Kellett XR-8 Helicopter
DAYTON, Ohio - Volunteer Dale Burnside works on the Kellett XR-8 as part of the extensive restoration process at the National Museum of the U.S. Air Force. Developed as a prototype for the USAAF in 1940s, the Kellett XR-8 tested the idea of stabilizing a helicopter by using dual offset horizontal rotors to eliminate the need to power a tail rotor. Nicknamed “Eggbeater,” the design used two intermeshing wooden propellers above the two person cabin. (U.S. Air Force photo by Ken LaRock)