pan under the upper thighs.
>
>John Galloway
>
>

It must have been my browser that was having a problem. I use Opera.
When I used internet explorer it came up fine.

[HL Falbaum]

--
Hartley Falbaum
"Ed Byars" > wrote in message
hlink.net...
> Hartley, I reread your post and perhaps I did not address your concerns
> completely. My installation was simple. One hole in the fiberglass seat
pan
> as high up as practical. I used a very short large AN bolt (~5/16th). This
> size bolt was gross overkill strength and weight wise but I did not have a
> suitable bushing. On the back side I used an AN 970 large area washer and
a
> NA365 nut. On the front was the head of the bolt and the triangular steel
> belt fitting. When this is good and tight the shear and bearing load on
the
> seat pan is spread out to the big washer size area. I'm sure in my case a
> good load was transferred to the pan, Not much way to guess the value. Too
> many variables.
> Months later when the insurance company sold the glider I offered to help
> and got a chance to examine the glider. I saw no localized damage at the
> strap attach point.
> Hope this helps,
> Ed Byars
>
>
>
>
>
> "Ed Byars" > wrote in message
> hlink.net...
> > Hi Hartley,
> > The crotch strap remained intact after doing it's job. I'm just lucky
that
> > no serious permanent damage was done to my sensitive genitals.
> > I like the ideas presented relative to a six point arrangement. This
sure
> > sounds safer, but any sensible arrangement would be virtually impossible
> to
> > get by the LBA/FAA.
> > It's a shame that it's not likely that any competent person or group
> > would/will develop and offer for sale such a glider system. Our legal
> system
> > just would not allow it. Maybe such a system designed for another more
> > numerous vehicle, auto probably, might be available for Experimental
> > licensed gliders. From an overall safety standpoint it may be just as
> > important to assure that any belting system is quickly free of the body
> with
> > one quick push or twist. We must not forget that provision for a quick
> > cockpit egress may be just as important.
> > I'm pleased that this thread seems to have made a few of us review our
> > restraint system and think about possible improvement.
> > Ed Byars
> >
> >
> > "HL Falbaum" > wrote in message
> > news:ouPwc.19014$%F2.12354@attbi_s04...
> > > ED
> > > Glad you're doing well. I am curious--did the crotch strap attach
point
> > > fail, or was it intact after the crash? If it did fail, at what
> estimated
> > > load did that occur? Pehaps it does not have to hold the entire load
to
> be
> > > effective--your thoughts?
> > > Thanks
> > >
> > > Hartley Falbaum
> > >
> > >
> > > "Ed Byars" > wrote in message
> > > hlink.net...
> > > > I sent the following to our magazine nine months ago and didn't
> receive
> > an
> > > > acknowledgement or receipt. I guess it was not suitable for them so
I
> > > > thought I would share it with ras to maybe provoke some safety
> > discussion.
> > > >
> > > > efb10-11-03-rev.6-5-04
> > > >
> > > > You may be interested in my latest crotch strap experience.
> > > >
> > > > I'm still analyzing my June 2003 accident and the cause. More later
on
> > > this.
> > > > The role of the crotch strap is significant and worthy of mention.
> > > >
> > > > The last half dozen gliders I've had I added a crotch strap (usually
> > > > available from Wings & Wheels), which easily clicks into the bottom,
> > front
> > > > or 5th slot of the standard Gadringer belt hardware. I secure the
> other
> > > end,
> > > > which terminates with the belt into a triangular link, with a
quarter
> > inch
> > > > hole that I bolt to the seat pan with a large "wood" washer behind
the
> > > seat
> > > > pan. My gliders are Experimental category so this is legal.
> > > >
> > > > I always heard that the main purpose of a crotch strap was to keep
the
> > lap
> > > > belt across the upper thighs and prevent it sliding up to the
stomach
> > > area.
> > > > I have since learned better.
> > > >
> > > > It of course depends on the direction of the accident loads and the
> > > > direction of the inertia of the body as to how all restraint straps
> come
> > > > into play.
> > > >
> > > > Many glider accidents involve "dropping in" vertically wherein the
> > > tailbone
> > > > (in the L-1, L-2 area) or higher are damaged so the belts don't help
> > much.
> > > > You seldom see accidents with lap belt overload, but it happens. I
> have
> > a
> > > > sad memory of helping remove a dead friend from an inverted Ventus
> > cockpit
> > > > where the lap belts on both sides had pulled lose from the seat pan.
> > > > Fortunately rare but it happens.
> > > >
> > > > In my "incident" the nose of the glider hit hard ground at about a
60
> > plus
> > > > degree angle. The "load" was about along the longitudinal axis of
the
> > > > glider. Since in our modern gliders (ASW-28 in my case) we recline
> (sit
> > > > supine), the inertia of my body was toward the nose with only the
> crotch
> > > > strap to resist. Actually Waibel designed the seat pan to take some
of
> > > this
> > > > forward load against the bottom of the thighs. In this seating the
> knees
> > > are
> > > > bent more upward.
> > > >
> > > > The nose of the glider (along with my feet) was crushed in a
> calculated
> > > > energy-absorbing manner. Thank you Gerhardt Waibel! I think his
> design
> > > and
> > > > the crotch strap saved my knees.
> > > >
> > > > I was conscious and lucid until the helicopter dropped me off at
the
> > > > Medical College of Georgia Trauma Center.
> > > >
> > > > After that I really was not with it for a couple of weeks, but after
> > that
> > > > time I suddenly noticed that my groin area was still quite swollen.
I
> > > > realized that my crotch area had sustained a significant load and
that
> > all
> > > > things considered had kept my body from moving more forward and no
> doubt
> > > > helped minimize the leg/knee damage. I had no shoulder strap or lap
> belt
> > > > marks or soreness.
> > > >
> > > > Since my guess is that a significant number of glider accidents
impose
> > > loads
> > > > and body reactions similar to mine, I recommend a crotch strap.
Trying
> > to
> > > > distribute the load to the pelvic area by wearing an athletic "cup"
> may
> > be
> > > > good for some flights, but for some flights there are other
> > disadvantages.
> > > > Many contest pilots regularly wear a male external catheter and I
> don't
> > > > think both would work. With just the crotch strap I always had to
be
> > > > careful that the strap was adjusted somewhat to the right, was not
too
> > > > tight, and did not interfere with the flow from the catheter that
was
> to
> > > the
> > > > left.
> > > >
> > > > I suggest reading Chip Bearden's posting which appeared in the
> > > > rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more
> > > complex
> > > > but better seat belt design.
> > > >
> > > > I hope this discussion will create more thought about glider
accident
> > > > safety.
> > > >
> > > > Ed Byars
> > > >
> > > >
> > >
> > >
> >
> >
>
>

[HL Falbaum]

That's the info. Thanks ED.
My thought was that if it failed at say half to 2/3 of the total potential
load it would mitigate the damage to the " soft tissues " and restrain
enough to help--the "progressive crush" idea.
BTW - Motorcyclists and their accidents demonstrate that the genitalia are
tougher than you may think---Thank the Lord!
Thanks Again
--
Hartley "KF" Falbaum
USA


"Ed Byars" > wrote in message
hlink.net...
> Hartley, I reread your post and perhaps I did not address your concerns
> completely. My installation was simple. One hole in the fiberglass seat
pan
> as high up as practical. I used a very short large AN bolt (~5/16th). This
> size bolt was gross overkill strength and weight wise but I did not have a
> suitable bushing. On the back side I used an AN 970 large area washer and
a
> NA365 nut. On the front was the head of the bolt and the triangular steel
> belt fitting. When this is good and tight the shear and bearing load on
the
> seat pan is spread out to the big washer size area. I'm sure in my case a
> good load was transferred to the pan, Not much way to guess the value. Too
> many variables.
> Months later when the insurance company sold the glider I offered to help
> and got a chance to examine the glider. I saw no localized damage at the
> strap attach point.
> Hope this helps,
> Ed Byars
>
>
>
>
>
> "Ed Byars" > wrote in message
> hlink.net...
> > Hi Hartley,
> > The crotch strap remained intact after doing it's job. I'm just lucky
that
> > no serious permanent damage was done to my sensitive genitals.
> > I like the ideas presented relative to a six point arrangement. This
sure
> > sounds safer, but any sensible arrangement would be virtually impossible
> to
> > get by the LBA/FAA.
> > It's a shame that it's not likely that any competent person or group
> > would/will develop and offer for sale such a glider system. Our legal
> system
> > just would not allow it. Maybe such a system designed for another more
> > numerous vehicle, auto probably, might be available for Experimental
> > licensed gliders. From an overall safety standpoint it may be just as
> > important to assure that any belting system is quickly free of the body
> with
> > one quick push or twist. We must not forget that provision for a quick
> > cockpit egress may be just as important.
> > I'm pleased that this thread seems to have made a few of us review our
> > restraint system and think about possible improvement.
> > Ed Byars
> >
> >
> > "HL Falbaum" > wrote in message
> > news:ouPwc.19014$%F2.12354@attbi_s04...
> > > ED
> > > Glad you're doing well. I am curious--did the crotch strap attach
point
> > > fail, or was it intact after the crash? If it did fail, at what
> estimated
> > > load did that occur? Pehaps it does not have to hold the entire load
to
> be
> > > effective--your thoughts?
> > > Thanks
> > >
> > > Hartley Falbaum
> > >
> > >
> > > "Ed Byars" > wrote in message
> > > hlink.net...
> > > > I sent the following to our magazine nine months ago and didn't
> receive
> > an
> > > > acknowledgement or receipt. I guess it was not suitable for them so
I
> > > > thought I would share it with ras to maybe provoke some safety
> > discussion.
> > > >
> > > > efb10-11-03-rev.6-5-04
> > > >
> > > > You may be interested in my latest crotch strap experience.
> > > >
> > > > I'm still analyzing my June 2003 accident and the cause. More later
on
> > > this.
> > > > The role of the crotch strap is significant and worthy of mention.
> > > >
> > > > The last half dozen gliders I've had I added a crotch strap (usually
> > > > available from Wings & Wheels), which easily clicks into the bottom,
> > front
> > > > or 5th slot of the standard Gadringer belt hardware. I secure the
> other
> > > end,
> > > > which terminates with the belt into a triangular link, with a
quarter
> > inch
> > > > hole that I bolt to the seat pan with a large "wood" washer behind
the
> > > seat
> > > > pan. My gliders are Experimental category so this is legal.
> > > >
> > > > I always heard that the main purpose of a crotch strap was to keep
the
> > lap
> > > > belt across the upper thighs and prevent it sliding up to the
stomach
> > > area.
> > > > I have since learned better.
> > > >
> > > > It of course depends on the direction of the accident loads and the
> > > > direction of the inertia of the body as to how all restraint straps
> come
> > > > into play.
> > > >
> > > > Many glider accidents involve "dropping in" vertically wherein the
> > > tailbone
> > > > (in the L-1, L-2 area) or higher are damaged so the belts don't help
> > much.
> > > > You seldom see accidents with lap belt overload, but it happens. I
> have
> > a
> > > > sad memory of helping remove a dead friend from an inverted Ventus
> > cockpit
> > > > where the lap belts on both sides had pulled lose from the seat pan.
> > > > Fortunately rare but it happens.
> > > >
> > > > In my "incident" the nose of the glider hit hard ground at about a
60
> > plus
> > > > degree angle. The "load" was about along the longitudinal axis of
the
> > > > glider. Since in our modern gliders (ASW-28 in my case) we recline
> (sit
> > > > supine), the inertia of my body was toward the nose with only the
> crotch
> > > > strap to resist. Actually Waibel designed the seat pan to take some
of
> > > this
> > > > forward load against the bottom of the thighs. In this seating the
> knees
> > > are
> > > > bent more upward.
> > > >
> > > > The nose of the glider (along with my feet) was crushed in a
> calculated
> > > > energy-absorbing manner. Thank you Gerhardt Waibel! I think his
> design
> > > and
> > > > the crotch strap saved my knees.
> > > >
> > > > I was conscious and lucid until the helicopter dropped me off at
the
> > > > Medical College of Georgia Trauma Center.
> > > >
> > > > After that I really was not with it for a couple of weeks, but after
> > that
> > > > time I suddenly noticed that my groin area was still quite swollen.
I
> > > > realized that my crotch area had sustained a significant load and
that
> > all
> > > > things considered had kept my body from moving more forward and no
> doubt
> > > > helped minimize the leg/knee damage. I had no shoulder strap or lap
> belt
> > > > marks or soreness.
> > > >
> > > > Since my guess is that a significant number of glider accidents
impose
> > > loads
> > > > and body reactions similar to mine, I recommend a crotch strap.
Trying
> > to
> > > > distribute the load to the pelvic area by wearing an athletic "cup"
> may
> > be
> > > > good for some flights, but for some flights there are other
> > disadvantages.
> > > > Many contest pilots regularly wear a male external catheter and I
> don't
> > > > think both would work. With just the crotch strap I always had to
be
> > > > careful that the strap was adjusted somewhat to the right, was not
too
> > > > tight, and did not interfere with the flow from the catheter that
was
> to
> > > the
> > > > left.
> > > >
> > > > I suggest reading Chip Bearden's posting which appeared in the
> > > > rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more
> > > complex
> > > > but better seat belt design.
> > > >
> > > > I hope this discussion will create more thought about glider
accident
> > > > safety.
> > > >
> > > > Ed Byars
> > > >
> > > >
> > >
> > >
> >
> >
>
>

[Eric Greenwell]

In article >,
says...
>>Perhaps DG offers this as an option? They seem to be the only real
>>innovaters left on the soaring scene.
>>
>>Ian
>
>Perhaps, but Herr Weber has always been one of the most vocal in skeaking out,
>saying that 5th. belt/crotch straps are not needed.

I believe they offer a 5th belt, but not the six belt style.

--
-------
Eric Greenwell USA

[Mark James Boyd]

I use a 4-point for positive G (only) aerobatics and have
found that with the shoulder harnesses placed at the right height,
a fairly firm cushion, and the belts tightened REAL
tight, I feel VERY secure.

For me setting up cushions and chute and harnesses in such a way
that I have excellent reach for everything, excellent vis, and
am yet quite snugly held in seems to make me feel secure.
I have a little trouble resnugging if I have to shift or
unbuckle momentarily, but it only seems to take
a few tries to get it back.

Ommitting for the moment the idea that perhaps 5 or 6 points might
be better, I wonder how important snugging it up is instead.
I've always assumed that very tight is better than
not, but haven't really heard much opinion. There was some cushion
discussion a while back and I have a fairly thick, fairly firm cushion
now (fortunately I'm quite short so no canopy issues). But
what about snugging tight? Anyone with thoughts or stories?

In article >,
Martin Gregorie > wrote:
>On 6 Jun 2004 16:55:50 GMT, Ian Cant
> wrote:
>
>>The 'crotch strap' is what used to be known as a 'negative-G'
>>strap. Usually it works to keep your skull away from
>>the canopy during the bumpy bits of sky; rarely, it
>>helps you in a crash by preventing submarining. However,
>>a single strap is both inconvenient and potentially
>>painful. A better design is a double strap, like an
--

------------+
Mark Boyd
Avenal, California, USA

[Don Johnstone]

At 23:42 07 June 2004, Hl Falbaum wrote: (snip)
>BTW - Motorcyclists and their accidents demonstrate
>that the genitalia are
>tougher than you may think---Thank the Lord!
>Thanks Again
>--
>Hartley 'KF' Falbaum
>USA

If you had ever suffered from fuel tank nuts you might
take a different view. Makes the eyes water just thinking
about it. The main reason why my glider will never
be fitted with a single crotch strap, there are certain
parts of the body not designed to absorb high loads,
and yes I speak from bitter experience. There are other,
less painful ways to avoid submarining.

[Martin Gregorie]

On Mon, 07 Jun 2004 16:42:04 -0500, JC Cunningham <jrc at visi dot
com> wrote:

>It must have been my browser that was having a problem. I use Opera.
>When I used internet explorer it came up fine.

No problem here with Opera 7.51.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Martin Gregorie]

On Sun, 06 Jun 2004 19:50:01 +0100, Martin Gregorie
> wrote:

>Are our 5-point rotary action quick-release units the same as the car
>racing gang use?

Following myself up: I've just been speaking to Willans Harnesses
(both the Stockbridge Racing operation and Willans Harnesses, the
division that used to do glider harnesses).

Stockbridge said that under no circumstances would they sell any of
their harnesses or upgrades for gliding use and quoted both
certification and product liability as the reasons for this.

Willans Harnesses do custom harnesses and tree climbing equipment and
used to make gliding harnesses. They no longer do glider harnesses in
any shape or form because the cost and time involved in obtaining JAR
certification was so great that they saw no nett benefit to themselves
in obtaining it.

It appears that Schroth is currently the only game in town on this
side of the pond.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Bob Mowry]

Ed,

My only question has to do with the title of this thread. Was that
intentional or subliminal? I'm assuming if you do install the 5th
belt you might be enjoying a permanent crouch for the reminder of your
life :)

One of the guys I work with suggested another title: Crouching
tiger, hidden strap.

-bob

[plasticguy]

"Martin Gregorie" > wrote in message
...
>
> Willans Harnesses do custom harnesses and tree climbing equipment and
> used to make gliding harnesses. They no longer do glider harnesses in
> any shape or form because the cost and time involved in obtaining JAR
> certification was so great that they saw no nett benefit to themselves
> in obtaining it.
>


Martin.

These belts do not conform to the TSO from the FAA either.
It's an American process to allow and document minor alterations
to the glider on a form 337 for Type Certificated aircraft. There
may be a similar process available to you poor souls across the pond.
Ask you administrator (I don't know what you call them) or the BGA
if there is a process similar to a Form 337/field approval for you to
follow.
I suspect that there is. The JAR regs are so close to the FAA regs in most
regards
that I suspect you can get it accomplished.

Scott.

[stephanevdv]

About the use of safety belts in cars: a few years ago a European car
manufacturer wanted to produce a very fast sports car, and wished to
install a formula one type safety belt system. He had to change back to
the usual three-point system with automatic roll-up mechanism, as it
was impossible to get the car approved for road use with the far more
effective formula one system!


--
stephanevdv
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

[Eric Greenwell]

JC Cunningham wrote:
> John Galloway > wrote:
>
>
>>At 18:12 07 June 2004, Jc Cunningham wrote:
>>
>>>John Galloway wrote:
>>>
>>>
>>>>Further to my posting yesterday I have identified the
>>>>6 point harness in our Std Cirrus as as Luke PRO6F
>>>>designed for single seat race cars.
>>>>
>>>>See:
>>>>
>>>>http://www.lukeracing.co.uk/rec.php?cat=17
>>>>
>>>>Flying with it today was the most comfortable I have
>>>>ever been in a glider as I felt totally secured with
>>>>the lap strap held low and no tendency to slide forward
>>>>in the seat pan with the lap strap rising as happens
>>>>in so many gliders. Even a deep seat pan like the
>>>>front seat of a Duo comes nowhere near in terms to
>>>>achieving that feeling.
>>>>
>>>>It may be non approved but I really don't care as the
>>>>benefits for comfort and safety are so clear cut.
>>>>
>>>>John Galloway
>>>>
>>>
>>>Could you double check and repost the URL. I am getting
>>>a blank page
>>>when I try to load the page.

>
> It must have been my browser that was having a problem. I use Opera.
> When I used internet explorer it came up fine.

It might also be your firewall or the level of security you are using in
Opera. It comes in fine with Netscape IF I turn off my Symantec
firewall (still have the router for protection).
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[[email protected]]

On Saturday, June 5, 2004 8:59:47 PM UTC-4, Ed Byars wrote:
> I sent the following to our magazine nine months ago and didn't receive an acknowledgement or receipt. I guess it was not suitable for them so I thought I would share it with ras to maybe provoke some safety discussion. efb10-11-03-rev.6-5-04You may be interested in my latest crotch strap experience.I'm still analyzing my June 2003 accident and the cause. More later on this. The role of the crotch strap is significant and worthy of mention.The last half dozen gliders I've had I added a crotch strap (usually available from Wings & Wheels), which easily clicks into the bottom, front or 5th slot of the standard Gadringer belt hardware. I secure the other end, which terminates with the belt into a triangular link, with a quarter inch hole that I bolt to the seat pan with a large "wood" washer behind the seat pan. My gliders are Experimental category so this is legal.I always heard that the main purpose of a crotch strap was to keep the lap belt across the upper thighs and prevent it sliding up to the stomach area. I have since learned better.It of course depends on the direction of the accident loads and the direction of the inertia of the body as to how all restraint straps come into play.Many glider accidents involve "dropping in" vertically wherein the tailbone (in the L-1, L-2 area) or higher are damaged so the belts don't help much. You seldom see accidents with lap belt overload, but it happens. I have a sad memory of helping remove a dead friend from an inverted Ventus cockpit where the lap belts on both sides had pulled lose from the seat pan. Fortunately rare but it happens.In my "incident" the nose of the glider hit hard ground at about a 60 plus degree angle. The "load" was about along the longitudinal axis of the glider. Since in our modern gliders (ASW-28 in my case) we recline (sit supine), the inertia of my body was toward the nose with only the crotch strap to resist. Actually Waibel designed the seat pan to take some of this forward load against the bottom of the thighs. In this seating the knees are bent more upward.The nose of the glider (along with my feet) was crushed in a calculated energy-absorbing manner. Thank you Gerhardt Waibel! I think his design and the crotch strap saved my knees.I was conscious and lucid until the helicopter dropped me off at the Medical College of Georgia Trauma Center.After that I really was not with it for a couple of weeks, but after that time I suddenly noticed that my groin area was still quite swollen. I realized that my crotch area had sustained a significant load and that all things considered had kept my body from moving more forward and no doubt helped minimize the leg/knee damage. I had no shoulder strap or lap belt marks or soreness.Since my guess is that a significant number of glider accidents impose loads and body reactions similar to mine, I recommend a crotch strap. Trying to distribute the load to the pelvic area by wearing an athletic "cup" may be good for some flights, but for some flights there are other disadvantages. Many contest pilots regularly wear a male external catheter and I don't think both would work. With just the crotch strap I always had to be careful that the strap was adjusted somewhat to the right, was not too tight, and did not interfere with the flow from the catheter that was to the left.I suggest reading Chip Bearden's posting which appeared in the rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more complex but better seat belt design.I hope this discussion will create more thought about glider accident safety.Ed Byars

After flying my 1-35 for about 4 years, generally without a parachute, I suddenly was very uncomfortable on longer flights with a parachute - my lap belt would ride up no matter what I did. Maybe the belts or my spine stiffened up?! Adding a crotch strap was the answer, very straightforward - I got a sketch for a suggested doubler from K&L Soaring, though I had to trim it to avoid interfering with aileron travel.

[[email protected]]

Excellent safety point Dr. Byars.

My experience with the Schroth HYBRID II 6 point design has been most acceptable.

http://www.schrothracing.com/competition/hybrid/hybrid-II

A salute to Richard at Craggy Aero for offering Schroth products. You may prefer the Profi II model he offers.

[son_of_flubber]

On Saturday, September 21, 2013 6:57:40 PM UTC-4, wrote:
>>My experience with the Schroth HYBRID II 6 point design has been most acceptable.<<

The 6-point harness sidesteps the oft-cited hazard of the 5-point harness because (for normal anatomy) the straps come nowhere near the genitals.

USA distributor and direct sales of Schroth harnesses. http://www.hmsmotorsport.com/store

The Hybrid II HANS http://www.hmsmotorsport.com/store/schroth-competition-belts/hybrid/hybrid-ii has 3" shoulder straps that taper to 2" to match a 2" anchor point.

None of these belts are TSO'd. I don't know of a modern TSO'd 6 point harness.

In some glider/human_body combinations, the thigh straps of a 6-point can be anchored to the same anchors as the lap belt with http://www.rei.com/product/737298/bluewater-1-climb-spec-tubular-webbing using a ring-bend knot http://www.animatedknots.com/waterknot/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com&Categ=climbing&File=waterknot

IMHO, the same magnitude and direction of force will be transmitted to the lap belt anchor with or without the thigh straps because the source of the force is the same restrained body in both cases... so I don't think that this arrangement overloads the lap belt anchors.

Make sure that any "wrapped" strap connections to anchors are not hidden beneath the seat pan because they can and do loosen up and you need to include them in your pre-flight inspection.

[[email protected]]

On Saturday, June 5, 2004 7:59:47 PM UTC-5, Ed Byars wrote:
> I sent the following to our magazine nine months ago and didn't receive an
> acknowledgement or receipt. I guess it was not suitable for them so I
> thought I would share it with ras to maybe provoke some safety discussion..
>
> efb10-11-03-rev.6-5-04
>
> You may be interested in my latest crotch strap experience.
>
> I'm still analyzing my June 2003 accident and the cause. More later on this.
> The role of the crotch strap is significant and worthy of mention.
>
> The last half dozen gliders I've had I added a crotch strap (usually
> available from Wings & Wheels), which easily clicks into the bottom, front
> or 5th slot of the standard Gadringer belt hardware. I secure the other end,
> which terminates with the belt into a triangular link, with a quarter inch
> hole that I bolt to the seat pan with a large "wood" washer behind the seat
> pan. My gliders are Experimental category so this is legal.
>
> I always heard that the main purpose of a crotch strap was to keep the lap
> belt across the upper thighs and prevent it sliding up to the stomach area.
> I have since learned better.
>
> It of course depends on the direction of the accident loads and the
> direction of the inertia of the body as to how all restraint straps come
> into play.
>
> Many glider accidents involve "dropping in" vertically wherein the tailbone
> (in the L-1, L-2 area) or higher are damaged so the belts don't help much..
> You seldom see accidents with lap belt overload, but it happens. I have a
> sad memory of helping remove a dead friend from an inverted Ventus cockpit
> where the lap belts on both sides had pulled lose from the seat pan.
> Fortunately rare but it happens.
>
> In my "incident" the nose of the glider hit hard ground at about a 60 plus
> degree angle. The "load" was about along the longitudinal axis of the
> glider. Since in our modern gliders (ASW-28 in my case) we recline (sit
> supine), the inertia of my body was toward the nose with only the crotch
> strap to resist. Actually Waibel designed the seat pan to take some of this
> forward load against the bottom of the thighs. In this seating the knees are
> bent more upward.
>
> The nose of the glider (along with my feet) was crushed in a calculated
> energy-absorbing manner. Thank you Gerhardt Waibel! I think his design and
> the crotch strap saved my knees.
>
> I was conscious and lucid until the helicopter dropped me off at the
> Medical College of Georgia Trauma Center.
>
> After that I really was not with it for a couple of weeks, but after that
> time I suddenly noticed that my groin area was still quite swollen. I
> realized that my crotch area had sustained a significant load and that all
> things considered had kept my body from moving more forward and no doubt
> helped minimize the leg/knee damage. I had no shoulder strap or lap belt
> marks or soreness.
>
> Since my guess is that a significant number of glider accidents impose loads
> and body reactions similar to mine, I recommend a crotch strap. Trying to
> distribute the load to the pelvic area by wearing an athletic "cup" may be
> good for some flights, but for some flights there are other disadvantages..
> Many contest pilots regularly wear a male external catheter and I don't
> think both would work. With just the crotch strap I always had to be
> careful that the strap was adjusted somewhat to the right, was not too
> tight, and did not interfere with the flow from the catheter that was to the
> left.
>
> I suggest reading Chip Bearden's posting which appeared in the
> rec.aviation.soaring newsgroup on Nov.20 1998 which outlines a more complex
> but better seat belt design.
>
> I hope this discussion will create more thought about glider accident
> safety.
>
> Ed Byars

Ed,
Over the last Winter, I purchased and installed a crotch belt for my LS8-18 using the convenient cross-enforcement rib molded into the seat pan. I've flown with it all season without having issues with the catheter tubing. The lap belts stay low on the hip area while they were riding up toward the belly without a crotch strap. I fully agree with your recommendations. Flying the New Castle ridge last week I found the belting now keeps the body better connected with the seat pan with less "floating".
Herb, J7

[JohnDeRosa]

On Sunday, June 6, 2004 9:26:17 PM UTC-5, Bob Korves wrote:
> Alan Silver is very much still in business. See http://www.pia.com/silver/

That pia URL seems faulty. I have the following URL for Allen Silver's 5 point harness and you can order the crotch strap as a separate item.

http://silverparachutes.com/acrobelt/

BTW: We had Allen as a speaker at the ChicagoLand Glider Council's bi-annual conference and he was GREAT. http://silverparachutes.com/safety-seminars/

- John