Combat experience highlighted that the faith placed in missiles was not entirely justified. Close-in dogfights with nimble North Vietnamese MiGs highlighted the difficulty of getting a lock on the aircraft. Missiles were expensive and vulnerable to countermeasures, while the rules of engagement demanded visual confirmation, negating the advantage of being able to fire at range. Although Phantoms carried podded guns, this was far from an ideal solution. What was needed was an integral weapon.
Gun Fighter
Work on a gun-armed Phantom was funded in June 1965 and a YRF-4C was modified with a six-barrel General Electric M61A1 rotary cannon in the nose, becoming the YF-4E, followed by conversions of a single F-4C and F-4D. Considerable work was required to reduce vibration when fired, which disrupted the AN/APQ-120 radar, while systems found to be unreliable in combat were replaced.
Originally known as the F-4E Plus, for ‘plus gun’, the initial production aircraft flew on June 30, 1967, with the second introducing a slotted stabilator to become the first truly representative F-4E. The F-4E went on to become the most numerous Phantom version; in addition to 993 for the US Air Force 394 were built for Germany, Greece, Iran, Israel, South Korea and Turkey, while 24 were loaned to Australia and others later supplied to Egypt.
The F-4E also served as the basis for the majority of the export variants. Japan received 140 optimized as interceptors as F-4EJs, 125 of which were manufactured by Mitsubishi. Germany originally wanted the single-seat F-4E(F) before opting for 175 F-4Fs, a lighter and simplified F-4E, delivered between September 1973 and April 1976.
The model was also modified for the suppression of enemy air defenses as the F-4G Wild Weasel V. Building on the interim ‘EF-4C’ Wild Weasel IV, 36 of which were used between 1969 and the mid-1970s, a total of 136 F-4Gs were created.
Initial US Air Force procurement focused on a minimum change version of the F-4B originally designated the F-110A. This ‘F-110A’ was actually F4H-1 BuNo 149405, one of two borrowed from the US Navy and ‘delivered’ to the US Air Force on January 24, 1962. In reality, no Phantoms were ready for the air force at that point
USAF
Although externally similar to its predecessor, the F-4D was more closely tailored to the US Air Force’s requirements. The 194th Fighter Interceptor Squadron of the California Air National Guard flew F-4Ds for six years from late 1983
USAF
Carrier-based fighters
The US Navy also sought to build on the capabilities of its F-4Bs with the F-4J. Take-off and landing performance was improved by adding a slot to the stabilator leading-edge, creating a powerful nose-up force on launch or recovery. Locking the inboard wing leading-edge flap-up improved the effectiveness of the slotted stabilator, while lift at low speeds was increased by a 16.5° droop for the ailerons. These modifications reduced approach speed by 12kt to 125kt (231km/h). This was all the more remarkable as the F-4J was heavier and had higher sink rates,requiring a strengthened landing gear and the wider tires of the US Air Force variants, with a bulged inner wing root to accommodate them. Engines were upgraded to J79-GE-10s, with longer afterburner ‘feathers’, while a seventh fuel cell was added in the fuselage. The F-4B’s AN/APQ-72 radar was replaced by the bulkier and heavier AN/APG-59, part of the AN/AWG-10 radar and fire-control system, while the undernose infrared search and track sensor was deleted. The second production F-4J was the first to fly, on May 27, 1966, having been preceded by three YF-4J prototypes.
The F-4G was produced to locate, identify and neutralize enemy air defenses using a wide range of systems and armament. It was the last dedicated Wild Weasel airframe, remaining in service until 1996
USAF
The second main production version for the US Navy was the F-4J, which could be distinguished from the F-4B by lacking the undernose infrared sensor of the earlier version. This aircraft served with VF-96 ‘Fighting Falcons’, which flew the variant between late 1968 and November 1975
US Navy
Upgrades
Carrier operations and combat over Vietnam took its toll on the F-4B fleet. By the end of the 1960s, the fleet needed refurbishment and updating. Under Bee Line F-4Bs were flown to NAS North Island in California where the Naval Air Rework Facility (NARF) stripped and inspected the aircraft, replacing wiring and parts to increase service life, as well as updating the avionics. Those F-4Bs not already fitted with slotted stabilators had them installed, while the inboard leading-edge flaps were locked shut. Reworked F-4Bs were redesignated F-4Ns, the first rejoining the fleet in February 1973. Altogether, 228 F-4Bs were reworked.
The success of Bee Line prompted a similar program for the F-4Js, to bridge the gap until they could be replaced by Grumman F-14 Tomcats in the Navy, and McDonnell Douglas F/A-18 Hornets with the Marines. One significant change was the addition of two-position slats on the wing leading-edges, decreasing combat turning radius by 50%, although the initial 47 conversions initially lacked the modification until they were retrofitted.
The first upgraded F-4J – redesignated a F-4S – made its initial post-conversion flight on July 22, 1977, and VMFA-451 became the first of 13 Marine (plus 12 Navy) squadrons with the new model in June 1978. The F-4S had the distinction of being the last naval Phantom fighters in service; VF-202 performed the final carrier landing by a Phantom on October 18, 1986, on board USS America, while VMF-112 retired the last F-4Ss during January 1992.
Eyes in the sky
Its performance made the Phantom a natural choice for a reconnaissance platform. The US Air Force ordered a variant of the F-4C as the RF-4C, with an elongated nose incorporating windows for a variety of cameras. The RF-4C also had equipment for laser reconnaissance, radar mapping and infrared detection. No provision for armament was provided, although the RF-4C did retain the ability to carry a single nuclear bomb on the centerline pylon. The first of 503 RF-4Cs flew on May 18, 1964, entering service that September. Deliveries continued until December 1973. While the RF-4B was externally similar to the RF-4C, the Marine Corps reconnaissance platform was based on the F-4B and flew after the US Air Force variant, on March 12, 1965. A total of 27 of the 46 built underwent a Sensor Update and Refurbishment Effort from 1978, which also added slotted stabilators.
CAJ
The RF-4B was the second reconnaissance variant, after the RF-4C of the US Air Force. It served with only the US Marine Corps, all survivors of the 46 built being assigned to VMFP-3 from 1975. The last was retired in 1990
US Navy
