Man, that's great, just great!! Be sure to encourage and allow him to develop an interest in building and repairing. In reflection, I've had the joy of teaching kids to fly but I was never able to follow through with the developing the love and desire for building. As such unless I was supplying the lines, planes and so forth, I don't know of any of the kids sticking with the hobby given the fact that there is a whole world of other "ready-to-use" interests and activities interspersed with school, family needs and so forth. Congratulations!!
Jim