Northrop F-5

The Northrop F-5A/B Freedom Fighter and the F-5E/F Tiger II are part of a family of widely used light supersonic fighter aircraft, designed and built by Northrop. Although less complex and advanced than some contemporary aircraft such as the McDonnell Douglas F-4 Phantom II, it was significantly cheaper to procure and operate, and the type became a popular aircraft on the export market. While not procured in volume by the United States, it was perhaps the most effective air-to-air fighter possessed by the U.S. in the 1960s and early 1970s. Strengths included the aircraft's compact size, a high level of maneuverability, favorable flying qualities and a low accident rate, and a high sortie generation rate. The capabilities, reliability, and maintainability of the F-5, similar to a Soviet counterpart, the Mikoyan-Gurevich MiG-21, led to hundreds of F-5s remaining in service into the 21st century.

The F-5 started life as a privately funded light fighter program by Northrop in the 1950s. The design team wrapped a small, highly aerodynamic fighter around two compact and high-thrust General Electric J85 engines, focusing on performance and low cost of maintenance. Armed with twin 20 mm cannons and missiles for air-to-air combat, the aircraft was also a capable ground-attack platform. The F-5A entered service in the early 1960s. During the Cold War, over 800 were produced through 1972 for U.S. allies. While the USAF had no acknowledged need for a light fighter, it procured roughly 1,200 trainer aircraft of an F-5 derivative, the Northrop T-38 Talon, instead.

As a result of winning the International Fighter Aircraft competition in 1970, a program aimed at providing effective low-cost fighters to American allies, Northrop introduced the second-generation F-5E Tiger II in 1972. This upgrade included more powerful engines, higher fuel capacity, greater wing area and improved leading edge extensions for a better turn rate, optional air-to-air refueling, and improved avionics including air-to-air radar. Though primarily used by American allies, it also served in U.S. military aviation as a training and aggressor aircraft. A total of 1,400 Tiger II versions were built before production ended in 1987.

The F-5 was also developed into a dedicated reconnaissance version, the RF-5 Tigereye. The F-5 also served as a starting point for a series of design studies which resulted in the Northrop YF-17 and the F/A-18 navalized fighter aircraft. The Northrop F-20 Tigershark was an advanced variant to succeed the F-5E which was ultimately cancelled. The F-5N/F variants remain in service with the United States Navy and United States Marine Corps as an adversary trainer.

Origins
In the mid-1950s, Northrop started development on a low-cost, low-maintenance fighter, with the company designation N-156, partly to meet a U.S. Navy requirement for a jet fighter to operate from its escort carriers, which were too small to operate the Navy's existing jet fighters. That requirement disappeared when the Navy decided to withdraw the escort carriers, but Northrop continued development of the N-156, with both a two-seat advanced trainer (the N-156T), and a single-seat fighter (the N-156F) planned.

The design effort was led by Northrop vice president of engineering and accomplished aircraft designer Edgar Schmued, who previously at North American Aviation had been the chief designer of the highly successful P-51 Mustang and F-86 Sabre fighters. Schmued recognized that an efficient supersonic light fighter could be developed, taking advantage of the compact but high thrust-to-weight ratio General Electric J85 turbojet engine and the transonic area rule, seeking to reverse the trend in fighter development towards greater weight and cost. The J85 powerplant was developed to power McDonnell's ADM-20 Quail decoy employed upon the Boeing B-52 Stratofortress.

Another highly influential figure was chief engineer Welko Gasich, who convinced Schmued that the engines must be located within the fuselage for maximum performance. Gasich also for the first time introduced the concept of "life cycle cost" into fighter design, which provided the foundation for the F-5's low operating cost and long service life.



The N-156T was selected by the United States Air Force as a replacement for the T-33 in July 1956. Development proceeded quickly, with the first prototype aircraft, later designated YT-38 Talon, taking its first flight on 12 June 1959. A total of 1,158 Talons would be built by the time production ended in January 1972.

Development of the N-156F continued at a lower priority as a private venture by Northrop, which was rewarded by an order for three prototypes on 25 February 1958 as a prospective low-cost fighter that could be supplied under the Military Assistance Program for distribution to less-developed nations. The first N-156F flew at Edwards Air Force Base on 30 July 1959, exceeding the speed of sound on its first flight.

Although testing of the N-156F was successful, demonstrating unprecedented reliability and proving superior in the ground-attack role to the USAF's existing North American F-100 Super Sabres, official interest in the Northrop type waned, and by 1960 it looked as if the program was a failure. Interest revived in 1961, but when the U.S. Army tested it, (along with the Douglas A-4 Skyhawk and Fiat G.91) for reconnaissance and close-support, although all three types proved capable during Army testing, operating fixed-wing combat aircraft was legally the responsibility of the Air Force, which would not agree to operate the N-156 or allow the Army to operate fixed-wing combat aircraft, a situation repeated with the C-7 Caribou.



In 1962, however, the Kennedy Administration revived the requirement for a low-cost export fighter, selecting the N-156F as winner of the F-X competition on 23 April 1962 subsequently becoming the "F-5A", being ordered into production in October that year. It was named under the 1962 United States Tri-Service aircraft designation system, which included a re-set of the fighter number series (the General Dynamics F-111 was the highest sequentially numbered P/F-aircraft to enter service under the old number sequence).

Northrop built 624 F-5As (including three YF-5A prototypes) before production ended in 1972. These were accompanied by 200 two-seat F-5B aircraft. These were operational trainers, lacking the nose-mounted cannon but otherwise combat-capable, while 86 RF-5A reconnaissance variants of the F-5A, fitted with a four-camera nose were also built. In addition, Canadair built 240 first generation F-5s under license, with CASA in Spain adding a further 70 aircraft.

F-5E and F-5F Tiger II


In 1970, Northrop won the International Fighter Aircraft (IFA) competition to replace the F-5A, with better air-to-air performance against aircraft like the Soviet MiG-21. The resultant aircraft, initially known as F-5A-21, subsequently became the F-5E. It had more powerful (5,000 lbf) General Electric J85-21 engines, and had a lengthened and enlarged fuselage, accommodating more fuel. Its wings were fitted with enlarged leading edge extensions, giving an increased wing area and improved maneuverability. The aircraft's avionics were more sophisticated, crucially including a radar (initially the Emerson Electric AN/APQ-153) (the F-5A and B had no radar). It retained the gun armament of two M39 cannon, one on either side of the nose) of the F-5A. Various specific avionics fits could be accommodated at customer request, including an inertial navigation system, TACAN and ECM equipment.

The first F-5E flew on 11 August 1972. A two-seat combat-capable trainer, the F-5F, was offered, first flying on 25 September 1974, with a new, longer nose, which, unlike the F-5B that did not mount a gun, allowed it to retain a single M39 cannon, albeit with a reduced ammunition capacity. The two-seater was equipped with the Emerson AN/APQ-157 radar, which is a derivative of the AN/APQ-153 radar, with dual control and display systems to accommodate the two-men crew, and the radar has the same range of AN/APQ-153, around 10 nmi.



A reconnaissance version, the RF-5E Tigereye, with a sensor package in the nose displacing the radar and one cannon, was also offered.

The F-5E eventually received the official name Tiger II; 792 F-5Es, 146 F-5Fs and 12 RF-5Es were eventually built by Northrop. More were built under license overseas: 91 F-5Es and -Fs in Switzerland, 68 by Korean Air in South Korea, and 308 in Taiwan. The F-5 proved to be a successful combat aircraft for U.S. allies, but had no combat service with the U.S. Air Force. The F-5E evolved into the single-engine F-5G, which was rebranded the F-20 Tigershark. It lost out on export sales to the F-16 in the 1980s.

Upgrades
The F-5E experienced numerous upgrades in its service life, with the most significant one being adopting a new planar array radar, Emerson AN/APQ-159 with a range of 20 nmi to replace the original AN/APQ-153. Similar radar upgrades were also proposed for F-5F, with the derivative of AN/APQ-159, the AN/APQ-167, to replace the AN/APQ-157, but that was cancelled. The latest radar upgrade included the Emerson AN/APG-69, which was the successor of AN/APQ-159, incorporating mapping capability. However, most nations chose not to upgrade for financial reasons, and the radar saw very little service in USAF aggressor squadrons and Swiss air force.

Various F-5 versions remain in service with many nations. Singapore has approximately 49 modernized and re-designated F-5S (single-seat) and F-5T (two-seat) aircraft. Upgrades include new FIAR Grifo-F X-band radar from Galileo Avionica (similar in performance to the AN/APG-69), updated cockpits with multi-function displays, and compatibility with the AIM-120 AMRAAM and Rafael Python air-to-air missiles.



One NASA F-5E was given a modified fuselage shape for its employment in the Shaped Sonic Boom Demonstration program carried out by DARPA. It is preserved in the Valiant Air Command Warbird Museum at Titusville, Florida.

The Royal Thai Air Force (RTAF) had their F-5s undergo an entensive upgrade program, resulting in the aircraft re-designated as F-5T Tigris. They are armed with Python III and 4 missiles; and equipped with the Dash helmet-mounted cueing system.

Similar programs have been carried out in Chile and Brazil with the help of Elbit. The Chilean upgrade, called the F-5 Tiger III Plus, incorporated a new Elta EL/M-2032 radar and other improvements. The Brazilian program, re-designated as F-5M, adds a new Grifo-F radar along with several avionics and cockpit refurbishments, including the Dash helmet. The F-5M has been equipped with new weapon systems such as the Beyond Visual Range Derby missile, Python IV short-range air-to-air missile, SMKBs smart bomb, and several other weapons.

United States
The first contract for the production F-5A was issued in 1962, the first overseas order coming from the Royal Norwegian Air Force on 28 February 1964. It entered service with the 4441st Combat Crew Training School of the USAF, which had the role of training pilots and ground crew for customer nations, on 30 April that year, it still not being intended that the aircraft be used in significant numbers by the USAF itself.



This changed with testing and limited deployment in 1965. Preliminary combat evaluation of the F-5A began at the Air Proving Ground Center, Eglin AFB, Florida, during the summer of 1965 under project Sparrow Hawk, with one airframe lost through pilot error on 24 June. In October 1965, the USAF began a five-month combat evaluation of the F-5A titled Skoshi Tiger. Twelve aircraft were delivered for trials to the 4503rd Tactical Fighter Squadron, and after modification with probe and drogue aerial refueling equipment, armor and improved instruments, were redesignated as the F-5C. Over the next six months, they performed combat duty in Vietnam, flying more than 2,600 sorties, both from the 3rd Tactical Fighter Wing at Bien Hoa over South Vietnam and from Da Nang Air Base where operations were flown over Laos. 9 aircraft were lost in Vietnam, 7 to enemy ground fire and two to operational causes. Although declared a success, with the aircraft generally rated as capable a ground-attack aircraft as the F-100, but suffering from a shorter range, the program was considered a political gesture intended to aid the export of more F-5s than a serious consideration of the type for U.S. service. From April 1966 the aircraft continued operations as 10th Fighter Commando Squadron with their number boosted to 17 aircraft. (Following Skoshi Tiger the Philippine Air Force acquired 23 F-5A and B models in 1965. These aircraft, along with remanufactured Vought F-8 Crusaders, eventually replaced the Philippine Air Force's North American F-86 Sabre in the air defense and ground attack roles.)



In June 1967, the 10th FCS's surviving aircraft were supplied to the air force of South Vietnam, which previously had only Cessna A-37 Dragonfly and Douglas A-1 Skyraider attack aircraft. This new VNAF squadron was titled the 522nd. The president of Vietnam had originally asked for F-4 Phantoms used by the Americans, but the VNAF flew primarily ground support as the communist forces employed no opposing aircraft over South Vietnam. When Bien Hoa was later overrun by Communist forces, several of the aircraft were captured and used operationally by the NVAF, in particular against Khmer Rouge. In view of the performance, agility and size of the F-5, it might have appeared to be a good match against the similar MiG-21 in air combat; however, U.S. doctrine was to use heavy, faster and longer-range aircraft like the Republic F-105 Thunderchief and McDonnell Douglas F-4 Phantom II over North Vietnam. 41 F-5s were captured by the NVA when they defeated South Vietnam on 30 April 1975, and the Russians were offered "their pick" of the captured equipment, at which time they quickly loaded up one complete F-5E, two spare engines, all spare parts, and all ground support equipment onto one of their waiting cargo ships. These, along with other samples were sent to Poland and Russia, for advanced study of U.S. aviation technology, while others were decommissioned and put on display at museums in Vietnam.

The F-5 was also adopted as an opposing forces (OPFOR) "aggressor" for dissimilar training role because of its small size and performance similarities to the Soviet MiG-21. In this role it has proven a dangerous opponent to more complex aircraft. In realistic trials at Nellis AFB in 1977, the F-14 scored slightly better than a 2:1 kill ratio against the much simpler F-5, while the F-15 scored slightly less. With further tuning of the rules that assigned a higher probability of kill to the long range missiles used by the F-14 and the F-15 and that handicapped use of guns and radar warning receivers by the F-5s, the F-14 scored slightly better than 1:1 while the F-15 scored nearly 2:1 against the F-5.



The F-5E served with the U.S. Air Force from 1975 until 1990, in the 64th Aggressor Squadron and 65th Aggressor Squadron at Nellis Air Force Base in Nevada, and with the 527th Aggressor Squadron at RAF Alconbury in the UK and the 26th Aggressor Squadron at Clark Air Force Base in the Philippines. The U.S. Marines purchased ex-USAF models in 1989 to replace their F-21s, which served with VMFT-401 at Marine Corps Air Station Yuma. The U.S. Navy used the F-5E extensively at the Naval Fighter Weapons School (TOPGUN) when it was located at NAS Miramar, California. When TOPGUN relocated to become part of the Naval Strike and Air Warfare Center at NAS Fallon, Nevada, the command divested itself of the F-5, choosing to rely on VC-13 (redesignated VFC-13 and which already used F-5s) to employ their F-5s as adversary aircraft. Former adversary squadrons such as VF-43 at NAS Oceana, VF-45 at NAS Key West, VF-126 at NAS Miramar, and VFA-127 at NAS Lemoore have also operated the F-5 along with other aircraft types in support of Dissimilar Air Combat Training (DACT).

The U.S. Navy F-5 fleet continues to be modernized with 36 low-hour F-5E/Fs purchased from Switzerland in 2006. These were updated as F-5N/Fs with modernized avionics and other improved systems. Currently, the only U.S. Navy units flying the F-5 are VFC-13 at NAS Fallon, Nevada and VFC-111 at NAS Key West, Florida. Currently, VFC-111 operates 18 Northrop F-5N/F Tiger-IIs, of which 17 are single-seater F-5Ns and the remainder being a twin-seater F-5F, which was dubbed "FrankenTiger" and is one of only three in service with the USN, being a product of grafting the older front half fuselage of the F-5Fs into the back half fuselage of the newer low-hours F-5Es acquired from the Swiss Air Force.

According to the FAA, there are 18 privately owned F-5s in the U.S., including Canadair CF-5Ds.

Brazil


In October 1974, the Brazilian Air Force (FAB) ordered 36 F-5E and 6 F-5B aircraft from Northrop for $72 million. The first three aircraft arrived on 12 March 1975. In 1988, FAB acquired 22 F-5E and four F-5EF second-hand USAF "agressor" fighters. A total of 15 of these aircraft were part of the initial batch of 30 aircraft produced by Northrop. In 1990, FAB retired all remaining five F-5Bs; later, they were sent to Brazilian museums around the country.

In 2001, Elbit Systems and Embraer started work on a $230 million Brazilian F-5 modernization program, performed over an eight-year period, upgrading 46 F-5E/F aircraft, re-designated as F-5EM and F-5FM. The modernization centered on several areas: new electronic warfare systems, the Grifo F radar, an air-to-air refueling system, INS/GPS-based navigation, support for new weapons, targeting and self-defense systems, HOTAS, LCD displays, Helmet Mounted Displays (HMDs), Radar Warning Receiver, encrypted communications, cockpit compatibility for night vision goggles, On-Board Oxygen Generation System (OBOGS) and various new onboard computer upgrades. One important capability is the secure communication with R-99 airborne early warning platforms and ground stations.

Externally, the new aircraft features a larger nose cone that accommodates the larger radar equipment. The first F-5EM was handed over on 21 September 2005. In 7 July 2003, four Rafael Litening III targeting pods were ordered at a cost of USD 13 million, to be used on F-5M together with three Rafael Sky Shield jamming pods ordered in 5 July 2006 at a cost of USD 42 million.

In 2009, FAB bought eight single-seat and three twin-seat F-5F used aircraft from Jordan in a US$21 million deal. These aircraft were built between 1975 and 1980. On 14 April 2011, a contract of $153 million was signed with Embraer and Elbit to modernize the additional F-5s bought from Jordan, and to supply one more flight simulator as a continuation of the contract signed in 2000. These F-5s will receive the same configuration as those from the initial 46 F-5s currently completing the upgrade process. The first delivery of this second batch of upgraded jet fighters is scheduled for 2013 and they are to be withdrawn in 2030.

Ethiopia
Ethiopia received 10 F-5As and two F-5Bs from the U.S. starting in 1966. In addition to these, Ethiopia had a training squadron equipped with at least eight Lockheed T-33 Shooting Stars. In 1970, Iran transferred at least three F-5As and Bs to Ethiopia. In 1975, another agreement was reached with the U.S. to deliver a number of military aircraft, including 14 F-5Es and three F-5Fs; later in the same year eight F-5Es were transferred while the others were embargoed and delivered to a USAF aggressor Squadron due to the changed political situation. The U.S. also withdrew its personnel and cut diplomatic relations. Ethiopian officers contracted a number of Israelis to maintain American equipment.

The Ethiopian F-5 fighters saw combat action against Somali forces during the Ogaden War (1977–1978). The main Somali fighter aircraft was the MiG-21MF delivered in the 1970s, supported by Mikoyan-Gurevich MiG-17s delivered in the 1960s by the Soviet Union. Ethiopian F-5E aircraft were used to gain air superiority because they could use the AIM-9B air to air missile, while the F-5As were kept for air interdiction and air strike. During this period Ethiopian F-5Es went on training against Ethiopian F-5As and F-86 Sabres (simulating Somali MiG-21s and MiG-17s).

On 17 July 1977, two F-5s flown by Israeli pilots were on combat air patrol near Harer, when four Somali MiG-21MFs were detected nearby. In the engagement, two MiG-21s were shot down while the other two had a midair collision while avoiding an AIM-9B missile. The better-trained F-5 pilots swiftly gained air superiority over the Somali Air Force, shooting down a number of aircraft, while other Somali aircraft were lost to air defense and to incidents. However at least three F-5s were shot down by air defense forces during attacks against supply bases in western Somalia.

Kenya
Starting on 16 October 2011 during Operation Linda Nchi, Kenyan Air Force F-5s are supporting the Kenyan forces fighting in Somalia against Al Shabab Islamists bombing targets inside Somalia and spearheading the ground forces.

Iran


The Imperial Iranian Air Force (IIAF) received extensive U.S. equipment in the 1960s and 1970s. Iran received its first 11 F-5As and two F-5Bs in February 1965 which were then declared operational in June 1965. Ultimately, Iran received 104 F-5As and 23 F-5Bs by 1972. From January 1974 with the first squadron of 28 F-5Fs, Iran received a total of 166 F-5E/Fs and 15 additional RF-5As with deliveries ending in 1976. While receiving the F-5E and F, Iran began to sell its F-5A and B inventory to other countries, including Ethiopia, Turkey, Greece and South Vietnam; by 1976, many had been sold, except for several F-5Bs retained for training purposes. F-5s, were also used by the IIAF's aerobatic display team, the Golden Crown.

After the Iranian revolution in 1979, the new Islamic Republic of Iran Air Force (IRIAF) was partially successful at keeping Western fighters in service during the war with Iraq in the 1980s and the simple F-5 had a good service readiness until late in the war. Initially Iran took spare parts from foreign sources, later it was able to have its new aircraft industry keep the aircraft flying.

During the Iran-Iraq War, IRIAF F-5s were heavily involved, flying air-to-air and air-to-ground sorties. Iranian F-5s took part in many air combats with Iraqi MiG-21, Mikoyan-Gurevich MiG-23, Mikoyan-Gurevich MiG-25, Su-20/22, Mirage F-1 and Super Etendards scoring many victories but also suffering many losses. However the exact combat record is not known with many different claims from Iraqi, Iranian and even Western and Russian sources. Adding to the haze surrounding the F-5's combat record is that many of the IRIAF's confirmed air-to-air kills were, for political reasons, attributed to the Revolutionary Guards. Nonetheless, there are reports that an F-5E, piloted by Major Yadollah Javadpour, managed to shoot down a MiG-25 on 6 August 1983.

From a general standpoint, during the first years of service, Iranian F-5 fighter aircraft had the advantage in missile technology, using advanced versions of the IR seeking Sidewinder, later lost with deliveries of new missiles and fighters to Iraq.

Iran currently produces an indigenous aircraft titled, "Saegeh", which is built on the same platform as the F-5, and probably armed with Russian-made or Chinese-made munitions such as AA-10 Alamo, AA-11 Archer or C-802.

Mexico


In 1982, Mexico received 12 F-5E/F after the purchase of 24 IAI Kfir C.1 was blocked by the U.S., because the Kfir used the American-produced J79 engine. These fighters accompanied the Lockheed T-33 and de Havilland Vampire Mk.I (received much earlier), two of the first combat jet aircraft in Mexico. The subsonic T-33 and the Vampire were developed in the 1940s. The F-5 gave Mexico its first supersonic platform and saw the formation of Air Squadron 401. On 16 September 1995, after more than 30 military parade flights without incidents, an F-5E collided in mid-air with three Lockheed T-33s during the military parade for the Independence of Mexico. A total of 10 deaths occurred. Since then, for safety, flyovers in Mexico have been smaller in participation. In 2007, the F-5 had its 25th anniversary in Mexican Air Force service. Mexico is looking to replace its ageing F-5s by 2015 and replace the T-33s it retired in 2007.

Norway
The Royal Norwegian Air Force received 108 Freedom Fighters: 16 RF-5A, 78 F-5A and 14 F-5B. The first 64 were received as military aid. They were in use by several squadrons, the first and last being 336 Squadron receiving the first aircraft in February 1966 (formal handing-over ceremony a month later), and deactivating in August 2000. Three aircraft were kept flying until 2007, serving with Kongsberg Defence & Aerospace for tests in the "Eye of the Tiger"-programme, developing a new seeker head for Naval Strike Missile and Joint Strike Missile. The aircraft received under military aid were handed off to Greece and Turkey. Of the aircraft bought by the Norwegian Government, nine were used in exchange with U.S. authorities for submarines of the Kobben class. In October 2011 five F-5s were given to aircraft maintenance schools around the country; including Skedsmo, Sola, Bodø and Bardufoss high schools, and the University of Agder's aerospace engineer program. The remaining 10 are being stored at Moss Airport, Rygge. Three survivors are exhibited at the Norwegian Armed Forces Aircraft Collection, two at Norsk Luftfartsmuseum in Bodø and one at Flyhistorisk Museum, Sola, near Stavanger.

Philippines


The Philippine Air Force acquired 37 F-5A/B from 1965 to 1998. The F-5A/Bs were used by the Blue Diamonds Aerobatic team, underwent an upgrade which equipped it with surplus AN/APQ-153 radars with significant overhaul at the end of the 1970s to stretch their service life another 15 years. In 2005, the Philippines decommissioned its remaining F-5A/B fleet, including those received from Taiwan and South Korea.

Singapore


Singapore is an important operator of the F-5E/F variant, first ordering the aircraft in 1976 during a massive expansion of the city-state's armed forces; delivery of this first batch of 18 F-5Es and three F-5Fs was completed by late February 1979, equipping the newly formed-up No. 144 Black Kite Squadron at Tengah Air Base. At the end of 1979, an order was placed for six more F-5Es, these were was delivered by 1981. In 1982, an order for three more F-5Fs was placed, these were forward delivered in September 1983 to RAF Leuchars in Scotland where they were taken over by pilots of the Republic of Singapore Air Force (RSAF). In 1983, the type took over the duties of airborne interception from the Royal Australian Air Force's Mirage IIIOs detachment (rotated between No. 3 & No. 75 Squadron RAAF) stationed at Tengah.

Another order for six more F-5Es was placed in 1985, these were delivered the same year and would go on to equip the newly formed-up No. 149 Shikra Squadron at Tengah. The following year, the RSAF placed an order for its final batch of three F-5Fs and five F-5Es, these were delivered in December 1987 and July 1989, respectively. In a bid to modernize their air force, the Royal Jordanian Air Force put up seven F-5Es for sale in 1994, these were later acquired by Singapore.

From 1990 to 1991, using jigs and toolings purchased from Northrop, Singapore Aircraft Industries (SAI, now ST Aerospace) converted eight existing F-5Es into RF-5E Tigereye variant. Subsequently, these were used to requipped No. 141 Merlin Squadron, which had traded in their older Hawker Hunter FR.74S for the newer Tigereyes in 1992 and was by then based at Paya Lebar Air Base, after the 144 Squadron had relocated there in 1986. By June 1993, all three squadrons had been relocated to the base, thus consolidating Singapore's F-5E/F operations at Paya Lebar.

In late 1991, SAI was further awarded a contract by RSAF as the main contractor to modernize and upgrade all the F-5E/F in RSAF's inventory (including the 7 ex-Jordanian F-5Es), with Elbit Systems as sub-contractor responsible for systems integration. Included in the package was a new X band multi-mode radar (the Italian FIAR Grifo-F, with Beyond-visual-range missile and Look-down/shoot-down capabilities), a revamped cockpit with new MIL-STD-1553R databuses, GEC/Ferranti 4510 Head-up display/weapons delivery system, two BAE Systems MED-2067 Multi-function displays, Litton LN-93 inertial navigation system (similar to all those found on ST Aerospace A-4SU Super Skyhawks) and Hands On Throttle-And-Stick controls (HOTAS) to reduce pilot workload. Reportedly, the Elisra SPS2000 radar warning receiver and countermeasure system was also installed. Additionally, the starboard M-39 20mm cannon mounted in the nose was removed to make way for additional avionics (the sole cannon fitted to the two-seaters was removed because of this), and to improve maneuverability, all the upgraded aircraft were also fitted with larger leading edge root extensions (LERX). The process of rebuilding and upgrading began in March 1996 and was completed by 2001. As a result, they received the new designation of F-5S/T. In 1998, the eight RF-5Es were also upgraded, receiving the full upgrade except for the radar, these were later redesignated as RF-5S. According to a press release to the nation's newspaper, it cost approximately SGD$6 million each to upgrade the F-5S/T.

By end of 2009, the type had accumulated more than 170,000 hours of flight time in Singapore service with only two F-5Es being lost in separate accidents (in 1984 and 1991, respectively). As of June 2011, only 141 and 144 Squadron are left operating the RF-5S and F-5S/T, as 149 Squadron has since formally transitioned to the McDonnell Douglas F-15SG Strike Eagles on 5 April 2010.

Taiwan (Republic of China)
The Republic of China Air Force (ROCAF) received its first batch of seven F-5As and two F-5Bs under the U.S. Military Assistance Program in 1965. By 1971, the ROCAF was operating 72 F-5As and 11 F-5Bs. During 1972, the U.S. decided to borrow 48 F-5As from Taiwan to boost the South Vietnam Air Force strength before withdrawing U.S. forces from South Vietnam. By 1973 most of those loaned F-5As in South Vietnam were not in flying shape consequently, the U.S. decided to return 20 F-5As to Taiwan by drawing nine F-5As from U.S. reserves while repairing a further 11 from those still in flying shape in South Vietnam. These were sent to Taiwan to make necessary repairs, with gave 28 F-5Es issued to Taiwan by May 1975 in return. By 1973, Taiwan's AIDC started local production of a first batch of 100 F-5Es in Taiwan, the first of six Peace Tiger production batches. By end of 1986 when the production line closed after completing Peace Tiger 6, the AIDC had produced 242 F-5Es and 66 F-5Fs. Adding the 28 original U.S.-made F-5E/Fs, this made Taiwan the largest F-5E/F operator at one time, with 336 F-5E/Fs in inventory. A bit of F-20 influence can be seen in the last batch of F-5E/Fs by AIDC in Taiwan that featured the F-20's shark nose.



With the introduction of 150 F-16s, 60 Mirage 2000-5s and 130 F-CK-1s in mid-to-late-1990s, the F-5E/F series became second line fighters in ROCAF service and mostly are now withdrawn from service as squadrons converted to new fighters entering ROCAF service. Seven low airframe hours F-5Es were sent to ST Aerospace to convert them to RF-5E standard to fulfill a reconnaissance role previously undertaken by the retiring RF-104G in ROCAF service. As of 2009, only about 40 ROCAF F-5E/Fs still remain in service in training roles with about 90–100 F-5E/Fs held in reserve. The other retired F-5E/F are either scrapped, or used as decoys painted in colors representing the main front line F-16, Mirage 2000-5 or F-CK-1 fighters, and deployed around major air bases.



Taiwan also tried to upgrade the F-5E/F fleet with AIDC's Tiger 2000/2001 program. The first flight took place on 24 July 2002. The program would replace the F-5E/F's radar with F-CK-1's GD-53 radar and allow the fighter to carry a single TC-2 BVRAAM on the centerline. But lack of interest from the Taiwan/ROC Air Force eventually killed the program. The only prototype is on display in AIDC in Central Taiwan.

The only air combat actions ROCAF F-5E/F pilots saw, were not over Taiwan, but in North Yemen. In 1979, a flareup between North and South Yemen prompted the U.S. to sell 14 F-5E/Fs to North Yemen to boost its air defense. Since no one in North Yemen knew how to fly the F-5E/F (only MiG-15s were operational at the time), U.S. and Saudi Arabia arranged to have 80+ ROCAF F-5E pilots plus ground crew and anti-air defense units sent to North Yemen as part of North Yemen Air Force's 115th Squadron at Sana‘a operating initially just six F-5E/Fs and then from April 1979 to May 1990, added eight more. The ROCAF piloted F-5E/F scored a few kills in a few air battles, but the ground early warning radar crews and anti-air units also suffered from air attacks from South Yemen, the aircraft being piloted by Soviet crews.

Republic of Korea (South Korea)
The Republic of Korea Air Force (ROKAF) purchased F-5A/Bs in 1965 and purchased F-5Es in August 1974. KF-5 variants were built by Korean Air under license between 1982 and 1986. A total of 214 F-5s were procured.

The ROKAF currently operates 170 F-5E/Fs and KF-5E/Fs. The F-5E/Fs and KF-5E/Fs are to be replaced by FA-50s and F-X Phase 3.

Vietnam


When South Vietnam was overrun by NVA forces on 30 April 1975, approximately 877 aircraft were captured by the communists. Of that number, 41 were F-5s. In November of that year the Soviets were offered the opportunity to "take their pick" from the captured U.S. equipment. The Russians quickly loaded one complete F-5E, along with 2 complete spare engines, any and all spare parts, and all ground support equipment onto a waiting Russian cargo ship. Several of the F-5s left over from the Vietnam war were sent to Poland and Russia, for advanced study of US aviation technology, while others were decommissioned and put on display at museums in Vietnam. The 935th fighter Regiment of the VPAF 372nd air division was the only unit in the world flying both MIG-21 and F-5 Fighters. Eventually, the lack spare parts grounded all the aircraft captured.

One F-5 was extensively tested by top Soviet pilots from Chkalov's State Flight Tests Center. In air combat with the MiG-21, the F-5 did show extremely well, winning almost all fights according to reports; this gave Soviet aircraft designers a push to develop new types, like the MiG-23.

Other operators
Morocco used 28 F-5A/B and 2 RF-5A in the Polisario War over Western Sahara. In the 1980s they received 24 F-5E/F, fighting against the Polisario Front. Threats faced included multiple SA-6 anti-aircraft systems, and several F-5s were lost during the conflict. Starting in 1990 they received 12 F-5 E/F from an ex-US aggressor, a total of 24 F-5Es having been upgraded to the F-5TIII standard.

Saudi Arabia deployed aircraft during the First Gulf War, the F-5Es flew close air support and aerial interdiction missions against Iraqi units in Kuwait. One RSAF F-5E was lost to ground fire on 13 February 1991, the pilot was killed. In Saudi service, approximately 20 Tigers have been lost due to various causes. The Hellenic Air Force was the first European air force to receive the Freedom Fighter. A total of 114 F-5As (including four ex-Iranian machines), 34 RF-5As, and 20 F-5Bs were supplied to Greece.

Single-seat versions



 * N-156F: Single-seat fighter prototype. Only three aircraft were built.


 * YF-5A: The three prototypes were given the U.S. Air Force designation YF-5A.


 * F-5A: Single-seat fighter version of F-5, originally without radar, but was later equipped with AN/APQ-153 radar during upgrades.


 * F-5A (G): Single-seat fighter version of the F-5A for the Royal Norwegian Air Force.


 * XF-5A: This designation was given to one aircraft used for static tests.


 * A.9: Designation of Spanish Air Force Northrop F-5A which served in the Ejército del Aire


 * F-5C Skoshi Tiger: 12 F-5A Freedom Fighters, were tested by the U.S. Air Force for four and a half months in Vietnam.


 * F-5E Tiger II: Single-seat fighter version with AN/APQ-159 replacing earlier AN/APQ-153 in F-5A.


 * F-5E Tiger III: Upgraded version of the F-5E in use by the Chilean Air Force, with EL/M-2032 radar replacing the original AN/APQ-159.


 * F-5E/F: A single Swiss Air Force F-5E with F-5F Wings. Currently (2011), this aircraft is part of the Museum at Meiringen AFB


 * F-5G: The temporary designation given to the F-20 Tigershark, armed with General Electric AN/APG-67 radar.


 * F-5N: Ex-Swiss Air Force F-5Es used by the U.S. Navy as "aggressor" aircraft, with AN/APG-69 replacing the original AN/APQ-159. Intended to replace high-time USN/USMC F-5Es in the adversary role, and see service through to 2015.


 * F-5S: Upgraded version of the F-5E in use by the Republic of Singapore Air Force, equipped with the Galileo Avionica's FIAR Grifo-F X-band radar and are capable of firing the AIM-120 AMRAAM.


 * F-5T Tigris: Upgraded version of the F-5E of Royal Thai Air Force by Israel, also armed with EL/M-2032.


 * F-5EM: Upgraded version of the F-5E of Brazilian Air Force armed with Italian Grifo-F radar.
 * F-5TIII: Upgraded version of the F-5E, in service with the Royal Moroccan Air Force.


 * F-5E Tiger 2000: Upgraded version of Taiwan AIDC,equipped with the GD-53 radar, are capable of firing the TC-2 Sky Sword II, MIL-STD-1553B Link andGPS/INS

Reconnaissance versions

 * RF-5A: Single-seat reconnaissance version of the F-5A fighter. Approximately 120 were built.


 * RF-5A (G): Single-seat reconnaissance version of the F-5A fighter for the Royal Norwegian Air Force.


 * RF-5E Tigereye: Single-seat reconnaissance version of the F-5E fighter. The RF-5E Tigereye was exported to Saudi Arabia and Malaysia.


 * RF-5E Tigergazer: Seven upgraded single-seat reconnaissance version of the F-5E for Taiwan by ST Aerospace.


 * RF-5S Tigereye: Single-seat reconnaissance version of the F-5S for the Republic of Singapore Air Force.


 * AR-9: Spanish reconnaissance aircraft


 * B.TKh.18: Thai designation of the RF-5A

Two-seat versions

 * AE.9:
 * Spanish designation of the Northrop F-5B.


 * F-5-21
 * Temporarily designation given to the YF-5B.


 * YF-5B
 * One F-5B was fitted with a 5,000 lbf (2,268 kgf) General Electric J85-GE-21 engine, and used as a prototype for the F-5E Tiger II.


 * F-5B
 * Two-seat fighter version for the Republic of Korea Air Force, armed with AN/APQ-157 radar.


 * F-5B(G)
 * Two-seat trainer version of the F-5B for the Royal Norwegian Air Force.


 * F-5B M
 * Two-seat trainer version in use by the Spanish Air Force for air combat training.


 * F-5D
 * Unbuilt trainer version.


 * F-5F Tiger II
 * Two-seat trainer version of F-5E Tiger II, AN/APQ-167 radar tested, intended to replace AN/APQ-157, but not carried out.


 * F-5F Tiger III
 * Upgraded trainer version of the F-5F in use by the Chilean Air Force.


 * F-5T
 * Upgraded F-5F in use by the Republic of Singapore Air Force.


 * F-5FM
 * Upgraded trainer version of the F-5F for the Brazilian Air Force.

Licensed versions

 * CF-5: Fighter versions for the Canadian Forces Air Command built under license by Canadair. Its Canadian designation is CF-116.


 * NF-5A: Single-seat fighter version of the CF-5A for the Royal Netherlands Air Force; 75 built.


 * NF-5B: Two-seat training version of the CF-5D for the Royal Netherlands Air force; 30 built.


 * SF-5A: Single-seat fighter version of the F-5A for the Spanish Air Force; built under licence in Spain by CASA.


 * SRF-5A: Single-seat reconnaissance version of the RF-5A for the Spanish Air force; built under license in Spain By CASA.


 * SF-5B: Two-seat training version of the F-5B for the Spanish Air Force. Built under license in Spain by CASA.


 * VF-5A: Single-seat version of the CF-5A for the Venezuelan Air Force. This designation was given to some Canadair CF-116s which were sold to the Venezuelan Air Force.


 * VF-5D: Two-seat training version of the CF-5D for the Venezuelan Air Force.


 * KF-5E: F-5E built in South Korea for Republic of Korea Air Force. First introduction: September 1982; 48 built.


 * KF-5F: F-5F built in South Korea for Republic of Korea Air Force. First introduction: September 1982; 20 built.


 * Chung Chen: F-5E/F built in Taiwan for Republic of China Air Force by AIDC. First introduction: 30 October 1974, one day before the late President Chiang Kai Shek's 88th birthday, and was thus christened "Chung Chen", an alias of President Chiang; 308 built.

Unlicensed versions



 * Azarakhsh: F-5E built in Iran with unknown modifications and a mid wing.
 * Sa'eqeh: F-5E modified in Iran with canted, twin vertical stabilizers.

F-20 Tigershark
Northrop attempted to develop an advanced version of the F-5E, originally designated F-5G, as an export competitor for the F-16 Fighting Falcon. The F-5G was later redesignated the F-20 Tigershark. It received favorable reviews as a less expensive but capable alternative to early-block variants of the F-16 (and superior to the similarly never-purchased export variant F-16/79), but it never had the appeal of the much newer fighter design even at a lower cost.

Northrop YF-17
The Northrop YF-17's aircraft's main design elements date from the F-5 based internal Northrop project N-300. The N-300 featured a longer fuselage, small leading-edge root extensions (LERX), and more powerful GE15-J1A1 turbojets. The wing was moved higher on the fuselage to increase ordnance flexibility. The N-300 further evolved into the P-530 Cobra. The P-530's wing planform and nose section was similar to the F-5, with a trapezoidal shape formed by a sweep of 20° at the quarter-chord line, and an unswept trailing edge, but was over double the area. While the YF-17 lost its bid for the USAF lightweight fighter, it would be developed into the larger McDonnell Douglas F/A-18 Hornet.

Operators



 * Austrian Air Force: On loan from Switzerland – all aircraft returned and replaced by Eurofighters
 * Bahrain Air Force received eight F-5Es and two F-5Fs in between 1985 and 1987.
 * Botswana Air Force purchased 10 upgraded CF-5As and 3 CF-5Ds from Canada in 1996. A further two CF-5Ds were purchased in 2000.
 * Brazilian Air Force operates 51 F-5EM and six F-5FM; to be withdrawn gradually between 2017 and 2030.
 * Canadian Forces – see Canadair CF-5
 * Chilean Air Force: Chile purchased 15 F-5Es and 3 F-5Fs in the 1970s, these being upgraded to Tiger III standard from 1993. A story about the purchase of Honduran F-5E/F for the Chilean Air Force is frequently cited but has proven to be baseless since the Honduran Air Force still operates this type. 16 F-5Es were replaced in 2009 by 16 F-16 Fighting Falcon MLU T5. A total of 10 F-5s remain operational as of 2009. In March 2013, the Uruguayan Air Force initiated talks for procuring 12 surplus F-5 Tiger III aircraft from Chile for $80 million.
 * Ethiopian Air Force first delivery in 1966 it has operated the A, B and E variants.
 * Hellenic Air Force received the first 55 F-5A's in 1965. In 1975, 10 aircraft were bought from Iran and later, another 10 followed from Jordan. In 1986, 9 aircraft were granted from Norway and in 1991, 10 NF-5A's were granted by Holland. During 1967 and 1968 this type of aircraft was used by the 3rd Hellenic Aerobatic Team "New Hellenic Flame". The last NF-5A's were retired in 2002.
 * Honduran Air Force The United States delivered ten F-5E and two F-5Fs starting in 1987 as replacements of Dassault Super Mystére, which were reassigned to air strike as they were in their last years of service. The F-5 were refurbished former United States Air Force aircraft.
 * Indonesian Air Force: Upgraded in Belgium in the middle to late 1990s. All 16 F-5E/Fs have been retired since late 2005 but are in reserve in case of future use. Will be replaced by ex-USAF F-16 Fighting Falcons.
 * Islamic Republic of Iran Air Force: 60 or 75 F-5E and F operational; 140 originally delivered to the Imperial Iranian Air Force.
 * Unknown numbers of HESA Saeqeh and HESA Azarakhsh fighters derived from the F-5 design
 * Royal Jordanian Air Force
 * Kenya Air Force: In July 2008, it was reported that Kenya will spend 1.5 billion KSh to buy 15 former Jordanian Air Force F-5s, 13 F-5E and two F-5F upgraded with Rockwell Collins avionics (plus training and spare parts).They will be added or eventually replace the current F-5 fleet
 * Republic of Korea Air Force received a total of 340 F-5s (88 F-5A, 30 F-5B, 8 RF-5A, 126 F-5E, 20 F-5F, 48 KF-5E, and 20 KF-5F). Plans to replace 20, by buying 20 of their Indigenous FA-50 aircraft from KAI(Korea Aeronautics Industry) and eventually replacing all with also the KF-X project. The KAI project starts in 2013.
 * Royal Libyan Air Force to 1969. 10 F-5s. May have been sold to Turkey after 1969.
 * Mexican Air Force received 12 F-5s in 1982. The service currently operates eight F-5Es and two F-5Fs.
 * Royal Moroccan Air Force operates 12 F-5A/Bs upgraded with Tiger II avionics and 24 upgraded F-5 Tiger III.
 * Royal Malaysian Air Force uses four as trainer aircraft while another eighteen of its Northrop F-5 Tiger IIs were upgraded for reconnaissance purposes, however the operational status for these are grounded.
 * Royal Netherlands Air Force (former operator), received 75 [Canadair built] NF-5A (Single-seat fighter version) and 30 NF-5B (Two-seat training version) between 7 October 1969 and 10 March 1972. After the aircraft were phased out by the modern F-16 Fighting Falcon, the aircraft were initially stored at Gilze-Rijen Air Base and Woensdrecht Air Base, until finally 60 aircraft were sold to Turkey, 11 to Greece and 7 to Venezuela. Several of the remaining aircraft can be found in aviation museums and technical schools.
 * No. 313 Squadron; Twente Air Base (transitioned to F-16 in 1987)
 * No. 314 Squadron; Eindhoven Air Base (transitioned to F-16 in 1990)
 * No. 315 Squadron, Operation Conversion Unit (OCU); Twente Air Base (transitioned to F-16 in 1986)
 * No. 316 Squadron; Gilze-Rijen Air Base (transitioned to F-16 in 1991)
 * Field Technic Training Unit NF-5 (1971–1984); Twente Air Base
 * Royal Norwegian Air Force (former operator)
 * Philippine Air Force received 19 F-5A (single seat) and three F-5B (two seat) aircraft in 1965–1967. In 1989, the PAF received three ex-Taiwanese F-5A and one F-5B. In the 1990s, at least eight ex-South Korean F-5A and two Jordanian F-5A were acquired. All F-5 upgrades were abandoned in 2008. The Philippines decommissioned its F-5A/B fleet in 2005.
 * Royal Saudi Air Force: 110 F-5E/Fs withdrawn from active service aside from in the trainer role, some squadrons such as #10 based in Taif will be replaced with Eurofighter Typhoon.
 * Republic of Korea Air Force received a total of 340 F-5s (88 F-5A, 30 F-5B, 8 RF-5A, 126 F-5E, 20 F-5F, 48 KF-5E, and 20 KF-5F). Plans to replace 20, by buying 20 of their Indigenous FA-50 aircraft from KAI(Korea Aeronautics Industry) and eventually replacing all with also the KF-X project. The KAI project starts in 2013.
 * Royal Libyan Air Force to 1969. 10 F-5s. May have been sold to Turkey after 1969.
 * Mexican Air Force received 12 F-5s in 1982. The service currently operates eight F-5Es and two F-5Fs.
 * Royal Moroccan Air Force operates 12 F-5A/Bs upgraded with Tiger II avionics and 24 upgraded F-5 Tiger III.
 * Royal Malaysian Air Force uses four as trainer aircraft while another eighteen of its Northrop F-5 Tiger IIs were upgraded for reconnaissance purposes, however the operational status for these are grounded.
 * Royal Netherlands Air Force (former operator), received 75 [Canadair built] NF-5A (Single-seat fighter version) and 30 NF-5B (Two-seat training version) between 7 October 1969 and 10 March 1972. After the aircraft were phased out by the modern F-16 Fighting Falcon, the aircraft were initially stored at Gilze-Rijen Air Base and Woensdrecht Air Base, until finally 60 aircraft were sold to Turkey, 11 to Greece and 7 to Venezuela. Several of the remaining aircraft can be found in aviation museums and technical schools.
 * No. 313 Squadron; Twente Air Base (transitioned to F-16 in 1987)
 * No. 314 Squadron; Eindhoven Air Base (transitioned to F-16 in 1990)
 * No. 315 Squadron, Operation Conversion Unit (OCU); Twente Air Base (transitioned to F-16 in 1986)
 * No. 316 Squadron; Gilze-Rijen Air Base (transitioned to F-16 in 1991)
 * Field Technic Training Unit NF-5 (1971–1984); Twente Air Base
 * Royal Norwegian Air Force (former operator)
 * Philippine Air Force received 19 F-5A (single seat) and three F-5B (two seat) aircraft in 1965–1967. In 1989, the PAF received three ex-Taiwanese F-5A and one F-5B. In the 1990s, at least eight ex-South Korean F-5A and two Jordanian F-5A were acquired. All F-5 upgrades were abandoned in 2008. The Philippines decommissioned its F-5A/B fleet in 2005.
 * Royal Saudi Air Force: 110 F-5E/Fs withdrawn from active service aside from in the trainer role, some squadrons such as #10 based in Taif will be replaced with Eurofighter Typhoon.
 * No. 316 Squadron; Gilze-Rijen Air Base (transitioned to F-16 in 1991)
 * Field Technic Training Unit NF-5 (1971–1984); Twente Air Base
 * Royal Norwegian Air Force (former operator)
 * Philippine Air Force received 19 F-5A (single seat) and three F-5B (two seat) aircraft in 1965–1967. In 1989, the PAF received three ex-Taiwanese F-5A and one F-5B. In the 1990s, at least eight ex-South Korean F-5A and two Jordanian F-5A were acquired. All F-5 upgrades were abandoned in 2008. The Philippines decommissioned its F-5A/B fleet in 2005.
 * Royal Saudi Air Force: 110 F-5E/Fs withdrawn from active service aside from in the trainer role, some squadrons such as #10 based in Taif will be replaced with Eurofighter Typhoon.
 * Philippine Air Force received 19 F-5A (single seat) and three F-5B (two seat) aircraft in 1965–1967. In 1989, the PAF received three ex-Taiwanese F-5A and one F-5B. In the 1990s, at least eight ex-South Korean F-5A and two Jordanian F-5A were acquired. All F-5 upgrades were abandoned in 2008. The Philippines decommissioned its F-5A/B fleet in 2005.
 * Royal Saudi Air Force: 110 F-5E/Fs withdrawn from active service aside from in the trainer role, some squadrons such as #10 based in Taif will be replaced with Eurofighter Typhoon.
 * Royal Saudi Air Force: 110 F-5E/Fs withdrawn from active service aside from in the trainer role, some squadrons such as #10 based in Taif will be replaced with Eurofighter Typhoon.
 * Republic of Singapore Air Force: operates 32 F-5S, 9 F-5T and 8 RF-5S fighters.
 * South Vietnam
 * Vietnam Air Force received fleet of 158 former US, Korean, Iranian and Chinese F-5A Freedom Fighters, 10 RF-5A and eight F-5B trainers, USA also provided newer F-5E Tiger IIs, most of F-5s were evacuated to Thailand in 1975, but many were captured by People's Army.
 * Spanish Air Force, operates 20 F-5Bs as trainers for fighter school.
 * 🇸🇩 Sudan
 * Sudanese Air Force: 10 F-5Es and two F-5F were delivered in 1978, One of the F-5Fs was sold to Jordan. further two F-5s defected to Sudan from Ethiopia during the Ogaden crisis.
 * 🇸🇩 Sudan
 * Sudanese Air Force: 10 F-5Es and two F-5F were delivered in 1978, One of the F-5Fs was sold to Jordan. further two F-5s defected to Sudan from Ethiopia during the Ogaden crisis.
 * Swiss Air Force: Operating 42 F-5E and 12 F-5F Tiger II. The Swiss chose the F-5 because it was simpler to maintain than the F-16.
 * Republic of China Air Force: Received 115 F-5A and B from 1965, 48 were transferred to South Vietnam before 1975. From 1973 to 1986, Taiwan produced 308 F-5E/Fs under license. Later batches of locally AIDC licensed production of Tiger IIs were fitted with flare/chaff dispensers, plus handling qualities upgrades with enlarged LEX and F-20's shark nose, and radar warning receivers(RWR).
 * Royal Thai Air Force: F-5A retired. Now operates F-5B/E/F/T, F-5B/E slated for retirement in 2011–2012, to be replaced by 12-JAS 39 Gripen. The last F-5 fleet, upgraded F-5T Tigris and F-5F will continue to serve to 2015–2020.
 * Tunisian Air Force : Eight F-5E and four F-5F Tiger II were delivered in 1984–1985. The TAF received five ex-USAF F-5E in 1989. 16 aircrafts still in service.
 * Royal Thai Air Force: F-5A retired. Now operates F-5B/E/F/T, F-5B/E slated for retirement in 2011–2012, to be replaced by 12-JAS 39 Gripen. The last F-5 fleet, upgraded F-5T Tigris and F-5F will continue to serve to 2015–2020.
 * Tunisian Air Force : Eight F-5E and four F-5F Tiger II were delivered in 1984–1985. The TAF received five ex-USAF F-5E in 1989. 16 aircrafts still in service.
 * Tunisian Air Force : Eight F-5E and four F-5F Tiger II were delivered in 1984–1985. The TAF received five ex-USAF F-5E in 1989. 16 aircrafts still in service.
 * Tunisian Air Force : Eight F-5E and four F-5F Tiger II were delivered in 1984–1985. The TAF received five ex-USAF F-5E in 1989. 16 aircrafts still in service.


 * Turkish Air Force: More than 200 F-5A/Bs and NF-5A/Bs were bought from various countries. Between 40 and 50 of them were upgraded to F-5/2000 standard during the 2000s (decade); Turkish Stars aerobatic team. In total, 50 NF-5A and 25 NF-5B remain operational.
 * F-5Es were received from Vietnam and the Derg regime in Ethiopia for performance tests and evaluation flights. They were tested in mock combat against MiG-21 and MiG-23 aircraft, ultimately aiding in the development of the MiG-23MLD and the MiG-29.
 * United States Air Force (former operator)
 * 26th Aggressor Squadron
 * 64th Fighter Weapons Squadron
 * 65th Fighter Weapons Squadron
 * 527th Aggressor Squadron
 * 64th Fighter Weapons Squadron
 * 65th Fighter Weapons Squadron
 * 527th Aggressor Squadron


 * United States Marine Corps
 * United States Navy
 * Venezuelan Air Force
 * Vietnam People's Air Force (several captured ex-VNAF aircraft). One F-5E (s/n 73-00867) was transferred to the Soviet Union for evaluation flights, i.e. against the MiG-21bis; 40+ F-5E/F/C were in VNAF's service. After the Vietnam War, Vietnamese forces used the captured F-5 fleet against Chinese forces during Sino-Vietnamese War.
 * Yemen Air Force: North Yemen Air Force's 14 F-5E/F fleet were initially piloted by ROCAF/Taiwan pilots as part of 115th Squadron at Sana‘a, from April 1979 to May 1990, to boost its air defense.
 * Vietnam People's Air Force (several captured ex-VNAF aircraft). One F-5E (s/n 73-00867) was transferred to the Soviet Union for evaluation flights, i.e. against the MiG-21bis; 40+ F-5E/F/C were in VNAF's service. After the Vietnam War, Vietnamese forces used the captured F-5 fleet against Chinese forces during Sino-Vietnamese War.
 * Yemen Air Force: North Yemen Air Force's 14 F-5E/F fleet were initially piloted by ROCAF/Taiwan pilots as part of 115th Squadron at Sana‘a, from April 1979 to May 1990, to boost its air defense.
 * Yemen Air Force: North Yemen Air Force's 14 F-5E/F fleet were initially piloted by ROCAF/Taiwan pilots as part of 115th Squadron at Sana‘a, from April 1979 to May 1990, to boost its air defense.

Greece

 * F-5A
 * 68-9071 – Athens War Museum.
 * 69-132 - Hellenic Air Force Museum.
 * 13-353 - Thessaloniki War Museum.
 * RF-5A
 * 69-7170 - Hellenic Air Force Museum.

Poland

 * F-5E
 * 73-00852 (R1033) (Vietnam Air Force) – Polish Aviation Museum, Kraków.

United States

 * YF-5A
 * 59-4989 – National Museum of the United States Air Force at Wright-Patterson AFB in Dayton, Ohio.
 * F-5B
 * 72-0441 – Pima Air and Space Museum in Arizona.
 * F-5E
 * 74-1564 – Flying Leatherneck Aviation Museum at MCAS Miramar in California.