Editing Northrop F-5 (section)

===F-5E and F-5F Tiger II===
[[File:Northrop F-5E (Tail No. 11417) 061006-F-1234S-067.jpg|thumb|Official roll-out of first USAF F-5E Tiger II]]
[[File:F5E Tiger II B83 HAFB.jpg|thumb|F-5E Tiger II with [[B83 nuclear bomb]] at [[Hill Aerospace Museum]]]]

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 [[Mikoyan-Gurevich MiG-21|MiG-21]]. The resulting aircraft, initially known as F-5A-21, subsequently became the F-5E. It had two more powerful GE J85-21 engines, each with {{convert|3600|lbf|kN|abbr=on}} dry thrust and {{convert|5000|lbf|kN|abbr=on}} in afterburner, and had a lengthened and enlarged fuselage to accommodate more fuel. Its wings were fitted with enlarged [[leading edge extension]]s, 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]]) (F-5A and B had no radar). It retained the gun armament of two [[M39 cannon]]s, 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 [[Electronic countermeasure|ECM]] equipment.<ref name="WAPJ 25 p58-9 70-1">{{harvnb|Lake|Hewson|1996|pp=58–59, 70–71}}</ref> Additionally the two position nose landing gear from the Canadian CF-5 was incorporated to reduce takeoff distance.<ref name="Claws p116"/>

The first F-5E flew on 11 August 1972.<ref name="Claws p116">{{harvnb|Braybrook|1982|p=116}}.</ref> 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.{{sfn|Lake|Hewson|1996|pp=71–72}} 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 [[nautical mile|nmi]]. On 6 April 1973, the 425th TFS at Williams Air Force Base, Arizona, received the first F-5E Tiger II.<ref>{{Cite book |last=Tambini |first=Anthony J. |url=https://books.google.com/books?id=JvANc4CpPnwC&dq=F-5E+Tiger+II+%221973%22+%22Williams+Air+Force+Base%22&pg=PA55 |title=F-5 Tigers Over Vietnam |date=2001 |publisher=Branden Books |isbn=978-0-8283-2059-7 |language=en}}</ref>

[[File:Northrop F-5E (Tail No. 11419) (cropped).jpg|thumb|left|An early series F-5E]]
A [[aerial reconnaissance|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.<ref name="WAPJ 25 p82-3"/> More were built under license overseas: 91 F-5Es and F-5Fs in Switzerland,<ref name="WAPJ 25 p103">{{harvnb|Lake|Hewson|1996|p=103}}</ref> 68 by [[Korean Air]] in South Korea,<ref name="WAPJ 25 p96">{{harvnb|Lake|Hewson|1996|p=96}}</ref> and 308 in [[Taiwan]].<ref name="WAPJ 25 p104">{{harvnb|Lake|Hewson|1996|p=104}}</ref>

The F-5E proved to be a successful combat aircraft in service with US allies, but had no combat service with the US Air Force, though the F-5A with modifications, designated F-5C, was flown by the US in Vietnam.<ref>Tambini, Anthony, ''F-5 Tigers over Vietnam'', 2014, {{ISBN|9780828320597}}.</ref> The F-5E evolved into the single-engine F-5G, which was rebranded the [[Northrop F-20 Tigershark|F-20 Tigershark]]. It lost out on export sales to the [[F-16 Fighting Falcon]] in the 1980s.