This aircraft was converted from its EC-135C status by E-systems for the 'Night Watch III' command post role with the 1000th ACCS at Andrews AFB in 1966 and was redesigned as an EC-135J in 1967. Reassigned to 1st ACCS in 1969 and demodified in 1975 when communications equipment was removed to be used in the replacement E-4A program. The aircraft then took on the 'Blue Eagle' role with the 9th ACCS at Hickam AFB which provided secure comms between CINCPAC HQ in Hawaii and US naval forces throughout the Pacific. Before being placed on display, the tail of EC-135P 55-3129 was substituted.