Grumman
Northrop Grumman E-2 Hawkeye

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.

Continual improvements in airborne radars through 1956 led to the construction of AEW airplanes by several different countries and several different armed forces. The functions of command and control and sea and air surveillance were also added. The first carrier-based aircraft to perform these missions for the U.S. Navy and its allies was the Douglas AD Skyraider, which was replaced in US Navy service by the Grumman E-1 Tracer, which was a modified version of the S-2 Tracker twin-engine anti-submarine warfare aircraft, where the radar was carried in an aerofoil-shaped radome carried above the aircraft's fuselageOnce considered for replacement by the "Common Support Aircraft", this concept was abandoned. The latest E-2 version is the E-2D Advanced Hawkeye, which features an entirely new avionics suite including the new AN/APY-9 radar, radio suite, mission computer, integrated satellite communications, flight management system, improved T56-A-427A engines, a glass cockpit and aerial refueling.^] The APY-9 radar features an active electronically scanned array (AESA), which adds electronic scanning to the mechanical rotation of the radar in its radome. The E-2D includes provisions for the copilot to act as a "Tactical 4th Operator" (T4O), who can reconfigure his main cockpit display to show radar, IFF, Link 16 (JTIDS)/CEC and access all acquired data. 

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. Wiki Link