Thanks for asking! Some semi-random commentary to put the issue in context:

* First off, you and JJ are probably right that, assuming a rigorous inspection shows the wing to be in good condition, a static test is probably not the best use of resources.

* You are also probably right that this isn’t something that the “Average Joe” is going to undertake with full confidence of success. But that’s what I find so completely enthralling about messing about with amateur-built and vintage gliders: The people who get into it are pretty uniformly extraordinarily resourceful.

* That said, I am always alert for the words “always” and “never,” because they often offer an opportunity to contribute an enlightening (or at least valid) counterexample.

* The HP-24 static test is described, with photos, on this old web page: http://www.hpaircraft.com/hp-24/update_10_dec_11.htm

* I insisted that we do some sort of static test on the first HP-24 wings. Me being a relapsed Liberal Arts dropout, I wanted some assurance that we had enough carbon in enough of the right places to make the wings safe to fly. Jim Marske had reviewed the basic main spar design, and we had done coupon tests on the lift pin anchors, so I had high confidence we were in the ballpark. But I wanted a bit more assurance and insisted on a static test to at least check the deflection. I originally wanted to go to 5.3g, but settled on 4.4g as a reasonable compromise between that and no test at all.

* My primary motivation was the cautionary tale of the American Spirit kit glider, of which two or three had demonstrated primary structural failures below (and on one case well below) the published limit load.

* All told, the static test cost us about $3k, but most of that was travel expenses to bring the wings south from Seattle and the crew north from the SF Bay Area. We borrowed a hangar and 2300 lbs of lead shot from a friend in central Oregon, and the test stand, built as JJ describes, cost about $300 to put together out of plywood and lumber and a couple of welded bits.

* We basically self-insured the test by promising to make a set of replacement wings in case the ones we tested broke. Assuming that risk was probably the most expensive part of the adventure.

* The engineers were all volunteers. When you set up to push things to the limits, they pretty much come out of the woodwork to kibitz and see if things to boom. We started out with just Steve Smith, but engineer and serial builder Bruce Patton chipped in to help build the test stand in his garage, and designers Ken Kruger and Dick VanGrunsven came by to watch things bend.

* My original proposed load distribution was basically a Schrenck’s (sp?) approximation that I whipped up in an hour with Excel. That’s basically where you take your area distribution and an elliptical lift distribution and split the difference between them. For our wings Steve Smith added a bit of load at the outboard end to approximate a winglet plus a deflected flaperon.

Thanks, Bob K.
https://www.facebook.com/HP-24-Sailp...-200931354951/

On Monday, December 19, 2016 at 9:42:34 AM UTC-8, Scott Williams wrote:
On Monday, December 19, 2016 at 10:27:22 AM UTC-6, Bob Kuykendall wrote:
On Sunday, December 18, 2016 at 6:24:51 PM UTC-8, Scott Williams wrote:

I do not think there is any way to perform a meaningful non destructive load test on potentially airworthy wings.


I posted an incomplete opinion, I stand corrected.

I do however doubt that an average 'Joe" in his garage or driveway could duplicate a professional calculated evaluation of 1963 Austria wings and end up with useful results and/or useful wings at the end of the exercise. However, with the correct application of money and expertise, load testing of the wings in question is more than easily done.

With respect, Bob would you entertain offering a reasonable cost/expense estimate of duplicating your exercise? including the engineer expertise? Please consider that the original poster seemed to indicate no prior knowledge, test fixture, data, or test area/facility.

I think my humble opinion was simply that such a procedure was beyond the average skill ability of the typical sailplane Do It Yourselfer, or even A..I.

The process of actual load testing of aerodynamic surfaces is of course a routine and usually mundane exercise for design development and production..

Thank you in advance,
Respectfully,
Scott W.