General Dynamics EF-111A Raven
The history of the F-111 goes back to the 1950’s when the USAF outlined the requirement for a replacement for their F-100, F-101 and F-105 fighter-bombers. By the time a realistic specification had begun to take shape and the more outlandish ideas for a Mach 2+, 60,000ft, all-weather STOVL fighter bomber had been discarded, the US Navy also started outlining their specification for a two-seat carrier based fleet air defence fighter. Although almost anyone with even the most rudimentary interest in aviation would see that these two requirements were utterly different, one man was convinced that he knew better – Robert S McNamara, the new Secretary of Defence appointed by John F Kennedy. McNamara had enjoyed a very successful career in industry, culminating with his appointment as the first President of Ford Motors from outside the family of Henry Ford. McNamara arrived at the Department of Defence with his own entourage of ‘wizz-kids’ who seemed determined to shake things up and inject some corporate practice and industry thinking into the military. McNamara was undoubtedly an outstanding businessman, who introduced some much needed reforms into the Department of Defence, but he was also rather intellectually arrogant and often tended to completely ignore advice from his senior military staff - something that contributed to his unpopularity with all the service chiefs. McNamara insisted that a study was undertaken to identify a single aircraft to undertake both missions and, just to really muddy the waters, he also added into the pot the Army and Marine Corps requirement for a close air support aircraft. The new project was known as the Tactical Fighter Experimental or TFX.
It was soon obvious, even to McNamara, that the close air support mission could not be met by the TFX and this requirement was quickly dropped. However, McNamara insisted that the USAF and USN continue working towards developing a joint aircraft. Eventually after protracted wrangling and disputes, the Defence Department selected a General Dynamics design in preference to a Boeing design preferred by the USAF and USN – a decision that created a huge political controversy, however, the real problems had only just started. The F-111A USAF version first flew on 21 Dec 64, two years after the contract had been signed, followed by the F-111B USN version that first flew on 18 May 65. However, both aircraft were severely overweight, suffered from poor engine performance and were riddled with technical problems that would take years to resolve. Weight and size was always going to be a bigger issue for the USN and eventually it began to dawn on everyone that the F-111B was just too big and heavy for carrier operations – eventually in Jun 68 further funding for the F-111B was finally withdrawn from the Defence Budget. Thankfully for the USN, the F-111B debacle eventually resulted in the development of the Grumman F-14 Tomcat, equipped with the Hughes Phoenix missile and complimentary radar system originally planned for the F-111B. After the usual teething troubles, the F-14 became a magnificent fighter and is only just being withdrawn from service as they are replaced by the Boeing F-18F Hornet.
The F-111A eventually entered service in Jun 67 with a detachment of the 4481st Tactical Fighter squadron at Nellis AFB where a select group of crews were used to iron out the aircraft’s remaining development problems and prepare the aircraft for combat in Vietnam. On 15 Mar 68, in Operation Combat Lancer, six F-111As flew from Nellis to Ta Khil Air Base in Thailand and during the next 8 months flew 55 missions at low level and generally at night and in poor weather, losing only three aircraft due to technical malfunctions. As the war in Vietnam slowly dragged on, it gradually dawned on many of the aircrew that effective electronic warfare would be one of the keys to survival in the era of multiple SAM threats. As an interim solution the USAF brought a number of Douglas B-66 Destroyers out of retirement and converted them to airborne jammers as the EB-66C. These aircraft operated in Vietnam from 1966-74 with the 41st and 42nd Tactical Electronic Warfare Squadrons and effectively set out the basic operating principles for all subsequent USAF EW squadrons.
However, although the EB-66s were effective in a stand-off role, they were old aircraft and really lacked the necessary performance to accompany strike aircraft all the way to the target and back home. Dedicated EW also pods were also available and were often mounted on weapons pylons, but they could only provide a limited amount of power and reduced the ordnance that could be carried - what was needed was a new dedicated airborne tactical jamming system. In 1971, based on its experiences in SE Asia, the USAF commenced a study to develop a total airborne jamming system. What was needed was a aircraft that was fast enough to escort the strike aircraft, whilst also carrying the necessary electronic equipment to neutralise air defence radar’s and sweep a clear path for them to hit the target. By the end of 1974 the study had determined that the General Dynamics F-111A was the most suitable platform for an unarmed dedicated EW aircraft. The Grumman Aerospace Corporation, with their extensive experience of EA-6B Prowler EW operations, was an ideal choice for the conversion work and on 30 Jan 75 the company received a $85m contract to convert two prototype EF-111A aircraft in a 38 month programme. The new aircraft was named Raven – a term commonly applied to EW/ELINT operators. Like all EW aircraft the EF-111A also had the capability to record EW emission and provide very effective intelligence on any new system it encountered.
It was soon determined that much of the 6,000lbs of EW equipment planned for the EF-111A would be housed in the weapons bay and covered by an extended aerodynamic ‘canoe’ radome. Inside the 16ft radome was the AN/ALQ-99E tactical jamming system, an improved version of the ALQ-99 used by the EA-6B Prowler. The AN/ALQ-99E had all 10 jamming transmitters, five exciters to drive the transmitters and six multi-channel digitally tuned receivers covering 7 wavebands mounted in the radome. The increased requirement of the EF-111A resulted in the aircraft being equipped with 90 kVA generators, replacing the original 60 kVA generators. The other significant change was the addition of a slim, deep pod on top of the fin that housed all the aircraft’s receivers, together with a processor to detect radar emissions - some 600lbs of weight. By 1977 the aircraft were ready and in September that year testing began by Det 3 of the Tactical Warfare Centre at Mountain Home AFB where it was intended to base the first operational squadron. After extensive testing, the USAF authorised conversion of a further six F-111As and then after further testing, a further 34 F-111As were authorised to be converted – bringing the final total of EF-111As to 42 aircraft. The final cost of the aircraft was around $900 million, including logistic support and spares.
Part of the work undertaken by Det 3 was to determine how best to utilize the new EF-111A against enemy threats. The most likely scenario would call for the EF-111A to be operated against Warsaw Pact forces in Europe should hostilities suddenly break out. Three major roles were planned, barrier stand-off, deep penetration and close support. In the barrier stand-off role the EF-111A would orbit over friendly forces outside the range of hostile ground based weapons and project a massive jamming barrier to disrupt enemy radars. Behind this barrier friendly forces would refuel safely or take up position without the knowledge of the enemy. In the deep penetration role, which involved the elimination of a high priority target, the EF-111A would escort strike aircraft into and out of enemy territory, jamming everything en-route. In the close support role, the EF-111A would accompany the strike aircraft to the target area and then loiter while the attack was completed, before accompanying them back out of hostile airspace. The real key to the success of the EF-111A was that its sheer performance allowed it to accomplish the 2nd and 3rd roles far better than any previous aircraft. Until the arrival of the EF-111A, EW aircraft lacked sufficient performance to accompany strike aircraft. Now there was an EW aircraft that was not only capable of supersonic speed at low level and Mach 2 at height, but also carried over 32,000lbs of fuel giving it a range of over 2,000 miles. In fact, as most strike aircraft usually carried fuel and weapons on under-wing pylons that greatly inhibited their performance, the EF-111A Raven was always capable of greater performance than the strike aircraft it was escorting.
The first unit to operate the EF-111A Raven was the 388th Electronic Combat Squadron (ECS) based at Mountain Home AFB which received its first aircraft on 5 Nov 81. The 388th ECS trained all the remaining Raven crews and was then deactivated and replaced by the 390th ECS that remained at Mountain Home. The only other unit to operate the EF-111A Raven was the 42 ECS which was reactivated on 1 Jul 83 at RAF Upper Heyford in England and received its final Raven in late 1985. In 1994 all the EF-111As were updated with 10 new subsystems, including a Doppler radar and internal navigation system. Then after a number of failures of the F-111s original analog flight control system, the installation of a new digital flight control system was completed in 1997. The EF-111A Ravens saw action first in the 1981 Operation Eldorado Canyon strike against Libya and then went on to even greater success during Operation Desert Storm in 1990.
However, after the collapse of the Soviet empire in the early 1990’s there was considerable pressure for a peace dividend and this began to have a serious affect on military budgets. One casualty was the F-111 fleet that began to shrink as aircraft were scrapped and, as the size of the fleet reduced, and the cost of supporting the remaining aircraft began to increase, the surviving EF-111As began to become a target for the budget cutters. Two other factors had a big hand in the final decision; the ALQ-99E jamming system needed a major upgrade to enable it to cope with the latest generation of Russian radars. Unlike the EA-6B Prowler where you could just replace an underwing pod, the EF-111A carried all its jamming equipment internally and this would necessitate a costly and lengthy refurbishment. The other factor was a change in USAF operational doctrine away from the Suppression of Enemy Air Defences (SEAD) to the Destruction of Enemy Air Defences (DEAD). Instead of jamming air defence radars and SAM sites, leaving them still capable of identifying and destroying subsequent aircraft, the new doctrine called for F-117 Stealth fighters and HARM equipped F-16CJ to destroy the sites ahead of and then alongside the strike force. A lengthy and acrimonious battle to determine the future of airborne EW broke out in the US EW community, but eventually the decision was made to cancel the upgrade to the ALQ-99E, retire all the EF-111As and replace the capability with the EA-6B manned by joint USN/UASF crews. Mountain Home AFB eventually closed as part of the draw-down of forces and the remaining Ravens were transferred to Cannon AFB, New Mexico and then eventually the final EF-111A Raven was retired on 2 May 98.
Many commentators believed at the time that the decision to retire the EF-111A Raven early was a very bad decision and probably only the most ardent supporter of the EA-6B would choose to disagree. Whilst the new doctrine has been generally effective, the most over-worked and over-tasked aircraft in all recent conflicts has been the EA-6B. Furthermore, it still hasn’t got the necessary speed for strike escort and is mainly used as a ‘stand-off’ jammer. New Soviet radars have yet to appear in great numbers, but many old SAM and surveillance radars remain in service with a variety of potential adversaries and these would still be vulnerable to the EF-111A. Because of the possibility of HARM attack, the crews of these old radar systems have become ‘emmision shy’, making the ability to locate and destroy them far more difficult. The most obvious solution is to simply jam them out of the equation – but with the Raven no longer around and with fewer EA-6Bs available, this sometimes simply isn’t an option – however, according to some people, that’s progress!