was a USAF[1] Cold War "Big L" Support System with computer equipment at The Pentagon and, in Pennsylvania, the Alternate National Military Command Center nuclear bunker.

[11]) An Experimental SAGE Subsector"[12] for testing a Semi Automatic Ground Environment (SAGE) was created using a July 1955 prototype air defense computer[13] ADC's 1955 command post blockhouse was completed at Ent AFB, and "in September 1955, the Air Force…replace[d its] command post's outmoded telephone system with a modern switchboard with 100 long-distance lines and room for more, so that 20 people in various parts of the country could hold as many as four conferences at a time".

[8] The Alternate Joint Communication Center in the Raven Rock nuclear bunker was equipped by the end of 1955,[9] and ADC broke ground in 1957 for deploying the Burroughs 416L SAGE Air Defense System[14] (the BMEWS 474L General Operational Requirement was specified in 1958.)

[16] On January 1, 1963, ESD's 473L System Program Office was expanded (473L/492L SPO) with the added 492L responsibility for developing the United States Strike Command's Joint Airborne Communications Center/Command Post (SPOs were separated on June 15, 1965).

)[22] After FYQ-11 problems, the USAF Chief of Staff in 1966 cancelled the AN/FYQ-11 and the Comptroller was directed to dispose of "the L-3055 system's equipment"[9] (1977 lawsuit claims by the 1968 Librascope parent--The Singer Company—were denied.)