Vertol Model 107/YHC-1A prototype cargo and troop transport for?US Army. The Army placed an intial order in December 1958 for ten YHC-1A cargo helicopters, however, only three were built, Vertol c/n 413-1, 413-2, & 413-3, serial numbers: 58-5514, 58-5515, & 58-5516 respectively. During late 1959, the Army cancelled the remaining seven unstarted airframes (58-5517/5523) and used the funds to order five of the larger Vertol Model 114 YHC-1B Chinook helicopters. The Army transferred 58-5514 to NASA in 1962, who reserialled it NASA533 in ~1964, assigned it to the Wallops Island Flight Center, wfu ~1975, fate unknown. The Army assigned 58-5515 to the US Army Aviation Test Activity (USAATA), Edwards AFB
in 1960, and loaned it to NASA who assigned it to their Dryden Flight Research Center at Edwards AFB, CA ~1962. It served as a tow aircraft for the unpowered PARASEV airfoil. It was returned to Vertol ~1964 and bailed to M.I.T. for R&D purposes. It is unclear whether it retained it US Army serial or wore the civil registration, N55927. Vertol delivered 58-5516 to the Army sometime in 1960. It was not modified into the first BV-107/II-1 prototype, N6671D, as some have assumed. Its history is unknown. It was registered N5588K at some point. Along with its sister, 58-5515, it was sold to McAllister Engineering Enterprises, Kent, WA, who hoped to modify them for logging. They were both stored in a hangar at SEA-TAC airport, circa 1984. Current status unknown. It is rumored (unconfirmed) that Columbia Helicopters has purchased both airframes.