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.