History of the F-14 Tomcat

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F-14 Tomcat
Type	Fighter
Manufacturer	Grumman
Primary user	US Navy

The history of the F-14 Tomcat is long and complicated, starting with the development of very long range air-to-air missiles in the late-1950s, to the evolution of the modern air superiority fighter, touching the paths of many famous and infamous aircraft designs from the 1950s to the 2000s and United States defense policy.

Contents 1 Origins 1.1 Missileer 1.2 TFX / F-111 1.3 Return of the dogfighter 1.4 Grumman 303 VFAX 2 Design History 2.1 F-111B cancellation 3 Development 4 Notes 5 References

[edit] Origins

[edit] Missileer

In the 1960s, U.S. Navy doctrine for fleet defense against nuclear missile-armed Soviet bombers, was defense in depth. As originally envisioned, the outer ring of this defense consisted of interceptors armed with long range missiles. This was originally to be fulfilled by the F6D Missileer, a slow, straight-winged jet, armed with eight Bendix AAM-N-10 Eagle missiles, but both projects were canceled. A supersonic alternative would have to accommodate the contradictory demands of high speed, long range, and low landing speeds for carrier operations. Variable geometry wings offered a solution to this conundrum.

[edit] TFX / F-111

Defense Secretary Robert McNamara believed commonality would save money over buying several specialized fighters for different services and roles. After successfully directing the Air Force to adopt the Navy's F-4 Phantom II and A-7 Corsair II, the Navy's new interceptor would be based on the Air Force's new strike fighter the TFX (Tactical Fighter Experimental), later denoted the F-111. In popular media, the F-111 was proclaimed to be the most versatile fighter ever, slow enough to land on dirt fields, faster than almost any other fighter, delivering massive bomb loads, and clearing the skies of enemy fighters. That vision would not come to fruition. The F-4, the plane that the F-111 was intended to replace that did not have the range, payload, maneuverability and long-ranged missiles to suit planners like McNamara, would be remembered as one of the most successful fighter designs of all time. It would be the last US fighter to fly in all three American air arms, excelling in all fighter and bomber roles. It would ironically be replaced by several specialized fighters roughly equivalent to the F-4 in speed and payload. In particular, the F-15E Strike Eagle would even eventually replace the bomber variant of the F-111.

The F-111's versatility did not exist in one airframe. The navalized F-111B had a single mission of fleet air defense (FADF). Its outstretched wings would allow a long time on station, then swept back, it would dash to meet oncoming targets and clear the sky with its 6 heavy AIM-54 Phoenix missiles. It was never meant for combat air patrol or escort. Whoever had written up the requirements never fitted it with armament as basic as a gun or even the simple AIM-9 Sidewinder fielded by the F-8 Crusader. Neither would it be equipped to deliver bombs, even though the nearly identical F-111A had a prodigious range, payload and low level navigation capabilities far exceeding either the A-6 Intruder or A-5 Vigilante. Similarly, the F-111A was not equipped to fire missiles like the Phantom's AIM-7 Sparrow. The winning contractor General Dynamics chose Grumman to apply their carrier aircraft expertise to the F-111B. However adapting what was really a medium low-level bomber meant compromises such as a smaller radar than the Navy required, it was drastically overweight at nearly 80,000 lb at takeoff. It was judged underpowered, as agile as a Greyhound bus, and its visibility was judged ill-suited to carrier operations.^[1]

[edit] Return of the dogfighter

Maneuverability in a daylight dogfight had been one of the most decisive factors in every previous air war, yet it had been thought to be obsolete by the missile age. The same year that the F-111B made its first flight, US Navy Phantom pilots encountered old but nimble MiG-17s and MiG-19s in 1965, similar to those that had shocked the fighter community by shooting down advanced supersonic F-105s over Vietnam.^[2] The Sparrow even to a lesser degree, the short range Sidewinder, was unreliable and ineffective at close ranges or while pulling gs^{[citation needed]}. Yet guns, which had been deleted as excess weight from the F-4 because it was tasked as the medium range interceptor complement to the F-8 Crusader, were often as effective as early Sidewinders or better^[3].

When the Navy ordered Grumman to study the effectiveness of the F-111B in such a scenario, they concluded it was much less maneuverable than the F-4, and would not survive in a dogfight. The silver lining was that the F-111B's performance was so abysmal, and the penny wise approach to fighter design was so discredited, that both the Navy and USAF embarked on studies on what would become a generation of 4 new air superiority fighters. The Navy's counterpart to FX was VFAX (Navy Fighter Attack Experimental). It called for a lightweight fighter that would complement the F-111B. It would be a more agile fighter than the F-4 and a more effective bomber than the A-7.

[edit] Grumman 303 VFAX

In 1967, seeing the writing on the wall for the F-111B, Grumman began preparing an advanced design, the G-303 as their answer to the VFAX.^[4]The basic goals were to make a plane superior to the McDonnell F-4 Phantom, "particularly in the air superiority, escort fighter, and deck-launched interception role". According to Charlie Brown, an original Grumman F-14 test pilot, to meet the air superiority requirement, it would have to be designed to be a nimble and agile dogfighter.^[5]. If the F-111 was proof that it was difficult to turn a medium bomber into a fighter, Grumman's solution demonstrated again how simple it can be to make a large agile fighter carry heavy loads like the Phoenix.

[edit] Design History

The design history of the F-14 is extensive. After its big brother, the F-111B was determined to be overweight and combat-ineffective, Congress cancelled the program and allowed the U.S. Navy to request bids to create a new swing-wing fighter. Grumman won the bid with overwhelming support. Those that have been credited with the winning design include chief engineers Bill Gunston, Bob Kress, David Roberts (the chief mechanic for Pratt & Whitney), two prototype mechanics: Robert Hynes and a fellow worker of his, who Kress later admitted sparked him with the design concept. Congressman Thomas Andrews also played a role in the decision.^{[citation needed]}. F-14 engineering manager Bob Kress insisted that the aircraft's wing sweep would be under computer control in a dogfight.^[6] Titanium, which was not mature enough to be used in the F-111, is about 35% of the structural weight of the F-14, and 100% of the wing box to increase strength and lower weight.^[6] Widely spaced engines increased survivability. A tall tandem crew canopy with ejection seats lowered drag and weight, also providing 360 degree vision compared to the F-111's side-by-side escape crew capsule with zero rear visibility.^[6] As a result of NASA windtunnel tests of the F-111 design, Grumman moved the wing pivots far outboard relative to the F-111's near centerline location to reduce transonic and supersonic trim drag.^[7] The F-14 was the first US supersonic fighter to incorporate twin tails. Twin tails have since become common on fighter aircraft including the F-15, F/A-18, F-22 Raptor, and F-35 Lightning II. Twin tails are valued for enhanced stability, and also reduce overall height (important on a carrier's hangar deck).

The F-14 has often been called "underpowered", but using the Pratt & Whitney TF30 engines from the cancelled F-111B reduced weight and gave it a better thrust to weight ratio than any previous US fighter^{[citation needed]}. Increased thrust to weight ratio improves sustained turn rates.^[8] While the F-14 was designed to accommodate future engines to provide a thrust to weight ratio of greater than 1.0, the versions which would rival the F-15 Eagle in power would not appear until late in its career. Rather than the F-111B's single Phoenix load out, the F-14 would be able to carry and deliver everything larger than a 20mm shell to almost anything smaller than the B-52's massive AGM-28 Hound Dog strategic missile. The 20mm M61 Vulcan Gatling gun, previously fitted to the USAF F-4E variant of the F-4 Phantom II was incorporated to destroy maneuvering targets at very close range.

According to Bill Gunston, the F-14 would employ essentially swinging versions of the same wings used by Grumman's A-6 Intruder subsonic bomber^{[citation needed]}. It had not only a large wing area, but a wide, flat pancake body to increase lift and lower drag. Flaps and slats could be deployed at full forward sweep for full maneuverability even at combat speeds, while special maneuvering flaps were designed, though later disabled after tests showing reduced stability. This gives an edge to the F-14 at very slow and supersonic speeds compared to fixed wings optimized for low supersonic speeds.^[9] Engineering manager Bob Kress says that the wings gave very good turning performance. Maneuverability was predicted to be twice that of the F-4, especially at high speed and altitude, later verified in tests against F-4Js.^[10]

The F-14 with wings at full forward sweep resembles a huge bat. Since the adoption of the F-14, the fighter slang term "bat turn" has been used to describe a maximum G 180 degree turn in full afterburner, a signature tactic of Tomcat crews^{[citation needed]}. Aviation writer Bill Gunston, however notes that opposing pilots have learned to read the F-14's wings to judge its energy status and speed.

When the Navy saw Grumman's design that combined the capabilities of the F-111B and the VFAX in a single airframe, plans would be dropped to adopt a mixed fleet of F-111B interceptors and small agile VFAX planes. The Navy hastily rewrote the VFX (Navy Fighter Experimental) specification in July 1968 evidently around Grumman's innovative proposal for an agile VFAX air superiority and strike fighter that could also carry the AWG-9/Phoenix for a fleet air defense in a single type in a form of commonality quite different from that promoted by the TFX. Though later offered to the Air Force, their FX would become a single seat, fixed wing fighter unburdened by heavy Phoenix missiles, the F-15 Eagle which would be delayed until the development of new technology engines, though planners designed in interchangeability between core engine design parameters.

[edit] F-111B cancellation

When the late Vice Admiral Thomas F. Connolly testified before Congress: "There isn't enough power in all Christendom to make that airplane what we want!", [1] that was the death knell for the General Dynamics F-111B.^[11] The "Tomcat" name is often attributed to Connolly's call sign "Tomcat", which also conformed with the Navy's tradition of giving feline names to Grumman fighters. Also citing weight and carrier suitability issues, the F-111B was canceled in 1968. The F-14 would enter service too late to serve in the Vietnam War, but the Navy would soon start realistic air combat training that would become Top Gun that gave the F-14 its fame. The F-14 would be the first of the famous teen-series fighters that embraced a new philosophy that placed a renewed emphasis on agility in U.S. fighter design. The curse of commonality would be so extensive that planners effectively bar any active ground attack role for the F-14 until the 1990s. The F-111A would prove to be an excellent single-role bomber, and the Royal Australian Air Force will be flying their F-111s long after the retirement of the F-14 in 2006.

[edit] Development

On January 14, 1969, the Navy announced the award of the contract for the VFX fighter, now designated F-14, to Grumman.^[7] It would be introduced in a brief captioned photo of an aircraft with canards in Flight Magazine International as the "VFX air superiority fighter". The F-14 would inherit not only the F-111B's radar / missile system and TF30 engines, but also adapt the subsonic wings, landing gear, and inlets of the A-6 Intruder, which lowered costs. Upon being granted the contract for the F-14, Grumman greatly expanded its Calverton, Long Island, New York facility to test and evaluate the new swing-wing interceptor. Much of the testing was in the air of the Long Island Sound as well as the first few in-flight accidents, including the first of many compressor stalls and ejections.

The Navy planned a series of upgrades, with F-14A assigned to the first airframe equipped with updated TF30 engines and the AN/AWG-9 weapons system from the F-111B. Its first flight took place on December 21, 1970. The original plan was to only build a few F-14As, as the TF30 was known to be a troublesome engine. In addition, the engine was not designed for rapid thrust changes or a wide flight envelope and only supplied 74% of the intended thrust for the F-14. An F-14B would follow in November 1987 using the engine from the advanced technology engine competition. The F-14C was intended to denote a variant implementing a replacement for the AN/AWG-9. However, it was delayed, and this variant was never produced. When it finally arrived as the AN/APG-71, the designation assigned to the new aircraft was F-14D, which first flew November 24, 1987. Though the Marine Corps initially sent pilots to VF-124 to train as instructors, the Corps pulled out of the program in 1976, after deciding the F-14 was too expensive for their needs.[2]

[edit] Notes

[edit] References

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