Northrop F-5
The Northrop F-5 is a family of supersonic light fighter aircraft initially designed as a privately funded project in the late 1950s by Northrop Corporation. There are two main models, the original F-5A and F-5B Freedom Fighter variants and the extensively updated F-5E and F-5F Tiger II variants. The design team wrapped a small, highly aerodynamic fighter around two compact and high-thrust General Electric J85 engines, focusing on performance and a low cost of maintenance. Smaller and simpler than contemporaries such as the McDonnell Douglas F-4 Phantom II, the F-5 cost less to procure and operate, making  it a popular export aircraft. Though primarily designed for a day air superiority role, the aircraft is 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. Though at the time the United States Air Force (USAF) did not have a need for a light fighter, it did procure approximately 1,200 Northrop T-38 Talon trainer aircraft, which was based on Northrop's N-156 fighter design. After winning the International Fighter Aircraft Competition, a program aimed at providing effective low-cost fighters to American  allies, in 1970 Northrop introduced the second-generation F-5E Tiger II in 1972. This upgrade included more powerful engines, larger fuel capacity, greater wing area and improved leading edge extensions for better turn rates, optional air-to-air refueling, and improved avionics including air-to-air radar. Primarily used by American allies, it remains in US service to support training exercises. It has served in a wide array of roles, being able to perform both air and ground attack duties; the type was used extensively in the Vietnam War. A total of 1,400 Tiger IIs were built before production ended  in 1987. More than 3,800 F-5s and the closely related T-38 advanced trainer aircraft were produced in Hawthorne, California. The F-5N/F variants are in service with the United States Navy and United States Marine Corps as adversary trainers. Over 400 aircraft were in service as of 2021. 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 naval fighter aircraft. The Northrop F-20 Tigershark was an advanced variant to succeed the F-5E  which was ultimately canceled when export customers did not emerge. Design and development. Origins. The design effort was led by Northrop vice president of engineering and aircraft designer Edgar Schmued, who previously at North American Aviation had been the chief designer of the successful North American P-51 Mustang and F-86 Sabre fighters. Schmued recruited a strong engineering team to Northrop. In December 1953, NATO issued NBMR-1, calling for a lightweight tactical fighter capable of carrying conventional and nuclear weapons and operating from rough airfields. In late 1954, a Northrop team toured Europe and Asia to examine both the NBMR-1 and  the needs of SEATO members. From this tour, Schmued gave his team the goal of reversing the trend in fighter development towards greater size and weight in order to deliver an aircraft with high performance, enhanced maneuverability, and high reliability, while still delivering a cost advantage over contemporary fighters. Recognizing that expensive jet aircraft could not viably be replaced every few years, he also demanded "engineered growth potential" allowing service longevity in excess of 10 years. The design began to firm up in 1955 with the introduction of the General Electric J85 turbojet engine. Originally developed for McDonnell's ADM-20  Quail decoy for use on the Boeing B-52 Stratofortress, the J85 had a thrust-to-weight ratio of 6.25 to 7.5 depending on the version, giving it a notable advantage over contemporaries such as the 4.7 ratio of the J79 engine used in the F-4 Phantom. Design evolution. Using a pair of J85s as the baseline, the team began considering a series of prospective designs. Among the earliest concepts was the N-156TX of March 1955. This mounted the engines in pods, one under each wing about mid-span. The fuselage was quite slim compared to the final design, with a  crew of two under a narrow cockpit canopy. That year, the US Navy expressed an interest in a fighter to operate from its escort carriers, which were too small to operate the Navy's existing jet fighters. Northrop responded with a radical redesign, PD-2706, which placed the engines against the fuselage in short ducts exiting in front of the tail area, like the F-4, and moved the elevator up to form a T-tail. The resulting design had a much shorter fuselage and was quite compact. Development along these lines ended when the Navy decided to withdraw the escort carriers . Northrop continued development of the N-156, both as a two-seat advanced trainer, designated as N-156T, and a single-seat fighter, designated as N-156F. Another highly influential figure was chief engineer Welko Gasich, who convinced Schmued that the engines must be located within the fuselage for maximum performance. This led to the January 1956 PD-2812 version which began to look a lot like the final product, although this version had a long-span low-mounted elevator with notable anhedral. March 1956's PD-2832 moved to a more conventional elevator and had a strongly swept vertical stabilizer. The design underwent  several further versions over the next year which experimented with different nose designs and continued to lengthen the fuselage. The final design, PD-2879D, emerged in December 1956. Gasich also 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. A Northrop design study stated "The application of advanced technology was used to provide maximum force effectiveness at minimum cost. This became the Northrop philosophy in the development of the T-38 and F-5 lightweight trainer and fighter aircraft." Into production. The N-156T was quickly selected  by the United States Air Force as a replacement for the T-33 in July 1956. On 12 June 1959, the first prototype aircraft, which was subsequently designated as YT-38 Talon, performed its first flight. By the time production had ended in January 1972, a total of 1,158 Talons had been produced. Development of the N-156F continued at a lower priority as a private venture by Northrop; on 25 February 1958, an order for three prototypes was issued for 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 when the United States 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 allow the Army to operate fixed-wing combat aircraft, a situation repeated with the C-7 Caribou. In 1962, 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", and was 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. Northrop  manufactured a total of 624 F-5As, including three YF-5A prototypes, before production ended in 1972. A further 200 F-5B two-seat trainer aircraft, lacking nose-mounted cannons but otherwise combat-capable, and 86 RF-5A reconnaissance aircraft, fitted with four-camera noses, were also built. In addition, Canadair built 240 first generation F-5s under license, CASA in Spain built 70 more 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 cannons, one on either side of the nose of the F-5A. Various specific avionics fits could be accommodated at a customer's request, including an inertial navigation  system, TACAN and ECM equipment. Additionally the two position nose landing gear from the Canadian CF-5 was incorporated to reduce takeoff distance. (http://f5e.org/section1.html) 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, at Edwards Air Force Base, with a new nose, that was three feet longer, 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. On 6 April 1973, the 425th TFS at Williams Air Force Base, Arizona, received the first F-5E Tiger II. 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-5E proved to be a successful combat aircraft in service with U.S. allies, but had no combat service with the U.S. Air Force, though the F-5A with modifications, designated F-5C, was flown by the U.S. in Vietnam. 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. Having taken delivery of  its first F-5 Tigers in 1979, Singapore operated approximately 49 modernized and re-designated F-5S (single-seat) and F-5T (two-seat) aircraft until the early 2010s when they were retired from service. Upgrades included 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 extensive upgrade program, resulting in the aircraft re-designated as F-5T Tigris. They are armed with Python III and IV 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. Operational history. 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 Squadron, USAF, at Williams Air Force Base, which had the role of training pilots and ground crew for customer nations, including Norway , on 30 April 1964. At that point, it was still not intended that the aircraft be used in significant numbers by the USAF itself. United States Air Force. USAF doctrine with regard to the F-5 changed following operational testing and limited deployment in 1965. Preliminary combat evaluation of the F-5A began at the Air Proving Ground Center, Eglin AFB, Florida, in mid-1965 under the code name Project "Sparrow Hawk". One airframe was lost in the course of the project, through pilot error, on 24 June. In October 1965, the USAF began a five-month combat evaluation of the F-5A titled  Skoshi Tiger. A total of 12 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 "F-5C". Over the next six months, they flew in combat 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. Nine aircraft were lost in Vietnam, seven to enemy ground fire and two to operational causes. Operations with 3rd TFW were declared a success, with  the F-5 generally rated as being as capable a ground-attacker as the F-100, albeit having a shorter range. However, the program was more a political gesture that was intended to aid the export of F-5s, than a serious consideration of the type for US service. (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 F-86 Sabre in the air defense and ground attack roles.) From April 1966, the USAF aircraft continued operations under the auspices of the 10th  Fighter Squadron, Commando, with their number boosted to 17 aircraft. In June 1967, the surviving aircraft of the 10th Fighter Squadron, Commando, were transferred to the Republic of Vietnam Air Force (RVNAF). 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. 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 realistic trials at Nellis AFB in 1977, called ACEVAL/AIMVAL, the F-14 reportedly scored slightly better than a 2:1 kill ratio against the simpler F-5, while the F-15 scored slightly less. There is some contradiction of these reports, another source reports that "For the first three weeks of the test, the F-14s and F-15s were hopelessly outclassed and demoralized"; after adapting to qualities of the F-5 carrying the new All Aspect Aim-9L missile and implementing rule changes to artificially favor long range radar-guided missiles, "the F-14s  did slightly better than breaking even with the F-5s in non-1 v 1 engagements; the F-15s got almost 2:1". A 2012 Discovery Channel documentary "Great Planes" reported that in USAF exercises, F-5 aggressor aircraft were competitive enough with more modern and expensive fighters to only be at small disadvantage in Within Visual Range (WVR) combat. 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 used F-5s from the Air Force 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 and U.S. Marine Corps units flying the F-5 are VFC-13 at NAS Fallon, Nevada, VFC-111 at NAS Key West, Florida, and  VMFT-401 at MCAS Yuma, Arizona. Currently, VFC-111 operates 18 Northrop F-5N/F Tiger IIs. 17 of these are single-seater F-5Ns and the last is a twin-seater F-5F "FrankenTiger", the product of grafting the older front-half fuselage of an F-5F into the back-half fuselage of a newer low-hours F-5E acquired from the Swiss Air Force. A total of three "FrankenTigers" were made. 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-5F second-hand USAF "aggressor" 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. On 7 July 2003, four Rafael Litening III targeting pods were ordered at a cost of US$13 million, to be used on F-5M together with three Rafael Sky Shield jamming pods ordered on 5 July 2006 at a cost of US$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 with expected use to 2030. In 2020, the FAB started implementing the new proprietary Datalink System of the Brazilian Armed Forces on the F-5EM, for integrated communication and real-time sharing battlefield/warfare data with AEW&C R-99/E-99 FAB/Embraer aircraft, other aircraft, ships, helicopters, tanks and front/back -ends battlefield control centers, called Link-BR2. 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 airstrike. 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 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. Records indicate that Ethiopian F-5s of the 9th Fighter Squadron "shot down 13 MiGs-17 and 12 MiGs-21 from  20th July until 1st September 1977. All aircraft were hit by Sidewinders (AIM-9)." However at least three F-5s were shot down by air defense forces during attacks against supply bases in western Somalia. Ethiopian pilots who had flown both the F-5E and the MiG-21 considered the F-5E to be the superior fighter because of its manoeuvrability at low to medium speeds and the fact that it was far easier to fly, allowing the pilot to focus on combat rather than controlling his airplane. This effect was enhanced by the poor quality of pilot training provided by the Soviets, which provided  limited flight time and focused exclusively on taking off and landing, with no practical training in air combat. Ethiopia's ace pilot and national hero was Legesse Tefera who is credited with shooting down 6 (or 7) Somali MiGs, thus making him the most successful F-5 pilot ever. 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  Iran–Iraq War 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. IRIAF F-5s were heavily involved, flying air-to-air and air-to-ground sorties. Iranian F-5s took part in air combat with Iraqi Mikoyan-Gurevich MiG-21, Mikoyan-Gurevich MiG-23, Mikoyan-Gurevich MiG-25, Su-20/22, Mirage F-1 and Super Etendards. The exact combat record is not known with many differing claims from Iraqi, Iranian, Western, and Russian sources. There are  reports that an IRIAF F-5E, piloted by Major Yadollah Javadpour, shot down a MiG-25 on 6 August 1983. Russian sources state that the first confirmed kill of a MiG-25 occurred in 1985. 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 Aircraft Manufacturing Industrial Company currently produces three aircraft, the Azarakhsh, Saeqeh, and Kowsar, derived from the F-5. Kenya. Starting on 16 October 2011 during Operation Linda Nchi, Kenyan Air Force F-5s supported  the Kenyan forces fighting in Somalia against Al Shabab Islamists bombing targets inside Somalia and spearheading the ground forces. Malaysia. In 1975, the Royal Malaysian Air Force received 14 F-5Es and two F-5Bs. In 1982, four F-5Fs were received and the two F-5Bs already in Malaysian service were transferred to the Royal Thai Air Force. In 1983, RMAF received two RF-5E Tigereye. Subsequently, two F-5Es (M29-21 & M29-22) and a F-5F (M29-23) which came with the new "shark nose" and with leading edge root extensions (LERX) version were ordered as attrition replacement. The F-5E was the first supersonic  fighter in Royal Malaysian Air Force service and it replaced the former RAAF CAC Sabre as the Royal Malaysian Air Force's primary air defense fighter throughout the 1980s and early '90s. It also served in secondary ground attack role alongside the Douglas A-4 Skyhawk. Five F-5Es and one F-5F were lost in the accident with three fatalities (2 pilots in E (1983 & 1995) and 1 in F (1986), all crashed into the sea). In 2000, all the RMAF F-5s were deactivated, but they were reactivated in 2003 as the Tactical Air Reconnaissance Squadron and Reserve. Several upgrade packages were  proposed to extend the service life of the aircraft, but none were taken. In 2015, the F-5s was pulled out of service, but some were kept in storage. Mexico. In 1982, the Mexican Air Force received 10 F-5Es and two F-5Fs 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 complemented the Lockheed T-33 and de Havilland Vampire Mk. I (received much earlier), two of the first combat jet aircraft in Mexico. The F-5 gave Mexico its first supersonic warplane, and it 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 midair with three Lockheed T-33s during the military parade for the Independence of Mexico resulting in 10 deaths. As of 2021, the Mexican Air Force has five Northrop F-5E and two F-5F fighters combat ready and for training purposes. Morocco. Three F-5As were involved in the failed 1972 Moroccan coup attempt, attacking King Hassan II of Morocco's Boeing 727 in mid-air, before strafing and bombing a military airfield and the royal palace. Morocco used 28 F-5A/B  and 2 RF-5A in the Western Sahara War over Western Sahara. In the 1980s, Morocco received 16 F-5E and four F-5F, fighting against the Polisario Front. Threats faced included multiple SA-6 antiaircraft systems, and several F-5s were lost during the conflict. Starting in 1990, Morocco received 12 more F-5Es from the United States, a total of 24 F-5Es having been upgraded to the F-5TIII standard. Netherlands. The Royal Netherlands Air Force (RNLAF) received 75 F-5A single seat fighters and 30 F-5B dual–seat trainers. They have been license built in Canada respectively as NF-5As and Bs in the 1969 CL-226  production line. These aircraft equalled the Canadian CF-5A and CF-5D versions with more powerful engines fitted. The first NF-5A was handed over in October 1969 at "Twente airbase" for 313 Squadron acting as Operational Conversion Unit. The last aircraft was handed over in March 1972. The NF-5As flew under the Dutch registrations K-3001 / K-3075 and the NF-5Bs under K-4002 / K-4030. They have been operational at "Twente airbase" (OCU, 313 and 315 Squadrons), at "Eindhoven airbase" (314 Sq) and "Gilze-Rijen airbase" (316 Sq). During the RNLAF F-16 transition the NF-5s and Bs have been stored at the "Gilze-Rijen" and  Woensdrecht airbases. 60 aircraft were sold to Turkey, 11 to Greece and 7 to Venezuela. Some aircraft have been written off during their operational life due to crashes and some remaining aircraft are displayed in museums or used in technical schools. The NF-5As and Bs were operational from 1971 to 1991. 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 used by six 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" program, supporting development of the Norwegian Penguin anti-ship 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 . In October 2011 five F-5A single seaters were given to aircraft maintenance schools around the country; including the Skedsmo, Sola, Bodø, and Bardufoss high schools, and the Royal Norwegian  Air Force's training center at Kristiansand Airport, Kjevik. The aircraft were disassembled at Moss Airport, Rygge, before delivery to the schools. Of the ten remaining Norwegian F-5s, eight F-5B two-seaters were still for sale as of 2011, six of which were stored in Norway and two in the United States. The two aircraft in the United States had been approved for sale to the American businessman Ross Perot Jr., in 2008, but the deal was blocked by the U.S. government initially. However, in 2015, Perot Jr. got permission and subsequently bought the aircraft for significantly below market price , which caused controversy and public criticism of the government of Norway. 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 and F-5B from 1965 to 1998. The F-5A/Bs were used by the 6th Tactical Fighter Squadron (Cobras) of the 5th Fighter Wing and the Blue Diamonds aerobatic team, replacing the F-86F Sabre previously used by 1965 and 1968 respectively. The F-5s also 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 lives another 15 years. In 2005, the Philippines decommissioned its remaining F-5A/B fleet, including those received from Taiwan and South Korea. South Korea. The Republic of Korea Air Force (ROKAF) purchased F-5A/Bs in 1965, and it purchased F-5Es in August 1974. KF-5 variants were built by Korean Air under license between 1982 and 1986. The F-5E/Fs and KF-5E/Fs are to be replaced by FA-50s and F-X Phase 3. 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, which were 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 its 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 reequip 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 1991, SAI was awarded a contract as the prime contractor to modernize all RSAF F-5E/Fs (including the 7 ex-Jordanian F-5Es); Elbit Systems was the sub-contractor responsible for systems integration. Upgrades include 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 the ST  Aerospace A-4SU Super Skyhawk) 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. In addition, the starboard M39 20 mm cannon mounted in the nose was removed to make way for additional avionics (the sole cannon on the two-seaters was removed because of this), and to improve maneuverability, upgraded aircraft received larger leading edge root extensions (LERX). The process began in March 1996 and was completed by 2001, receiving the new designation of "F-5S/T". In 1998, the eight RF-5Es also received the  upgrades (except for the radar) and were redesignated as "RF-5S". Each F-5S/T upgraded reportedly cost SGD$6 million. 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. 144 Squadron, the last squadron operating F-5Es, disbanded in September 2015 after the F-5S was  retired. The RSAF use F-5s as a trainer aircraft. Switzerland. The Swiss Air Force flies a total of 22 F-5E and 4 F-5F aircraft, down from a peak of 98 and 12 in 1981. They were chosen chiefly because of their excellent performance, suitability for the unique Swiss Air Force mission, and their relatively low maintenance cost per flight hour. It had been expected these aircraft would be replaced by the Saab JAS 39 Gripen, but in May 2014, a referendum by the Swiss people decided against the purchase of the Gripens. For the foreseeable future, the Swiss Air Force  will continue to fly its present F-5s. There are still plans by the Swiss Air Force and in the Swiss parliament to fly 18 F-5E and four F-5F models. This would also include the continued operation of the Patrouille Suisse, in F-5Es until 2018. In September 2020 the Swiss people voted yes in a referendum to get a replacement. With 50.1% to 49.9% and only 8670 votes between. The Swiss Air Force has decided to replace the aircraft with 36 F-35As. Taiwan. The Republic of China Air Force (ROCAF, Taiwan's air force) 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. borrowed 48 ROCAF F-5As to lend to the Republic of Vietnam Air Force before the withdrawal of U.S. forces from Vietnam. By 1973, most of those loaned F-5As were not in flying condition, thus the U.S. opted to return 20 F-5As to Taiwan by drawing nine F-5As from U.S. reserves while repairing 11 from South Vietnam. An additional 28 new F-5Es were issued to Taiwan by May 1975. By 1973, Taiwan's AIDC started  local production of a first batch of 100 F-5Es, 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. Taiwan was the largest operator of the type at one time, having 336 F-5E/Fs in inventory. The last batch of AIDC F-5E/Fs featured the F-20's shark nose. With the introduction of 150 F-16s, 60 Mirage 2000-5s and 130 F-CK-1s in the 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 Lockheed 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 ROCAF eventually killed the program. The only prototype is on display in AIDC in Central Taiwan. On 22 March 2021, two Taiwanese pilots flying F-5E's crashed into each other during a training mission resulting in  the third crash within the last six months. Two pilots died after the crash. South Vietnam / Vietnam. In June 1967, the US donated the surviving aircraft of 10th FCS USAF to South Vietnam. The president of South Vietnam had asked the US for F-4 Phantoms, but these were in high demand and the Republic of Vietnam Air Force (RVNAF) was flying only ground support missions, operating only Douglas A-1 Skyraider attackers at that point. In addition, the North Vietnamese Air Force was not sending aircraft over South Vietnam. Hence the RVNAF did not require an aircraft with advanced air to  air capabilities (like the F-4). A dedicated RVNAF unit was formed – the 522nd Fighter Squadron. When South Vietnam was overrun by NVA forces on 30 April 1975, approximately 877 aircraft were captured by the communists. Of that number, 87 were reported as F-5As and 27 were F-5Es. In November 1975, the Vietnamese government gave the Soviet military an opportunity to select captured US equipment for research and intelligence purposes. A complete F-5, along with two complete spare engines, spare parts, and ground support equipment, were loaded onto a Soviet cargo ship. Several other F-5s were later transferred by Vietnam to  the USSR, Poland and Czechoslovakia. The Vietnam People's Air Force (VPAF) reportedly used 41 F-5s operationally. Others were decommissioned and put on display at museums in Vietnam. The 935th Fighter Regiment of the VPAF 372nd Air Division became the only unit in the world to simultaneously fly both the MiG-21 and F-5. The type was used for combat by the VPAF, in ground–attack sorties against the Khmer Rouge. Gradually, a lack of critical spare parts in Vietnam caused initially by a US embargo and later by termination of manufacturing and dwindling stocks – grounded the remaining F-5s. However, in  May 2017 it was reported that the VNAF was considering upgrading particular systems in some retired aircraft, in order to put them back into service. Venezuela. After a reorganization of the Venezuelan Air Force in the late 1960s, the government realized that it was time to replace its obsolete de Havilland Vampires and Venoms active at that time, as well as the last surviving F-86 Sabres in active duty. In 1971, 54 Canadian-built CF-5As were put in storage, after the RCAF could not take them due to budget cuts. From this batch, Venezuela acquired 16 CF-5As and two CF-5Ds . In 1972, after all the aircraft were delivered, the F-86s, Venoms, and Vampires were finally scrapped. The F-5 became the first military plane in Venezuela capable of flying at supersonic speeds. After a legal dispute between Canadair and Northrop, two more CF-5Ds were built and delivered to Venezuela in 1974. Their first base of operations was the General Rafael Urdaneta Air Base in Maracaibo. After 1974, the fleet was relocated to Teniente Vicente Landaeta Gil Air Base in Barquisimeto. In 1979, after several upgrades to the fleet's communication, navigation and approximation equipment, the aircraft were renamed VF-5s, designating the  CF-5As as VF-5As and the CF-5Ds as VF-5Ds. Venezuelan F-5s could also carry weaponry such as the AIM-9 Sidewinder missile, Mk.82 and M117 bombs, and 70mm rocket launchers. In 1991, after tensions between Colombia and Venezuela almost led to a conflict, the air force started yet another modernization program for the F-5s, called "Proyecto Grifo" (Project Gryphon). Some aircraft (VF-5D number 5681 and VF-5A number 9124) were sent to Singapore for testing, then brought back for upgrade of the remaining airframes. That same year, a small fleet of four NF-5Bs and a single NF-5A, was acquired from the Netherlands  to replace aircraft lost in previous years. In 1992, during the coup d'état attempt against president Carlos Andres Perez, 3 F-5s were lost to a rebel-operated OV-10 Bronco bombing Barquisimeto Air Base. The failed coup delayed the modernization program for a year, finally coming together in 1993. The fleet was equipped with inertial laser navigation systems (similar to those in Venezuelan F-16s), IFFs, HUDs, refueling probes and modernized engines with an estimated lifespan of 22 years. In 2002, small upgrades were made to the remaining F-5s. The fleet was kept operational until 2010, when a batch of Hongdu JL-8s  was delivered as their replacement. By late 2010, it was known that at least one VF-5D was in flight-worthy condition; it is unknown if more aircraft are in operational condition. Between 1972 and 2002, a total of 9 Venezuelan F-5s were lost. Yemen. In March 1979, following North Yemen's defeat in the Yemenite War of 1979, the United States gave Saudi Arabia the permission to transfer four Northrop F-5B trainers to North Yemen. Additionally, Saudi Arabia financed the procurement of twelve F-5E fighters. By the end of the year, all 16 aircraft had arrived. This did not leave  enough time to properly train local pilots and ground crews to operate them. Hence, the Saudis agreed with Taiwan to deploy a group of 80 Republic of China Air Force pilots and ground personnel to Sana'a. They formed the 112th Squadron of the Yemen Arab Republic Air Force (YARAF), which was also known as the Desert Squadron. Most of the Squadron's members were Taiwanese until 1985, by when enough Yemenis were trained on the F-5 to take over their duties. However, some Taiwanese personnel remained in the country: in 1990, no less than 700 Taiwanese served in Yemen. They  were finally withdrawn in 1991, after the Yemeni unification. North Yemeni F-5Es have seen combat during the 1994 civil war. On 6 May, two South Yemeni MiG-21s were claimed shot down by Major Nabi Ali Ahmad, using AIM-9 Sidewinder missiles. According to South Yemeni sources, only one MiG-21bis was shot down in an air combat, and its pilot killed. Reportedly, the North Yemenis subsequently deployed their Tiger IIs for air-to-air combat only. On 15 May, two helicopters (probably Mil Mi-8s) were shot down, one of them supposedly by Major Nabi Ali Ahmad. On 28 May, an F-5E was  shot down by anti-aircraft fire. On 20 June, a South Yemeni MiG-21 was shot down over Al Anad Air Base in an air combat with two F-5Es, and its pilot was killed. Lastly, on 29 June, an encounter between two YARAF F-5Es and a single South Yemeni MiG-29 was reported. However, neither side opened fire. Following the North's victory in the civil war, the F-5 fleet was integrated into the unified Yemeni Air Force. However, the number of F-5s in service declined over the years. In 2003, negotiations with Singapore for the overhaul and upgrade of the remaining  aircraft. However, nothing came out of it. Around 2010, only six aircraft were operational, partly thanks to US aid packages. In the night of 29–30 March 2015, at least one F-5B and one F-5E were destroyed on the ground at Sanaa International Airport by Royal Saudi Air Force bombardments, in the first days of the Saudi-led intervention. Others. Saudi Arabia deployed F-5Es during the Gulf War, flying close air support and aerial interdiction missions against Iraqi units in Kuwait. One Royal Saudi Air Force F-5E was lost to ground fire on 13 February 1991, the pilot killed. The Hellenic  Air Force was the first European air force to receive the Freedom Fighter. The first F-5As were delivered in 1965, and over the next 8 years a total of about 70 F-5A/Bs were operational. The Hellenic Air Force bought an additional 10 F-5A/Bs from Iran in 1975, and around the same period another batch of 10 F-5A/Bs were acquired from Jordan. Another 10 were acquired from Norway in 1986, and a final 10 NF-5As were purchased from the Netherlands in 1991. The total number of F-5s in operation (including the ex-Iranian machines, 34 RF-5As, and 20  F-5Bs) in the Hellenic Air Force was about 120 aircraft, from 1965 to 2002, when the last F-5 was decommissioned and the type went out of operation in the Hellenic Air Force. AeroGroup, a private commercial company in the US, operates the CF-5B as a fighter lead-in aircraft for training and for other support services. There were 17 aircraft originally purchased from the Canadian Government with U.S. State Department approval and then imported into the US in 2006. Since 2013, Tunisian F-5s have been used in strike missions in support of major military offensives in the border region of  Mount Chaambi against Ansar al-Sharia and al-Qaeda-linked militants. F-5s were used by the Libyan Air Force at Wheelus AB in Tripoli, Libya from 1968 to 1969 (at least). Variants. Derivatives. F-20 Tigershark. In comparison to later fighters, the improved F-5E had some weaknesses; these included marginal acceleration, rearward visibility, and fuel fraction, and a lack of Beyond Visual Range (BVR) weapons once such radar–guided missiles became reliable during the 1980s. The F-5G, later renamed the F-20 Tigershark, aimed to correct these weaknesses while maintaining a small size and low cost to produce a competitive fighter . Compared to the F-5E, it had 60% more power, a higher climb rate and acceleration, better cockpit visibility, more modern radar and BVR capability, and competitive performance with fourth generation fighters. Like the F-5, it had better cost–effectiveness as it had the minimum necessary features relative to its competition to perform its air superiority mission. As an example, in the 1960s and early 1970s, the F-5's lack of BVR missiles was not a significant disadvantage as the kill rate of such missiles was approximately 8% to 10%, and the performance and loss of surprise (radar warning to the  enemy) cost of carrying them was not practically justified. By the early 1980s, the American AIM-7 Sparrow radar-guided missile in its "M" version was realistically exceeding a 60% kill rate, and was integrated onto the F-20. Brigadier General Chuck Yeager, test pilot and the first man to break the sound barrier, referred to the F-20 as "the finest fighter". Despite its performance and affordable cost, the F-20 lost out for foreign sales against the similarly capable but more expensive F-16, which was being procured in large numbers by the U.S. Air Force and was viewed as having greater support . Northrop YF-17. The Northrop YF-17'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. Shaped Sonic Boom Demonstration. A single ex-USN F-5E was modified to carry out research into reducing noise from supersonic flight by shaping the shock waves produced by the aircraft.