other than bending landing gear and the dings that come along with that, most of the problems I have had with repairing was due to transporting or my cat chewing on a wing here and there, minor covering repairs, I have only had 2 airplanes destroyed, one was I got rear ended by a van while my plane was in the back of my truck, the other was letting my brother use one of my airplanes he crashed on takeoff, and that was repairable. I still have some of the old u control planes I built 30 some odd years ago. I would say my favorite type plane would be a sport plane.they normally take from 40 to 70 hours to build.i have built many ww2 type planes from kits for friends they take longer.