There are a lot of very inexpensive electric “Almost Ready to Fly” RC planes available at Toys R Us, Target, etc. I’d start with one of these just because they are cheap and tough. It takes awhile to think 3D from the perspective of a little plane that you are looking at from various angles, and to look ahead, react to gusts, etc. Especially when you’re a little kid without much experience to draw from. Let him get used to a couple of these little $30 planes and then get him a real RC trainer.