Here's how I did it in my LS-6a about 20 years ago:

I was given the brand new 5-point harness intended to be installed in a 1-34
which had recently crashed. I installed the shoulder and waist straps in
their normal locations. For the crotch strap, I procured the biggest steel
bumper washer I could find at the local hardware store and glued it to the
under side of the seat pan in a good location using flox and bi directional
glass and epoxy. I drilled through the washer and seat pan and, using grade
8 bolt, another couple of washers, and a locking nut, secured the belt
mounting piece to the floor of the seat pan. Of course, the LS-6 was
Experimental.

When he crashed several years later, my partner told me that it's his firm
belief that that fifth strap saved his life.

I'm not a mechanic and the above is not advice, only a description of how I
did it.

I once installed an oxygen system in my ASW-19 and had my IA submit a 337.
The FAA rejected it on the basis of "no reference to manufacturer's
installation instructions". But that was a Standard Airworthiness aircraft.


wrote in message
...
On Monday, March 4, 2013 8:48:26 PM UTC-5, wrote:
Is there any way technically and legally to add a fifth strap to an ASW
15? No matter how tight I pull the lap belts they ride up when ridge
flying allowing the shoulder straps to become loose. My head is pretty
close to the canopy and a stiff jolt can lead to head banging if the
harness becomes loose. I also know having the lap belts out of position
can be very dangerous in the event of a crash and would love to alleviate
these problems. mdfaddenatgmaildotcom

I have done several installations of a 5th point in Schleicher gliders, but
not an ASW-15.
I'll use '19 as an example.
First, you must use a harness assembly intended for the purpose with a
receptacle for the added point. You may have to replace your harness.
Procure the additional belt intended to be used with that harness. No home
made stuff.
The belt is secured to the bulkhead that mounts the aft end of the control
stick. This means it will be a bit, about 2 inches off to one side, and will
be near the aft edge of the stick boot. It comes up through a hole about 2
1/4 by 1/2 in the seat pan. On some gliders the belt can wrap around a
convenient feature. On others you will need to put in a fitting.
Care must be taken not to interfere with controls and proper anchoring, but
this is not rocket science.
There is no reason that this would be considered anything other than a minor
modification as long as the original harness mounting is not affected.
It may pay to ask Schleicher if they have instructions, however I doubt it.
Good luck
UH