Bolts are just a single part of a multi-faceted protection system. Two bolts will actually shear nicely, IF there is not a square stop behind it. My Giant Super Sportster fell thirty feet straight down and hit on the front corner of a wing last weekend. The wing, held in place by two 1/4-20 bolts, is also held in the saddle by a square stop (the same thickness as the wing's trailing edge) right behind it. It's an ARF. The wing DID NOT separate upon impact, and the fuse snapped in half. I saw how it was mounted, and I didn't change it. Now I'm rebuilding a fuse snapped apart in the center, and a wingtip that was smashed because it didn't break away.

Many of the planes I built through the years have had two of the same bolts holding the wings on, but I did not build stops behind the wing, I ramped it so the wing's force transferred through the bolts, and anytime there was a crash, the force carried the wings away rather than the wing taking the hit full-force. It reduced the stress on all parts of the aircraft.

When there's a crash, SOMETHING is going to carry the force of the impact. When the pieces breakaway, they carry the force away from each other, and minimize it.

I think two bolts are just fine, but make sure you build your plane in such a way that they can shear when they really need to. Your plane will thank you for it.

~ Jim ~