My motor mount is 1/4 aluminum with a bunch of 1/2 lightening holes, bolted and glued to the ply "backbone". It's the original and has been thumped many times, all by me. Mine really doesn't glide all that bad, maybe the CG has something to do with it? Mine glides about 1/3 as good as my Flight Streaks, so it really isn't bad. It will do a nice smooth landing if I don't mess it up. The way it is now though, it really wouldn't be a good trainer. Too abrupt and "twitchy", but it is fun, especially when the 35 breaks into a 2 stroke.