Editing Northrop F-5 (section)

==Variants==
{{more citations needed|section|date=July 2020}}

===Single-seat versions===
[[File:Three F-5E agressors from Alconbury 1983.jpg|thumb|A trio of USAF [[aggressor squadron]] F-5Es in formation]]
[[File:F5 Brazilian Air Force.jpg|thumb|Brazilian Air Force F-5EM]]

;N-156F
: Single-seat fighter prototype. Only three aircraft were built.
;YF-5A
: The three prototypes were given the US Air Force designation ''YF-5A''.<ref>{{cite web |title=Northrop YF-5A Freedom Fighter |url=https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/196074/northrop-yf-5a-freedom-fighter/ |website=National Museum of the U.S. Air Force |publisher=United States Air Force}}</ref>
;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
: Designation was given to one aircraft used for static tests.
;A.9
: Designation of [[Spanish Air and Space Force]] Northrop F-5As.
;F-5C ''Skoshi Tiger''
: Twelve F-5A Freedom Fighters were tested by the US Air Force for four and a half months in Vietnam. Modified at Palmdale plant by adding removable, non retractable air-refueling probe on the left side, 90 lb of external armor plates under the cockpit and engine, and jettisonable stores pylons.<ref>{{cite web |title=USAF Vietnam Operations |url=https://www.the-northrop-f-5-enthusiast-page.info/AirForces/USAFVietnamOperations.html |website=The Northrop F-5 Enthusiast Page |access-date=18 April 2021 |archive-date=18 April 2021 |archive-url=https://web.archive.org/web/20210418011603/https://www.the-northrop-f-5-enthusiast-page.info/AirForces/USAFVietnamOperations.html |url-status=dead}}</ref>
;F-5E Tiger II
: Single-seat fighter version with [[AN/APQ-159]], replacing earlier AN/APQ-153.
;F-5E Tiger III
[[File:Chile Air Force Northrop F-5E Tigre III Lofting-1.jpg|thumb|Chilean Air Force 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 and capable of firing advanced versions of the [[Python (missile)|Python]] missile
;F-5E/F
: A single, prototype built for the Swiss Air Force, comprising an F-5E fuselage and tail section, with wings from an F-5F. As of 2011, this aircraft was at the [[Meiringen Air Base]] Museum.
;F-5G
: The temporary designation given to the [[Northrop F-20 Tigershark]], equipped with [[General Electric]] [[AN/APG-67]] radar.
;F-5N
: Ex-Swiss Air Force F-5Es used by the US Navy as an "adversary" 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 saw service through 2015.<ref name="USN F-5N" />
;F-5S
: Upgraded version of the F-5E, was in use with 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]].<ref name ="AFM275"/><ref name="FSRSAF" /><ref name="FGBRF5" />
;F-5TH Super Tigris
: Formerly known as the ''F-5T Tigris'' before being officially redesignated. An upgraded version of the F-5E of [[Royal Thai Air Force]] by Israel's [[Elbit Systems]] and Thai's RV Connex, it has a new glass cockpit and [[head-up display]] upgrade and equipped with [[EL/M-2032]] radar, RTAF-developed Link-T/TH tactical [[datalink]], [[Sky Shield]] jamming pod and are capable of firing the [[AIM-9 Sidewinder#AIM-9M (USAF/USN)|AIM-9M]], [[IRIS-T]], [[Python (missile)|Python-4]] and beyond visual range air-to-air [[Derby (missile)|Derby missile]].<ref>{{Cite web|date=24 February 2023|title=RTAF completes upgrades to F-5 fighter aircraft fleet|url=https://www.janes.com/defence-news/news-detail/rtaf-completes-upgrades-to-f-5-fighter-aircraft-fleet|website=Janes}}</ref><ref>{{Cite web|date=13 November 2019|title=อัพเกรดแล้ว "F-5TH" เสือโคตรดุ ทอ.ไทย เทียบชั้นเครื่องขับไล่ยุค 4.5|url=https://www.thairath.co.th/news/politic/1702723|website=Thairath}}</ref>
;F-5EM
: Upgraded version of the F-5E of [[Brazilian Air Force]] equipped with Italian [[Grifo radar#Grifo-F|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, capable of firing the [[Sky Sword II|TC-2 Sky Sword II]], MIL-STD-1553B Link and GPS/INS. This variant did not enter service as the ROCAF decided to acquire additional F-16s instead to completely replace its F-5E/Fs.{{Citation needed|date=March 2020}}
;F-5/2000
: The F-5/2000 modernisation programme for the [[Turkish Air Force]] was to upgrade the aircraft, to serve as lead-in trainers for the F-16 force, by [[Israeli Aerospace Industries]] and [[Turkish Aerospace]]. The upgrade covers two areas – with a structural upgrade as well as an avionics modernisation such as MIL-STD-553 datalink, HUD, MFD, HOTAS, RWR, GPS+INS and [[ASELSAN]] CNI system.<ref>{{Cite web|url=https://www.savunmasanayist.com/turkiyenin-f-5a-b-freedom-fighter-seruveni/|title=Türkiye'nin F-5A/B Freedom Fighter Serüveni &#124; SavunmaSanayiST|first=Muhammed|last=Ayyildiz|date=13 August 2020}}</ref>
;B.Kh.18
: ({{langx|th|บ.ข.๑๘}}) [[Royal Thai Air Force]] designation for the F-5A.<ref name=":2">{{Cite web |title=Thai Military Aircraft Designations |url=https://designation-systems.net/non-us/thailand.html |access-date=2025-03-18 |website=designation-systems.net}}</ref>
;B.Kh.18B
: ({{langx|th|บ.ข.๑๘ข}}) Royal Thai Air Force designation for the F-5E.<ref name=":2" />
;A.9
:[[Spanish Air Force]] designation for the F-5.  Originally designated '''C.9'''.<ref>{{Cite web |title=Spanish Military Aircraft Designations |url=https://www.designation-systems.net/non-us/spain.html |access-date=2025-03-21 |website=www.designation-systems.net}}</ref>

===Reconnaissance versions===
;RF-5A
: Single-seat reconnaissance version of the F-5A fighter. Approximately 120 were built.<ref>{{harvnb|Johnsen|2006|p=81}}</ref>
;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]].<ref name="AFM275"/>
;RF-5S Tigereye
: Single-seat reconnaissance version of the F-5S for the [[Republic of Singapore Air Force]].<ref name="AFM275"/>
;AR-9
: Spanish reconnaissance aircraft
;B.TKh.18
: ({{langx|th|บ.ตข.๑๘}}) Royal Thai Air Force designation for the RF-5A.<ref name=":2" />

===Two-seat versions===
[[File:AE.9-00123-23 F-5M Freedom Fighter Ala 23 Spanish Air Force Dijon AB 2008.jpg|thumb|A Spanish F-5M Freedom Fighter at [[Dijon Air Base]] ]]
[[File:Northrop F-5F Tiger II, Bahrain - Air Force AN2253130.jpg|thumb|right|A Bahraini Air Force F-5F on the taxiway at [[RAF Alconbury]]]]

;F-5-21
:Temporary designation for the YF-5B.
;YF-5B
:One F-5B was fitted with a 5,000&nbsp;lbf (2,268&nbsp;kgf) General Electric J85-GE-21 engine, and used as a prototype for the F-5E Tiger II.
;F-5B
:Two-seat trainer version.
;F-5B(G)
:Two-seat trainer version of the F-5B for the Royal Norwegian Air Force.
;F-5BM
:Two-seat trainer version in use by the [[Spanish Air and Space 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, was in service with the [[Republic of Singapore Air Force]].<ref name="AFM275"/>
;F-5THF (บ.ข.18 ค){{#tag:ref|The designation '''THF''' is unofficial since the Royal Thai Air Force only designated it in Thai, not in English.{{Citation needed|date=December 2020}}|group="N"}}
:Twin-seat version of F-5TH in service with the [[Royal Thai Air Force]] as of May 2020.
;F-5FM
:Upgraded trainer version of the F-5F for the [[Brazilian Air Force]].
;AE.9
:Spanish designation of the Northrop F-5B.
;B.Kh.18A
: ({{langx|th|บ.ข.๑๘ก}}) Royal Thai Air Force designation for the F-5B.<ref name=":2" />
;B.Kh.18C
: ({{langx|th|บ.ข.๑๘ค}}) Royal Thai Air Force designation for the F-5F.<ref name=":2" />

===Foreign variants===
[[File:Northrop (Canadair) CF-116D (CL-219), Canada - Air Force AN1166146.jpg|thumb|A [[Royal Canadian Air Force|Canadian Air Force]] CF-116D]]

====Licensed versions====
;CF-5: Fighter versions for the [[Canadian Forces Air Command]] built under license by [[Canadair]]. Its Canadian designation is ''[[Canadair CF-5|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 and Space Force]]; built under license in Spain by [[Construcciones Aeronáuticas SA|CASA]].
;SRF-5A: Single-seat reconnaissance version of the RF-5A for the Spanish Air and Space Force; built under license in Spain by CASA.
;SF-5B: Two-seat training version of the F-5B for the Spanish Air and Space Force. Built under license by CASA in Spain.

;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 the [[Republic of Korea Air Force]]. First introduction: September 1982; 48 built.
;KF-5F: F-5F built in South Korea for the Republic of Korea Air Force. First introduction: September 1982; 20 built.

;Chung Cheng: F-5E/F built in Taiwan for [[Republic of China Air Force]] by AIDC. First introduction: 30 October 1974, one day before President [[Chiang Kai-shek]]'s 88th birthday, and was thus christened "Chung Cheng", the true name of President Chiang; 308 built.<ref>{{Cite web |last=Lee |first=Ching-tang |date=13 January 2018 |title=守護台海40年 老當益壯的「中正號」F-5戰機 |url=https://www.chinatimes.com/realtimenews/20180113002117-260417?chdtv |access-date=17 March 2023 |website=China Times}}</ref>

====Unlicensed versions====
[[File:An IRIAF HESA Azarakhsh in Vahdati Airbase Air Show.JPG|thumb|Iranian Azarakhsh]]

;[[HESA Azarakhsh|Azarakhsh]]: F-5E built or modified in Iran with unknown changes and mid-wing intakes.{{citation needed|date=February 2023}}
;[[HESA Saeqeh|Sa'eqeh]]: F-5E modified in Iran with canted, twin vertical stabilizers.
;[[HESA Kowsar|Kowsar]]: Two-seat F-5F built or modified in Iran.

===Derivatives===

====F-20 Tigershark====
{{main|Northrop 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.<ref name="Sprey, p. 145">Sprey 1982, p. 145.</ref> 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%,<ref>Sprey 1982, p. 118.</ref> 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".<ref>Yeager and Janos 1985, pp. 248–249.</ref> 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.<ref>Hammond 2001, p. 99.</ref>

====Northrop YF-17====
{{main|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====
{{main|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.