The E-3 Sentry is an American early warning and control (AEW&C) aircraft manufactured by Boeing, commonly known as the AWACS (Airborne Early Warning and Control System). Developed by Boeing from the Boeing 707 passenger aircraft, it provides all-weather surveillance, command, control and communications and is used by the United States Air Force, NATO, the French Aerospace Forces, the Royal Saudi Arabian Air Force and the Chilean Air Force. The E-3 features a distinctive rotating radar dome (rotodome) above the fuselage. Production ceased in 1992 after 68 aircraft had been built.
In the mid-1960s, the U.S. Air Force was looking for an aircraft to replace its piston engine powered Lockheed EC-121 Warning Star, which had been in service for over a decade. After awarding preliminary development contracts to three companies, the U.S. Air Force selected Boeing to build two airframes to test competing radars from Westinghouse Electric and Hughes. Both radars used pulse-Doppler technology, with the Westinghouse design winning the contract. Testing of the first production E-3 began in October 1975.
The first Boeing E-3 Sentry AWACS aircraft was delivered in March 1977. A total of 34 aircraft were built over the next seven years. E-3s were also purchased by NATO (18), the United Kingdom (7), France (4) and Saudi Arabia (5).
During the Persian Gulf War in 1991, Boeing E-3 Sentry AWACS performed the tasks of controlling the refueling of aircraft in the air, radar tracking of B-52 strategic bombers, and the direction of groups of strategic, tactical, and carrier-based aviation to areas for strikes on ground targets. They managed direct air support for ground forces, detection of Iraqi helicopters, and security surveillance of reconnaissance aircraft.
In April 2022, the US Air Force announced their intention to replace the Boeing E-3 Sentry AWACS with the Boeing E-7 Wedgetail in 2027.