The Boeing 737 Airborne Early Warning and Control (AEW&C) is a twin-engine aircraft based on the Boeing 737 Next Generation design. It is lighter than the 707-based Boeing E-3 Sentry, and has a fixed, active electronically scanned array radar antenna instead of a rotating one. It was designed for the Royal Australian Air Force (RAAF) under "Project Wedgetail" and designated E-7A Wedgetail. The 737 AEW&C has also been selected by the Turkish Air Force (under "Project Peace Eagle", Turkish: Barış Kartalı, designated E-7T, the Republic of Korea Air Force ("Project Peace Eye", Korean: "피스 아이"), and the United Kingdom (designated Wedgetail AEW1). In April 2022, the United States Air Force announced that the AEW&C will be replacing the E-3 beginning in 2027. Design and development The Australian Department of Defence evaluated industry proposals for airborne surveillance and early warning systems as early as 1986. Further studies led to the approval of the first phase of Project AIR 5077 in 1994. In 1996, Australia issued a request for proposal (RFP) for the aircraft for the RAAF under Project Wedgetail, which refers to the indigenous eagle. In 1999, Australia awarded Boeing Integrated Defense Systems a contract to supply four AEW&C aircraft with options for three additional aircraft. The 737 AEW&C is roughly similar to the 737-700ER. It uses the Northrop Grumman Electronic Systems Multi-role Electronically Scanned Array (MESA) radar. The electronically scanned AEW and surveillance radar is located on a dorsal fin on top of the fuselage, dubbed the "top hat", and is designed for minimal aerodynamic effect. The radar is capable of simultaneous air and sea search, fighter control and area search, with a maximum range of over 600 km (look-up mode). In addition, the radar antenna array is also doubled as an ELINT array, with a maximum range of over 850 km at altitude. Radar signal processing equipment and central computer are installed directly below the antenna array. Other modifications include ventral fins to counterbalance the radar and countermeasures mounted on the nose, wingtips and tail. In-flight refueling is via a receptacle on top of the forward fuselage. The cabin features eight operator consoles with sufficient space for four more; the Australian fleet will operate ten consoles with space for two more (four on starboard side and six on the port side). Operational history Australia Australia ordered four AEW&C aircraft with options for three additional aircraft, two of which have