Highly modified CH-47A. First flew as such in 1970 and used for various tests. To the museum around 1973 after testing was completed.

Highly modified CH-47A with first flight on 27 May 1970. Changes included lengthened cabin, retracting landing gear, four blade rotors, advanced cockpit instrumentation, and a variable incidence wing. It was capable of performing 2G turns. Although not put into production, many of the upgrades tested were later used in new generation helicopter designs.