Originally Posted by Tom Hunt
Those were not stock VTOL aircraft. They were Durafly EFX racers from www.hobbyking.com
modified into quad-copter hybrids by Adam Woodward.
Yes, basically, the quad and airplane controls were "y'd" from the receiver into the flight controller and the aircraft controls. The forward propulsion motor had a separate throttle control from the quad throttle stick to operate them in dependently. When transitioning, the quad throttle was gradually reduced as the forward propulsion was increased. Vice a versa for the return to vertical flight.