v1.0.2 / chapter 1 of 3 / 01 aug 04 / greg goebel / public domain
* The Phantom was a step forward in aircraft design, incorporating many new features when it was introduced in the late 1950s. In the following decades, new Phantom variants were developed to enhance its capabilities, as well as adapt it to new roles, such as reconnaissance and defense suppression. This chapter describes the different variants of the Phantom in US service. A few other variants that only flew in foreign service are discussed in a later chapter.
* The McDonnell Aircraft Company was founded in 1939 by James S. McDonnell. The company survived the war years through subcontract work for major aircraft manufacturers such as Grumman and Vought. The McDonnell firm did develop a prototype twin-piston-engine interceptor during the war, the XP-67, but it did not reach production.
At the end of the war, the company produced the US Navy's (USN) first operational jet fighter, the FH-1 Phantom, which performed its initial flight in 1945. Only 60 FH-1s were built, since its performance wasn't much better than that of current piston-engined fighters, but it did lead to the much more successful F2H Banshee, a scaled-up and improved Phantom. First flight of the Banshee was in 1947, and 895 were built, with the type performing service in the Korean War. The Banshee was followed by a swept-wing fighter, the F3H Demon, which performed its first flight in 1951, with a total of 521 built. However, McDonnell was only getting warmed up.
* As a follow-up to the Demon, McDonnell began design studies for a more advanced naval fighter-bomber in the early 1950s, with the studies conducted under a team led by Herman D. Barkey. Early concepts envisioned a single-engine aircraft with four 20 millimeter cannon. Since the Demon was the starting point for these designs, they were given company designations of "F3H-C", "F3H-E", and "F3H-G".
The F3H-C and F3H-E were single-seat, single-engine aircraft, with the F3H-C very much resembling an improved Demon, while the F3H-E represented more advanced design concepts. The really interesting concept, from the point of view of what the future had in store, was the F3H-G. The F3H-G was a single-seat twin-engine aircraft, to be powered by twin Wright J65 turbojets, which were license-built British Rolls-Royce Sapphire axial-flow engines. The F3H-G incorporated features from the Demon, as well as the McDonnell F-101 Voodoo, a twin-engine interceptor the company was developing for the US Air Force (USAF).
Although the "F" in the F3H-G designation indicated a fighter, the designers saw it as a multirole combat aircraft that could be adapted to different roles by splicing on a new forward fuselage. Possible variants included:
Since aircraft were becoming increasingly complicated during the 1950s, McDonnell also proposed a tandem two-seat version of the F3H-G, with the "back-seater" taking care of aircraft's electronic systems.
* McDonnell passed the F3H-G design on to the Navy Bureau of Aeronautics in the fall of 1953, only to have it rejected in a few weeks. One of the reasons for the quick rejection was that the Navy had just signed contracts for the Vought F8U-1 Crusader as its first supersonic fighter and felt it met the service's immediate needs. However, the Navy encouraged McDonnell to continue work on the concept, and the design team went on to build a mockup of the F3H-G, completing it in early 1954. Senior Navy officials were invited to Saint Louis to look it over.
The F3H-G concept then began to converge with reality. In mid-1954, BuAer issued a request for a new all-weather fighter. McDonnell submitted both the single-engine F3H-E and the twin-engine F3H-G proposals, and Grumman and North American submitted proposals as well. The BuAer selected the F3H-G, issuing a "letter of intent" for two prototypes of the type, now to be designated "AH-1", on 18 October 1954.
This was very encouraging, but there was also less to it than met the eye. The Navy was still considering the precise needs of the service, and in the absence of specific requirements there was no way to move on to "cutting metal". However, the Navy was definitely giving the matter serious thought, and over the following months clarified their needs. In the end, what they wanted was a carrier-based fleet defense interceptor that could patrol at a combat radius of 465 kilometers (250 nautical miles) for over two hours. As the machine was clearly no longer an "attack" aircraft, the designation was changed to "F4H-1".
Although the McDonnell mock-up had featured four 20 millimeter cannon, the Navy wanted the F4H-1 to be armed only with missiles, specifically four of the new Sparrow AAMs. This was a great age of optimism in the whizzy new missiles, and gun armament was for the moment seen as obsolete. The decision to delete the cannon would come back to haunt the Navy and other F4H users.
McDonnell engineers tweaked their concepts, and within weeks gave the Navy a modification of the original F3H-G design. The new aircraft would be armed with four Sparrows, mounted on extensible racks under the fuselage. The designers also decided to abandon the Wright J65 engine, which would have given the F4H-1 a top speed of Mach 1.5, and instead adopt the new General Electric J79-GE-2 turbojet, then the state-of-the-art in jet engine design. Two J79s would give the F4H-1 a top speed of Mach 2.
McDonnell proposed both single-seat and two-seat versions of the F4H-1, and the Navy promptly selected the two-seat variant. One final change was to delete the stores pylons, except for a centerline pylon for a drop tank, with a tank eventually designed with a capacity of 2,270 liters (600 US gallons). A formal contract was signed on 25 June 1955 for two "XF4H-1" prototypes and five "YF4H-1" pre-production aircraft.
* The first XF4H-1 was rolled out on 8 May 1958. Its initial flight was on 27 May 1958, with Robert C. Little, McDonnell's chief test pilot, at the controls. There were minor problems with the first few flights, but in a few days the aircraft was flying well.
By this time, the XF4H-1 had competition. The Navy wanted to hedge their bets on their new fleet-defense interceptor, and so the Vought company had submitted a rival design, the XF8U-3 Crusader III, a fast and powerful aircraft that amounted to a bigger and badder descendant of Vought's F8U-1 Crusader, then going into Navy service. There was a competitive fly-off between the XF4H-1 and the XF8U-3 in the fall of 1958. The McDonnell design was selected as the winner on 17 December 1958. Although the Crusader III was an impressive aircraft and might have been capable of Mach 3, it was a single-seat, single-engine aircraft. The Navy felt that a back-seater was required to handle the electronic systems of a modern fighter, and that twin engines offered greater survivability.
By the spring of 1959, McDonnell had orders for 40 more F4H-1s, in addition to the original order for seven, and by summer eight machines were flying. On 3 July 1959, the McDonnell Corporation celebrated its 20th anniversary, and the F4H-1 was formally given the name "Phantom II", in honor of the FH-1 Phantom. However, the FH-1 hadn't been produced in quantity, didn't have a long service life, and had been largely forgotten, so the "Phantom II" quickly became the "Phantom".
* The Phantom began carrier trials began in the fall of 1959, with the first carrier take-off performed on 15 February 1960. In the meantime, while the type was being qualified for operational service, it was also breaking speed and altitude records.
The second XF4H-1 set the first record, reaching an altitude of 30,048 meters (98,557 feet) with a "zoom climb" under OPERATION TOP FLIGHT on 6 December 1959. Similar exercises were conducted over the next 28 months. Highlights included:
The Phantom was proving it could fly. The next step was to see if it could fight, but that would have to wait a few years.
* The XF4H-1 Phantom provided a baseline for the Phantom family that would, with various changes, be retained through the production life of the type.
The Phantom that was rolled out of the McDonnell factory very much resembled the original F4H-1 concept, but also unsurprisingly incorporated a number of refinements dictated by changed requirements; wind-tunnel tests; and improved design calculations.
The general configuration of the aircraft remained unchanged. As with the initial design, the XF4H-1 featured twin engines mounted on either side of the fuselage, with intakes just behind the pilot and next to the back-seat position, and exhausts under the tail. A stinger-type arresting hook was mounted on the tail between the exhausts. The single-wheel main gear hinged in the wings, retracting towards the fuselage, and the twin-wheel nose gear retracted backwards. The nose gear was steerable through 360 degrees, and had hydraulically-boosted steering.
The low-mounted wings retained their broad, strongly sweptback configuration. In the original F3H-G design they had no dihedral, but in development the outer wing panels were given 12 degrees of dihedral to ensure roll stability. The panels were also extended forward to create a distinctive "dogtooth" that helped prevent wingtip airflow separation, and they folded upward using a hydraulic actuation system for carrier storage. Some variants of the Phantom would delete the hydraulics for the wing fold, but every Phantom ever built would have folding wings, even though the majority of them never flew off a carrier deck.
The Phantom did not have traditional ailerons that could tilt up and down to provide roll control. It instead used "flaperons", flaplike underwing surfaces outboard of the main flaps. The flaperons, like the flaps, could only tilt down, but worked in conjunction with overwing spoilers to provide roll control.
The Phantom was also fitted with leading-edge flaps. The trailing-edge flaps and the flaperons deflected 60 degrees, while the inboard leading-edge flaps deflected 30 degrees. In addition, the aircraft featured a "boundary layer control (BLC)" or "blown flaps" scheme, in which engine bleed air was blown over the flaps and flaperons to increase their effectiveness at low speed, improving low-speed handling for carrier landings. The Phantom was one of the first operational aircraft to use BLC.
The horizontal tailplane, which was of "all-flying" or "all-moving" configuration and called a "stabilator", had been flat in the original F3H-G concept, but had acquired a distinctive 23 degree anhedral. This was done to ensure that the stabilator remained effective at high angles of attack, while keeping it out of the engine exhaust flow.
* Considerable thought was put into the J79 engine installation. A large, fixed, sharp-edged "ramp" or "splitter plate" was installed in front of each inlet, set off from the fuselage about 5 centimeters (2 inches) to ensure that sluggish "boundary layer" air hugging the fuselage stayed out of the inlets.
The ramp included a hinged plate set back from its leading edge that was automatically moved in and out by hydraulic actuators at different speeds, providing a variable "throat" that reduced drag-inducing excess airflow at high speeds. The ramp was perforated with a grid of holes to tapped the airflow for the engine-bleed system. This innovative variable-inlet scheme was copied by later aircraft, such as the Soviet Mikoyan MiG-23.
There was also an auxiliary intake door on the bottom of each engine housing. This was opened for ground taxi operation, when the aircraft wasn't moving or moving slowly and the airflow was inadequate. The intake doors were also hydraulically "loaded" to pop open in flight under excess-pressure conditions, such as might occur when the engines were abruptly throttled back.
* The four Sparrow missiles were mounted in recesses under the fuselage, instead of on extensible rails as in the original F4H-1 concept. A pylon was added under each wing for another Sparrow, for a total of six. Each pylon could alternatively be fitted with a rack for two Sidewinder heat-seeking missiles, for a total of four Sparrows and four Sidewinders.
Another pylon was fitted under each wing for carriage of a 1,400 liter (370 US gallon) external tank. During evaluations, McDonnell had demonstrated fitting the five stores pylons with "multiple ejector racks (MERs)" to allow carriage of bombs, and evaluations showed that the Phantom could handle an external load of up to 10,200 kilograms (22,500 pounds), though in practice 7,250 kilograms (16,000 pounds) was the normal limit. Although the Navy had ordered the Phantom as an interceptor, it had originally been designed as a multirole aircraft, and the creeping reinstatement of stores pylons and the simple logic of usefulness brought it quickly back to its multirole roots, though the Navy would be reluctant to use it as an attack aircraft for several years.
The Phantom was fitted with a suite of avionics gear, including a "Tactical Air Navigation (TACAN)" system, which used ground beacons for guidance; a radiocompass; a radio altimeter for low-altitude flight; an air data computer; "identification friend or foe (IFF)" gear; and a UHF radio.
* The two crewmen sat in tandem configuration, each with their own clamshell canopy, and rode in British Martin-Baker Mark 5 ejection seats. The back-seater, known in Navy and Marine terminology as the "Radar Intercept Officer (RIO)", had a poor forward view and did not have flight controls, though the aircraft had been designed to allow them if desired.
A retractable mid-air refueling probe was installed on the left side of the aircraft, alongside the back-seat cockpit. The initial prototypes did not have the refueling probe, and fit of the probe required some rearrangement of the rear cockpit layout.
Considerable thought had gone into making the Phantom serviceable. 199 access doors were fitted. Two huge doors allowed the engines to be removed without pulling the aircraft apart, and the radar set, a temperamental piece of electronics gear at the time, could be slid out on rails for servicing. Initially, the Phantom was fitted with the AMCS "Aero-1A" fire control system (FCS) with a Westinghouse "AN/APQ-50" radar set, a vacuum-tube set that was part of the Westinghouse "Aero-13" family.
The Aero-13 had been designed for the Douglas F4D Skyray naval fighter, and introduced the notion of building a radar set as an integrated cylindrical module that could be plugged into the nose of an aircraft, rather than a set of semi-independent black boxes. The Aero-1A included a "continuous wave" illuminator to "spotlight" a target for the Phantom's Sparrow missiles.
The Phantom also had an AN/AAA-4 "infrared search and track (IRST)" sensor mounted under the nose. The IRST could provide direction but not range data on a target.
* The Phantom was made mostly of aviation aluminum alloys, but about 10% of the aircraft was built of titanium, a new metals technology at the time. There were seven major aircraft subassemblies, including forward, center, and aft fuselage assemblies; a wing center section; wing outer panels; and the tail assembly. There were initially six fuel cells in the aircraft, four in the fuselage and one in each wing. Flight controls were operated by a triple-redundant hydraulic system.
* The Phantom was, overall, a big, angular, brutish-looking aircraft, and at first glance many Navy and Marine aviators didn't think much of it, believing it was a "triumph of thrust over aerodynamics." One disgusted observed said that it looked like "someone had stepped on its nose and kicked it in the butt." However, the many virtues of the aircraft won most of them over, and eventually it didn't seem so strange-looking after all.
US Navy Lieutenant-Commander Paul Spencer, who flew the first carrier takeoff with the Phantom, praised it to help encourage the doubters to take a second look: "The F4H is a big airplane. It is twice the weight of the F-11F Tiger and nearly three times the weight of the A4D Skyhawk, but for all its bulk, it handles better than any modern Navy fighter. Former single-engine fighter pilots will find the response of the F4H's twin J79 engines close to sensational."
* The initial XF4H-1 prototype performed its first flights with J79-GE-3 engines, but was then refitted with J79-GE-2s and finally J79-GE-2As, providing 46.0 kN (4,695 kgp / 10,350 lbf) dry thrust and 71.8 kN (7,325 kgp / 16,150 lbf) afterburning thrust each.
The 19th aircraft built replaced the AN/APQ-50 radar set with the evolved AN/APQ-72, which had a larger antenna that required fit of a new and bigger nose. This gave the Phantom a "droopy nose" appearance that made it look even more awkward, and also dictated a new canopy scheme. Earlier aircraft had a canopy that was flush with the aircraft's spine, but with the 19th aircraft and every other Phantom ever built, the cockpit was raised and bulged to give a better view over the big nose. Forward visibility was still not the best and rearward visibility was terrible, though the raised cockpit did improve the view to the back a bit.
The 46th aircraft introduced fully-rated J79-GE-8 engines with 48.5 kN (4,945 kgp / 10,900 lbf) dry thrust and 75.6 kN (7,710 kgp / 17,000 lbf) afterburning thrust each, along with minor modifications to the engine installation.
In March 1961, the first 45 Phantoms, following the two XF4H-1 prototypes, were retroactively given the new designation of "F4H-1F", while the others in this series retained the F4H-1 designation. The F4H-1Fs were all evaluation and test aircraft and never reached operational service.
Full-production F4H-1s were in service with the US Navy and Marine Corps by 1962. In September of that year, the US military adopted a tri-service aircraft designation scheme, and the F4H-1F became the "F-4A" and the F4H-1 became the "F-4B". A total of 649 F-4Bs were built from 1961 into 1967.
Of total F-4B production, 12 were built with an AN/ASW-21 datalink for an automatic carrier landing system, along with an "automatic approach compensation" system that performed automatic throttle control on carrier approaches to ensure constant speed. These aircraft were designated "F-4G", with the first flying in March 1963. The new electronics gear was fitted in a compartment in the upper forward fuselage created by chopping off an edge of the forward fuselage fuel cell.
The F-4Gs went through operational evaluation in Southeast Asia in 1965:1966. They were then returned to the F-4B specification, but the F-4G designation would be "recycled" in a later Phantom variant. The new avionics compartment was carried on to other variants.
* Between 1972 and 1974, 226 Navy and Marine F-4Bs were put through an update program with structural strengthening, new wiring, 30 kilowatt electrical power generators, and new avionics. The updated aircraft were known as "F-4Ns".
* Robert S. McNamara, US secretary of defense in the Kennedy and Johnson Administrations, was very enthusiastic about "commonality" between the different US armed services. He wanted the services to adopt common equipment to reduce acquisition, logistical, and training costs. In 1961, the word came down that the USAF should evaluate the Navy Phantom. The Navy loaned what would eventually be a total of 29 F-4Bs for the evaluation.
Such attempts to enforce commonality didn't always work out well, partly due to interservice rivalries, as well as the fact that the services really did sometimes have clearly different needs and requirements. The Phantom proved to be an extraordinary exception. The evaluation showed the Air Force that the Phantom, even though it carried the weight of additional gear required for carrier operations, was a match or more for existing Air Force fighters. The USAF would eventually acquire over twice as many Phantoms as the Navy and Marine Corps combined.
In the spring of 1962, the USAF decided to adopt the Phantom, under the initial designation of "F-110A Spectre", which was applied to the Navy F-4Bs then being evaluated by the Air Force. The USAF-optimized variant actually went into service as the "F-4C" but retained the Navy Phantom name, with the first example of the variant flying on 27 May 1963. 563 were built into 1966.
* The F-4C was very similar to the F-4B, even retaining arresting gear and folding wings, but featured a number of changes:
After the F-4C went to Vietnam in 1965 a number of problems emerged, including fuel leaks and poor tolerance to humidity. A field update program was implemented to address the problems.
* The F-4C was followed in USAF service by the "F-4D", which performed its first flight on 9 December 1965, leading to initial service deliveries in 1966. The F-4D was the USAF's workhorse over Southeast Asia. 825 were built into 1968.
The F-4D airframe was basically the same as that of the F-4C. The primary improvements were in avionics, particularly AN/APQ-109 radar. The AN/APQ-109 was an improved, more reliable version of the AN/APQ-100 with solid-state components in the low-voltage sections. The F-4D also featured new attack and navigation systems, and uprated 30 kilowatt electric power generators.
As combat experience over southeast Asia had shown the need for a gun, a 20 millimeter cannon pod designated the "SUU-16/A" was hastily introduced, to be eventually replaced by the similar but improved "SUU-23/A". The F-4D was wired for carriage of the cannon pod, and had an ASG-22 lead-computing gunsight fitted for aiming it. Apparently some F-4Cs were also retrofitted to carry cannon pods.
The AN/AAA-4 IRST was deleted in most F-4D production, as it had proven ineffective in practice. Confusingly, late production F-4Ds were fitted with the fairing used for the AN/AAA-4, but it contained elements of an AN/APR-25/26 radar warning receiver (RWR), not an infrared sensor.
* Combat experience led to the definitive "F-4E", which performed its initial flight on 30 June 1967. The F-4E featured:
The cannon pod had been a big help, but it was "draggy" and tended to become misaligned on its stores pylon, making it inaccurate. The built-in cannon was a much better solution. However, early production F-4Es suffered from engine "flameouts" due to ingestion of gases expelled from the muzzle of the cannon, and to fix this problem GE quickly came up with a longer-barreled cannon, which was fitted into a longer cannon fairing with improved ventilation. This fix was refitted to earlier F-4E production.
The F-4E became the primary USAF variant, and was also heavily exported, as
is discussed later. Including exports, 1,387 were built into 1979.
MCDONNELL DOUGLAS F-4E PHANTOM II:
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spec metric english
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wingspan 11.77 meters 38 feet 8 inches
wing area 49.24 sq_meters 530 sq_feet
length 19.2 meters 63 feet
height 5.02 meters 16 feet 6 inches
empty weight 13,760 kilograms 30,330 pounds
loaded weight 28,030 kilograms 61,795 pounds
max speed at altitude 2,415 KPH 1,500 MPH / 1,305 KT
service ceiling 16,580 meters 54,400 feet
combat radius 1,265 kilometers 785 MI / 680 NMI
_____________________ _________________ _______________________
In response to the maneuverability problems, a program named "Agile Eagle" was initiated, in which the Phantom was fitted with various experimental aerodynamic modifications. The solution in the end was to fit the wing with leading-edge slats, which extended automatically when the aircraft's AOA exceeded six degrees, and retracted when the AOA went back to four degrees. Installation of the slats required removal of the BLC system.
The leading-edge slats were introduced into F-4Es beginning in mid-1972 and were retrofitted to older aircraft. Beginning the next year, 1973, F-4Es went through a structural strengthening program after an F-4E was lost due to a wing structural failure.
The Northrop "Target Identification System Electro-Optical (TISEO)" camera system was also introduced in late F-4E production and retrofitted to older aircraft. TISEO involved a steerable, stabilized telescopic camera mounted on the left wing, and was used primarily to inspect targets before engaging them. TISEO imagery was displayed on the WSO's radarscope. The camera could be slaved to the AN/APQ-120 radar, and apparently there was an upgrade that allowed it to be linked to the navigation system to target flight checkpoints as well. Of course, it was a daylight / clear-weather only system. Most export F-4Es were not fitted with TISEO.
* The Navy and Marines procured a variant similar to the F-4E, designated the "F-4J", with the following improvements:
Three F-4Bs were rebuilt as "YF-4J" prototypes, with the first prototype performing its initial flight on 27 May 1966. 522 new-build F-4Js were manufactured into 1972, following the prototype conversions. A special version of the F-4J was proposed for the USMC but not built, incorporating an enhanced fire-control system and F-4E-style leading-edge maneuvering slats.
Incidentally, the "F-4F" was a specialized Phantom variant flown only by the German Luftwaffe, discussed in a later chapter; the "F-4H" designation was not used since it might cause confusion with the old "F4H" designation; and the "F-4I" designation wasn't used either, since it could be misinterpreted as "F-41".
* Beginning in 1978 248 F-4Js were brought up to "F-4S" standards, with structural strengthening; leading-edge slats; a substantially updated AN/AWG-10A radar set and other new avionics; and uprated J79-GE-10B engines, which also featured improvements to eliminate the tendency of the J79 to leave behind a dirty smoke trail, which had proven a liability in combat. Fit of the leading-edge slats required removal of the BLC system.
* There were also some unusual or unbuilt Phantom variants. The 226th Phantom built was used as an experimental platform. It started life as an F-4B, to be reconfigured as the prototype for several Phantom variants. In 1972, it was given a fly-by-wire (FBW) control system, and was later given canard foreplanes. This aircraft was retired and donated to the US Air Force Museum in Dayton, Ohio, in 1978.
In the late 1970s, McDonnell Douglas proposed an air superiority variant of the F-4E designated the "F-4T" that would have deleted all gear needed for ground attack. Nothing came of the notion.
The most dramatic proposed modification of the Phantom was a "swing wing" or "variable geometry" derivative of the F-4J, designated the "F-4 (FVS)", promoted in the mid-1960s by McDonnell. The wings would be shoulder-mounted and would be able to sweep from 23 to 75.5 degrees. The Navy was very leery of this idea, since the service wanted a new fighter rather than an updated version of an older one, and lobbied for the Grumman F-14 Tomcat instead.
* After adopting the Phantom, the Air Force was very enthusiastic about the type, and shortly after ordering their first production Phantom fighters decided to acquire a reconnaissance variant to replace to their current McDonnell RF-101 Voodoo. The "recce" (pronounced "rekky") Phantom was originally designated the "RF-110A", but was redesignated "RF-4C" in September 1962.
The Phantom was adapted to the reconnaissance role through fit of a new forward fuselage to carry cameras and other reconnaissance gear. Initial flight of the first of two "YRF-4C" prototypes was on 8 August 1963. 505 RF-4Cs, including the two prototypes, were built into 1974.
The cameras were fitted in a new nose that stretched the aircraft's length by 84 centimeters (33 inches). The wing-mounted pitot tube was moved to the nose from the leading edge of the taifin as well, resulting in a total increase in length of 147 centimeters (57.8 inches). As noted, a modified version of this nose was fitted to the F-4E to accommodate the M61 cannon, and resulted in the same increase in length.
The RF-4C's nose featured three camera "stations" that could be configured by ground crews with different camera fits:
In addition to the cameras, the RF-4C carried electronic reconnaissance gear, as well as systems to support the reconnaissance mission:
The AN/APQ-102 also had a "moving target indicator (MTI)" capability that picked out any vehicle moving at more than 9.25 KPH (5.75 MPH or 5 knots) perpendicular to the aircraft's flight path, highlighting the target on the film strip. The SLAR was mounted under the pilot's position, with the SLAR antennas fitted unobtrusively into the fuselage at that location, forward of the engine intake ramps.
The RF-4C could also be fitted with electronic intelligence (ELINT) systems carried in pods on stores pylons.
The RF-4C was not intended as an active combat aircraft. Fire control systems were deleted; the recesses for Sparrow missiles under the fuselage were deleted, since the RF-4C didn't have the radar to guide the Sparrows; and the pilot's weapons sight was replaced by an LA-313 optical viewfinder to help target camera shots.
Instead of an AN/APQ-100 radar set, the RF-4C was fitted with a more compact Texas Instruments AN/APQ-99 forward-looking radar set, intended to support air navigation rather than combat. The AN/APQ-99 provided a ground mapping capability, along with terrain-following and terrain-avoidance modes. The RF-4C also featured an improved AN/ASN-56 INS, and a long-range HF communications system.
Although in Air Force terminology the back-seater was still known as as WSO, as the RF-4C didn't have any weapons, he was more often known simply as the "navigator".
Following the Vietnam War, USAF RF-4Cs were given various upgrades to keep them up to date, the most important being fit of the AN/ALQ-125 ELINT system.
* The RF-4C's nose and reconnaissance gear was fitted to the F-4B airframe to yield the "RF-4B" for the US Marine Corps, with initial flight on 12 March 1965, leading to operational introduction in May 1965. The equipment fit differed slightly from the RF-4C's in that the station 2 cameras could be rotated in flight.
The RF-4B actually followed the F-4C into service, reversing the usual sequence of subvariant codes. The Navy did not use the type since that service had no requirement for it, relying on the RF-8A Crusader and RA-5C Vigilante for the reconnaissance role. 46 RF-4Bs were built. The last ten were odd hybrids, with the original RF-4B nose, RF-4C fuselage and tail, and F-4J wings. In the last half of the 1970s, the RF-4Bs were given a substantial update under Project SURE, involving structural strengthening, new reconnaissance systems, a datalink, defensive countermeasures, and other avionics.
* The F-4E was fitted with a recce nose to yield the "RF-4E". Initial flight of the prototype was on 15 September 1970, and 146 were built, strictly for the export market. Late production F-4Es had a modified nose that was less angular than earlier recce Phantoms. RF-4Es also had slight variations in equipment fit for their specific customers.
By this time, the Phantom was properly known as the "McDonnell Douglas" Phantom, as the two companies had merged in 1967. Three decades later, McDonnell Douglas would be bought out by Boeing, but nobody would think to call an F-4 a "Boeing Phantom".
* The last Phantom was rolled out of the McDonnell Douglas factory at Saint Louis on 26 October 1979, after manufacture of 5,057 of the type there, not counting 138 assembled or built in Japan, as discussed in a later chapter. However, given the widespread use of the type, that was by no means the end of the story.
One of the nasty surprises encountered by the US military in Vietnam was the effectiveness of North Vietnamese air defenses, and so developing counter-defenses was a high priority. One possible counter-defense was a "defense suppression" aircraft that could target air-defense radars and attack SAM sites, and this led to the "Wild Weasel" series of "defense-suppression" aircraft.
The original "Wild Weasel I" was a modified tandem-seat F-100F Super Sabre, but this aircraft could not keep with strike packages, and amounted to a proof-of-concept system. It was followed into service by the "Wild Weasel II", a modified F-105F Thunderchief, and then a more optimized F-105F modification, the F-105G "Wild Weasel III", which performed the burden of defense suppression over North Vietnam.
Late in the war, about 36 F-4Cs were modified to the "Wild Weasel IV" configuration, carrying radar detection and targeting systems along with the AGM-45 "Shrike" anti-radar missile (ARM), which was a Sparrow with a radar seeking head. The Wild Weasel IV conversion left something to be desired, and after the war 116 F-4Es were converted into the "Wild Weasel V" or "Advanced Wild Weasel", which was given the "vacant" designation "F-4G".
The nose cannon was deleted, with the space occupied taken up by gear for an AN/APR-38 RHAWS, with 52 antennas littered over the fuselage. Combat avionics systems were retained. The AN/APR-38 could not only locate and identify radar emitters, it could also target them for attack with ARMs, or cluster bombs and other munitions. At first, the F-4G carried the Shrike, but in the early 1980s this missile was generally replaced by the Texas Instruments AGM-88 "High Speed Anti-Radiation Missile (HARM)", more or less a scaled-up Shrike with a better seeker system. The HARM would become the F-4G's most characteristic weapon.
* With plenty of old Phantoms available, it is unsurprising that the type has been favored for conversion into high-performance target drones. Some F-4Bs were converted to "QF-4B" target drones and "DF-4B" drone controllers, and as later Phantom variants were removed from first-line service, they were often converted to target drones as well, collectively referred to simply as "QF-4s". The conversions cost a few million USD each.
Interestingly, some of the QF-4s retain a piloted capability. This is because test and training scenarios require a high degree of choreography to make them as realistic as possible, and so pilots have to fly the QF-4s through "dry runs" to ensure that all details are considered. The USAF refers to unpiloted flights using the acronym "NULLO (Not Utilizing Local Live Operator)", while the Navy more tidily calls them "NOLO (No Onboard Live Operator)".
Up to four QF-4s can be flown in formation during NULLO flights. The drones do not interact with each other, they are simply commanded to follow a specific moving point in space known as a "rabbit", with each aircraft maintaining a specific three-dimensional offset from the rabbit. The autopilot system on the QF-4 is very sophisticated. For example, the remote operator can land the aircraft simply by giving it a single command to land.
Although missiles used in air combat tests don't usually have combat warheads, once a QF-4 is used as actual target in exercises, its predicted lifetime is no more than four missions. The QF-4 carries a self-destruct system to destroy itself if missile damage fails to shoot it down but causes it to become a potential threat to populated areas.
While QF-4s continue to be "manufactured", they are now nearing the end of their useful lives even as targets, as they are increasingly unrepresentative of any adversary American pilots might face. A new generation of targets is now under consideration, possibly based on retired F-16A fighters.