RE: Taylorcraft crash
Just a word on "gripping area" -
I recently got a 30% 50cc Yak54 from Pilot RC. When I screwed in the wing bolts (it has two per wing), I tightened them very hard the first tine to see if the will hold, and the front one on both wings let go. The bolts went in very loosely to begin with. I thought I had over-tightened them and so they must have stripped, but when I unscrewed them I found that nothing was stripped. I got some good quality replacement bolts and the same thing happened. I removed the blind nuts and found that they were extra long, with about 10 threads to grip. Even with 10 threads, it let go because the manufacturer must have used a tap that was a bit too large when they cut the threads. I got new blind nuts made by Hangar9 that have only a few threads, and with these I can tighten the bolts until breaking point. So I guess it's not about "gripping area", but more about the quality / tolerance of the threads.