WTB Pacific Scientific (Gadringer) 5th point strap

[JS]

Looking to put a 5th point into a Schleicher.
Currently a Pacific Scientific 4-point harness. Would be OK with a complete Schroth 5-point harness.
6-point solutions also considered. Have seen a few on auto racing supply websites, but unsure of the (physical) installation logistics.
Thanks,
Jim

[[email protected]]

Aviation Safety Products (aircraftseatbelts.com)recently made me a fifth strap for Schroth belts in my ASW 15. I haven't had it installed yet but have an idea that looks good. E mail me at mdfaddenatgmail.com if you'd like details.

[Dan Marotta]

Not sure you could legally install auto parts in your glider unless it's
"Experimental". Having said that, I installed a fifth strap in my LS-6a
many years ago by bonding large steel washers into the seat pan with
flox and bidirectional glass cloth and then bolting the hardware through
that. My former partner claims it saved his life in a low altitude
stall/spin accident. He's still around and I witnessed the crash. I'm
sold on the fifth (or sixth) strap(s)!


Dan Marotta 5J . .

On 5/28/2014 9:21 PM, JS wrote:
> Looking to put a 5th point into a Schleicher.
> Currently a Pacific Scientific 4-point harness. Would be OK with a complete Schroth 5-point harness.
> 6-point solutions also considered. Have seen a few on auto racing supply websites, but unsure of the (physical) installation logistics.
> Thanks,
> Jim

[son_of_flubber]

> Currently a Pacific Scientific 4-point harness. Would be OK with a complete Schroth 5-point harness.
>
> 6-point solutions also considered. Have seen a few on auto racing supply websites, but unsure of the (physical) installation logistics.
>


I'm very glad that I installed a 6 point automotive Schroth harness in my 'experimental AW' SZD. The immediate payback is that the shoulder straps now restrain me from hitting my head on the canopy(and consequently hurting my neck from disc compression)in turbulence. The 6 point makes a huge difference compared to some 4 point harness/glider/body combinations that I have experienced.

The geometry of my glider-harness-body worked out perfectly to allow me to attach the thigh straps to the lap belt attachment points (shared with the lap belts). I made the attachment with 4000 lb test rock climbing tubular webbing with the correct knot and Schroth anchor hardware. The tubular webbing lies flat and does not cause pain where it presses on my side-butt. (The A&P left everything in place but untied the knots of the webbing before giving me my annual Condition Inspection and told me that climbing webbing was not TSO'd. No mention of the non-TSO'd Schroth harness.)

My thinking is that the extra two belts of a 6 point do not change the vector of force generated by my body by various acceleration/deceleration scenarios, so the resultant forces applied to the anchor points are not changed significantly. Obviously, if the 6-point harness is restraining me better than the 4-point then the forces are somewhat higher. When the 6-point prevents a 'submarineing' incident, the forward horizontal force vector exerted by the thigh straps might be higher than from the 4-point that allows me to submarine forward out of the harness... but for this to be a problem, one would have to assume that the lap belt anchors were not designed to resist the forward vector of a submarineing scenario. I'd rather bet that my anchors will hold than take my chances submarineing forward.

My understanding is that thigh straps oppose the upward pull of the shoulder straps and thus keep the lap belt centered between the crests of the pelvis and thus preventing submarineing. The thigh straps should not put much force on thighs and they entirely skirt my other regional appendages.

One drawback of putting effective harness in your personal glider... you may forever forward be unhappy with the harnesses that you find in rental gliders.

I welcome all criticism about the FARs and 'common sense' that I'm violating with this approach.