In the late 1960s, the U.S. Air Force sought to replace its aging EB-66 and EB-57electronic warfare aircraft. The Air Force studied the use of Navy EA-6B Prowlers during 1967–1968.[2] However, the Air Force desired a penetrating electronic jamming aircraft with supersonic speed,[1][2] and, in 1972, decided to modify F-111As into electronic warfare aircraft as a cost-effective option.[3]
In January 1974, the Air Force awarded electronic warfare study contracts to Grumman and General Dynamics.[1] Grumman was selected as the EF-111 prime contractor in December 1974, then was awarded a contract to modify two F-111As into EF-111 prototypes in January 1975.[3] The first fully equipped model, known then as the "Electric Fox", flew on 10 March 1977. A total of 42 airframes were converted at a total cost of US$1.5 billion. The first EF-111s were deployed in November 1981 to the 388th Tactical Electronic Squadron, Mountain Home AFB, Idaho.[4] The last was delivered in 1985.[5]
An EF-111A Raven in the foreground with a tail-mounted receiving pod and an underside-mounted transmitting pod, accompanied by an F-111F
The Raven retained the F-111A's navigation systems, with a revised AN/APQ-160 radar primarily for ground mapping. The primary feature of the Raven, however, was the AN/ALQ-99E jamming system, developed from the Navy's ALQ-99 on the Prowler. The aircraft also utilized the ALR-62 Countermeasures Receiving System (CRS) as a Radar Homing and Warning (RHAW) System, the same system carried by all F-111 fighter/bomber models in the United States and Australia. The ALQ-99E primary electronics were installed in the weapons bay, with transmitters fitted in a 16 feet (4.9 m) long ventral "canoe" radome; the complete installation weighed some 6,000 pounds (2,700 kg). Receivers were installed in a fin-tip pod, or "football", similar to that of the EA-6B. The aircraft's electrical and cooling systems had to be extensively upgraded to support this equipment. The cockpit was also rearranged, with all flight and navigation displays relocated to the pilot's side, and flight controls except throttles being removed from the other seat, where the electronic warfare officer's instrumentation and controls were installed.
The EF-111 was unarmed. Its speed and acceleration were its main means of self-defense. It was not capable of firing anti-radiation missiles in the Suppression of Enemy Air Defenses (SEAD) role, which was a tactical limitation. The Raven's engines were upgraded to the more powerful TF30-P-9 of the D-model, with 12,000 pounds-force (53 kN) dry and 19,600 lbf (87 kN) afterburning thrust[6] in 1986.[7] From 1987 to 1994 the "Spark 'Vark" underwent an Avionics Modernization Program (AMP), similar to the Pacer Strike program for the F-model. This added a dual AN/ASN-41 ring laser gyroscope INS, AN/APN-218 Doppler radar, and an updated AN/APQ-146 terrain-following radar. Cockpit displays were upgraded with multi-function displays.
The Raven served in the Gulf War during Operation Desert Storm in 1991. On 17 January 1991, a USAF EF-111 crew of Captain James Denton and Captain Brent Brandon achieved an unofficial kill against an IraqiDassault Mirage F1, which they managed to maneuver into the ground, making it the only member of the F-111 family to achieve an aerial victory over another aircraft.[5][10]
No Coalition aircraft were lost to a radar-guided missile during Desert Storm while an EF-111 Raven was on station.
On 13 February 1991, EF-111A, AF Ser. No. 66-0023, call sign Ratchet 75, crashed[11] into terrain while maneuvering to evade a perceived threat.[12][13] killing the pilot, Capt Douglas L. Bradt, and the EWO, Capt Paul R. Eichenlaub. It was the only EF-111A lost during combat, the only loss killing its crew, and one of just three EF-111s lost during the aircraft's service.[14] However, it is disputed whether there was an enemy present at the time, as two F-15Es watched Ratchet 75 make violent evasive maneuvers and crash into the ground, with no hostile aircraft in the area.[vague][15]
The last deployment of the Raven was a detachment of EF-111s stationed at Al Kharj/Prince Sultan Air BaseinSaudi Arabia until April 1998.[7] Shortly afterward, the USAF began withdrawing the final EF-111As from service, and placed them in storage at the Aerospace Maintenance and Regeneration Center (AMARC) at Davis-Monthan AFB, Arizona. The last EF-111s were retired on 2 May 1998, at Cannon AFB, New Mexico. These were the final USAF F-111s in service.[7]
Of the converted aircraft, three were destroyed in crashes, four are on display, and the other 35 were scrapped.[17][18]
66-0016 is on display at Cannon Air Force Base, New Mexico. It was the first EF-111 to fly a combat mission and was unofficially credited with the Mirage F1 kill.[19][20]
^Development of the EF-111A Raven ["Spark Varks"] began in 1974 when the Air Force awarded electronic warfare study contracts to Grumman and General Dynamics in January 1974.[1]
^Note: 2,000 miles (1,740 nautical miles) for EF-111A.[27]
^Cannon airpark to relocateArchived 23 February 2014 at the Wayback Machine – "EF-111 aircraft will be moved to the triangular, grassy area at the entrance of Joe Cannon Estates". 7 February 2013. Retrieved 10 Feb 2014.
United States[edit]
