The F-16 Fighting Falcon (commonly called "Viper") was manufactured by General Dynamics from 1974 to 1993, Lockheed Corporation from 1993 to 1995, and since 1995, it has been manufactured by Lockheed Martin. The F-16 variants, along with major modification programs and derivative designs significantly influenced by the F-16, are detailed below.

Pre-production variants

YF-16

Two single-seat YF-16 prototypes were built for the Light Weight Fighter (LWF) competition. The first YF-16 was rolled out at Fort Worth on 13 December 1973 and accidentally accomplished its first flight on 21 January 1974, followed by its scheduled "first flight" on 2 February 1974. The second prototype first flew on 9 March 1974. Both YF-16 prototypes participated in the flyoff against the Northrop YF-17 prototypes, with the F-16 winning the Air Combat Fighter (ACF) competition, as the LWF program had been renamed.

72-1567 - on display at the Virginia Air and Space Science Center in Hampton, Virginia."Aircraft." Virginia Air & Space Science Center. Retrieved: 11 July 2023. 72-1568 - under restoration for display at the Fort Worth Aviation Museum in Fort Worth, Texas."YF-16 #2 Fighting Falcon." Fort Worth Aviation Museum. Retrieved: 11 July 2023.

F-16 FSD In January 1975, the Air Force ordered eight full-scale development (FSD) F-16s – six single-seat F-16A and a pair of two-seat F-16B – for test and evaluation. The first FSD F-16A flew on 8 December 1976 and the first FSD F-16B on 8 August 1977. Over the years, these aircraft have been used as test demonstrators for a variety of research, development and modification study programs.

F-16A (FSD) 75-745 - modified as F-16/101 with GE F101 engine. Used as a travelling exhibit for USAF recruiting service.< 75-746 - Gate guard at McEntire ANGB, South Carolina. 75-747 - modified as F-16XL/B with cranked-arrow. On display at the Air Force Flight Test Museum at Edwards Air Force Base near Rosamond, California."Aircraft Inventory List." Air Force Flight Test Museum. Retrieved: 31 July 2023. 75-748 - on display at the Air Force Academy in Colorado Springs, Colorado. 75-749 - modified as F-16XL/A with cranked-arrow wing. In storage at the Air Force Flight Test Museum at Edwards Air Force Base near Rosamond, California. 75-750 - modified as AFTI test bed. In storage at the National Museum of the United States Air Force."General Dynamics NF-16A AFTI." National Museum of the United States Air Force. Retrieved: 31 July 2023.

F-16B (FSD) 75-751 - in storage at the Air Force Flight Test Museum at Edwards Air Force Base near Rosamond, California. 75-752 - modified as Wild Weasel test bed, later modified as F-16/79 with GE J79. On display at the Frontiers of Flight Museum in Dallas, Texas."General Dynamics YF-16B Fighting Falcon." Frontiers of Flight Museum. Retrieved: 31 July 2023.

Main production variants BlocksModelsEngine1–15F-16A/BPW F100-PW-20015OCU, 20F-16A/BPW F100-PW-22025,32,42F-16C/DPW F100-PW-220E30,40F-16C/DGE F110-GE-10050,70F-16C/D/VGE F110-GE-12952,72F-16C/D/VPW F100-PW-22960F-16E/FGE F110-GE-132

F-16A/B

The F-16A (single seat) and F-16B (two seat) were initially equipped with the Westinghouse AN/APG-66 pulse-doppler radar, Pratt & Whitney F100-PW-200 turbofan, rated at 14,670lbf (64.9kN) and 23,830lbf (106.0kN) with afterburner. The USAF bought 375 F-16As and 125 F-16Bs, with delivery completed in March 1985.

F-16A/B Block 1/5/10 Early blocks (Block 1/5/10) featured relatively minor differences between each. Most were later upgraded to the Block 10 configuration in the early 1980s. There were 94 Block 1, 197 Block 5, and 312 Block 10 aircraft produced. Block 1 is the early production model with the radome painted black.

It was discovered that the Block 1 aircraft's black radome became an obvious visual identification cue at long range, so the color of the radome was changed to the low-visibility grey for Block 5 aircraft. During the operation of F-16 Block 1, it was discovered that rainwater could accumulate in certain spots within the fuselage, so drainage holes were drilled in the forward fuselage and tail fin area for Block 5 aircraft.

The Soviet Union significantly reduced the export of titanium during the late 1970s, so the manufacturers of the F-16 used aluminum instead wherever practical. New methods were also used: the corrugated aluminum is bolted to the epoxy surface for Block 10 aircraft, replacing the old method of aluminum honeycomb being glued to the epoxy surface used in earlier aircraft.

The breakdown is as follows: 90 F-16A Block 1, 4 F-16B Block 1, 100 F-16A Block 5, 97 F-16B Block 5, 300 F-16A Block 10, and 12 F-16B Block 10. It is unclear how many of each type were produced, but these figures are generally reasonable. As mentioned above, 375 A-types and 125 B-types were delivered to the U.S. Air Force, and the remaining aircraft were exported.

F-16A/B Block 15 The first major change in the F-16, the Block 15 aircraft featured larger horizontal stabilators, the addition of two hardpoints to the inlet chin, an improved AN/APG-66(V)2 radar, an extra aerial refueling light located on the vertical stabilizer, and increased capacity for the underwing hardpoints. The Block 15 also gained the Have Quick II secure UHF radio. To counter the additional weight of the new hardpoints, the horizontal stabilizers were enlarged by 30%. Furthermore, the lower UHF/IFF antenna, the lower threat warning antenna, the total air temperature probe and two ambient air sense ports, originally located on the inlet chin, were relocated due to the placement of the new hardpoints.

The Block 15 is the most numerous variant of the F-16, with 983 produced. Nine hundred F-16A Block 15s and eighty-three F-16B Block 15s were produced and rolled out, the last of which was delivered to the Royal Thai Air Force in 1996.

F-16A/B Block 20 According to some sources, the F-16A/B variants for the Republic of China Air Force are designated F-16AM Block 20 and F-16BM Block 20. Other sources refer to them simply as F-16A/B Block 20 without reference to the "M" designation for Mid-Life Update. Block 20 added some F-16C/D block 50/52 capabilities: improved AN/APG-66(V)3 radar with added CW mode to guide two types of BVR missiles – AIM-7M Sparrow missiles and AIM-120 AMRAAM, carriage of AGM-84 Harpoon missiles, as well as the LANTIRN navigation and targeting pod. The Block 20 computers are significantly improved in comparison to that of the earlier versions that later integrated into post 1997 Block 50/52, and also getting color MFD. The Republic of China (Taiwan) received 150 F-16A/B Block 20 aircraft. Some sources refer to the F-16 Mid-Life Update as Block 20, but the Block 20 designation was specifically used for new-production jets with upgraded jets being referred to as MLU or Block 15 MLU. The breakdown is 100 F-16A Block 20 and 50 F-16B Block 20, but 10 A-models have been lost during missions. At one point, 14 aircraft were sent to the US mainland for training.

F-16C/D

F-16C (single seat) and F-16D (two seat). The final number of aircraft built and used by the US Air Force were 209 F-16C Block 25, 200 F-16C Block 30, 100 F-16C Block 32, 200 F-16C Block 40, 115 F-16C Block 42, 35 F-16D Block 25, 200 F-16D Block 30, 133 F-16D Block 32, 200 F-16D Block 40, and 100 F-16D Block 42. At this stage, the A/B models were retired and either exported, scrapped for parts, or mothballed and sent to storage facilities. Currently, with the introduction of the F-22 stealth fighter and the mass production of the F-35, the C/D models are being rapidly retired, and the current (2024) fleet remaining in the U.S. Air Force and National Guard consists of 123 F-16C Block 25, 200 F-16C Block 30, 100 F-16C Block 32, 200 F-16C Block 40, 115 F-16C Block 42, 37 F-16D Block 40, and 100 F-16D Block 42.

F-16C/D Block 25 The Block 25 F-16C first flew in June 1984 and entered USAF service in September. The aircraft version is fitted with the Westinghouse AN/APG-68 radar and has improved precision night-attack capability. Block 25 introduced a very substantial improvement in cockpit avionics, including improved fire-control and stores management computers, an Up-Front Controls (UFC) integrated data control panel, data-transfer equipment, multifunction displays, radar altimeter, and many other changes. Block 25s were first delivered with the Pratt & Whitney F100-PW-200 engine and later upgraded to the Pratt & Whitney F100-PW-220E. With 209 Block 25 C-models and 35 D-models delivered, today the USAF's Air National Guard and Air Education and Training Command are the only remaining users of this variant. One F-16C, nicknamed the "Lethal Lady", had flown over 7,000 hours by April 2008.

F-16C/D Block 30/32

This was the first block of F-16s affected by the Alternative Fighter Engine project under which aircraft were fitted with the traditional Pratt & Whitney engines or, for the first time, the General Electric F110-GE-100. From this point 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. The first Block 30 F-16 entered service in 1987. Major differences include the carriage of the AGM-45 Shrike, AGM-88 HARM, and the AIM-120 missiles, which entered service in September 1991. From Block 30D, aircraft were fitted with larger engine air intakes (called a Modular Common Inlet Duct) for the increased-thrust GE engine. Since the Block 32 retained the Pratt and Whitney F100 engine, the smaller (normal shock inlet) was retained for those aircraft. 200 F-16C Block 30, 200 F-16D Block 30, 100 F-16C Block 32, and 133 F-16D Block 32 were built. Of these, only the early Block 30s were exported to six countries. The Block 32H/J aircraft assigned to the USAF Thunderbird flight demonstration squadron were built in 1986 and 1987 and are some of the oldest operational F-16s in the Air Force.

The Air National Guard procured many upgrades for their fleet of aging block 32s including the addition of improved inertial guidance systems, improved electronic warfare suite (AN/ALQ-213), and upgrades to carry the Northrop Grumman LITENING targeting pod. The standard Inertial Navigation Unit (INU) was first changed to a ring laser gyro, and later upgraded again to an Embedded GPS/INS (EGI) system which combines a Global Positioning System (GPS) receiver with an Inertial navigation system (INS). The EGI provided the capability to use Joint Direct Attack Munition (JDAM) and other GPS-aided munitions (see Block 50 list below). This capability, in combination with the LITENING targeting pod, greatly enhanced the capabilities of this aircraft. The sum of these modifications to the baseline Block 30 is commonly known as the F-16C++ (pronounced "plus plus") version.

F-16C/D Block 40/42

Entering service in 1988, the Block 40/42 is the improved all-day/all-weather strike variant equipped with LANTIRN pod; also unofficially designated the F-16CG/DG, the night capability gave rise to the name "Night Falcons". This block features strengthened undercarriage for LANTIRN pods, an improved radar, and a GPS receiver. From 2002, the Block 40/42 increased the weapon range available to the aircraft including JDAM, AGM-154 Joint Standoff Weapon (JSOW), Wind-Corrected Munitions Dispenser (WCMD) and the (Enhanced) EGBU-27 Paveway "bunker-buster". Also incorporated in this block was the addition of cockpit lighting systems compatible with Aviator's Night Vision Imaging System (ANVIS) equipment. The USAF's Time Compliance Technical Order (TCTO) that added the night vision (NVIS)-compatible systems was completed in 2004. 200 F-16C Block 40, 200 F-16D Block 40, 115 F-16C Block 42, and 100 F-16D Block 42 were built. All served with the United States Air Force, but were later exported after being replaced by their successors.

F-16C/D Block 50/52