551st Electronic Systems Wing The 551st Electronic Systems Wing ( 551 ELSW ) is a wing of the United States Air Force whose focus is on ' behind the scenes ' electronic work . Located at Hanscom Air Force Base , Massachusetts , they work on AWACS , Joint STARS , MP - RTIP , Mission Planning , and weather systems . Now responsible for the development and sustainment of command and control systems , the 551st ELSW takes its designation from a wing that laid the foundation for modern - day airborne surveillance . History . Cold War period . The 551st Airborne Early Warning and Control Wing , established and activated in 1954 , was charged with tracking air and sea activity along the United States eastern seaboard . The wing received its first airborne asset on March 2 , 1955 , when an RC - 121D landed at Otis Air Force Base . The plane was the first of many assigned to the 551st to patrol the skies over much of the Atlantic Ocean . The RC - 121D was eventually upgraded to the EC - 121H Warning Star in 1963 . The newer model supplanted the slower voice and manual Teletype data relay system previously employed by the RC - 121D and instead provided instantaneous automated relay of air defense surveillance and early - warning information by data - link directly to ground - based communication facilities . The 551 AEWC Wing provided critical surveillance data to Air Defense Command and Control computers and the North American Air Defense Combat Operations Center in Colorado Springs , Colo . , for air defense evaluation and action . The data also enabled more versatile airborne control of interceptor missile and aircraft weapons systems . During the Cold War period , the 551st provided surveillance support for major world events , including tracking over Cuba during the Cuban Missile Crisis and tracking Russian aircraft and naval vessels off Iceland and the East Coast of the United States . The wing also provided surveillance over Johnston and Christmas islands during nuclear testing by the Atomic Energy Commission and performed a variety of surveillance services in Southeast Asia during the Vietnam War . In its first 10 years , the wing flew continuous missions over the Atlantic Ocean 24 hours a day , seven days a week , compiling more than 350 , 000 flying hours . Among other honors awarded to the wing was the Air Force Outstanding Unit Award for its significant performance . Between 1965 and 1967 , three aircraft of the wing crashed into the Atlantic killing fifty members of the wing . The tail numbers of the aircraft were 55 - 0136 , 55 - 5262 , and 53 - 0549 . The wing was inactivated December 31 , 1969 . Re - designation . The wing was re - designated April 18 , 2006 , when the Battle Management Systems Wing changed to the 551st Electronic Systems Wing . The 551st ELSW is now responsible for rapid development and fielding of airborne battle management command , control and communications systems in support of combatant commanders , special operations forces and worldwide allies . The 551st Electronic Systems Group , formerly the Airborne Warning and Control Systems Group , is responsible for all aspects of modernization and sustainment of the United States and international E - 3 Sentry aircraft and airborne early warning and control fleets .