Anyone want to take a stab at my drilling problem?

[drums4money]

I'd never trust something like that in an airplane, even if it *is* an ultralight or something. A proper cotter pin won't vibrate loose.

Do it right . . .use a Welcome Back Kotter pin

[rboe]

Used hook & loop on my Quota seat. Worked.

Thinking out loud here, I wonder if someone couldn't weld your cap to the pin (gonna call it a root canal now!  ).

I do like what you did though. 

[Mayor_of_BBQ]

Well it works!
Very VERY solid connection
I used two clips, one around the bolt under the head and one thru the hole I drilled



Clean install!

[kirb]

Velcro , don't laugh , a couple of loops will hold a seat in place , no drilling , get back on the road .
  Dusty

WAY better than velcro: http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Brands/Dual-Lock-Reclosable-Fasteners/

Works when wet, there isn't a hook side and a loop side- both are the same, very good adhesive- can also be mounted with hardware: http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/~/3M-Dual-Lock-Reclosable-Fastener-SJ3463?N=5927706+3294281449&rt=rud

Seems like this was sorted out in a much better way, but the dual lock is ideal for a lot of different uses.

[Chuck in Indiana]

I used two clips, one around the bolt under the head and one thru the hole I drilled

Belt *and* suspenders..