 Lockheed designed the Cheyenne as a compound helicopter , which combines a helicopter with fixed @-@ wing features for increased performance , usually speed . The design included features such as a rigid main rotor , low @-@ mounted wings , and a pusher propeller . The Cheyenne was powered by a General Electric T64 turboshaft engine . Thrust was provided by a pusher propeller at the rear of the aircraft . At high speeds , the amount of lift provided by the wings , along with thrust from the pusher prop , reduced the aerodynamic loading of the rotor . At such speeds , the rotor produced 20 % of the lift and could be adjusted by collective pitch control changes . Rotor tilt was controlled through gyroscopic precession . The Cheyenne achieved speeds over 200 knots ( 230 mph , 370 km / h ) , but as a compound helicopter was unable to qualify for speed records in helicopter categories . 
