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. E-2C Hawkeye: Although the upgraded E-2B was a vast improvement on the unreliable E-2A, it was an interim measure. The US Navy knew the design had much greater capability and had yet to achieve the performance and reliability parameters set out in the original 1957 design. In April 1968, a reliability improvement program was initiated. In addition, now that the capabilities of the aircraft were starting to be realized, more were desired; 28 new E-2Cs were ordered to augment the 49 E-2Bs that would be upgraded. Improvements in the new and upgraded aircraft were concentrated in the radar and computer performance.

Two E-2A test machines were modified as E-2C prototypes, the first flying on 20 January 1971. Trials proved satisfactory and the E-2C was ordered into production. The first production aircraft performed its initial flight on 23 September 1972. The original E-2C, known as Group 0, consisted of 55 aircraft; the first aircraft became operational in 1973 and serving on carriers in the 1980s and 1990s, until they were replaced in first-line service by Group II aircraft. US Navy Reserve used some aircraft for tracking drug smugglers. The type was commonly used in conjunction with Grumman F-14 Tomcat fighters; monitoring airspace and then vectoring Tomcats over the Link-4A datalink to destroy potential threats with long range AIM-54C Phoenix missiles. The next production run, between 1988 and 1991, saw 18 aircraft built to the Group I standard. Group I aircraft replaced the E-2’s older APS-125 radar and T56-A-425 turboprops with their successors, the APS-139 radar system and T56-A-427 turboprops. The first Group I aircraft entered service in August 1981. Upgrading the Group 0 aircraft to Group I specifications was considered, but the cost was comparable to a new production aircraft, so upgrades were not conducted. Group I aircraft were only flown by the Atlantic fleet squadrons. This version was followed within a few years by the Group II, which had the improved APS-145 radar. A total of 50 Group II aircraft were delivered, 12 being upgraded Group I aircraft. This new version entered service in June 1992 and served with the Pacific and Atlantic Fleet squadrons.

By 1997, the US Navy intended that all front line squadrons would be equipped, for a total of 75 Group II aircraft. Grumman merged with Northrop in 1994 and plans began on the Group II Plus, also known as the Group II / NAV upgrade. This kept the same computer and radar as the Group II while upgrading the pilot avionics, such as replacing the mechanical Inertial Navigation System (INS) with a more reliable and accurate laser Ring Gyroscope-driven INS, installing dual Multifunction Display Units (MFCDUs) (vice one in the Group II) and integrating GPS into the weapon system. A variant of the Group II with upgrades to the mission computer and CIC workstations is referred to as the MCU/ACIS, these were produced in small numbers due to production of the Hawkeye 2000 soon after its introduction. All Group II aircraft had their 1960s vintage computer processors replaced by a mission computer with the same functionality via modern computer technology, referred to as the GrIIM RePr (Group II Mission Computer Replacement Program, pronounced “grim reaper”).

Another upgrade to the Group II was the Hawkeye 2000, which featured the same APS-145 radar but incorporated an upgraded mission computer and CIC (Combat Information Center) workstations (Advanced Control Indicator Set or ACIS and carries the U.S. Navy’s new CEC (cooperative engagement capability) data-link system. It is also fitted with a larger capacity vapor cycle avionics cooling system. Starting in 2007 a hardware and software upgrade package began to be added to existing Hawkeye 2000 aircraft. This upgrade allows faster processing, double current trackfile capacity and access to satellite information networks. Hawkeye 2000 cockpits being upgraded include solid-state glass displays and a GPS-approach capability. The remaining Hawkeye Group II NAV Upgrade aircraft received GPS approach capability, but did not get the solid-state glass displays. In 2004, the E-2C’s propeller system was changed; a new eight-bladed propeller system named NP2000 was developed by the Hamilton-Sundstrand company to replace the old four-bladed design. Improvements included reduced vibrations and better maintainability as a result of the ability to remove prop blades individually instead of having to remove the entire prop and hub assembly. The propeller blades are of carbon fiber construction with steel leading edge inserts and de-icing boots at the root of the blade. Design:

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 (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. 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 long-patented 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 center 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 defense, 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. France:

The French Naval Aviation (Aeronavale) operates three E-2C Hawkeye 2000’s and has been the only operator of the E-2 Hawkeye from an aircraft carrier besides the U.S. Navy. The French nuclear-powered carrier, Charles de Gaulle, currently carries two E-2C Hawkeyes on her combat patrols offshore. The third French E-2C Hawkeye has been upgraded with eight-bladed propellers as part of the NP2000 program. In April 2007, France requested the purchase of an additional aircraft. The Flottille 4F of the French Navy’s Aeronavale was stood up on 2 July 2000 and flies its E-2C Hawkeyes from its naval air station at Lann-Bihoue, deploying to the Charles de Gaulle. They took part in operations in Afghanistan and Libya. In September 2019 Florence Parly, French Minister of the Armed Forces, announced that three new E-2D Advanced Hawkeyes would be purchased in 2020 to replace the E-2Cs in service.

General characteristics:

Crew: 5: pilot, copilot, radar officer (RO), combat information center officer (CICO), aircraft control officer (ACO) Length: 57 ft 9 in (17.596 m) Wingspan: 80 ft 7 in (24.56 m) Height: 18 ft 4 in (5.582 m) Wing area: 700 sq ft (65 m2) Empty weight: 40,200 lb (18,234 kg) Gross weight: 43,068 lb (19,535 kg) Max takeoff weight: 57,500 lb (26,082 kg) Powerplant: 2 x Allison/Rolls-Royce T56-A-427 (E-2C), T56-A-427A (E-2D) turboprop, 5,100 shp (3,800 kW) each Maximum speed: 350 kn (400 mph, 650 km/h) Cruise speed: 256 kn (295 mph, 474 km/h) Ferry range: 1,462 nmi (1,682 mi, 2,708 km) Endurance: 6 hours (8 hours land-based) Service ceiling: 34,700 ft (10,600 m) Avionics: AN/APS-145 Radar OL-483/AP IFF interrogator system APX-100 IFF Transponder OL-698/ASQ Tactical Computer Group AN/ARC-182 UHF/VHF radio AN/ARC-158 UHF radio AN/ARQ-34 HF radio AN/USC-42 Mini-DAMA SATCOM system