I had a bent wing tube on a Somethin' Extra that fell straight down from 80 feet after another plane cut the tail off. Amazingly the wings were untouched, but the wing tube bent slightly.

I tried all the obvious things to straighten it, but that sucker is strong! Finally I stuck a big iron water pipe into the tube, propped it up, and stood on it. Finally got the job done, and flew happily everafter.