The two certificated rotorcraft pilots were conducting a ferry flight. According to both pilots, the helicopter was on approach to land for a refueling stop when the airline transport pilot flying asked the private pilot to apply carburetor heat. The private pilot inadvertently pulled-out the engine mixture control with the mixture control guard, which resulted in an immediate total loss of engine power. The helicopter was at an altitude between 300 to 400 feet, and the airline transport pilot entered an autorotation, while the private pilot attempted to restart the engine. The engine did not restart before the helicopter struck trees, a fence, and then nosed over. The helicopter sustained substantial damage to the airframe and both the main and tail rotor drive systems. Both pilots reported there were no mechanical malfunctions during the flight. The private pilot reported 220 hours of total flight experience, which included about 54 hours in the same make and model as the accident helicopter.