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Design & Development
The origins of McDonnell’s F-4 can be traced to a 1953 request by the Navy for an upgrade of the McDonnell F3H Demon carrier-borne fighter. Although the Vought F8U Crusader won the contract, the "Super Demon" (as McDonnell’s entrant was dubbed) was developed as a ground attack aircraft under the designation AH, which by 1955 had evolved into an all-weather air superiority fighter designated F4H. The F4H first flew in 1958 and remained in production from 1959 until 1981. Dave Lewis was the chief of preliminary design and, ultimately, the program manager for development and the sales effort.
In 1952, McDonnell’s Chief of Aerodynamics, Dave Lewis, was appointed by CEO Jim McDonnell to be the company’s Preliminary Design Manager. With no new aircraft competitions on the horizon, internal studies concluded the Navy had the greatest need for a new and different aircraft type, an attack fighter. At the time, the Navy had separate fighter and attack branches, each with separate systems and operational requirements. After many iterations and various "enemy capability" assumptions, an unsolicited attack fighter was presented to the Navy. The McDonnell design called for two engines. The primary air-to-air armament was provided by the new Sparrow III air-to-air missiles, semi-recessed in the fuselage. The air-to-ground armament was to be as many bombs as could be carried on stations under the wings and aft of the Sparrows on the fuselage. No guns were offered. It took two years of hard work with the Bureau of Aeronautics and the Naval Air Warfare Division in the Pentagon, but the F-4 was sold with a configuration similar to what was originally proposed.
Super Demon
In 1953, McDonnell Aircraft began work on revising its F3H Demon naval fighter, seeking expanded capabilities and better performance. The company developed several projects including a variant powered by a Wright J67 engine, and variants powered by two Wright J65 engines, or two General Electric J79 engines. The J79-powered version promised a top speed of Mach 1.97. On 19 September 1953, McDonnell approached the United States Navy with a proposal for the "Super Demon". Uniquely, the aircraft was to be modular—it could be fitted with one- or two-seat noses for different missions, with different nose cones to accommodate radar, photo cameras, four 20 millimeter cannon, or 56 FFAR unguided rockets in addition to the nine hardpoints under the wings and the fuselage. The Navy was sufficiently interested to order a full-scale mock-up of the F3H-G/H but felt that the upcoming Grumman XF9F-9 and Vought XF8U-1 already satisfied the need for the supersonic fighter.
The McDonnell design was therefore reworked into an all-weather fighter-bomber with 11 external hardpoints for weapons and on 18 October 1954, the company received a letter of intent for two YAH-1 prototypes. On 26 May 1955, four Navy officers arrived at the McDonnell offices and, within an hour, presented the company with an entirely new set of requirements. Because the Navy already had the A-4 Skyhawk for ground attack and F-8 Crusader for dogfighting, the project now had to fulfill the need for an all-weather fleet defense interceptor. A second crewman was added to operate the powerful radar.
XF4H-1 prototype
The XF4H-1 was designed to carry four semi-recessed AAM-N-6 Sparrow III radar-guided missiles, and to be powered by two J79-GE-8 engines. As in the F-101 Voodoo, the engines sat low in the fuselage to maximize internal fuel capacity and ingested air through fixed geometry intakes. The thin-section wing had a leading edge sweep of 45 degrees and was equipped with a boundary layer control system for better low-speed handling.
Wind tunnel testing had revealed lateral instability requiring the addition of five degrees dihedral to the wings. To avoid redesigning the titanium central section of the aircraft, McDonnell engineers angled up only the outer portions of the wings by 12 degrees which averaged to the required five degrees over the entire wingspan. The wings also received the distinctive "dogtooth" for improved control at high angles of attack. The all-moving tailplane was given 23 degrees of anhedral to improve control at high angles of attack while still keeping the tailplane clear of the engine exhaust. In addition, air intakes were equipped with movable ramps to regulate airflow to the engines at supersonic speeds. All-weather intercept capability was achieved thanks to the AN/APQ-50 radar. To accommodate carrier operations, the landing gear was designed to withstand landings with a sink rate of 23 ft per second (7 m/s), while the nose strut could extend by some 20 inches (50 cm) to increase angle of attack at takeoff.
Naming the aircraft
There were proposals to name the F4H "Satan" and "Mithras", the Persian god of light. In the end, the aircraft was given the less controversial name "Phantom II," the first "Phantom" being another McDonnell jet fighter, the FH-1. The Phantom II briefly carried the designation F-110A and was also given the name of "Spectre" by the USAF, neither title was used.
Prototype testing
On 25 July 1955, the Navy ordered two XF4H-1 test aircraft and five YF4H-1 pre-production fighters. The Phantom made its maiden flight on 27 May 1958 with Robert C. Little at the controls. A hydraulic problem precluded retraction of the landing gear but subsequent flights went more smoothly. Early testing resulted in redesign of the air intakes, including the distinctive addition of 12,500 bleed air holes on each ramp; and the aircraft soon squared off against the XF8U-3. Due to operator workload, the Navy wanted a two-seat aircraft and on 17 December 1958 the F4H was declared a winner. Delays with the J79-GE-8 engines meant that the first production aircraft were fitted with J79-GE-2 and -2A engines, each having 16,100 pound-force (71.8 kN) of afterburning thrust. In 1959, the Phantom began carrier suitability trials with the first complete launch-recovery cycle performed on 15 February 1960 from USS Independence.
Production
Early in production, the radar was upgraded to a larger AN/APQ-72, necessitating the bulbous nose, and the canopy was reworked to improve visibility and make the rear cockpit less claustrophobic. The Phantom underwent a great many changes during its career, summarized in the "Variants" section below.
The United States Air Force received Phantoms as the result of Robert McNamara’s push to create a unified fighter for all branches of the military. After an F-4B won the "Operation Highspeed" fly-off against the F-106 Delta Dart, the USAF borrowed two Naval F-4Bs, temporarily designating them F-110A "Spectre" in January 1962, and developed requirements for their own version. Unlike the Navy focus on interception, the USAF emphasized a fighter-bomber role. With McNamara’s unification of designations on 18 September 1962, the Phantom became the F-4 with the Naval version designated F-4B and USAF F-4C. The first Air Force Phantom flew on 27 May 1963, exceeding Mach 2 on its maiden flight.
Phantom II production ended in the United States in 1979 after 5,195 had been built (5,057 by McDonnell Douglas and 138 in Japan by Mitsubishi), making it the second most produced and exported American military-jet; the F-86 Sabre still remains the most numerous jet-powered warplane produced and exported by the United States. Of these, 2,874 went to the USAF, 1,264 to the Navy and Marine Corps, and the rest to foreign customers. The last U.S.-built F-4 went to Turkey, while the last F-4 ever built was completed in 1981 as an F-4EJ by Mitsubishi Heavy Industries in Japan. As of 2001, about 1,100 Phantoms remained in service worldwide, including QF-4 drones operated by the U.S. military.
World records
To show off their new fighter, the Navy led a series of record-breaking flights early in Phantom development:
Operation Top Flight: On 6 December 1959, the second XF4H-1 performed a zoom climb to a world record 98,557 ft (30,040 m). The previous record of 94,658 ft (28,852 m) was set by a Soviet Sukhoi T-43-1 prototype. Commander Lawrence E. Flint Jr. accelerated his aircraft to Mach 2.5 at 47,000 ft (14,330 m) and climbed to 90,000 ft (27,430 m) at a 45 degree angle. He then shut down the engines and glided to the peak altitude. As the aircraft fell through 70,000 ft (21,300 m), Flint restarted the engines and resumed normal flight.
On 5 September 1960, an F4H-1 averaged 1,216.78 mph (1,958.16 km/h) over a 500 kilometer (311 mi) closed-circuit course.
On 25 September 1960, an F4H-1 averaged 1,390.21 mph (2,237.26 km/h) over a 100 kilometer (62 mi) closed-circuit course.
Operation LANA: To celebrate the 50th anniversary of Naval aviation (L is the Roman numeral for 50 and ANA stood for Anniversary of Naval Aviation) on 24 May 1961, Phantoms flew across the continental United States in under three hours and included several tanker refuelings. The fastest of the aircraft averaged 869.74 mph (1,400.28 km/h) and completed the trip in 2 hours 47 minutes, earning the pilot (and future NASA Astronaut), Lt. Richard Gordon, and navigator, Lt. Bobbie Long, the 1961 Bendix trophy.
Operation Sageburner: On 28 August 1961, a Phantom averaged 902.769 mph (1,452.826 km/h) over a three-mile (1.86 km) course flying below 125 ft (40 m) at all times. Navy Commander J.L. Felsman was killed during the first attempt at this record on 18 May 1961 when his aircraft disintegrated in the air after pitch damper failure.
Operation Skyburner: On 22 December 1961, a modified Phantom with water injection set an absolute world record speed of 1,606.342 mph (2,585.086 km/h).
On 5 December 1961, another Phantom set a sustained altitude record of 66,443.8 ft (20,252.1 m).
Operation High Jump: A series of time-to-altitude records was set in early 1962; 34.523 seconds to 3,000 m (9,840 ft), 48.787 seconds to 6,000 m (19,680 ft), 61.629 seconds to 9,000 m (29,530 ft), 77.156 seconds to 12,000 m (39,370 ft), 114.548 seconds to 15,000 m (49,210 ft), 178.5 seconds to 20,000 m (65,600 ft), 230.44 seconds to 25,000 m (82,000 ft), and 371.43 seconds to 30,000 m (98,400 ft). Although not officially recognized, the Phantom zoom-climbed to over 100,000 ft (30,480 m) during the last attempt.
All in all, the Phantom set 16 world records. With the exception of Skyburner, all records were achieved in unmodified production aircraft. Five of the speed records remained unbeaten until the F-15 Eagle appeared in 1975.
Flight characteristics
In air combat, the Phantom's greatest advantage was its thrust, which permitted a skilled pilot to engage and disengage from the fight at will.
The massive aircraft, designed to fire radar-guided missiles from beyond visual range, lacked the agility of its Soviet opponents and was subject to adverse yaw during hard maneuvering. Although thus subject to irrecoverable spins during aileron rolls, pilots reported the aircraft to be very communicative and easy to fly on the edge of its performance envelope. In 1972, the F-4E model was upgraded with leading edge slats on the wing, greatly improving high-angle-of-attack maneuverability at the expense of top speed.
The J79 engines produced copious amounts of black smoke at military power which made the Phantoms easy to spot from a distance, a severe disadvantage in air combat against smaller aircraft. Pilots could eliminate the smoke by using afterburner, but at the cost of fuel efficiency. Some pilots adopted the procedure of running one engine in dry thrust at normal power setting, and the other in afterburner, resulting in the same total thrust as using both engines at full rated military power without generating the tell-tale smoke trail.
The F-4's biggest weakness, as it was initially designed, was its lack of an internal cannon. For a brief period, doctrine held that turning combat would be impossible at supersonic speeds and little effort was made to teach pilots air combat maneuvering. In reality, engagements quickly became subsonic. Furthermore, the relatively new heat-seeking and radar-guided missiles at the time were frequently reported as unreliable and pilots had to use multiple shots just to hit one target. To compound the problem, rules of engagement in Vietnam precluded long-range missile attacks in most instances, as visual identification was normally required. Many pilots found themselves on the tail of an enemy aircraft but too close to fire short-range Falcons or Sidewinders. Although in 1967 USAF F-4Cs began carrying SUU-16 or SUU-23 external gunpods containing a 20 millimeter M61 Vulcan Gatling cannon, USAF cockpits were not equipped with lead-computing gunsights, virtually assuring a miss in a maneuvering fight. Some Marine Corps aircraft carried two pods for strafing. In addition to the loss of performance due to drag, combat showed the externally mounted cannon to be inaccurate, yet far more cost-effective than missiles. The lack of cannon was finally addressed by adding an internally mounted 20mm M61 Vulcan on the F-4E.
Sources:
Wikipedia: F-4 Phantom II
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