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 Soviet jet bombers and submarines. The 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 aircraft’s fighter performance.
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 Connolly, Deputy Chief of Naval Operations for Air Warfare, took the developmental F-111A variant for a flight and discovered 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]
[edit] 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]
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, its size 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.
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 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.
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-CD” configuration.
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.[17] 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.[18] 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.[19]
Adding ground attack capability
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 were 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 and F/A-18 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.
Pale gray jet aircraft flying over water towards right, perpendicular to the camera. Horizon located two-thirds down the photo. Sky made up of two shades, dark blue covers the top, blending with a lighter shade until it is almost white above horizon
An F-14D(R) from VF-213 over Iraq on last Tomcat deployment with LANTIRN pod on starboard wing glove station and LGB underneath fuselage.
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).[20] 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.[20]
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. So 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[21][22] 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.
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.[citation needed] 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.[23] 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.
Design
Overview
The F-14 Tomcat was designed as both an air superiority fighter and a long-range naval interceptor.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.It was designed to improve on the F-4 Phantom’s air combat performance in most respects.
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; as well as the underside being used to carry the F-14′s compliment of Phoenix or Sparrow missiles or assorted bombs.[15]
Variable geometry wings
The F-14′s wing sweep can be varied between 20° and 68° in flight,[28] 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.When parked, the wings can be “overswept” to 75°, overlapping the horizontal stabilizers to save deck space onboard 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 be typically 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.
Rear view of stationary aircraft.
Rearview of the F-14, note 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,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.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.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.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”.
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.[31] However, the F-14 would normally fly at a cruising speed for reduced fuel consumption, which was important for conducting lengthy patrol missions.[32] Both of the engine’s rectangular air intakes were equipped with movable ramps and bleed doors to meet the oxygen 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, told Congress that the F-14/TF30 combination was “probably the worst engine/airframe mismatch we have had in years” and that the TF30 was “a terrible engine”;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 reduced 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.
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 USgal (9,100 l): 290 USgal (1,100 l) in each wing, 690 USgal (2,600 l) in a series of tanks aft of the cockpit, and a further 457 USgal (1,730 l) in two feeder tanks. It can carry two 267 USgal (1,010 l) external drop tanks under the engine intakes.There is also an air-to-air refueling probe, which folds into the starboard nose.
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.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.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.
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.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.[citation needed]
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.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.
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 adopted on the later F-14D.
Armament
The F-14 was designed to combat highly maneuverable aircraft as well as the Soviet cruise missile and bomber threats.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.The F-14 was an air superiority fighter, not just a long-range interceptor.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.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 recover aboard an aircraft carrier. 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.The Phoenix missile was used twice in combat by the US Navy, both over Iraq in 1999,but the missiles didn’t score any kills.
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