The F-4G was the designation applied to 116 USAF F-4Es which were converted to the Wild Weasel anti-SAM configuration. These aircraft should not be confused with the Navy F-4G, which was the designation applied to twelve F-4Bs that were fitted with automatic carrier landing systems.
Throughout the late 1960s, the Wild Weasel III adaptation of the F-105F two-seat Thunderchief had been the primary anti-SAM attack aircraft in Vietnam. However, by 1970 the F-105 airframe was no longer in production, and attrition in Vietnam had made it a scarce resource. The need for a replacement for the F-105F Wild Weasel had become apparent. 36 F-4C airframes had been converted to the EF-4C Wild Weasel IV configuration, but they suffered from certain deficiencies which limited their combat effectiveness. For example, they were unable to carry the Standard ARM. Consequently, the EF-4C was seen only as an interim Wild Weasel aircraft, pending the introduction of a more suitable type.
McDonnell and the USAF both agreed that the more capacious airframe of the F-4E would be able to carry the electronics for the more capable AGM-78 Standard antiradiation missile. A YF-4E (65-0713) was fitted with a mockup installation of the AN/APR-38 radar warning and attack system, and the results were sufficiently satisfactory that the decision was made to convert 116 low-time F-4E airframes for the anti-SAM role. The code name Wild Weasel V was assigned to the project.
Several EF-4Ds and F-4Es were used in support of the program. F-4E 69-7254 served as the YF-4G prototype, although it was originally known as the F-4E Advanced Wild Weasel. This F-4G was fitted with leading-edge maneuvering slats. The M61A1 cannon and ammunition drum were removed and replaced by an under-nose fairing that housed forward- and side-looking radar antenna as well as line replacement units for the AN/APR-38 radar warning and attack system. This system can be reprogrammed at squadron level, and can identify known enemy air-defense radar systems and display their locations in a predetermined order of priority. The under-nose fairing has a ram inlet that admits cooling air to the interior, which helps to cool the avionics systems inside the nose.
There are a total of 52 receiving and emitting antenna found all over the aircraft. The main receivers are housed in front of the chin gondola that replaced the gun, with others being housed in a pod mounted on top of the fin. Eight of the blade antennas that protrude from the fuselage provide low-band omnidirectional signal reception, with five others being directional and capable of giving the threat bearing on the display in the rear cockpit.
The main radar of the F-4G was the same Westinghouse AN/APQ-120 that was fitted to the F-4E, although a new digital processor was added.
Boxes for dispensing chaff or flare cartridges can be attached to the sides of the underwing pylons. The usual pattern is the Tracor ALE-40, with 30 tubes firing aft.
The backseat crew member has three main displays: a plan-position indicator, a panoramic analysis display, and a homing indicator. The plan-position indicator is duplicated on the pilot's control panel. The plan-position indicator gives the range and bearing of each threat that is identified by the system. The type of each threat is then designated on the display, and the threat deemed by the system to be the most dangerous is identified by having a bright triangle superimposed over it.
In support of its mission, the F-4G could carry the AGM-45 Shrike and the AGM-78 Standard antiradiation missiles.
The Texas Instruments AGM-45 Shrike was the first missile specifically designed for the anti-radiation role. It was based in part on the Sparrow air-to-air missile and had more or less the same configuration. It has a launch weight of about 390 pounds and carries a 145 pound explosive warhead. The range is of the order of 18 to 25 miles. The guidance of the Shrike is provided by a monopulse crystal video receiver. When the receiver in the missile's nose locks onto a target, the crew fires the missile. After launch, the Shrike flies a ballistic path until the control system is activated. At that time, the receiver onboard the Shrike begins updating the guidance by determining the direction of arrival of the hostile radiation, and the missile then homes onto the enemy radar signal with its cruciform center-body wings. The Shrike first became operational in 1965. In Vietnam, the initial experience with the Shrike was rather disappointing. After some trial and error, the enemy found that he could "spoof" the Shrike by simply turning off his radar set, which would cause the Shrike to lose its lock on the target and fall out of control. In addition, the receiver of the Shrike was not able to deal with enemy radars that were frequency-agile; all that the enemy had to do to defeat a Shrike attack was to switch his radar to a different frequency. Many versions of the Shrike were produced in an attempt to correct its deficiencies, but none were very successful.
The General Dynamics AGM-78 Standard anti-radiation missile was an attempt to correct some of the deficiencies of the Shrike. It had a longer range and a larger warhead than the Shrike. The AGM-78 was based on the Standard RIM-66A ship-to-air missile. It has a launch weight of about 1400 pounds and carries a 215-pound warhead. Maximum range was about 35 miles. The missile flies on a dual-thrust rocket motor and steers with tail controls and very low-aspect ratio fixed wings. The Standard ARM first appeared in service in 1968. The first version of the Standard had the simple Shrike seeker, but later versions had the Maxson broadband radiation seeker and had memory circuits to deal with radar shutdown tactics.
In addition, the F-4G could carry the AGM-65 Maverick air-to-ground missile which existed in both TV-guided and imaging infrared versions. It could also carry the Mk 84 electro-optical glide bomb, the homing bomb system, and cluster weapons such as the Rockeye, CBU-52, and CBU-58.
In later years, the Texas Instruments AGM-88 High-Speed Anti-Radiation Missile (HARM) superseded most of the former anti-radiation weapons, offering a greatly enhanced kill capability and greater launch versatility. It was designed to provide much higher speeds and much quicker target acquisition times so that enemy radars could be destroyed before they had a chance to be switched off or take other sorts of evasive actions. The HARM has a launch weight of about 800 pounds and has an effective range of about 17 miles. The warhead of the HARM is of a fragmentation variety, which destroys the target by producing a deadly shower of steel cubes. I don't know the weight of the warhead--presumably this is classified information. There are three basic modes of operation for the HARM: Self Protect, Target of Opportunity, and Pre-Briefed. In the Self-Protect mode, the launching aircraft's systems detect the threat and assign its priority. The aircraft's on-board computers then sort the data and pass along to the HARM's computer a set of digital instructions needed to reach the target, and the missile is then launched. The HARM can continue to fly toward the target even if the enemy radar is switched off. In the Target of Opportunity mode, the HARM's sensitive seeker is used to help to determine when to launch against a previously unknown threat. In the Pre-Briefed mode, the HARM can be programmed on the ground for up to three known types of enemy radar emissions. Once in the air, the launching aircraft can fire the HARM blind in the general direction of these known enemy radar emitters. If they are silent, the HARM will self-destruct, but if an enemy site begins to radiate, the HARM will automatically home in on it. Test flights of the HARM began in 1976, and deployment began in early 1983. Earlier versions of the HARM had to be sent back to a depot in the US for reprogramming, but later versions can be reprogrammed on the flight line.
For self-protection, the F-4G could carry up to four AIM-9 Sidewinder air-to-air missiles on the sides of the inboard underwing pylons. In addition, four AIM-7 Sparrows could be carried in the underfuselage slots. However, the left front slot was often taken up by the installation of a ALQ-119 or ALQ-141 jammer pod.
All of the F-4Gs were rebuilds of Block 42 to 45 F-4Es. The first of these aircraft (69-7254) was modified by McDonnell and began flight trials in December of 1975. Subsequent F-4G aircraft were modified by the Air Force at Hill AFB in Utah. The last modification was completed in 1981.
The first F-4Gs went in April of 1978 to the 39th TFTS of the 35th TFW, based at George AFB in California. In 1981, the F-4Gs of the etth TFW were turned over to the 37th TFW, also based at George. In 1989, the 37th TFW was transferred to Tonopah, Nevada to take over the operation of the F-117, and turned their F-4Gs back over to the 35th TFW.
In 1979, F-4Gs were issued to the 52nd TFW based at Spangdahlem AFB in Germany. In the same year, F-4Gs were assigned to the 90th TFS of the 3rd TFW based at Clark AFB in the Philippines.
A two-part Performance Update Program (PUP) was undertaken in the mid-1980s. The first phase was the expansion of the capability of the on-board computer by adding a new Unisys CP-1674 digital processor. The second phase was the upgrading of the APR-38 to APR-47 standards.
By the time of Desert Shield, the F-4G equipped two squadrons of the 35th TFW, the 561st TFS and the 562nd TFTS.
Following the Iraqi invasion of Kuwait on August 2, 1990, the 561st TFS (part of the 35th TFW based at George AFB) deployed to the Middle East as a part of Desert Shield. Twenty-four F-4Gs were deployed. They were configured with three external fuel tanks (one on the centerline and two underneath the outboard underwing pylons), four chaff/flare dispensers, two AGM-88 HARM missiles on the inboard pylons, and three AIM-7M Sparrow missiles and an ALQ-184 electronic countermeasures pod in the four missile slots.
At the time of Desert Storm, the F-4G was still the only Wild Weasel aircraft available to the USAF. The F-4Gs of the 35th TFW played an important part in Operation Desert Storm in 1991, when they cut a path through Iraqi air defenses during the initial attack on January 17. The F-4Gs of the 52nd TFW based at Spangdahlem in Germany were also added to the assets of the 35th TFW based at Sheik Isa AFB in Bahrain and to the 7440th Composite Wing based at Incirlik AFB in Turkey.
During the Gulf war, only one F-4G was lost. It was 69-7571, which crashed on January 18, 1991. It was not actually lost as the result of any enemy action, but because it simply ran out of gas. While coming back from a target, it missed the orbit of the tanker it was to refuel from. There was not enough fuel to fly past the tanker and then circle back to line up for another refuelling attempt, so the pilot was ordered to divert to the airfield at King Khalid Military City, which was about 50 nm south of the Saudi Arabian-Iraqi border. As luck would have it, the base was covered in fog and it was seriously below approach minima. To make matters even worse, heavy earthmoving equipment had accidentally knocked out the wiring to the runway landing lights. The F-4G was right over the runway, made several passes but couldn't see it. So, the crew members ejected and 7571 bellied in. After the crash, the plane still looked surprisingly good, attesting to the robustness of the design.
The F-4G was the last version of the Phantom to remain in front-line service with the USAF. Following Desert Storm and the general defense drawdown after the collapse of the Warsaw Pact, many USAF F-4Gs were turned over to the Air National Guard. On April 12, 1991, the Department of Defense announced that the F-4Gs would all be reassigned to ANG units. Under this plan, the 90th FS at Clark AB in the Philippines was scheduled to convert from F-4E/Gs to F-15Es and move to Alaska. The 35th FW at George AFB in California was to be inactivated, and the 52nd FW at Spangdahlem AB in Germany was to lose all of its F-4Gs. The F-4Gs were to be transferred to the Idaho and Kentucky ANG.
The 190th TRS of the Idaho ANG began its conversion from the RF-4C to the F-4G in June of 1991. Another RF-4C ANG unit, the 192nd TRS of the Nevada ANG, had been scheduled to convert to the F-4G (and had even painted F-4G 69-7580 in its distinctive "High Rollers" insignia), but the Defense Department changed its mind in April of 1991, and the Idaho ANG was to be the only ANG unit to operate the F-4G.
Combat experience during Desert Storm had indicated that the phaseout of the F-4G was premature, and a new active duty USAF squadron, the 561st FS of the 57th FW, was activated at Nellis AFB. The parent unit of the 561st was redesignated 57th Wing in April 1993.
The 81st TFS, 52nd FW at Spangdahlem in Germany continued throughout 1993 to deploy to Incirlik in Turkey in support of Operation Provide Comfort, the enforcement of the no-fly zone over northern Iraq. These F-4Gs returned to Germany at the end of 1993. However, the need to provide Wild Weasels to support Operation Southern Watch in Saudi Arabia and Operation Provide Comfort in Turkey resulted in the 52nd FW retaining a few F-4Gs until February 1994. The 81st TFS returned their last F-4Gs to the USA on March 18, 1994. These planes were the last US-operated Phantoms to be based in Europe.
In April 1993, the 124th FW of the Idaho ANG took over this responsibility and was assigned to active duty in Saudi Arabia to support Operation Southern Watch, the enforcement of the no-fly zone over southern Iraq. One of the ANG F-4Gs had to fire an AGM-88 HARM missile in response to a threatening Iraqi radar site near Basra. The Idaho ANG F-4Gs were later transferred to Incirlik AB in Turkey to support Operation Provide Comfort II. Overall, there were a total of four deployments to the Gulf. The last such deployment returned to the USA in December of 1995.
The F-4G was replaced by the F-16 in its Wild Weasel role. The last active USAF F-4G squadron, the 561st Fighter Squadron, was inactivated at Nellis AFB in March of 1996 and its planes placed in storage. On April 20, 1996, the last F-4Gs were withdrawn by the 124th FW of the Idaho ANG and were consigned to the boneyards at Davis Monthan AFB. This marked the final departure of the Phantom from active service with any American unit. The only Phantoms now remaining with the USAF are drones.
In 1991, it was decided that those F-4Gs not transferred to the ANG or placed in storage would be converted into drones under the designation QF-4G. Tracor Flight Systems of Austin, Texas was to do the conversion work. The company reportedly had gotten F-4Gs 69-7261, 69-7301, and 69-7263 for the initial conversion work. Following the conversion of 7301 and 7261, the droning program was halted, at least temporarily. 7301 crashed on May 14, 1993, killing its Tracor civilian crew.
The F-4G was operated by the following squadrons:
Air National Guard:
69-0236/0243, 69-0245/0248, 69-0250/0255, 69-0257/0259, 69-0261,
69-0263, 69-0265, 69-0267, 69-0269/0275, 69-0277, 69-0279/0281,
69-0283/0286, 69-0292/0293, 69-0297, 69-0304, 69-0306, 69-7201/7202,
69-7204/7220, 69-7223, 69-7228, 69-7231/7236, 69-7251, 69-7253/7254,
69-7256/7260, 69-7262/7263, 69-7270, 69-7272, 69-7286/7291, 69-7293,
69-7295, 69-7298, 69-7300/7303, 79-7546, 69-7550, 69-7556, 69-7558,
69-7560/7561, 69-7566, 69-7571/7572, 69-7574, 69-7579/7584, and
69-0244, 69-0249, 69-0260, 69-0264, 69-0278, 69-0290, 69-0298, 69-0303, 69-0305, 69-0307, 69-7252, 69-7261, 69-7267, 69-7268, 69-7274, 69-7297, 69-7551, and 69-7557.