Hmm, let me check on that. I was sure I read that somewhere. What would happen is that you plug a cable, square on both ends, into the back of the realflight box and into the back of your Futaba radio. Instructor holds Futaba radio, gets your plane in the air, then hits a switch on the Futaba radio which gives control to your box. When you make a mistake, he lets go of the switch on the Futaba and it regains control.