Crouch Strap story

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

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

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.

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

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

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

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

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

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

"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.