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.

[7] 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.

[18][19] 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.

[28] 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 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.

[36] 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.

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.

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.

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.

[63] 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.

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.

These aircraft were grouped into a newly established dedicated reconnaissance unit, the Erige squadron; one of its main tasks was to track the Polisario Front's surface-to-air missile systems.

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.

[107] 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.

[108] 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.

[110] 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.

[118] 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.

[122] In March 2024, The Swiss Federal Office for Armaments started delivery of 22 decommissioned F-5E/F Tiger II fighter jets to the United States.

The sale, finalized in 2020, encompasses 16 single-seat F-5E and 6 twin-seat F-5F variants, along with associated ground equipment, spare parts, and logistical support for in-country storage and preparation for transport to the U.S.

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.

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.

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.

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).

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 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.

[147] Saudi Arabia deployed F-5Es during the Gulf War, flying close air support and aerial interdiction missions against Iraqi units in Kuwait.

[citation needed] 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.

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.

[164] 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 US Air Force and was viewed as having greater support.

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.