The Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft, after Grumman’s merger with Northrop in 1994 it is called the Northrop-Grumman Hawkeye.
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.
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 all 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 (take-off).
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.
Land-based aircraft with rotodomes include the Boeing E-3 Sentry, a larger AWACS airplane operated by the U.S. Air Force and NATO air forces in large numbers.
The similarly placed stationary radome of the E-2’s piston-engined predecessor, the E-1 Tracer, also mandated the E-2’s adoption of a modern version of Grumman’s Sto-Wing folding wing system, preventing the folded wing panels from making contact with the E-2’s rotodome.
The aircraft is operated by a crew of five, with the pilot and co-pilot on the flight deck and the combat information centre officer, air control officer and radar operator stations located in the rear fuselage directly beneath the rotodome.
In U.S. service, the E-2 Hawkeye provides all-weather airborne early warning and command and control capabilities for all aircraft-carrier battle groups.
In addition, its other purposes include sea and land surveillance, the control of the aircraft carrier’s fighter planes for air defence, the control of strike aircraft on offensive missions, the control of search and rescue missions for naval aviators and sailors lost at sea, relaying radio communications, air-to-air and ship-to-air.
It can also serve in an air traffic control capacity in emergency situations when land-based ATC is unavailable.
The E-2C and E-2D Hawkeyes use advanced electronic sensors combined with digital computer signal processing, especially its radars, for early warning of enemy aircraft attacks and anti-ship missile attacks, controlling the carrier’s combat air patrol (CAP) fighters, and secondarily for surveillance of the surrounding sea and land for enemy warships and guided-missile launchers and any other electronic surveillance missions as directed.
Original designation of the Hawkeye, changed to E-2A in 1962.
Initial production versionwas W2F-1 before 1962. 59 built.
Two E-2As converted as crew trainers.
Two E-2As, BUNOs 148147 and 148148, converted as prototypes of the C-2 Greyhound
As E-2A but fitted with improved computing, enlarged outer fins.
52 converted from E-2A.
Two E-2As, BUNOs 148712 and 148713, converted as E-2C prototypes.
Designated as YE-2C and NE-2C respectively.
These airframes then finished out their useful life being used as TE-2C pilot trainers.
As the E-2B but with all new electronics, surveillance radar and search radar, 63 built.
In “plus-models” the E-2C also has upgraded turboprop engines.
E-2C Group 0
Initial production version of E-2C, fitted with AN/APS-120 or AN/APS-125 radar.
Lengthened nose compared to earlier versions
E-2C Group I
New radar (AN/APS-139), plus upgraded mission computer and upgraded engines.
18 new build aircraft.
E-2C Group 2
AN/APS-145 radar, further improved electronics.
E-2C Group 2 Plus (Nav Upgrade)
Avionics upgrade, inclusion of GPS into weapon system.
E-2C Hawkeye 2000
New mission computer, Cooperative Engagement Capability (CEC) and additional satellite communications aerial.
Originally designated Group 2+.
A variant with new avionics suite, improved engines, a new “glass cockpit” and the potential for air-to-air refuelling.
E-2C variant for Republic of China (Taiwan), with parts taken from retired E-2Bs.
However, these aircraft have the same level of electronics as the E-2C Group II Hawkeyes with their APS-145 radars and are referred to as E-2T, with “T” standing for Taiwan.
On July 31, 1999, Taiwan was approved to acquire two additional E-2 built to Hawkeye 2000 standard.
Later, the four original E-2T were also upgraded to the same standard.
The upgraded aircraft were referred to as E-2K.
57 ft 8+3⁄4 in (17.596 m)
80 ft 7 in (24.56 m)
18 ft 3+3⁄4 in (5.582 m)
Radome could retract by 2 feet to fit into the 17′ 6″ clear height hangar of Essex and Midway class carriers.