Prototypes/pre-production aircraft, six built. List of Operators of YCH-54A Years Model Org 1964/90 S-64 CH-54 US Army Aviation Global Distribution of YCH-54A 6ych-54a Construction Numbers C/N Year History 64-004 w/o 1966 1963 64-14202 64-005 1963 64-14203 64-006 w/o 1966 1964 64-14204 64-007 w/o 1968 1964 64-14205 64-008 w/o 1967 1965 64-14206 64-009 w/o 1967 1965 64-14207