Grumman F-14 Tomcat

The Grumman F-14 Tomcat is a supersonic, twin-engine, two-seat, variable-sweep wing fighter aircraft. The Tomcat was developed for the United States Navy's Naval Fighter Experimental (VFX) program following the collapse of the F-111B project. The F-14 was the first of the American teen-series fighters which were designed incorporating the experience of air combat against MiG fighters during the Vietnam War.
The F-14 first flew in December 1970 and made its first deployment in 1974 with the U.S. Navy aboard USS Enterprise (CVN-65), replacing the McDonnell Douglas F-4 Phantom II. The F-14 served as the U.S. Navy's primary maritime air superiority fighter, fleet defense interceptor and tactical reconnaissance platform. In the 1990s, it added the Low Altitude Navigation and Targeting Infrared for Night (LANTIRN) pod system and began performing precision ground-attack missions.^[1]
The Tomcat was retired from the U.S. Navy's active fleet on 22 September 2006, having been supplanted by the Boeing F/A-18E/F Super Hornet.^[2] As of 2012, the F-14 was only in service with the Islamic Republic of Iran Air Force, having been exported to Iran in 1976, when the U.S. had amicable diplomatic relations with Iran's government.

 

Background

Beginning in the late 1950s, the U.S. Navy sought a long-range, high-endurance interceptor to defend its carrier battle groups against long-range anti-ship missiles launched from the jet bombers and submarines of the Soviet Union. The U.S. Navy needed a Fleet Air Defense (FAD) aircraft with a more powerful radar, and longer range missiles than the F-4 Phantom II to intercept both enemy bombers and missiles.^[3] The navy was directed to participate in the Tactical Fighter Experimental (TFX) program with the U.S. Air Force by Secretary of Defense Robert McNamara. McNamara wanted "joint" solutions to service aircraft needs to reduce development costs, and had already directed the air force to buy the F-4 Phantom II, which was developed for the navy and marine corps.^[4] The navy strenuously opposed the TFX as it feared compromises necessary for the air force's need for a low-level attack aircraft would adversely impact the aircraft's performance as a fighter .

The F-111B was designed to fulfil the carrier based interceptor role, but was found to have serious problems concerning both weight and performance. Additionally, it was not suited to the types of aerial combat then becoming apparent in Vietnam.

However, weight and performance issues plagued the U.S. Navy F-111B variant for TFX and would not be resolved to the navy's satisfaction. The F-111 manufacturer General Dynamics partnered with Grumman on the navy F-111B. With the F-111B program in distress, Grumman began studying improvements and alternatives. In 1966, the navy awarded Grumman a contract to begin studying advanced fighter designs. Grumman narrowed down these designs to its 303 design.^[5] Vice Admiral Thomas F. Connolly, Deputy Chief of Naval Operations for Air Warfare, took the developmental F-111A variant for a flight and discovered that it had difficulty going supersonic and had poor carrier landing characteristics. He later testified to congress about his concerns against the official Department of the Navy position and, in May 1968, congress stopped funding for the F-111B, allowing the navy to pursue an answer tailored to their requirements. The name "Tomcat" was partially chosen to pay tribute to Admiral Connolly, as the nickname "Tom's Cat" had already been widely used by the manufacturer, although the name also followed the Grumman tradition of naming its fighter aircraft after felines.^[6]

VFX

The F-111B had been designed for the long-range Fleet Air Defense (FAD) interceptor role, but not for new requirements for air combat based on experience of American aircraft against agile MiG fighters over Vietnam. The navy studied the need for VFAX, an additional fighter that was more agile than the F-4 Phantom for air-combat and ground-attack roles.^[7] Grumman continued work on its 303 design and offered it to the navy in 1967, which led to fighter studies by the navy. The company continued to refine the design into 1968.^[5]
In July 1968, the Naval Air Systems Command (NAVAIR) issued a request for proposals (RFP) for the Naval Fighter Experimental (VFX) program. VFX called for a tandem two-seat, twin-engined air-to-air fighter with a maximum speed of mach 2.2. It would also have a built-in M61 Vulcan cannon and a secondary close air support role.^[8] The VFX's air-to-air missiles would be either six AIM-54 Phoenix or a combination of six AIM-7 Sparrow and four AIM-9 Sidewinder missiles. Bids were received from General Dynamics, Grumman, Ling-Temco-Vought, McDonnell Douglas and North American Rockwell;^[9] four bids incorporated variable-geometry wings.^{[8][N 1]}

Grumman's VFX entry was designed around the TF30 engines, AWG-9 radar and AIM-54 missile intended for the F-111B; this eventually became the F-14A

McDonnell Douglas and Grumman were selected as finalists in December 1968. Grumman was selected for the contract award in January 1969.^[10] Grumman's design reused the TF30 engines from the F-111B, though the navy planned on replacing them with the Pratt & Whitney F401-400 engines under development for the navy, along with the related Pratt & Whitney F100 for the USAF.^[11] Though lighter than the F-111B, it was still the largest and heaviest U.S. fighter to fly from an aircraft carrier, a consequence of the requirement to carry the large AWG-9 radar and AIM-54 Phoenix missiles (from the F-111B) and an internal fuel load of 16,000 lb (7,300 kg).^[12]
Upon being granted the contract for the F-14, Grumman greatly expanded its Calverton, Long Island, New York facility for evaluating the aircraft. Much of the testing, including the first of many compressor stalls and multiple ejections, took place over Long Island Sound. In order to save time and forestall interference from Secretary McNamara, the navy skipped the prototype phase and jumped directly to full-scale development; the air force took a similar approach with its F-15.^[13] The F-14 first flew on 21 December 1970, just 22 months after Grumman was awarded the contract, and reached initial operational capability (IOC) in 1973. The United States Marine Corps was initially interested in the F-14 as an F-4 Phantom II replacement; going so far as to send officers to Fighter Squadron One Twenty-Four (VF-124) to train as instructors. The marine corps pulled out of any procurement when development of the stores management system for ground attack munitions was not pursued. An air-to-ground capability was not developed until the 1990s.^[13]
Firing trials involved launches against simulated targets of various types, from cruise missiles to high-flying bombers. AIM-54 Phoenix missile testing from the F-14 began in April 1972. The longest single Phoenix launch was successful against a target at a range of 110 nmi (200 km) in April 1973. Another unusual test was made on 22 November 1973, when six missiles were fired within 38 seconds at Mach 0.78 and 24,800 ft (7,600 m); four scored direct hits.^[14]

Improvements and changes

With time, the early versions of all the missiles were replaced by more advanced versions, especially with the move to full solid-state electronics that allowed better reliability, better ECCM and more space for the rocket engine. So the early arrangement of the AIM-54A Phoenix active-radar air-to-air missile, the AIM-7E-2 Sparrow Semi-active radar homing air-to-air missile, and the AIM-9J Sidewinder heat-seeking air-to-air missile was replaced in the 1980s with the B (1983) and C (1986) version of the Phoenix, the F (1977), M (1982), P (1987 or later) for Sparrows, and with the Sidewinder, L (1979) and M (1982). Within these versions there are several improved batches (for example, Phoenix AIM-54C++).^[15]
The Tactical Airborne Reconnaissance Pod System (TARPS) was developed in the late 1970s for the F-14. Approximately 65 F-14As and all F-14Ds were modified to carry the pod.^[16] TARPS was primarily controlled by the RIO, who had a specialized display to observe reconnaissance data. The TARPS was upgraded with digital camera in 1996 with the "TARPS Digital (TARPS-DI)". The digital camera was further updated beginning in 1998 with the "TARPS Completely Digital (TARPS-CD)" configuration that provided real-time transmission of imagery.^[17]
Some of the F-14A aircraft underwent engine upgrades to the GE F110-400 in 1987. These upgraded Tomcats were redesignated F-14A+, which was later changed to F-14B in 1991.^[18] The F-14D variant was developed at the same time; it included the GE F110-400 engines with newer digital avionics systems such as a glass cockpit, and compatibility with the Link 16 secure datalink.^[19] The Digital Flight Control System (DFCS) notably improved the F-14's handling qualities when flying at a high angle of attack or in air combat maneuvering.^[20]

Adding ground attack capability

An F-14D launching an AIM-7 Sparrow; a GBU-24 Paveway III is also being carried.

In the 1990s, with the pending retirement of the A-6 Intruder, the F-14 air-to-ground program was resurrected. Trials with live bombs had been carried out in the 1980s; the F-14 was cleared to use basic iron bombs in 1992. In Operation Desert Storm, most air-to-ground missions were left to A-7, A-6 Intruder and F/A-18 Hornet squadrons, the F-14 focused on air defense operations. Following Desert Storm, F-14As and F-14Bs underwent upgrades to avionics and cockpit displays to enable the use of precision munitions, enhance defensive systems, and apply structural improvements. The new avionics were comparable with the F-14D; upgraded aircraft were designated F-14A (Upgrade) and F-14B (Upgrade) respectively.^[16]

By 1994, Grumman and the Navy were proposing ambitious plans for Tomcat upgrades to plug that gap between the retirement of the A-6 and F/A-18E/F Super Hornet entering service. However, the upgrades would have taken too long to implement to meet the gap, and were priced in the billions; Congress considered this too expensive for an interim solution.^[16] A quick, inexpensive upgrade using the Low Altitude Navigation and Targeting Infrared for Night (LANTIRN) targeting pod was devised. The LANTIRN pod provided the F-14 with a forward-looking infrared (FLIR) camera for night operations and a laser target designator to direct laser-guided bombs (LGB).^[21] Although LANTIRN is traditionally a two-pod system, an AN/AAQ-13 navigation pod with terrain-following radar and a wide-angle FLIR, along with an AN/AAQ-14 targeting pod with a steerable FLIR and a laser target designator, the decision was made to only use the targeting pod. The Tomcat's LANTIRN pod was altered and improved over the baseline configuration, such as a Global Positioning System / Inertial Navigation System (GPS-INS) capability to allow an F-14 to accurately locate itself. The pod was carried on the right wing glove pylon.^[21]

An F-14D(R) from VF-213 flying over Iraq on last Tomcat deployment with LANTIRN pod on starboard wing glove station and LGB underneath fuselage.

The LANTIRN pod did not require changes to the F-14's own system software, but the pod was designed to operate on a MIL-STD-1553B bus not present on the F-14A or B. Consequently, Martin Marietta specially developed an interface card for LANTIRN. The Radar Intercept Officer (RIO) would receive pod imagery on a 10-inch Programmable Tactical Information Display (PTID) or another Multi-Function Display in the F-14^[22][23] rear cockpit and guided LGBs using a new hand controller installed on the right side console. Initially, the hand controller replaced the RIO's TARPS control panel, meaning a Tomcat configured for LANTIRN could not carry TARPS and the reverse, but eventually a workaround was later developed to allow a Tomcat to carry LANTIRN or TARPS as needed.^[21]
An upgraded LANTIRN named "LANTIRN 40K" for operations up to 40,000 ft (12,000 m) was introduced in 2001, followed by Tomcat Tactical Targeting (T3) and Fast Tactical Imagery (FTI), to provide precise target coordinate determination and ability to transmit images in-flight.^[24] Tomcats also added the ability to carry the GBU-38 Joint Direct Attack Munition (JDAM) in 2003, giving it the option of a variety of LGB and GPS-guided weapons.^[25] Some F-14Ds were upgraded in 2005 with a ROVER III Full Motion Video (FMV) downlink, a system that transmits real-time images from the aircraft's sensors to the laptop of Forward Air Controller (FAC) on the ground.[26

Overview

 

F-14 Tomcat flight demonstration video

The F-14 Tomcat was designed as both an air superiority fighter and a long-range naval interceptor.^[27][28][29] The F-14 has a two-seat cockpit with a bubble canopy that affords all-round visibility. It features variable geometry wings that swing automatically during flight. For high-speed intercept, they are swept back and they swing forward for lower speed flight.^[15] It was designed to improve on the F-4 Phantom's air combat performance in most respects.^[27]
The F-14's fuselage and wings allow it to climb faster than the F-4, while the twin-tail arrangement offers better stability. The F-14 is equipped with an internal 20 mm M61 Vulcan Gatling cannon mounted on the left side, and can carry AIM-54 Phoenix, AIM-7 Sparrow, and AIM-9 Sidewinder anti-aircraft missiles. The twin engines are housed in nacelles, spaced apart by 1 to 3 ft (0.30 to 0.91 m). The flat area of the fuselage between the nacelles is used to contain fuel and avionics systems such as the wing-sweep mechanism and flight controls, and the underside used to carry the F-14's complement of Phoenix or Sparrow missiles, or assorted bombs.^[15] By itself, the fuselage provides approximately 40 to 60 percent of the F-14's aerodynamic lifting surface depending on the wing sweep position.^[30]

Variable geometry wings

The F-14's wing sweep can be varied between 20° and 68° in flight,^[31] and can be automatically controlled by the Central Air Data Computer, which maintains wing sweep at the optimum lift-to-drag ratio as the Mach number varies; pilots can manually override the system if desired.^[15] When parked, the wings can be "overswept" to 75° to overlap the horizontal stabilizers to save deck space aboard carriers. In an emergency, the F-14 can land with the wings fully swept to 68°,^[15] although this presents a significant safety hazard due to greatly increased airspeed, thus an aircraft would typically be diverted from an aircraft carrier to a land base if an incident did occur. The F-14 has even flown and landed safely with an asymmetrical wing-sweep even on an aircraft carrier during emergencies.^[32]

Rearview of the F-14 showing the area between the engine nacelles

The wings have a two-spar structure with integral fuel tanks. Much of the structure, including the wing box, wing pivots and upper and lower wing skins is made of titanium,^[15] a light, rigid and strong material, but also difficult and costly to weld. Ailerons are not fitted, with roll control being provided by wing-mounted spoilers at low speed (which are disabled if the sweep angle exceeds 57°), and by differential operation of the all-moving tailerons at high speed.^[15] Full-span slats and flaps are used to increase lift both for landing and combat, with slats being set at 17° for landing and 7° for combat, while flaps are set at 35° for landing and 10° for combat.^[15] The twin tail layout helps in maneuvers at high AoA (angle of attack) while reducing the height of the aircraft to fit within the limited roof clearance of hangars aboard aircraft carriers. Two under-engine nacelle mount points are provided for external fuel tanks carrying an additional 4,000 lb (1,800 kg) of fuel.
Two triangular shaped retractable surfaces, called glove vanes, were originally mounted in the forward part of the wing glove, and could be automatically extended by the flight control system at high Mach numbers. They were used to generate additional lift ahead of the aircraft's center of gravity, thus helping to compensate for the nose-down pitching tendencies at supersonic speeds. Automatically deployed at above Mach 1.4, they allowed the F-14 to pull 7.5 g at Mach 2 and could be manually extended with wings swept full aft. They were later disabled, however, owing to their additional weight and complexity.^[15] The air brakes consist of top-and-bottom extendable surfaces at the rearmost portion of the fuselage, between the engine nacelles. The bottom surface is split into left and right halves, the arrestor hook hangs between the two halves, an arrangement sometimes called the "castor tail".^[33]

Engines and landing gear

The F-14 was initially equipped with two Pratt & Whitney TF30 (or JT10A) turbofan engines, providing a total thrust of 5.670/9.480 kg/t and giving the aircraft an official maximum speed of Mach 2.34.^[34] However, the F-14 would normally fly at a cruising speed for reduced fuel consumption, which was important for conducting lengthy patrol missions.^[35] Both of the engine's rectangular air intakes were equipped with movable ramps and bleed doors to meet the airflow requirements of the engine but prevent dangerous shockwaves from entering. Variable nozzles were also fitted to the engine's exhaust.

An F-14D prepares to refuel with probe extended

The performance of the TF30 engine became an object of criticism. John Lehman, Secretary of the Navy in the 1980s, told the U.S. Congress that the TF30/F-14 combination was "probably the worst engine/airframe mismatch we have had in years" and that the TF30 was "a terrible engine";^[31][33] 28% of all F-14 accidents were attributed to the engine. A high frequency of turbine blade failures led to the reinforcement of the entire engine bay to limit damage from such failures. The engines also had proved to be extremely prone to compressor stalls, which could easily result in loss of control, severe yaw oscillations, and could lead to an unrecoverable flat spin. At specific altitudes, exhaust produced by missile launches could cause an engine compressor stall; leading to the development of a bleed system to temporarily reduce engine power and block the frontal intake during missile launch. With the TF30, the F-14's overall thrust-to-weight ratio at maximum takeoff weight is around 0.56, considerably less than the F-15A's ratio of 0.85; when fitted with the General Electric F110 engine, an improved thrust-to-weight ratio of 0.73 at maximum weight and 0.88 at normal takeoff weight was achieved.^[34]
The undercarriage is very robust, in order to withstand the harsh takeoffs and landings necessary for carrier operation. It comprises a double nose wheel and widely spaced single main wheels. There are no hardpoints on the sweeping parts of the wings, and so all the armaments are fitted on the belly between the air intakes and on pylons under the wing gloves. Internal fuel capacity is 2,400 US gal (9,100 l): 290 US gal (1,100 l) in each wing, 690 US gal (2,600 l) in a series of tanks aft of the cockpit, and a further 457 US gal (1,730 l) in two feeder tanks. It can carry two 267 US gal (1,010 l) external drop tanks under the engine intakes.^[15] There is also an air-to-air refueling probe, which folds into the starboard nose.^[36]

Avionics and flight controls

The cockpit has two seats, arranged in tandem, outfitted with Martin-Baker GRU-7A rocket-propelled ejection seats, rated from zero altitude and zero airspeed up to 450 knots.^[37] The canopy is spacious, and fitted with four mirrors to provide effectively all-round visibility. Only the pilot has flight controls; the flight instruments themselves are of a hybrid analog-digital nature.^[15] The cockpit also features a head-up display (HUD) to show primarily navigational information; several other avionics systems such as communications and direction-finders are integrated into the AWG-9 radar's display. A significant feature of the F-14 was its Central Air Data Computer (CADC), designed by Garrett AiResearch, that formed the onboard integrated flight control system. It used a MOS-based LSI chipset, the MP944, making it possibly the first microprocessor in history.^[38]

F-14 with landing gear deployed

The nose of the aircraft is large because it contains a two-person crew and several bulky avionics systems. The main element is the Hughes AWG-9 X-band radar; the antenna is a 36 in (91 cm)-wide planar array, and has integrated IFF antennas. The AWG-9 has several search and tracking modes, such as Track-While-Scan (TWS), Range-While-Search (RWS), Pulse-Doppler Single-Target Track (PDSTT), and Jam Angle Track (JAT); a maximum of 24 targets can be tracked simultaneously, and six can be engaged in TWS mode up to around 60 mi (97 km). Cruise missiles are also possible targets with the AWG-9, which can lock onto and track small objects even at low altitude when in Pulse-Doppler mode.^[15] For the F-14D, the AWG-9 was replaced by the upgraded APG-71 radar. The Joint Tactical Information Display System (JTIDS)/Link 16 for data communications was added later on.^[39]
The F-14 also features electronic countermeasures (ECM) and radar warning (RWR) systems, chaff/flare dispensers, fighter-to-fighter data link, and a precise inertial navigation system.^[15] The early navigation system was inertial-based, point-of-origin coordinates were programmed into a navigation computer and gyroscopes would track the aircraft's every motion to calculate distance and direction from that starting point. GPS later was integrated to provide more precise navigation and redundancy in case either system failed. The chaff/flare dispensers were located on the underside of the fuselage and on the tail. The RWR system consisted of several antennas on the aircraft's fuselage, which could roughly calculate both direction and distance of enemy radar users; it could also differentiate between search radar, tracking radar, and missile-homing radar.^[40]
Featured in the sensor suite was the AN/ALR-23, an infrared sensor using indium antimonide detectors, mounted under the nose; however this was replaced by an optical system, Northrop's AAX-1, also designated TCS (TV Camera Set). The AAX-1 helped pilots visually identify and track aircraft, up to a range of 60 miles (97 km) for large aircraft. The radar and the AAX-1 were linked, allowing the one detector to follow the direction of the other. A dual infrared/optical detection system was adopted on the later F-14D.^{[citation needed]}

Armament

The F-14 was designed to combat highly maneuverable aircraft as well as the Soviet cruise missile and bomber threats.^[29] The Tomcat was to be a platform for the AIM-54 Phoenix, but unlike the canceled F-111B, it could also engage medium and short range threats with other weapons.^[27][29] The F-14 was an air superiority fighter, not just a long-range interceptor.^[29] Over 6,700 kg (15,000 lb) of stores could be carried for combat missions on several hardpoints under the fuselage and under the wings. Commonly, this meant a maximum of two–four Phoenixes or Sparrows on the belly stations, two Phoenixes/Sparrows on the wing hardpoints, and two Sidewinders on the wing hardpoints.^{[citation needed]} The F-14 was also fitted with an internal 20 mm M61 Vulcan Gatling-type cannon.
Operationally, the capability to hold up to six Phoenix missiles was never used, although early testing was conducted; there was never a threat requirement to engage six hostile targets simultaneously and the load was too heavy to safely recover aboard an aircraft carrier in the event that the missiles were not fired. During the height of Cold War operations in the late 1970s and 1980s, the typical weapon loadout on carrier-deployed F-14s was usually only one AIM-54 Phoenix, augmented by two AIM-9 Sidewinders, two AIM-7 Sparrow IIIs, a full loadout of 20 mm ammunition and two drop tanks.^{[citation needed]} The Phoenix missile was used twice in combat by the U.S. Navy, both over Iraq in 1999,^[41][42][43] but the missiles didn't score any kills.

Variants

A total of 712 F-14s were built^[66] from 1969 to 1991.^[67] F-14 assembly and test flights were performed at Grumman's plant in Calverton on Long Island, NY. Grumman facility at nearby Bethpage, NY was directly involved in F-14 manufacturing and was home to its engineers. The airframes were partially assembled in Bethpage and then shipped to Calverton for final assembly. Various tests were also performed at the Bethpage Plant. Over 160 of the U.S. aircraft were destroyed in accidents.^[68]

Close-up view of the distinctive afterburner petals of the GE F110 engine

F-14A

The F-14A was the initial two-seat all-weather interceptor fighter variant for the U.S. Navy. It first flew on 21 December 1970. The first 12 F-14As were prototype versions^[69] (sometimes called YF-14As). Modifications late in its service life added precision strike munitions to its armament. The U.S. Navy received 478 F-14A aircraft and 79 were received by Iran.^[66] The final 102 F-14As were delivered with improved TF30-P-414A engines.^[70] Additionally, an 80th F-14A was manufactured for Iran, but was delivered to the U.S. Navy.^[66]

F-14B

The F-14 received its first of many major upgrades in March 1987 with the F-14A Plus (or F-14A+). The F-14A's P&W TF30 engine was replaced with the improved GE F110-400 engine. The F-14A+ also received the state-of-the-art ALR-67 Radar Homing and Warning (RHAW) system. Much of the avionics as well as the AWG-9 radar were retained. The F-14A+ was later redesignated F-14B on 1 May 1991. A total of 38 new aircraft were manufactured and 48 F-14A were upgraded into B variants.^[18]
The TF30 had been plagued from the start with susceptibility to compressor stalls at high AoA and during rapid throttle transients or above 30,000 ft (9,100 m). The F110 engine provided a significant increase in thrust, producing 27,600 lbf (123 kN) with afterburner. The increased thrust gave the Tomcat a better than 1:1 thrust-to-weight ratio at low fuel quantities. The basic engine thrust without afterburner was powerful enough for carrier launches, further increasing safety. Another benefit was allowing the Tomcat to cruise comfortably above 30,000 ft (9,100 m), which increased its range and survivability. The F-14B arrived in time to participate in Desert Storm.
In the late 1990s, 67 F-14Bs were upgraded to extend airframe life and improve offensive and defensive avionics systems. The modified aircraft became known as F-14B Upgrade or as "Bombcat".^[70]

F-14D

The final variant of the F-14 was the F-14D Super Tomcat. The F-14D variant was first delivered in 1991. The original TF-30 engines were replaced with GE F110-400 engines, similar to the F-14B. The F-14D also included newer digital avionics systems including a glass cockpit and replaced the AWG-9 with the newer AN/APG-71 radar. Other systems included the Airborne Self Protection Jammer (ASPJ), Joint Tactical Information Distribution System (JTIDS), SJU-17(V) Naval Aircrew Common Ejection Seats (NACES) and Infra-red search and track (IRST).^[71]

An upgraded F-14D(R) Tomcat with the ROVER transmit antenna circled with USS Theodore Roosevelt (CVN-71) in the background

Although the F-14D was to be the definitive version of the Tomcat, not all fleet units received the D variant. In 1989, Secretary of Defense Dick Cheney refused to approve the purchase of any more F-14D model aircraft for $50 million each and pushed for a $25 million modernization of the F-14 fleet instead. Congress decided not to shut production down and funded 55 aircraft as part of a compromise. A total of 37 new aircraft were completed, and 18 F-14A models were upgraded to D-models, designated F-14D(R) for rebuild.^[18] An upgrade to the F-14D's computer software to allow AIM-120 AMRAAM missile capability was planned but was later terminated.^[16]
While upgrades had kept the F-14 competitive with modern fighter aircraft technology, Cheney called the F-14 1960s technology. Despite an appeal from the Secretary of the Navy for at least 132 F-14Ds and some aggressive proposals from Grumman for a replacement,^[72] Cheney planned to replace the F-14 with a fighter that was not manufactured by Grumman. Cheney called the F-14 a "jobs program", and when the F-14 was canceled, an estimated 80,000 jobs of Grumman employees, subcontractors, or support personnel were affected.^[73] Starting in 2005, some F-14Ds received the ROVER III upgrade.

Projected variants

The first F-14B was to be an improved version of the F-14A with more powerful "Advanced Technology Engine" F401 turbofans. The F-14C was a projected variant of this initial F-14B with advanced multi-mission avionics.^[74] Grumman also offered an interceptor version of the F-14B in response to a U.S. Air Force proposal to replace the Convair F-106 Delta Dart as an Aerospace Defense Command interceptor in the 1970s. The F-14B program was terminated in April 1974.^[75]

Grumman's proposed F-14 Interceptor for USAF Aerospace Defense Command in 1972 with the simulated "Buzz Code" and Aerospace Defense Command livery and emblem on the tail

Grumman proposed a few improved Super Tomcat versions. The first was the Quickstrike, which was an F-14D with navigational and targeting pods, additional attach points for weapons, and added ground attack capabilities to its radar. The Quickstrike was to fill the role of the A-6 Intruder after it was retired. This was not considered enough of an improvement by Congress, so the company shifted to the Super Tomcat 21 proposed design. The Super Tomcat 21 was a proposed lower cost alternative to the Navy Advanced Tactical Fighter (NATF). The Grumman design would have the same shape and body as the Tomcat, and an upgraded AN/APG-71 radar. New GE F110-129 engines were to provide a supercruise speed of Mach 1.3 and featured thrust vectoring nozzles. The version would have increased fuel capacity and modified control surfaces for improved takeoffs and lower landing approach speed. The Attack Super Tomcat 21 version was the last Super Tomcat proposed design. It added even more fuel capacity, more improvements to control surfaces, and possibly an Active Electronically Scanned Array (AESA) radar from the canceled A-12 attack aircraft.^[76]
The last "Tomcat" variant was the ASF-14 (Advanced Strike Fighter-14), Grumman's replacement for the NATF concept. By all accounts, it would not be even remotely related to the previous Tomcats save in appearance, incorporating the new technology and design know-how from the Advanced Tactical Fighter (ATF) and Advanced Tactical Aircraft (ATA) programs. The ASF-14 would have been a new-build aircraft; however, its projected capabilities were not that much better than that of the (A)ST-21 variants.^[77] In the end the Attack Super Tomcat was considered to be too costly. The Navy decided to pursue the cheaper F/A-18E/F Super Hornet to fill the fighter-attack role.

General characteristics

• Crew: 2 (Pilot and Radar Intercept Officer)
• Length: 62 ft 9 in (19.1 m)
• Wingspan: ** Spread: 64 ft (19.55 m)
  • Swept: 38 ft (11.58 m)
• Height: 16 ft (4.88 m)
• Wing area: 565 ft² (54.5 m²)
• Airfoil: NACA 64A209.65 mod root, 64A208.91 mod tip
• Empty weight: 43,735 lb (19,838 kg)
• Loaded weight: 61,000 lb (27,700 kg)
• Max. takeoff weight: 74,350 lb (33,720 kg)
• Powerplant: 2 × General Electric F110-GE-400 afterburning turbofans
  • Dry thrust: 13,810 lbf (61.4 kN) each
  • Thrust with afterburner: 27,800 lbf (123.7 kN) each
• Maximum fuel capacity: 16,200 lb internal; 20,000 lb with 2x 267 gallon external tanks^[34]

Performance

• Maximum speed: Mach 2.34 (1,544 mph, 2,485 km/h) at high altitude
• Combat radius: 500 nmi (575 mi, 926 km)
• Ferry range: 1,600 nmi (1,840 mi, 2,960 km)
• Service ceiling: 50,000+ ft (15,200 m)
• Rate of climb: >45,000 ft/min (229 m/s)
• Wing loading: 113.4 lb/ft² (553.9 kg/m²)
• Thrust/weight: 0.92

Armament

• Guns: 1× 20 mm (0.787 in) M61 Vulcan 6-barreled gatling cannon, with 675 rounds
• Hardpoints: 10 total: 6× under-fuselage, 2× under nacelles and 2× on wing gloves^{[156][N 2]} with a capacity of 14,500 lb (6,600 kg) of ordnance and fuel tanks^[157]
• Missiles: ** Air-to-air missiles: AIM-54 Phoenix, AIM-7 Sparrow, AIM-9 Sidewinder
• Loading configurations:
  • 2× AIM-9 + 6× AIM-54 (Rarely used due to weight stress on airframe)
  • 2× AIM-9 + 2× AIM-54 + 3× AIM-7 (Most common load during Cold War era)
  • 2× AIM-9 + 4× AIM-54 + 2× AIM-7
  • 2× AIM-9 + 6× AIM-7
  • 4× AIM-9 + 4× AIM-54
  • 4× AIM-9 + 4× AIM-7
• Bombs: ** JDAM precision-guided munition (PGMs)
  • Paveway series of laser-guided bombs
  • Mk 80 series of unguided iron bombs
  • Mk 20 Rockeye II
• Others:
  • Tactical Airborne Reconnaissance Pod System (TARPS)
  • LANTIRN targeting pod
  • 2× 267 US gal (1,010 l; 222 imp gal) drop tanks for extended range/loitering time

Avionics

• Hughes AN/APG-71 radar
• AN/ASN-130 INS, IRST, TCS
• Remotely Operated Video Enhanced Receiver (ROVER) upgrade

 From Wikipedia