Three of the prototypes were delivered to the Army in March 1976, for evaluation against the rival Boeing-Vertol design, the YUH-61A, and one was kept by Sikorsky for internal research.
Tres dos protitipos foron entregados ao Exército en marzo de 1976 para ser avaliado contra o deseño de Boeing-Vertol, o YUH-61A, e Sikorsky quedou con el para investigación interna.