F-16 Fighting Falcon

The F-16 Fighting Falcon is a compact, multirole fighter aircraft. It is highly maneuverable and has proven itself in air-to-air combat and air-to-surface attack. It provides a relatively low-cost, high-performance weapon system for the United States and allied nations.

In an air combat role, the F-16's maneuverability and combat radius (distance it can fly to enter air combat, stay, fight and return) exceed that of all potential threat fighter aircraft. It can locate targets in all weather conditions and detect low flying aircraft in radar ground clutter. In an air-to-surface role, the F-16 can fly more than 500 miles (860 kilometers), deliver its weapons with superior accuracy, defend itself against enemy aircraft, and return to its starting point. An all-weather capability allows it to accurately deliver ordnance during non-visual bombing conditions.

F-16 pilots may suffer Gravity-induced loss of consciousness (GLOC) when conducting high-speed turns. When flyers are in a high-G, combat environment, aircraft acceleration presents the biggest demand on their bodies. The F-16 is a high technology aircraft that requires pilot physical conditioning to perform up to nine G maneuvers. Sharp turns can induce loss of consciousness when gravity pulls blood toward the lower extremities, carrying oxygen away from the brain. After about 5 seconds of pressure, vision is progressively lost from peripheral vision to central vision. When blood flow is allowed to resume, vision is smoothly and rapidly recovered. Cerebral failure and recovery is much less graceful and predictable (Houghton, McBride, & Hannah, 1985). After about 5 seconds of blood flow stoppage to the brain, GLOC occurs suddenly and lasts from 10 to 30 seconds (average about 13 seconds). When consciousness is regained, it is usually accompanied by brief seizure-like activity and a period of confusion,which lasts about 12 seconds. During this 12 seconds, the aviator is unable to function effectively. An additional period of up to 2 minutes is required before cognitive and psychomotor performance ability recovers to normal. GLOC is a real threat to F-16 pilots. Over the lifetime of the F-16, by 2007 the US Air Force had lost 12 pilots and 16 aircraft to GLOC. GLOC is not a new problem, it has been around for every 70 years. Because of the emergence of high performance aircraft such as the F-16 and the fact that these aircraft can perform beyond the acceleration tolerance limits of the human, GLOC became the U.S. Tactical Air Force's second most serious human factors problem, second only to spatial disorientation.

The F-16 was built under an unusual agreement creating a consortium between the United States and four NATO countries: Belgium, Denmark, the Netherlands and Norway. These countries jointly produced with the United States an initial 348 F-16s for their air forces. Final airframe assembly lines were located in Belgium and the Netherlands. The consortium's F-16s are assembled from components manufactured in all five countries. Belgium also provides final assembly of the F100 engine used in the European F-16s. The long-term benefits of this program was technology transfer among the nations producing the F-16, and a common-use aircraft for NATO nations. This program increases the supply and availability of repair parts in Europe and improves the F-16's combat readiness.

USAF F-16 multi-mission fighters were deployed to the Persian Gulf in 1991 in support of Operation Desert Storm, where more sorties were flown than with any other aircraft. These fighters were used to attack airfields, military production facilities, Scud missiles sites and a variety of other targets.

Originally conceived as a simple air-superiority day fighter, the aircraft was armed for that mission with a single six-barrel Vulcan 20-mm cannon and two Sidewinder missiles, one mounted at each wingtip. Over the years, however, the mission capability of the aircraft has been extended to include ground-attack and all-weather operations With full internal fuel, the aircraft can carry up to 12 000 pounds of external stores including various types of ordnance as well as fuel tanks.

The original F-16 was designed as a lightweight air-to-air day fighter. Air-to-ground responsibilities transformed the first production F-16s into multirole fighters. The empty weight of the Block 10 F-16A is 15,600 pounds. The empty weight of the Block 50 is 19,200 pounds. The A in F-16A refers to a Block 1 through 20 single-seat aircraft. The B in F-16B refers to the two-seat version. The letters C and D were substituted for A and B, respectively, beginning with Block 25. Block is an important term in tracing the F-16's evolution. Basically, a block is a numerical milestone.The block number increases whenever a new production configuration for the F-16 is established. Not all F-16s within a given block are the same. They fall into a number of block subsets called miniblocks. These sub-block sets are denoted by capital letters following the block number (Block 15S, for example). From Block 30/32 on, a major block designation ending in 0 signifies a General Electric engine; one ending in 2 signifies a Pratt & Whitney engine.

The US Air Force took delivery of its last F-16 Fighting Falcon on March 18, 2005, the last of 2,231 F-16s produced for the Air Force. The first delivery was in 1978.

In 2004 ACC solicited Boeing and Lockheed Martin for pricing information proposals to purchase additional F-15 and F-16 aircraft. The request was for as many as two fighter wings or 140 aircraft. This request by ACC was discovered by senior program and acquisition mangers — F-16s and F-15s in service will reach the end of their service life before replacement aircraft are fielded.14 The motivation to purchase more aircraft may have been risk aversion for any additional delays in the F-22 or predicted developmental delays of the F-35.

Some argue that the Air Force could purchase the F-16C block 50 and keep the F-16 production lines open. The need to compete for dollars in a fiscally constrained environment would cease, since there would be a logical sequence of purchasing enhanced F-16s as the Navy did with the F/A-18E/F. This F-16 purchase could serve as an insurance policy with aircraft delivered from 2005 to 2010. The result, should Congress delay or cancel the F-35 (as in the case of the F-22, C-17, and others), would be a manned fighter stopgap until the F-35 [or UCAV] is in full production.


Service Life

The F-16 fleet consists of several different configurations that were acquired in a long and successful evolutionary program. The Air Force has invested billions over the years to upgrade capabilities, engines, and structural enhancements needed to achieve its original life expectancy of 8,000 hours. Significant unknowns exist about extending the life beyond 8,000 hours should that be necessary. The oldest F-16s are to be retired by 2010, and the Air Force has halted modifications and funding for these aircraft.

As of 2007 the Air Force was not currently purchasing any new F-16’s, but the contractor was still producing them for foreign sale. The production is slated to continue past 2009 to accommodate recent sales. If the Air Force were to buy new aircraft, officials estimated that it would cost $380 million for development and about $50 million per aircraft procured.

In April 1990, the Secretary of Defense announced that a review of the Air Force’s Advanced Tactical Fighter (ATF) program had found that the ATF is needed to replace the F-16 for the air superiority mission, but its production could be delayed because of changed world conditions and the possibility of a longer F-16 service life. The review showed that ATF production could be delayed because of a reduced conventional threat in Europe and indications that the life of the F-16 airframe could be extended beyond the year 2000. The Secretary directed that the initial production of the ATF be delayed from fiscal year 1994 to 1996.

The US Air Force’s Multi-Role Fighter (MRF) program began in 1991 as a relatively low-cost F-16 replacement. Similar in size to the F-16, the MRF was to have been a single-seat / single-engine aircraft, with a unit flyaway cost in the range of $35 to $50 million. A formal program start was expected around 1994. The MRF was expected to replace a large number of F-16s reaching the end of service life. The MRF might also have replaced Air Force A-10s and Navy F/A-18C/Ds. However, the post-Cold War defense drawdown made the F-16 service life situation considerably less critical. A reduction in the total number of U.S. Air Force fighter wings meant that the existing aircraft would not be replaced one-for-one. Furthermore, F-16 aircraft flying hours were reduced, allowing F-16s to remain in service longer than originally projected. In August 1992, the MRF program was effectively put on hold.

The readiness of America’s Armed Forces generally deteriorated throughout the 1990s. During this time, combat readiness of the Air Force fighter aircraft declined in varying degrees. One indicator of aircraft combat readiness, the mission capable (MC) rate, is used to identify the percentage of aircraft able to perform their primary wartime missions. The not mission capable (NMC) rate shows the converse. From fiscal year (FY) 1991 through fall 2001, the aggregate Air Force aircraft total not mission capable rate for maintenance (TNMCM) for all aircraft steadily increased from 7.6 percent to 18.1 percent while total not mission capable rate for supply (TNMCS) increased from 5.5 percent in FY86 to 13.4 percent in FY01.

The F-16 "sustainment crisis" in the late 1990s resulted from an inadequate life-cycle sustainment strategy, which negatively affected aircraft readiness. Preliminary analysis obtained from AFLMA’s TNMCM study of the F-16 block 42 aircraft revealed the total man-hours expended on TCTOs increased 120 percent from FY95 to FY99 and the man-hours per TCTO event increased 69 percent, indicating TCTOs may be becoming more manpower intensive and technically challenging. The analysis also indicated that low manning and fewer experienced technicians contributed to increases in man-hours required to complete them.

As a system’s cumulative operating time increases, the probability of its failure tends to increase, decreasing the system’s potential reliability. Reliability also decreases when the conditions under which the system was designed to operate change. Many of these aircraft are at critical points in their life cycles. For example, by 2001 many F-16s had reached 2,400 hours flying time, a significant point in an 8,000-hour service life. As these aircraft age and operating conditions changed, the reliability of systems and components decreases, and failures occur more often, which increased maintenance costs. Increased failures affect aircraft maintainability, requiring more maintenance and often increasing repair times when more hard breaks occur. In the case of the F-16, operational usage had been more severe than design usage (eight times more), resulting in the acceleration of its airframe service life at a rate that may not let it reach its expected overall service life.

The mission-capable rate for Air Force Reserve F-16s increased from 69.7% in fiscal 2001 to 76.3% during the first three months of fiscal 2002, despite Operation Noble Eagle flight activity.

In the late 1990s, the Air Force Reserve Component [ARC] recognized there was no follow-on replacement for the F-16 and reduced the annual flying-hour program in ANG and AFRC squadrons to 210 airframe hours per year. This number is a generalization with some fighter squadrons flying more to support spinup training and actual overseas AEF deployment rotations of Northern and Southern Watch. However, in 2002 and 2003, the aircraft were flown an average 300 hours per aircraft, way beyond their programmed 210 flying hours used in support of contingencies at home and abroad. Fiscal year (FY) 2002 saw ANG and AFRC aircraft heavily taxed in support of Operation Noble Eagle. Combat air patrol flying conditions were favorable to slow the effect of upper and wing-support bulkhead cracking caused by excessive wing root bending movement. FY03 saw continued support for Operation Enduring Freedom (Afghanistan) and excessive use of F-16C aircraft supporting Operation Iraqi Freedom. These contingencies resulted in additional stress on the bulkheads and airframes alike. This was caused by excessive munition loads and heavy landings to deliver the payload during combat in support of close air support and air interdiction missions.

Simple calculation of 210 airframe and flying hours per year would mean the fleet would be able to support missions for another 19 years. At 300 airframe and flying hours, that number is reduced to 13 years or a 32- percent reduction. These numbers are actual flight hours. To receive a true meaning of the impact on the airframe, one needs to calculate using equivalent flight hours. Equivalent flight hours are the actual accounting of structural degradation that is determined from damage index data stored in the individual aircraft-tracking database, which is part of the aircraft structural integrity program.

The Falcon Up Structural Improvement Program program incorporates several major structural modifications into one overall program, affecting all USAF F-16s. Falcon Up will allow Block 25/30/32 aircraft to meet a 6000 hour service life, and allow Block 40/42 aircraft to meet an 8000 hour service life. Falcon UP and the Falcon STAR programs include numerous depot level structural modifications required to extend the service life of all F-16 aircraft to 8,000 hours. The F-16 CUPID program brought older F-16s (Blocks 25-32) new life by adding night vision equipment, enhanced avionics, and the ability to carry an infrared targeting pod and laser-guided munitions. Ultimately, CUPID-modified aircraft will have the capability to carry JDAM and other GPS-guided munitions. A small decrease in Ogden Air Logistics Center (OO-ALC) capacity in the outyears is due to the completion of the F-16 Falcon-up Program and to a decrease in the F-16 Service Life Improvement Program (SLIP) quantity.

In view of the challenges inherent in operating F-16s to 8,000 flight hours, together with the moderate risk involved in JSF integration, the Department established a program to earmark by FY 2000 some 200 older, Block 15 F-16 fighter aircraft in inactive storage for potential reactivation. The purpose of this program was to provide a basis for constituting two combat wings more quickly than would be possible through new production. This force could offset aircraft withdrawn for unanticipated structural repairs or compensate for delays in the JSF program. Reactivating older F-16s was not a preferred course of action, but represented a relatively low-cost hedge against such occurrences.

One analysis in 2002 estimated that by fiscal year 2008, the Air Force would have a 108-fighter deficit based on a 20 Fighter Wing Equivalent requirement, with that number growing to 311 by fiscal year 2021. These numbers were based on the today's programmed F-16 attrition rate of 3.6%, an estimated 8,000-hour F-16 service life, and fielding of the Joint Strike Fighter beginning in fiscal year 2009.

Even relatively “young” aircraft like the F-16 (average age 9 years in 1998) are affected by age: skin corrosion, bulkhead cracks and landing gear wear are common. The F-16 Service Life Extension Program (SLEP) extends the F-16A/B service life to 8,000 hours at a cost of $703K per aircraft in Fiscal Year 98. The F-16 Pre-Block 40 aircraft were developing structural cracks that must be repaired. As of 1999 an estimated 152 aircraft could be grounded due to structural cracks within the next two years. The Air Force’s fiscal year 1999 appropriations included $15 million to define a service life extension program and capability enhancement package for F-16- aircraft. But the Air Force did not plan to define this life extension program or the capability enhancement package. The F-16 Service Life Extension Program was completed in FY 2003.

FALCON STAR (Structural Augmentation Roadmap) is an effort to modify the airframe to allow the F-16 to reach the original 8,000 hours estimated for its flight life. The roughly $1 billion program is the result of more than four years of design and planning and ensures the F-16's original service life while allowing for an operational capability beyond the year 2020. Falcon STAR will allow the aircraft to remain in service through 2025. The first F-16 fighter jet to be a part of Falcon STAR, was handed off in February 2004 to members of the 148th Fighter Wing, Minnesota Air National Guard. The planning for the Falcon STAR program began in 1999. Aircraft modifications will continue through 2014, the majority of which will be performed at Hill AFB. By program's end, more than American 1,200 F-16s will have been modified including active-duty, Air National Guard and Air Force Reserve aircraft. As of 2005 a total of more than 2,000 aircraft were to be modified by 2014. Participants in the program include the Air Force and air forces in Belgium, Denmark, the Netherlands, Norway, Portugal, Israel, Greece, Singapore, Thailand and Bahrain. On average, it takes 175 days to modify an aircraft with the Falcon STAR kit.

Falcon STAR is a US Air Force-managed structural modification program for the F-16 that addresses service-life deficiencies for the Air Force. Falcon STAR modifications are applied to existing aircraft and added to all new F-16's to compensate for aircraft stress increased usage rates and heavier gross weights cause. Each aircraft, which uses an array of weaponry from GPS guided bombs to radar-guided air-to-air missiles, has a current [2007] maximum operational weight of approximately 39,000 pounds; the old, designed weight for the F-16 was only 22,500 pounds. Originally designed primarily for air-to-air missions, in practice it has mainly been used for air-to-ground operations.

Due to increased workload and weight that exceed the original specifications of the aircraft, the F-16 must be structurally modified to compensate for the increases. A number of common avionics and capabilities upgrades are necessary to provide increased processor speed and memories, color displays, and incorporate the Joint Helmet Mounted Cueing System. The F110 engine service life extension program addresses safety, reliability and maintainability concerns and new engines for the Block 42 aircraft will provide needed thrust improvements.

Under the Falcon STAR program, maintainers replace or repair known life-limited structures to avoid the onset of widespread fatigue damage. This is done to maintain flight safety, enhance aircraft availability and extend the life of affected components. Before Falcon STAR, some aircraft exhibited fatigue damage as early as 3,500 hours, he said. Once modified, the aircraft will meet its designed service life of 8,000 flight hours. The entire program involves modifying 13 different structural components, including wing fittings, and reworking skin areas. F-16 system program office experts at the Ogden Air Logistics Center manage the Falcon STAR program. Somewhere between 40 and 100 iterations of the kit are expected. The kit configuration is constantly changing because of the different aircraft configurations.

By 2007 the F-16C/D fleet was in the midst of standardizing capabilities through the Common Configuration Implementation Program. This modification program is a combination of several upgrades to F-16 avionics that enable integration of advancedprecision weapons, Link-16 communications, improved situational awareness, and off-bore sight cueing of sensors and weapons. It provides for a new modular mission computer, color displays, advanced interrogator/transponder (Block SO/52only), Link-16 communication capability, and the joint helmet-mounted cueing system. It also enables the Block 40/42 aircraft to use the same operational flight program (OFP) software as the block SO/52 aircraft, which will reduce the sustainment cost of future OFPs. The FY08 PB requests $72.6M in FY08 to continue the modification of Block 40 aircraft. Block 50 modifications are complete.

Without improvements, as of 2007 it was estimated that almost 90 percent of the fleet would exceed design limits on engines by 2010. High usage, increased stresses, and more weight than planned threatened to cut life expectancy in half. Significant unknowns exist about extending the life beyond 8,000 hours should that be necessary. If it became necessary to enable the newest F-16 aircraft to reach a 10,000 flying hour life, a program official estimated in 2007 an additional cost of $2.2 billion for structural enhancements. The program office also identified another $3.2 billion in unfunded requirements, including radar upgrades to aircraft capable of suppressing enemy air defenses.


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