Crouch Strap story

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
newsuPwc.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

"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

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

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.

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

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

"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=gr...aol.com&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

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.

--
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
newsuPwc.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

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
newsuPwc.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