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Friday, August 30, 2013

General Dynamics F-16 Fighting Falcon

From Wikipedia, the free encyclopedia

F-16 Fighting Falcon
Aerial view of jet aircraft, carrying cylindrical fuel tanks and ordnance, overflying desert
A USAF F-16C over Iraq in 2008
Role Multirole fighter aircraft
National origin United States
Manufacturer General Dynamics
Lockheed Martin
First flight 20 January 1974
Introduction 17 August 1978
Status In service, in production
Primary users United States Air Force
25 other users (see operators page)
Number built 4,500+
Unit cost F-16A/B: US$14.6 million (1998 dollars)[1]
F-16C/D: US$18.8 million (1998 dollars)[1]
Variants General Dynamics F-16 VISTA
Developed into Vought Model 1600
General Dynamics F-16XL
Mitsubishi F-2
The General Dynamics (now Lockheed Martin) F-16 Fighting Falcon is a single-engine multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful all-weather multirole aircraft. Over 4,500 aircraft have been built since production was approved in 1976.[2] Although no longer being purchased by the U.S. Air Force, improved versions are still being built for export customers. In 1993, General Dynamics sold its aircraft manufacturing business to the Lockheed Corporation,[3] which in turn became part of Lockheed Martin after a 1995 merger with Martin Marietta.[4]
The Fighting Falcon is a fighter with numerous innovations including a frameless bubble canopy for better visibility, side-mounted control stick to ease control while maneuvering, a seat reclined 30 degrees to reduce the effect of g-forces on the pilot, and the first use of a relaxed static stability/fly-by-wire flight control system helps to make it a nimble aircraft. The F-16 has an internal M61 Vulcan cannon and 11 locations for mounting weapons and other mission equipment. The F-16's official name is "Fighting Falcon", but "Viper" is commonly used by its pilots, due to a perceived resemblance to a viper snake as well as the Battlestar Galactica Colonial Viper starfighter.[5][6]
In addition to active duty U.S. Air Force, Air Force Reserve Command, and Air National Guard units, the aircraft is also used by the USAF aerial demonstration team, the U.S. Air Force Thunderbirds, and as an adversary/aggressor aircraft by the United States Navy. The F-16 has also been procured to serve in the air forces of 25 other nations.[7]

Development

Lightweight Fighter Program

Experience in the Vietnam War revealed the need for air superiority fighters and better air-to-air training for fighter pilots.[8] Based on his experiences in the Korean War and as a fighter tactics instructor in the early 1960s Colonel John Boyd with mathematician Thomas Christie developed the Energy-Maneuverability theory to model a fighter aircraft's performance in combat. Boyd's work called for a small, lightweight aircraft that could maneuver with the minimum possible energy loss, and which also incorporated an increased thrust-to-weight ratio.[9][10] In the late 1960s, Boyd gathered a group of like-minded innovators that became known as the Fighter Mafia and in 1969 they secured DoD funding for General Dynamics and Northrop to study design concepts based on the theory.[11][12]
Air Force F-X proponents remained hostile to the concept because they perceived it as a threat to the F-15 program. However, the Advanced Day Fighter concept, renamed F-XX gained civilian political support under the reform-minded Deputy Secretary of Defense David Packard, who favored the idea of competitive prototyping. As a result in May 1971, the Air Force Prototype Study Group was established, with Boyd a key member, and two of its six proposals would be funded, one being the Lightweight Fighter (LWF). The Request for Proposals issued on 6 January 1972 called for a 20,000-pound (9,100 kg) class air-to-air day fighter with a good turn rate, acceleration and range, and optimized for combat at speeds of Mach 0.6–1.6 and altitudes of 30,000–40,000 feet (9,100–12,000 m). This was the region where USAF studies predicted most future air combat would occur. The anticipated average flyaway cost of a production version was $3 million. This production plan, though, was only notional as the USAF had no firm plans to procure the winner.[13][14]

Finalists selected and flyoff

Two jet aircraft flying together over mountain range and cloud
A right side view of a YF-16 (foreground) and a Northrop YF-17, each armed with AIM-9 Sidewinder missiles.
 
Five companies responded and in 1972, the Air Staff selected General Dynamics' Model 401 and Northrop's P-600 for the follow-on prototype development and testing phase. GD and Northrop were awarded contracts worth $37.9 million and $39.8 million to produce the YF-16 and YF-17, respectively, with first flights of both prototypes planned for early 1974. To overcome resistance in the Air Force hierarchy, the Fighter Mafia and other LWF proponents successfully advocated the idea of complementary fighters in a high-cost/low-cost force mix. The "high/low mix" would allow the USAF to be able to afford sufficient fighters for its overall fighter force structure requirements. The mix gained broad acceptance by the time of the prototypes' flyoff, defining the relationship of the LWF and the F-15.[15][16]
The YF-16 was developed by a team of General Dynamics engineers led by Robert H. Widmer.[17] The first YF-16 was rolled out on 13 December 1973, and its 90-minute maiden flight was made at the Air Force Flight Test Center (AFFTC) at Edwards AFB, California, on 2 February 1974. Its actual first flight occurred accidentally during a high-speed taxi test on 20 January 1974. While gathering speed, a roll-control oscillation caused a fin of the port-side wingtip-mounted missile and then the starboard stabilator to scrape the ground, and the aircraft then began to veer off the runway. The GD test pilot, Phil Oestricher, decided to lift off to avoid crashing the machine, and safely landed it six minutes later. The slight damage was quickly repaired and the official first flight occurred on time. The YF-16's first supersonic flight was accomplished on 5 February 1974, and the second YF-16 prototype first flew on 9 May 1974. This was followed by the first flights of the Northrop's YF-17 prototypes on 9 June and 21 August 1974, respectively. During the flyoff, the YF-16s completed 330 sorties for a total of 417 flight hours;[18] the YF-17s flew 288 sorties, covering 345 hours.[19]

Air Combat Fighter competition

Increased interest would turn the LWF into a serious acquisition program. North Atlantic Treaty Organization (NATO) allies Belgium, Denmark, the Netherlands, and Norway were seeking to replace their F-104G fighter-bombers.[20] In early 1974, they reached an agreement with the U.S. that if the USAF ordered the LWF winner, they would consider ordering it as well. The USAF also needed to replace its F-105 and F-4 fighter-bombers. The U.S. Congress sought greater commonality in fighter procurements by the Air Force and Navy, and in August 1974 redirected Navy funds to a new Navy Air Combat Fighter (NACF) program that would be a navalized fighter-bomber variant of the LWF. The four NATO allies had formed the "Multinational Fighter Program Group" (MFPG) and pressed for a U.S. decision by December 1974; thus the USAF accelerated testing.[21][22][23]

YF-16 on display at the Virginia Air and Space Center
 
To reflect this more serious intent to procure a new fighter-bomber design, the LWF program was rolled into a new Air Combat Fighter (ACF) competition in an announcement by U.S. Secretary of Defense James R. Schlesinger in April 1974. Schlesinger also made it clear that any ACF order would be for aircraft in addition to the F-15, which extinguished opposition to the LWF.[22][23] ACF also raised the stakes for GD and Northrop because it brought in competitors intent on securing what was touted at the time as "the arms deal of the century".[24] These were Dassault-Breguet's proposed Mirage F1M-53, the SEPECAT Jaguar, and the proposed Saab 37E "Eurofighter". Northrop offered the P-530 Cobra, which was similar to the YF-17. The Jaguar and Cobra were dropped by the MFPG early on, leaving two European and the two U.S. candidates. On 11 September 1974, the U.S. Air Force confirmed plans to place an order for the winning ACF design to equip five tactical fighter wings. Though computer modeling predicted a close contest, the YF-16 proved significantly quicker going from one maneuver to the next, and was the unanimous choice of those pilots that flew both aircraft.[25] On 13 January 1975, Secretary of the Air Force John L. McLucas announced the YF-16 as the winner of the ACF competition.[26]
The chief reasons given by the Secretary were the YF-16's lower operating costs, greater range, and maneuver performance that was "significantly better" than that of the YF-17, especially at supersonic speeds. Another advantage of the YF-16 – unlike the YF-17 – was its use of the Pratt & Whitney F100 turbofan engine, the same powerplant used by the F-15; such commonality would lower the cost of engines for both programs.[27] Secretary McLucas announced that the USAF planned to order at least 650, possibly up to 1,400 production F-16s. In the Navy Air Combat Fighter (NACF) competition, on 2 May 1975 the Navy selected the YF-17 as the basis for what would become the McDonnell Douglas F/A-18 Hornet.[28][29]

Into production

Upright aerial photo of gray jet aircraft flying above clouds.
A F-16C of the Colorado Air National Guard with AIM-9 Sidewinder missiles and a centerline fuel tank (300 gal capacity) after disengaging from a refueling boom.
 
The U.S. Air Force initially ordered 15 "Full-Scale Development" (FSD) aircraft (11 single-seat and four two-seat models) for its flight test program, but this was reduced to eight (six F-16A single-seaters and two F-16B two-seaters).[30] The YF-16 design was altered for the production F-16. The fuselage was lengthened by 10.6 in (0.269 m), a larger nose radome was fitted for the AN/APG-66 radar, wing area was increased from 280 sq ft (26 m2) to 300 sq ft (28 m2), the tailfin height was decreased, the ventral fins were enlarged, two more stores stations were added, and a single door replaced the original nosewheel double doors. The F-16's weight was increased by 25% over the YF-16 by these modifications.[31][32]
The FSD F-16s were manufactured at General Dynamics' Fort Worth, Texas plant in late 1975; the first F-16A rolled out on 20 October 1976 and first flew on 8 December. The initial two-seat model achieved its first flight on 8 August 1977. The initial production-standard F-16A flew for the first time on 7 August 1978 and its delivery was accepted by the USAF on 6 January 1979. The F-16 was given its formal nickname of "Fighting Falcon" on 21 July 1980, entering USAF operational service with the 34th Tactical Fighter Squadron, 388th Tactical Fighter Wing at Hill AFB on 1 October 1980.[33]
On 7 June 1975, the four European partners, now known as the European Participation Group, signed up for 348 aircraft at the Paris Air Show. This was split among the European Participation Air Forces (EPAF) as 116 for Belgium, 58 for Denmark, 102 for the Netherlands, and 72 for Norway. There would be two European production lines, one in the Netherlands at Fokker's Schiphol-Oost facility and the other at SABCA's Gossellies plant in Belgium; production would be divided among them as 184 and 164 units, respectively. Norway's Kongsberg Vaapenfabrikk and Denmark's Terma A/S also manufactured parts and subassemblies for EPAF aircraft. European co-production was officially launched on 1 July 1977 at the Fokker factory. Beginning in November 1977, Fokker-produced components were sent to Fort Worth for fuselage assembly, which were in turn shipped back to Europe for final assembly of EPAF aircraft at the Belgian plant on 15 February 1978, with deliveries to the Belgian Air Force from January 1979. The Dutch line started up in April 1978 and delivered its first aircraft to the Royal Netherlands Air Force in June 1979. In 1980 the first aircraft were delivered to the Royal Norwegian Air Force by SABCA and to the Royal Danish Air Force by Fokker.[34][35]
During the late 1980s and 1990s, Turkish Aerospace Industries (TAI) produced 232 Block 30/40/50 F-16s on a production line in Ankara under license for the Turkish Air Force. TAI also produced 30 Block 50 from 2010, and built 46 Block 40s for Egypt in the mid-1990s. Korean Aerospace Industries opened a domestic production line for the KF-16 program, producing 140 Block 52s from the mid-1990s to mid-2000s (decade). If India had selected the F-16IN for its Medium Multi-Role Combat Aircraft procurement, a sixth F-16 production line would be built in India.[36]

Improvements and upgrades

One change made during production was augmented pitch control to avoid deep stall conditions at high angles of attack. The stall issue had been raised during development, but had originally been discounted in the early design stages. Model tests of the YF-16 conducted by the Langley Research Center revealed a potential problem, but no other laboratory was able to duplicate it. YF-16 flight tests were not sufficient to expose the issue; it required later flight testing on the FSD aircraft to demonstrate there was a real concern. In response, the areas of the horizontal stabilizer were increased 25% on the Block 15 aircraft in 1981 and retrofitted later on to earlier aircraft. In addition, a manual override switch to disable the horizontal stabilizer flight limiter was placed more prominently on the control console, allowing the pilot to regain control of the horizontal stabilizers (which the flight limiters otherwise lock in place) and recover. Besides a significant reduction in the risk of deep stalls, the larger horizontal tail also improved stability and permitted faster takeoff rotation.[37][38]
In the 1980s, the Multinational Staged Improvement Program (MSIP) was conducted to evolve new capabilities for the F-16, mitigate risks during technology development, and ensure the aircraft's worth. The program upgraded the F-16 in three stages. The MSIP process permitted the introduction of new capabilities quicker, at lower costs and with reduced risks, compared to traditional independent programs to upgrade and modernize aircraft.[39] Other upgrade programs, including service life extensions, have been conducted on the F-16.[40]
Due to the slow pace of F-35 development, the USAF will spend $2.8 billion to upgrade and retain 350 F-16s.[41] The more versatile multirole F-16s are being retained as the USAF reduces more focused platforms such as the A-10.[42] One limitation on the upgrades has been the limited power and cooling capabilities of the aircraft, which have been stretched thinner in more advanced variants with more power hungry avionics.[43]
While Lockheed has won most of the contracts to upgrade F-16s for different countries, BAE Systems, through its MTC Technologies subsidiary, gained the South Korean upgrade order in July 2012.[44] In the fall of 2012, the USAF assigned the total upgrade contract to Lockheed, bundling in the radar selection in order to have a more cohesive package.[45] This includes Raytheon’s Center Display Unit, which will replace several analog flight instruments in a single digital display.[46]

Continued production

In May 2013, Lockheed Martin stated it has enough orders to keep producing F-16s until 2017, with more orders possible.[47]

Design

Overview

Comparison between F-16's inset cannons; early aircraft had four vents, while later aircraft had two.
 
The F-16 is a single-engine, very maneuverable, supersonic, multi-role tactical fighter 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, and reclined seat to reduce g-force effects on the pilot. The F-16 has an internal M61 Vulcan cannon in the left wing root and has multiple locations 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.[1]
The F-16 was designed to be relatively inexpensive to build and 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. The leading-edge flaps, tailerons, and ventral fins make use of bonded aluminum honeycomb structures and graphite epoxy laminate coatings. The number of lubrication points, fuel line connections, and replaceable modules is significantly lower than predecessors; 80% of access panels can be accessed without stands.[36] The air intake was designed: "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."[48]
Although the LWF program called for an aircraft structural life of 4,000 flight hours, capable of achieving 7.33 g with 80% internal fuel; GD's engineers decided to design the F-16's airframe life for 8,000 hours and for 9-g maneuvers on full internal fuel. This proved advantageous when the aircraft's mission changed from solely air-to-air combat to multi-role operations. Since introduction, changes in operational usage and additional systems have increased aircraft weight, necessitating several programs to strengthen its structure.[49]

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