The Lockheed AH-56 Cheyenne was without a doubt the niftiest helicopter ever to *almost* make it into production. but, alas, it was ahead of its time… more precisely, ahead of the available technology.
The gunner sat in a seat that could spin 360 degrees (like the gunner in the Gunstar… and if you don’t get the reference, you’ve a geekiness deficiency). The Cheyenne had a pusher prop for very high speed for a helicopter, and small wings to generate lift and offload the rotor at speed. Lockheed had considerable faith in the future of that propulsion concept and incorporated it into designs for civilian passenger transport helicopters such as the CL-1026 9described in US VTOL Projects issue #01).