The Northrop Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft. This twin-turboprop aircraft was designed and developed during the late 1950s and early 1960s by the Grumman Aircraft Company for the United States Navy as a replacement for the earlier, piston-engined E-1 Tracer, which was rapidly becoming obsolete.The aircraft's performance has been upgraded with the E-2B and E-2C versions, where most of the changes were made to the radar and radio communications due to advances in electronic integrated circuits and other electronics. The fourth major version of the Hawkeye is the E-2D, which first flew in 2007. The E-2 was the first aircraft designed specifically for its role, as opposed to a modification of an existing airframe, such as the Boeing E-3 Sentry. Variants of the Hawkeye have been in continuous production since 1960, giving it the longest production run of any carrier-based aircraft. The E-2 also received the nickname "Super Fudd" because it replaced the WF (later E-1) "Willy Fudd". In recent decades, the E-2 has been commonly referred to as the "Hummer" because of the distinctive sounds of its turboprop engines, quite unlike that of turbojet and turbofan jet engines. In addition to U.S. Navy service, smaller numbers of E-2s have been sold to the armed forces of Egypt, France, Israel, Japan, Mexico, Singapore and Taiwan. Grumman also used the basic layout of the E-2 to produce the Grumman C-2 Greyhound cargo aircraft. The E-2 is a high-wing airplane, with one Allison T56 turboprop engine (5250 shp rating) on each wing and retractable tricycle landing gear. As with most carrier-borne airplanes, the E-2 is equipped with a tail hook for recovery (landing) and the nose gear can attach to a shuttle of the aircraft carrier's catapults for launch (takeoff). A distinguishing feature of the Hawkeye is its 24-foot (7.3 m) diameter rotating radar dome (rotodome) that is mounted above its fuselage and wings. This carries the E-2's primary antennas for its long-range radar and IFF systems. No other carrier-borne aircraft possesses one of these. For more informatin on the background, development, design and operational history, as well as the 15 variants, click here.