I attached the outboard aileron bracket to the rear spar.
The inboard bracket didn't go on quite as easy, mostly because I found out I had swapped a left and a right piece of angle during assembly (holes were not exactly symmetrical between the two, but since they weren't labeled parts, I didn't realize it while I was putting it all together). So I had to drill out a number of rivets and switch the angle pieces before I could attach everything to the spar. There is a service bulletin for this attach bracket because apparently some people have found cracks. The fix is to put two doublers in place during assembly. Easy enough to do now, but sure wouldn't be fun to try to do it on a flying plane.
