When I was working on airplanes, we safety wired everything. Just drill a small hole in one of the tabs of the nut, and use a piece of bare steel wire to connect it to a handy bolt head or other lock point. I believe if you tighten the nut firmly that won't be necessary, but it's always an option.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!