Also be prepared to give him some ground school explaining how RC things work. You will have an advantage with THIS student in that he understands aerodynamics, perhaps even better than you. But he has no clue about RC, how it works or the disorientations he will experience. You're gonna have the job of explaining how to tune engines, range check radios, preflight planes, how many rubber bands & why. All of the basics that YOU take for granted as any dummy knowing, HE doesn't. It's going to require a lot of patience, trust me on this one. You will also have to keep him away from the field "idiots" that will try to take over and interfere with his training. Listen carefully to what they tell him so you can confirm or contradict what they say, always allowing for simple differences of opinion.

Above all else, you both need to have fun.