F-16C Fighting Falcon

Description
Genesis of the successful F-16 multirole fighter lies in reaction to severe deficiencies in US fighter design revealed by the Vietnam War. Following the success of the small, highly maneuverable F-86 Sabre day fighter in the Korean War, US fighter design changed to emphasize maximum speed, altitude, and radar capability at the expense of maneuverability, pilot vision, and other attributes needed for close combat. This trend reached its extremity in the McDonnell Douglas F-4 Phantom, which was the principal fighter for both the US Air Force and Navy during the Vietnam War.

The Air Force establishment wanted no part of a new small fighter, with or without radar. It was regarded as a threat to the F-15, which was USAF's highest priority program. But the Fighter Mafia gained considerable resonance in Congress and within the Office of the Secretary of Defense. In 1971 Deputy Secretary of Defense David Packard began a Lightweight Fighter (LWF) program to explore the concept.The LWF was to be about 20,000 pounds, or half the weight of the F-15, and was to stress low cost, small size, and very high performance at speed below Mach 1.6 and altitude below 40,000 feet. Two competing designs would be chosen for prototyping.

Of the two surviving designs, now designated the General Dynamics YF-16 and the Northrop YF-17., the YF-17 was a relatively conventional design, to some extent an outgrowth of the F-5, while the YF-16 was an all-new design incorporating highly innovative technologies that in many respects reached beyond those of the more expensive F-15. The competing Northrop YF-17 design was somewhat larger than the YF-16, and used two smaller pure jet engines. At the price of reduced range and persistence, the YF-17 avoided the main problem of the YF-16's turbofan: the inertia of the large fan required too long - in some cases six seconds - to spool up from idle to full power. In other respects, the YF-17 progressed better than expected, given its initial last place position.

Northrop argued that its twin-engine design added an essential safety factor, citing its experience with the small twin-engine F-5 fighter as an example. USAF did not find this persuasive, in part because a two engine plane with one engine out is useless in combat, and the probability of an engine failure was nominally twice as high with two engines as with one. The higher performance, better transient maneuverability, longer range, and lower cost of the YF-16 carried the day, and in 1976 the F-16 was chosen over the YF-17. The price for one unit is around $18,800,000 USD.

Overview
The F-16 is a single-engined, supersonic, multi-role tactical aircraft. The F-16 was designed to be a cost-effective combat "workhorse" that can perform various kinds of missions and maintain around-the-clock readiness. It is much smaller and lighter than its predecessors, but uses advanced aerodynamics and avionics, including the first use of a relaxed static stability/fly-by-wire  (RSS/FBW) flight control system, to achieve enhanced maneuver performance. Highly nimble, the F-16 can pull 9-g maneuvers and can reach a maximum speed of over Mach 2.

The Fighting Falcon includes innovations such as a frameless bubble canopy for better visibility, side-mounted control stick to ease control while under high g-forces, and reclined seat to reduce the effect of g-forces on the pilot. The F-16 has an internal M61 Vulcan cannon in the left wing root and has 11 hardpoints for mounting various missiles, bombs and pods. It was also the first fighter aircraft purpose built to sustain 9-g turns. It has a thrust-to-weight ratio greater than one, providing power to climb and accelerate vertically—if necessary.

The F-16A is distinguished by having four vents behind the port for the M61 cannon whereas the subsequent F-16C has only two vents behind the cannon port.

Early models could also be armed with up to six AIM-9 Sidewinder heat-seeking short-range air-to-air missiles (AAM), including a single missile mounted on a dedicated rail launcher on each wingtip. Some variants can also employ the AIM-7 Sparrow long-range radar-guided AAM, and more recent versions can be equipped with the AIM-120 AMRAAM. It can also carry other AAM; a wide variety of air-to-ground missiles, rockets or bombs; electronic countermeasures (ECM), navigation, targeting or weapons pods; and fuel tanks on eleven hardpoints – six under the wings, two on wingtips and three under the fuselage.

General configuration
The F-16 design employs a cropped-delta planform incorporating wing-fuselage blending and forebody vortex-control strakes; a fixed-geometry, underslung air intake inlet supplying airflow to the single turbofan  jet engine; a conventional tri-plane empennage  arrangement with all-moving horizontal “stabilator” tailplanes; a pair of ventral fins beneath the fuselage aft of the wing’s trailing edge; a single-piece, bird-proof “bubble” canopy; and a tricycle landing gear configuration with the aft-retracting, steerable nose gear deploying a short distance behind the inlet lip. There is a boom-style aerial refueling receptacle located a short distance behind the rear of the canopy. Split-flap speedbrakes are located at the aft end of the wing-body fairing, and an arrestor hook is mounted underneath the aft fuselage. Another fairing is situated at the base of the vertical tail, beneath the bottom of the rudder, and is used to house various items of equipment such as ECM gear or drag chutes. Several later F-16 models, such as the F-16I variant of the Block 50 aircraft, also have a long dorsal fairing “bulge” that runs along the “spine” of the fuselage from the rear of the cockpit to the tail fairing; these fairings can be used to house additional equipment or fuel.

The air intake was designed to be "far enough forward to allow a gradual bend in the air duct up to the engine face to minimize flow losses and far enough aft so it wouldn’t weigh too much or be too draggy or destabilizing."

The F-16 was designed to be relatively inexpensive to build and much simpler to maintain than earlier-generation fighters. The airframe is built with about 80% aviation-grade aluminum alloys, 8% steel, 3% composites, and 1.5% titanium. Control surfaces such as the leading-edge flaps, tailerons, and ventral fins make extensive use of bonded aluminum honeycomb structural elements and graphite epoxy laminate skins. The F-16A had 228 access panels over the entire aircraft, about 80% of which can be reached without work stands. The number of lubrication points, fuel line connections, and replaceable modules was also greatly reduced compared to its predecessors.

Although the USAF’s LWF program had called for an aircraft structural life of only 4,000 flight hours, and capable of achieving 7.33 g with 80% internal fuel, GD’s engineers decided from the start to design the F-16’s airframe life to last to 8,000 hours and for 9-g maneuvers on full internal fuel. This proved advantageous when the aircraft’s mission was changed from solely air-to-air combat to multi-role operations. However, changes over time in actual versus planned operational usage and continued weight growth due to the addition of further systems have required several structural strengthening programs.

Wing and strake configuration
Aerodynamic studies in the early 1960s demonstrated that the phenomenon known as “vortex lift” could be beneficially harnessed by the utilization of highly swept wing configurations to reach higher angles of attack through use of the strong leading edge vortex flow off a slender lifting surface. Since the F-16 was being optimized for high agility in air combat, GD’s designers chose a slender cropped-delta wing with a leading edge sweep of 40° and a straight trailing edge. To improve its ability to perform in a wide range of maneuvers, a variable-camber wing with a NACA 64A-204 airfoil was selected. The camber is adjusted through the use of leading-edge and trailing edge flaperons linked to a digital flight control system (FCS) that automatically adjusts them throughout the flight envelope. The F-16 has a moderate wing loading, which is lower when fuselage lift is considered.

This vortex lift effect can be increased by the addition of an extension of the leading edge of the wing at its root, the juncture with the fuselage, known as a strake. The strakes act as a sort of additional slender, elongated, short-span, triangular wing running from the actual wing root to a point further forward on the fuselage. Blended fillet-like into the fuselage, including along with the wing root, the strake generates a high-speed vortex that remains attached to the top of the wing as the angle of attack increases, thereby generating additional lift. This allows the aircraft to achieve angles of attack beyond the point at which it would normally stall. The use of strakes also permits the use of a smaller, lower-aspect-ratio wing, which in turn increases roll rates and directional stability, while decreasing aircraft weight. The resulting deeper wingroots also increase structural strength and rigidity, reduce structural weight, and increase internal fuel volume. As a result, the F-16’s high fuel fraction of 0.31 gives it a longer range than other fighter aircraft of similar size and configuration.

Flight controls
Negative static stability The YF-16 was the world’s first aircraft intentionally designed to be slightly aerodynamically unstable. This technique, called "relaxed static stability" (RSS), was incorporated to further enhance the aircraft’s maneuver performance. Most aircraft are designed with positive static stability, which induces an aircraft to return to its original attitude following a disturbance. However, positive static stability hampers maneuverability, as the tendency to remain in its current attitude opposes the pilot’s effort to maneuver; on the other hand, an aircraft with negative static stability will, in the absence of control input, readily deviate from level and controlled flight. Therefore, an aircraft with negative static stability will be more maneuverable than one that is positively stable. When supersonic, a negatively stable aircraft actually exhibits a more positive-trending (and in the F-16’s case, a net positive) static stability due to aerodynamic forces shifting aft between subsonic and supersonic flight. At subsonic speeds, however, the fighter is constantly on the verge of going out of control. Fly by wire To counter this tendency to depart from controlled flight—and avoid the need for constant minute trimming inputs by the pilot—the F-16 has a quadruplex (four-channel) fly-by-wire (FBW) flight control system (FLCS). The flight control computer (FLCC), which is the key component of the FLCS, accepts the pilot’s input from the stick and rudder controls, and manipulates the control surfaces in such a way as to produce the desired result without inducing a loss of control. The FLCC also takes thousands of measurements per second of the aircraft’s attitude, and automatically makes corrections to counter deviations from the flight path that were not input by the pilot, coordinated turn is also obtained in such a way that it updates itself by thousands of instructions and produces the required control deflection that comes from dynamics of F-16, thereby allowing for stable flight. This has led to a common aphorism among F-16 pilots: “You don’t fly an F-16; it flies you.”

The FLCC further incorporates a series of limiters that govern movement in the three main axes based on the jet’s current attitude, airspeed and angle of attack, and prevent movement of the control surfaces that would induce an instability such as a slip or skid, or a high angle of attack inducing a stall. The limiters also act to prevent maneuvering that would place more than a 9 g load on the pilot or airframe.

Though the FLCC's limiters work well to limit each axis of movement, it was discovered in early production flight testing that "assaulting" multiple limiters at high angles of attack and slow speed can result in angles of attack far exceeding the 25-degree threshold of limiting. This is colloqually referred to as simply "departing". Depending on the attitude of the aircraft, it may settle into a deep stall; a near-freefall at 50° to 60° AOA, either upright or inverted. In this "pocket" of very high AOA, the aircraft's attitude is stable, but being far above stall AOA, the control surfaces do not operate effectively. Further, the pitch limiter of the jet, sensing the high AOA, "freezes" the stabilators in an extreme pitch-up or pitch-down in an attempt to recover. To recover, an override is provided that disables the pitch-limiting, which then allows the pilot to "rock" the aircraft's nose up and down using pitch control, eventually overcoming the 50° threshold and achieving a nose-down attitude which will reduce AOA and allow a return to controlled flight.

Unlike the YF-17 which featured a FBW system with traditional hydromechanical controls serving as a backup, the F-16’s designers took the innovative step of eliminating mechanical linkages between the stick and rudder pedals and the aerodynamic control surfaces. The F-16’s sole reliance on electronics and wires to relay flight commands, instead of the usual cables and mechanical linkage controls, gained the F-16 the early moniker of "the electric jet". The quadruplex design permits “graceful degradation” in flight control response in that the loss of one channel renders the FLCS a “triplex” system. The FLCC began as an analog system on the A/B variants, but has been supplanted by a digital computer system beginning with the F-16C/D Block 40.

Cockpit and ergonomics
One of the more notable features from a pilot’s perspective is the F-16’s exceptional field of view from the cockpit, a feature that is vital during air-to-air combat. The single-piece, bird-proof polycarbonate bubble canopy provides 360° all-round visibility, with a 40° down-look angle over the side of the aircraft, and 15° down over the nose (compared to the more common 12–13° of its predecessors); the pilot’s seat is mounted on an elevated heel line to accomplish this. Furthermore, the F-16's canopy lacks the forward bow frame found on most fighters, which obstructs some of the pilot’s forward vision. (The length of the tandem arrangement of two-seat F-16s does, however, necessitate a structural frame between the pilots.)

The rocket-boosted ACES II zero/zero ejection seat is reclined at an unusually high tilt-back angle of 30°; the seats in older and contemporary fighters were typically tilted back at around 13–15°. The F-16’s seat-back angle was chosen to improve the pilot’s tolerance of high g forces, and to reduce his susceptibility to gravity-induced loss of consciousness. The increased seat angle, however, has also been associated with reports of increased risk of neck ache when not mitigated by proper use of the head-rest. Subsequent U.S. jet fighter designs have more modest tilt-back angles of 20°. Because of the extreme seat tilt-back angle and the thickness of its polycarbonate single-piece canopy, the F-16’s ejection seat lacks the steel rail canopy breakers found in most other aircraft’s ejection systems. Such breakers shatter a section of the canopy should it fail to open or jettison to permit emergency egress of the aircrew. On the F-16, crew ejection is accomplished by first jettisoning the entire canopy; as the relative wind pulls the canopy away from the plane, a lanyard triggers the seat’s rockets to fire.

The pilot flies the aircraft primarily by means of a side-stick controller mounted on the right-hand armrest (instead of the more common center-mounted stick) and an engine throttle on the left side; conventional rudder pedals are also employed. To enhance the pilot’s degree of control of the aircraft during high-g combat maneuvers, a number of function switches formerly scattered about the cockpit have been moved to "hands on throttle-and-stick (HOTAS)" controls found on both of these controllers. Simple hand pressure on the side-stick controller causes the transmission of electrical signals via the FBW system to adjust the various flight control surfaces used for maneuvering. Originally, the side-stick controller was non-moving, but this arrangement proved uncomfortable and difficult for pilots to adjust to, sometimes resulting in a tendency to "over-rotate" the aircraft during takeoffs, so the control stick was given a small amount of “play”. Since its introduction on the F-16, HOTAS controls have become a standard feature among modern fighters (although the side-stick application is less widespread).

The F-16 cockpit also has a head-up display (HUD), which projects visual flight and combat information in the form of symbols and alphanumeric characters in front of the pilot without obstructing his view. Being able to keep his head “out of the cockpit” further enhances the pilot’s situational awareness of what is occurring around him. Boeing’s Joint Helmet Mounted Cueing System (JHMCS) is also available from Block 40 onwards for use with high-off-boresight  air-to-air missiles like the AIM-9X. JHMCS permits cuing the weapons system to the direction in which the pilot’s head is facing—even outside the HUD’s field of view—while still maintaining his situational awareness. JHMCS was first operationally deployed during Operation Iraqi Freedom.

The pilot obtains further flight and systems status information from multi-function displays (MFD). The left-hand MFD is the primary flight display (PFD), which generally shows radar and moving-map displays; the right-hand MFD is the system display (SD), which presents important information about the engine, landing gear, slat and flap settings, fuel quantities, and weapons status. Initially, the F-16A/B had only a single monochrome cathode ray tube (CRT) display to serve as the PFD, with system information provided by a variety of traditional “steam gauges”. The MLU introduced the SD MFD in a cockpit made compatible for usage of night-vision goggles (NVG). These CRT displays were replaced by color liquid crystal displays on the Block 50/52. The Block 60 features three programmable and interchangeable color MFDs (CMFD) with picture-in-picture capability that is able to overlay the full tactical situation display on the moving map.

Radar
The F-16A/B was originally equipped with the Westinghouse AN/APG-66  fire-control radar. Its slotted planar-array antenna was designed to be sufficiently compact to fit into the F-16’s relatively small nose. In uplook mode, the APG-66 uses a low pulse-repetition frequency (PRF) for medium- and high-altitude target detection in a low-clutter environment, and in downlook employs a medium PRF for heavy clutter environments. It has four operating frequencies within the X band, and provides four air-to-air and seven air-to-ground operating modes for combat, even at night or in bad weather. The Block 15’s APG-66(V)2 model added a new, more powerful signal processor, higher output power, improved reliability, and increased range in a clutter or jamming environments. The Mid-Life Update (MLU) program further upgrades this to the APG-66(V)2A model, which features higher speed and memory. Taiwan's Block 20 has APG-66(V)3 that added CW mode in order to guide AIM-7M initially sold to Taiwan in the US announced 1992 deal. The APG-66(V)3 radar already able to guide AMRAAM BVR missiles.

The AN/APG-68, an evolution of the APG-66, was introduced with the F-16C/D Block 25. The APG-68 has greater range and resolution, as well as 25 operating modes, including ground-mapping, Doppler beam-sharpening, ground moving target, sea target, and track-while-scan (TWS) for up to ten targets. The Block 40/42’s APG-68(V)1 model added full compatibility with Lockheed Martin Low-Altitude Navigation and Targeting Infra-Red for Night (LANTIRN) pods, and a high-PRF pulse-Doppler track mode to provide continuous-wave (CW) target illumination for semi-active radar-homing (SARH) missiles like the AIM-7 Sparrow. The Block 50/52 F-16s initially received the more reliable APG-68(V)5 which has a programmable signal processor employing Very-High-Speed Integrated Circuit (VHSIC) technology. The Advanced Block 50/52 (or 50+/52+) are equipped with the APG-68(V)9 radar which has a 30% greater air-to-air detection range, and a synthetic aperture radar (SAR) mode for high-resolution mapping and target detection and recognition. In August 2004, Northrop Grumman received a contract to begin upgrading the APG-68 radars of the Block 40/42/50/52 aircraft to the (V)10 standard, which will provide the F-16 with all-weather autonomous detection and targeting for the use of Global Positioning System (GPS)-aided precision weapons. It also adds SAR mapping and terrain-following (TF) modes, as well as interleaving of all modes.

The F-16E/F is outfitted with Northrop Grumman’s AN/APG-80 Active Electronically Scanned Array (AESA) radar, making it only the third fighter to be so equipped. Northrop Grumman has continued to develop this system into the Scalable Agile Beam Radar (SABR).

In July 2007, Raytheon announced that it was developing a new Raytheon Next Generation Radar (RANGR) based on its earlier AN/APG-79 AESA radar as an alternative candidate to Northrop Grumman’s AN/APG-68 and AN/APG-80 for new-build F-16s as well as retrofit of existing ones.

Propulsion
The powerplant first selected for the single-engined F-16 was the Pratt & Whitney F100-PW-200 afterburning turbofan, a slightly modified version of the F100-PW-100 used by the F-15. Rated at 23,830 lbf (106.0 kN) thrust, it remained the standard F-16 engine through the Block 25, except for new-build Block 15s with the Operational Capability Upgrade (OCU). The OCU introduced the 23,770 lbf (105.7 kN) F100-PW-220, which was also installed on Block 32 and 42 aircraft; while not offering a noteworthy difference in thrust, it introduced a Digital Electronic Engine Control (DEEC) unit that improved reliability and reduced the risk of engine stalls (an unwelcome occasional tendency with the original "-200" that necessitated a midair engine restart). Introduced on the F-16 production line in 1988, the "-220" also supplanted the F-15’s "-100," thereby maximizing commonality. Many of the "-220" jet engines on Block 25 and later aircraft were upgraded from mid-1997 to the "-220E" standard, which further enhanced reliability and maintainability, including a 35% reduction of the unscheduled engine removal rate.

Development of the F100-PW-220/220E was the result of the USAF’s Alternate Fighter Engine (AFE) program (colloquially known as “the Great Engine War”), which also saw the entry of General Electric as an F-16 engine provider. Its F110-GE-100 turbofan, however, required modification of the F-16’s inlet; the original inlet limited the GE jet’s maximum thrust to only 25,735 lbf (114.5 kN), while the new Modular Common Inlet Duct allowed the F110 to achieve its maximum thrust of 28,984 lbf (128.9 kN) in afterburner. (To distinguish between aircraft equipped with these two engines and inlets, from the Block 30 series on, blocks ending in "0" (e.g., Block 30) are powered by GE, and blocks ending in "2" (e.g., Block 32) are fitted with Pratt & Whitney engines.)

Further development by these competitors under the Increased Performance Engine (IPE) effort led to the 29,588 lbf (131.6 kN) F110-GE-129 on the Block 50 and 29,100 lbf (129.4 kN) F100-PW-229 on the Block 52. F-16s began flying with these IPE engines on 22 October 1991 and 22 October 1992, respectively. Altogether, of the 1,446 F-16C/Ds ordered by the USAF, 556 were fitted with F100-series engines and 890 with F110s. The United Arab Emirates’ Block 60 is powered by the General Electric F110-GE-132 turbofan, which is rated at a maximum thrust of 32,500 lbf (144.6 kN), the highest ever developed for the F-16 aircraft.

Trivia

 * Over 4,400 F-16s have been sold to 25 foreign air forces.

Aces



 * Bill (STFS/AC)
 * Tallman (URF/AC2)
 * Metal Sphere (URF/AC2)
 * Tempel (FEAF/AC4)
 * Trinker (BAF/ACZ)
 * UAF 6th AD 4th AFU/Crow Squadron (UAF/ACZ)
 * BAF 51st AD, 126th TFS/Silber Squadron (BAF/ACZ)
 * Ice (LAF/ACX)
 * Windhover Squadron (REAF/AC6)
 * Garuda Team (REAF/AC6)

Armament

 * Gun: 1x 20mm M61A1 Vulcan Cannon
 * Missiles: AIM-9M Sidewinder
 * LAGM: AGM-88 HARM (ACZ & ACX)
 * RCL: LAU-69 Rocket Pods (ACX & AC6)
 * UGBL: Mk-84 (ACZ)
 * UGBS: Mk-82 (AC04 & AC6)
 * UGBM: Mk-83( AC5)
 * XAGM: AGM-65G Maverick (AC04)
 * XMAA: AIM-120C AMRAAM (ACZ, ACX)
 * XMA4: AIM-120C AMRAAM (AC6)

Ace Combat

 * Stability: 10
 * Defense: 10
 * Offense: 50
 * Power: 100
 * Mobility: 90

Ace Combat 2

 * Power: 70
 * Defense: 35
 * Mobility: 45
 * Stability: 65
 * Climbing Ability: 55
 * Air-to-Air: 60
 * Air-to-Ground: 60

Ace Combat 5/Zero

 * Speed: 73
 * Mobility: 44
 * Stability: 46
 * Defense: 46
 * Air-to-Air: 30
 * Air-to-Ground: 55

Comparable Aircraft

 * Mirage 2000C
 * MiG-29A Fulcrum
 * J-10 Vanguard
 * F/A-18C Hornet
 * F/A-18D Hornet
 * F-20A Tigershark
 * HAL Tejas
 * IAI Lavi
 * JF-17 Thunder
 * JAS-39C Gripen
 * EF-2000 Typhoon

Related Development

 * F-16C Block 60
 * F-16XL
 * F-16XF Gyrfalcon
 * F-16XA Sakerfalcon
 * F-2A Viper Zero
 * T-50 Golden Eagle
 * F-CK-1 Ching-kuo
 * KF-16C/D Block 52 Fighting Falcon (F-16C built under license by Korean Aerospace Industries).