The Lockheed Cheyenne was an innovative compound rotary wing/fixed wing aircraft developed in the late 1960s - early 1970s. The company that brough us aircraft like the SR-71 was also highly innovative in its short-lived foray into rotary wing aviation. The cheyenne was capable of higher speeds and different flight attitudes than most (or any?) conventional helicopter before or since, owing to it's short stubby wings and pusher propeller located behind the tail rotor. A second twist-grip forward of the conventional throttle control on the collective lever controlled the 'beta' or pusher propeller pitch angle.