Eight USAF H-65B/C upgraded by the Pave Low II program for the Combat Search and Rescue role. Later redesignated MH-53H List of Operators of Sikorsky HH-53H From Organisation with model HH-53H 1968 US Air Force S-65 H-53 78 1968/08 Construction Numbers Help Us C/NYearHistory 65-385 1974 73-1647 1 C/N.