Editing Light fighter (section)

==History==

===Interwar period===
[[File:Ferte-Alais Air Show 2004 16.jpg|thumb|A replica of the Caudron C.714 at the [[La Ferté-Alais Air Show]], 2004]]
The light fighter class originally stemmed from concern at the growing size and cost of the frontline fighters in the 1920s. During the late 1920s and 1930s the light fighter would receive significant attention, especially in France.<ref>Green and Swanborough (1994), p.19: ''"the French and 'thirties vogue for lightweight fighters.''</ref>

One early light fighter project was the [[List of aircraft of the French Air Force during World War II|French Air Force]]'s 'Jockey' interceptor program of 1926. Several aircraft, including the [[Nieuport-Delage NiD 48]] and [[Amiot 110]], were trialed without much success as they offered little over [[Nieuport-Delage NiD 62|aircraft already in production]]<ref>Green and Swanborough (1994), p.439.</ref> In the late 1920s the British similarly issued [[List of Air Ministry specifications|specification F.20/27]] for a short-range fast-climbing daylight interceptor. The [[de Havilland DH.77]] and [[Vickers Jockey]] monoplanes were among seven designs tendered to meet the specification but neither went into production, the heavier but faster biplane [[Hawker Fury]] being preferred.

Despite the failure of their Jockey program, the French returned to lightweight fighters during the 1930s as a means to expand [[France]]'s fleet of aircraft and counter the buildup of the German air force. This focused on light wooden fighters that could be built quickly without affecting production of other aircraft. A mid-thirties specification requiring fixed undercarriage produced two prototypes and in 1936 a revised requirement for retractable gear resulted in three prototypes. The most numerous of the two designs which went into production was the [[Caudron C.714]]. Delivery began in early 1940, but less than 100 had been built before [[Battle of France|the fall of France]].<ref>Green and Swanborough (1994), pp.18, 19, 30, 71-2, 111-2.</ref> Although underpowered, it was of necessity used by Polish air force pilots serving in France.

===WWII===

There was debate before and during World War II about the optimum size, weight and number of engines for fighter aircraft.<ref>Stevenson, 1993, pp. 62–72.</ref><ref>Wagner, 1990, pp. 2–23.</ref> During the war, fighters in the light to middle-weight range proved to be the most effective. Properly designed with competitive power to weight and thrust to drag ratios, these aircraft out-performed heavy fighters in combat due to greater surprise and maneuverability.<ref>Sprey, 1982, pp. 159–160.</ref><ref>Galland, "The First and the Last", p. 43 and p. 190.</ref><ref>Andersen, Clarence, "To Fly and Fight: Memoirs of a Triple Ace", p. 112, iBooks and Simon & Schuester, 1990, {{ISBN|0-7434-7972-6}}.</ref>  They were also more cost effective, allowing greater numbers to be deployed as a combat advantage. Some single-engined fighters (including the P-51 Mustang and A6M Zero) could also match or beat the range of their heavy twin-engined counterparts.{{efn| The ranges of the P-51 and Zero vs. the better long range heavy fighters, with weapons loaded, is as follows:
1. P-38: 1300 miles.
2. Me 410: 1400 miles.
3. P-51: 1650 miles.
4. A6M Zero: 2010 miles.}}

====Germany====
[[File:Me 109E-4Trop JG27 off North African coast 1941.jpg|thumb|left|The German Bf 109 was the second smallest major fighter of WWII, and produced in greater numbers than any fighter in history.]]
The German [[Messerschmitt Bf 109]] entered service in 1937 as a high speed interceptor and became the most-produced fighter in history, with nearly 34,000 built. The design philosophy of the [[Messerschmitt Bf 109|Bf 109]] was to wrap a small airframe around a powerful engine using Messerschmitt's "lightweight construction" principle, which aimed to minimize the weight and number of separate parts in the aircraft.<ref>[http://www.chuckhawks.com/best_fighter_planes.htm "The Best Fighter Planes of World War II"]. Retrieved July 1, 2016.</ref> By concentrating wing, engine and landing gear weight in the firewall, the structure of the Bf 109 could be made relatively light and simple.<ref>Cross and Scarborough 1976, pp. 56–66.</ref> The Bf 109 was the second-smallest major fighter aircraft of World War II and the lightest in the European theater. The "E" version used in the [[Battle of Britain]] had an empty weight of {{convert|2,010|kg|lb|abbr=on}}.<ref>Cross, 1962, "The Fighter Aircraft Pocket Book", p. 93.</ref> The more heavily armed and powerful G version used later in the war had an empty weight of {{convert|2,700|kg|lb|abbr=on}}. In comparison, its main fighter opponents{{clarify|date=January 2020}} weighed {{convert|2,100|to|5,800|kg|lb|abbr=on}}.{{citation needed|date=January 2020}}

====Japan====
[[File:Japanese Zero.jpg|thumb|The Japanese A6M2 Zero was the lightest major fighter of WWII. Extremely maneuverable and long range, it was highly successful early in the war, though surpassed in the later stages.]]
The lightest major fighter of World War II was the Japanese [[Mitsubishi A6M Zero]] naval fighter. Entering service in 1940 and remaining in use throughout the war, it had an empty weight of {{convert|1,680|kg|lb|abbr=on}} for the A6M2 version, which was extremely light even by the standards of its time. The design team leader, [[Jiro Horikoshi]], intended it to be as light and agile as possible, embodying the qualities of a [[samurai sword]].<ref>Mikesh, Robert. "Zero: Combat and Development History of Japan's Legendary Mitsubishi A6M Zero Fighter". MBI Publishing Company, 1994, p. 15.</ref> With Japanese engine technology lagging behind that of the west, but required to out-perform western fighters, the designers minimised weight to maximize range and maneuverability.<ref>Mikesh, 1994, pp. 17–21.</ref> This was achieved by methods including the use of light weaponry and the absence of armour and self-sealing fuel tanks.<ref>Mikesh, 1994, p. 19.</ref> Early in World War II the Zero was considered the most capable carrier-based fighter in the world,<ref name="Hawks">Hawks, Chuck. [http://www.chuckhawks.com/best_fighter_planes.htm "The Best Fighter Planes of World War II"]. chuckhawks.com. Retrieved June 30, 2016.</ref> and the extremely long range meant that the Zero could appear in and strike locations where Japanese air power was otherwise not expected to reach. In early combat operations, the Zero gained a reputation as an excellent [[dogfight]]er, achieving a kill ratio of 12 to 1.<ref name= "Thompson with Smith p. 231.">Thompson with Smith 2008, p. 231.</ref> However, Japan was unable to keep improving the aircraft through the war, primarily limited by lagging engine technology, and by mid-1942 a combination of new tactics and the introduction of better aircraft enabled the Allied pilots to engage the Zero on equal or superior terms.<ref>{{citation |last=Mersky |first=Peter B. (Cmdr. USNR) |url=http://www.ibiblio.org/hyperwar/USMC/USMC-C-Aces/index.html |title=Time of the Aces: Marine Pilots in the Solomons, 1942–1944 |series=Marines in World War II Commemorative Series |publisher=History and Museums Division, US Marines |access-date=18 January 2007 |pages=7–10}}</ref> For instance, the larger and heavier [[Grumman F6F Hellcat]] had superior performance to the Zero in all aspects other than manoeuvrability. Combined with the US Navy's superior training standards, units equipped with the type achieved a large victory-to-loss ratio against the Zero and other Japanese aircraft.<ref>{{cite book|last1=Young|first1=Edward M.|title=F6F Hellcat Vs A6M Zero-sen : Pacific Theater 1943–44|date=2014|publisher=Osprey Publishing|location=Oxford|isbn=9781782008132|pages=71–73}}</ref>

====United Kingdom====
[[File:Spitfire mk2a p7350 arp.jpg|thumb|right|The British Spitfire was only slightly larger than the Bf 109, and an effective match for it during the Battle of Britain.]]
The Royal Air Force entered World War II with two modern single-engined fighters forming the majority of the fighter force of the RAF – the [[Supermarine Spitfire]] and the [[Hawker Hurricane]]. Initially introduced as bomber interceptors, both started with eight machine gun armament but changed to cannons in the course of the war.

The Spitfire, designed by [[R. J. Mitchell]], entered service in 1938 and remained in production throughout the war. The empty weight of the [[Battle of Britain]]-era Spitfire IIA was {{convert|2,142|kg|lb|abbr=on}}, increasing to {{convert|2,984|kg|lb|abbr=on}} in a later variant. It was highly maneuverable and was generally a match for its German opponents. Most Spitfires had a [[Rolls-Royce Merlin]] engine, but later variants used one of the most powerful engines of the war – the [[Rolls-Royce Griffon]]. The Spitfire was produced and improved throughout the war but was complex to build and had limited range. In other respects it was considered an outstanding fighter.

The Hawker Hurricane played an important role in the [[Battle of Britain]], but its performance was inferior to the Spitfire and during the war was removed from frontline duty as a fighter and used for ground attack. Production ceased in mid-1944. The Hurricane IIC weighed {{convert|2,605|kg|lb|abbr=on}} empty.

====United States====
[[File:P-51-361.jpg|thumb|The P-51 is widely considered to be the finest piston fighter of WWII. With drop tanks as shown here, the relatively light P-51 could perform long range bomber escort.]] On the eve of the war, the [[United States Army Air Corps]] contracted for several "very light" fighter designs based on the [[Ranger V-770]] engine, an air-cooled inverted V12 engine, that delivered up to 700&nbsp;hp. Two prototypes were the [[Bell XP-77]] (empty weight {{convert|2,855|lb|kg|abbr=on}}) and the [[Douglas XP-48]] (empty weight {{convert|2,655|lb|kg|abbr=on}}). Problems with the engine and performance and a perceived lack of need saw both programs canceled. However, they were specifically defined as "light" or "very light" fighter aircraft.<ref>Norton, Bill. ''U.S. Experimental & Prototype Aircraft Projects: Fighters 1939–1945''. North Branch, Minnesota: Specialty Press, 2008. {{ISBN|978-1-58007-109-3}}.</ref>

Instead, the US developed a number of standard pursuit fighters, the most efficient being the relatively lightweight [[North American P-51 Mustang]]. The P-51 was more economical, costing less per air-to-air kill than any other American aircraft.<ref>Paul Ludwig, “Development of the P-51 Long-Range Escort Fighter”, p. 34.</ref><ref>Ray Wagner, “Mustang Designer”, pp. 139-146, p. 196.</ref><ref>"Fighter aircraft like the P-51, F8F Bearcat, and F-16 are examples of fighters that are lighter than their contemporaries, are less expensive, and have greater performance. Because fighter aircraft of lower weight can have increased performance, can cost less, and can create a larger force, these three benefits are embodied in the term lightweight fighter." James Stevenson, "The Pentagon Paradox", Naval Institute Press, 1993, p. 62.</ref>

The [[United States Navy]], also made aware of lightweight advantages by combat results,<ref>Stevenson, 1993, p. 70 specifically and pp. 68–72 in general.</ref> ordered a lighter version of the [[Grumman F6F Hellcat]], which at {{convert|9,238|lb|kg|abbr=on}} empty weight had limited maneuverability and rate of climb. The planned [[Grumman F8F Bearcat]] replacement used the same engine, but with empty weight reduced to {{convert|7,070|lb|abbr=on}} had excellent performance. It entered production too late to see combat in World War II. Postwar, it equipped 24 fighter squadrons in the Navy and a smaller number in the Marines. Navy author James Perry Stevenson called the Bearcat "the quintessential lightweight fighter".<ref>Stevenson, 1993, p. 70.</ref>

====USSR====
The Soviet [[Yakovlev Yak-3]], which entered service in 1944, was an attempt to develop the smallest and lightest fighter around the {{convert|1,600|hp|abbr=on}} V-12 Klimov M-107 engine.<ref name="Hawks"/> As this engine was not available in time, the {{convert|1,300|hp|abbr=on}} [[Klimov M-105]] was substituted, with a resulting empty weight of {{convert|2,100|kg|lb|abbr=on}}. Despite the reduced power, the Yak-3 had a top speed of {{convert|655|km/h|mph|abbr=on}}. The Yak-3 could out-turn the German Bf 109 and Fw 190. German pilots were ordered to avoid dogfights with the Yak-3 at low level.

The Soviet [[Yakovlev Yak-9]] was also a lightweight fighter, initially using the M-105 engine. With an empty weight {{convert|2,350|kg|lb|abbr=on}}, it was among the lighter major fighters of World War II. A development of the [[Yakovlev Yak-7]], it entered combat in late 1942 and was the Soviet Union's most-produced fighter with 16,769 built. At low altitudes, the Yak-9 was faster and more maneuverable than the Bf 109. However, its armament of one cannon and one machine gun was relatively light.

===Early jet age===
[[File:Heinkel He162A-1 No 120067 (4980318999).jpg|thumb|The first jet light fighter in service was the German [[Heinkel He 162]] of 1945.]]
[[File:Foland Gnat F Mk.I - testing the Testing Center.jpg|thumb|UK's [[Folland Gnat]] showing its size relative to the [[North American F-86 Sabre]]s in the background, which it dominated in several conflicts.]]
The Luftwaffe's [[He 162|Heinkel He 162 ''Volksjäger'']] of 1945 was a very deliberate attempt at producing a low cost jet fighter without materials that were in short supply at the end of the war. It was a low cost [[emergency fighter]], one of several designs for the [[Emergency Fighter Program]] using rockets or jets, which could be built by unskilled labour and would be flown by inexperienced pilots to defend the Third Reich. With an empty weight of {{convert|1660|kg|lb|abbr=on}}, it was very light even for the time. The He 162A was powered by a [[BMW 003]] engine.<ref>Christopher, John. ''The Race for Hitler's X-Planes'' (The Mill, Gloucestershire: History Press, 2013), p. 145.</ref> With a top speed of {{convert|790|km/h|mph|abbr=on}} at normal thrust at sea level, and {{convert|840|km/h|mph|abbr=on}} at {{convert|6000|m|ft|abbr=on}}, it was about {{convert|130|km/h|mph|abbr=on}} faster than Allied fighters but had no more than 30 minutes fuel. Test pilots reported it to be a fine handling and conceptually well designed aircraft, and considered its problems to be rushed delivery more than any fundamental design flaws. It never formally entered operational service, and did not receive the benefit of being flown by well trained pilots using a well considered operational plan. Only 120 were delivered to units, and it scored only a few kills in experimental use before the war ended.

After World War II fighter design moved into the jet era, and many jet fighters followed the successful World War II formula of highly efficient mostly single-engine designs. Prominent early examples include the British mid-50s [[Folland Gnat]], the American [[North American F-86 Sabre]],<ref>Sprey, pp. 88–89</ref><ref>Hammond, p36</ref> [[Northrop F-5]] and the Soviet [[Mikoyan MiG-15]].

The [[Mikoyan-Gurevich MiG-15]] was a Soviet jet fighter developed shortly after World War II. It weighed {{convert|3,630|kg|lb|abbr=on}} empty and was one of the first successful jet fighters to use swept wings for high transonic speeds. It first saw service in the Chinese Civil War. In combat during the Korean War, it outclassed straight-winged jet day fighters. Some 18,000 were produced.

The [[North American F-86 Sabre]], a [[transonic]] jet fighter manufactured from 1949, was the United States's first [[swept wing]] fighter. With an empty weight of {{convert|5000|kg|lb|abbr=on}} it was nearly 40 per cent heavier than the MiG-15, but light compared with today's fighters. The F-86 had a bubble canopy, small size, moderate cost, high maneuverability, and an armament of six {{convert|.50|in|mm|abbr=on}} calibre machine guns. It could turn faster than any modern fighter.<ref>Sprey, 1982, p. 104.</ref> It saw combat against the Mig 15 in high-speed dogfights during the [[Korean War]]. Considered (with the MiG 15) as one of the best fighters in the Korean War, it was the most-produced Western jet fighter, with total production of 9,860 units.<ref name="Winchester">Winchester 2006, p. 184.</ref> It continued as a front-line fighter in numerous air forces until 1994.

The [[Folland Gnat]] was a British private venture design for a light fighter and was the product of [[W.E.W. Petter|"Teddy" Petter]]'s theories about fighter aircraft design.<ref>[http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200427.html "Thoughts on the Gnat"] ''Flight'' 3 April 1953</ref> Although only adopted by the UK as a trainer,{{efn|The trainer was a two-seater with larger wing. It was the first aircraft of the Red Arrows display team.}} the Gnat served successfully as a fighter for the Indian Air Force and was in service from 1959 to 1979. India produced an improved derivative of it, the [[HAL Ajeet]]. With an empty weight of {{convert|2,177|kg|lb|abbr=on}} it was the lightest{{efn|It is only about half of the weight of other successful light jet fighters such as the F-5.}} successful post-World War II jet fighter, though at the cost of shorter range compared to other fighters. The Gnat is credited as having shot down seven Pakistani F-86s in the [[Indo-Pakistani War of 1965|1965 war]],<ref name="Rakshak">Rakshak, Bharat. [http://www.bharat-rakshak.com/IAF/History/Misc/Kill1965.html "Indian Air Force Combat Kills, Indo Pakistan War 1965."] {{webarchive|url=https://web.archive.org/web/20061105015854/http://www.bharat-rakshak.com/IAF/History/Misc/Kill1965.html |date=2006-11-05 }} ''History.'' Retrieved 4 November 2010.</ref> for the loss of two Gnats downed by PAF fighters. During the [[Indo-Pakistani War of 1971]], Indian Gnats shot down several Pakistani F-86s without loss.<ref name="Sprey, 1982, p. 137">Sprey, 1982, p. 137.</ref> The Gnat was successful against the capable F-86 flown by well-trained Pakistani pilots<ref>Chuck Yeager and Leo Janos, ''Yeager: An Autobiography'', p. 311, Bantam Books, 1985, {{ISBN|9780553050936}}.</ref><ref name="Sprey, 1982, p. 137"/> because its smaller size allowed a superior level of surprise and greater agility in dogfighting.

[[File:Fiat G-91-R3 3267 LEKG 43 CHIV 07.08.71 edited-2.jpg|thumb|left|A Luftwaffe [[Fiat G.91]]]]

In the early 1950s, the NATO [[NBMR-1]] competition for a cheap "light weight tactical strike fighter" able to carry conventional or tactical nuclear weapons and operate from dispersed airfields with minimum ground support led to designs including the French [[SNCASE Baroudeur]], [[Breguet Taon]]<ref>[http://www.flightglobal.com/pdfarchive/view/1958/1958%20-%200837.html "Military Aircraft of the World "] ''Flight'' 20 June 1958 p853</ref> and [[Dassault Étendard VI]], the Italian [[Aeritalia G.91]] and [[Aerfer Ariete]]. Other competitors included the Northrop F-5A. The British chose to continue production of the [[Hawker Hunter]], while the French decided to work independently of the competition. Italy produced the Fiat G.91 while the competition was underway and, in 1957, this was selected as NATO's standard strike fighter.<ref>[http://www.globalsecurity.org/military/world/europe/nbmr-1.htm NMBR-1], retrieved Sept. 19, 2014.</ref> With an empty weight of {{convert|3,100|kg|lb|abbr=on}} it was very light for a jet fighter. The G.91 entered service with the [[Italian Air Force]] in 1961, with the [[German Air Force|West German ''Luftwaffe'']], in 1962, and later with the [[Portuguese Air Force]]. It was in production for 19 years, with production ceasing in 1977 with 756 aircraft built.<ref name="Angelucci Matricardi p. 272">Angelucci Matricardi 1980, p. 272.</ref>

[[File:Northrop F-5E (Tail No. 11417) 061006-F-1234S-067.jpg|thumb|left|Official roll-out of the [[United States Air Force]]'s first [[Northrop F-5|Northrop F-5E Tiger II]].]]
In the mid-1950s, it was realized that fighter costs were escalating to possibly unacceptable levels, and some companies sought to reverse the trend to heavier and more expensive fighters. A prominent result was the Mach 1.3 to Mach 1.6, {{convert|4335|kg|lb|abbr=on}} [[Northrop F-5]].<ref>Wagner, p. 195. Chapter 9 of this book is devoted to the F-5.</ref> Smaller, cheaper and simpler than the contemporary F-4 Phantom, the F-5 had excellent performance and was popular on the export market. It was perhaps the most effective US-produced fighter in the 1960s and early 1970s, with a high sortie rate, low accident rate, high maneuverability, and an effective armament of 20mm cannon and heat-seeking missiles.<ref>Sprey, pp. 143, 145</ref> Though the United States never procured the F-5 for main line service, it did adopt it as an opposing forces (OPFOR) "aggressor" for dissimilar training role because of its small size and similarity in performance to the Soviet MiG-21. It also participated in large scale trials of aircraft and missile effectiveness. In the extensive 9 month long AIMVAL/ACEVAL trial at Nellis AFB in 1977, the F-5 "Red Force" was quite effective against the considerably larger [[F-14 Tomcat]] naval fighter and [[F-15 Eagle]] single seat fighters making up the "Blue Force". These modern aircraft are approximately five to ten times more expensive than the various versions of the F-5. The final result was the F-5 fighting the more modern fighters to an effective plane for plane draw.<ref>Stevenson, James, "The Pentagon Paradox", Naval Institute Press, 1993, p. 41.</ref> In direct combat against the similar MiG-21 (which performed well against American fighters in Vietnam), the F-5 is known to have scored 13 victories against 4 losses.<ref>{{Cite web|url=https://nationalinterest.org/blog/buzz/iran-iraq-war-saw-us-f-5es-and-soviet-mig-21s-battle-death-107386|title = The Iran-Iraq War Saw U.S. F-5Es and Soviet MiG-21s Battle to the Death|date = 21 December 2019}}</ref> Just under 1000 of the F-5A Freedom Fighter were sold worldwide, and another 1,400 of the updated F-5E Tiger II version. As of 2016 the F-5 remains in service with many nations, some of which have undertaken extensive upgrade programs to modernize its abilities with digital avionics and radar guided missiles.<ref>For example, see "The National Interest" article at https://news.yahoo.com/no-f-35-future-why-143000348.html for details on F-5 modernization.</ref>

The light middleweight [[Saab 35 Draken]] was a second to third generation Mach 2 fighter produced from 1955 to 1974 and in service for 45 years, with empty weights from 6,577&nbsp;kg (14,500) to {{convert|7,440|kg|lb|abbr=on}}. It was a double-delta wing single-engine fighter. Its steeply swept inner delta wing allowed for a high cruise speed. The double-delta, with a shallower rake at the outer wing, improved maneuverability. It was designed to be cheap enough for small countries and simple enough to be maintained by conscripted mechanics. Its high acceleration, light wing loading, and extreme maneuverability enabled it to be an excellent dogfighter. However, it had an overly complex fire control system.<ref name="Sprey, p. 147">Sprey, p. 147.</ref> It remained in service until 2005.

[[File:Czechoslovak Air Force Mikoyan-Gurevich MiG-21R Lofting-5.jpg|thumb|The lightweight, supersonic MiG-21 proved a dangerous opponent to heavier American fighters in the Vietnam War.]]

The French [[Dassault Mirage III]] is another late 2nd/early 3rd generation delta wing Mach 2 fighter. Stemming from a French requirement for a lightweight all-weather interceptor, it has been in service since 1961.<ref name=mirage>{{Citation |title=Mirage |first=James Hay |last=Stevens |journal=[[Flight (magazine)|Flight]] |date=22 April 1960 |pages=558–562 |url=https://www.flightglobal.com/pdfarchive/view/1960/1960%20-%200558.html}}</ref> With an empty weight of {{convert|7,076|kg|lb|abbr=on}} in the "E" version with added ground attack capability, the Mirage III is a light fighter by modern standards (though twice as heavy as initial Mirage I<ref name=mirage />). Its maneuverability, modest cost, reliability and armament of 30mm cannons and heat seeking missiles proved effective. It served the French Air Force and was exported to many countries. It performed very well for Israel in the [[Six-Day War]] of 1967 and [[Yom Kippur War]] of 1973.<ref>Sprey, pp. 134–135 and p. 143.</ref> However, Argentina's Mirage IIIs were out-performed by British Sea Harriers during the [[Falklands War]] of 1982.<ref>{{cite book|last1=Dildy|first1=Douglas C.|last2=Calcaterra|first2=Pablo|title=Sea Harrier FRS 1 Vs Mirage III/Dagger: South Atlantic 1982|date=2017|publisher=Osprey Publishing|location=Oxford|isbn=9781472818898|pages=72–74}}</ref>

Similar in size to the F-5, the Russian [[Mikoyan-Gurevich MiG-21]] entered service in 1959, was produced until 1985, and is still in widespread use today. The late Generation 2 to Generation 3, Mach 2 MiG-21 has an empty weight of {{convert|4535|kg|lb|abbr=on}}, and has served nearly 60 nations. It shot down 37 to 104 US Phantoms, in the Vietnam War, with the Phantoms shooting down 54 to 66 MiG-21s in return.<ref>"MiG-21 Against the Phantom", http://survincity.com/2013/01/mig-21-against-the-phantom/ {{Webarchive|url=https://web.archive.org/web/20141129015210/http://survincity.com/2013/01/mig-21-against-the-phantom/ |date=2014-11-29 }}</ref> In December 1966 the MiG-21 pilots of the 921st FR downed 14 F-105s without any losses.<ref>{{cite web|url=http://acepilots.com/vietnam/viet_aces.html |title=Vietnamese Aces – MiG-17 and MiG-21 pilots |publisher=Acepilots.com |access-date=9 August 2013}}</ref> Its weaknesses include poor visibility and relatively short range, but has otherwise proven to be a capable fighter.

[[File:Outof f8.gif|thumb|left|upright|F-8 pilots insignia]]
The US's [[Vought F-8 Crusader]] used in Vietnam weighed {{convert|8000|kg|lb|abbr=on}}, as compared with {{convert|13,750|kg|lb|abbr=on}} for an F-4 Phantom. It was a simple, supersonic, single engine, gun- and heat-seeker armed fighter in front-line service from 1957 to 1976. It had no radar except a simple ranging gunsite radar. The US claims the Crusader (up to 1968) shot down six enemy aircraft for every loss, compared with 2.4 for every Phantom lost.<ref>Stevenson, 1993, p. 89.</ref> The three F-8s shot down in air-to-air{{efn|A total of 170 F-8s were lost in the Vietnam War, about half from ground fire and half from accidents. Ref: Hobson, Chris. ''Vietnam Air Losses, USAF, USN, USMC, Fixed-Wing Aircraft Losses In Southeast Asia 1961–1973'', pp. 269–271. Specialty Press, 2001. {{ISBN|1-85780-115-6}},  [http://www.crusader.gaetanmarie.com/articles/goebel/part2.htm#23 Crusader In Action]}} were all lost to MiG-17 cannon fire.

The first few decades of the jet fighter era showed a combat history similar in general trend to that of the propeller fighters of World War II. So long as lighter fighters are of sufficient [[power-to-weight ratio]] and airframe sophistication, and flown by similarly skilled pilots, they tend to dominate over heavier fighters using surprise, numbers, and maneuverability. However, one significant difference did emerge in design strategy in the early jet fighter era. In World War II fighter design was strongly influenced by the seeking of higher speeds that were valuable in combat in order to close with the enemy or to escape. This trend was instinctively continued in some jet fighters through the 3rd generation (F-4 at Mach 2.23) and into the 4th generation (F-14 at Mach 2.35 and F-15 at Mach 2.5+). The aerodynamic requirements to operate at such speeds add considerable complexity, weight, and cost to the airframe.<ref name="Hammond, 2001, p. 78">Hammond, 2001, p. 78.</ref>  But, these Mach 2 and above class speeds have zero utility in combat.<ref>Stuart, 1978, pp. 65–79.</ref> Combat speeds never exceed Mach 1.7 and seldom 1.2, for two reasons. First, it requires extensive use of the afterburner, which typically increases fuel consumption by about a factor of three or even four,<ref>[http://www.jet-engine.net/miltfspec.html Military Turbojet/Turbofan Specifications] jet-engine.net</ref> and rapidly reduces operational radius. Second, speeds even above about Mach 0.7 to Mach 1 (depending on circumstances) so widen the turn radius in maneuvering combat that the fighter is thrown too wide to get a tracking solution on an opponent. Speed had reached the limit of its practical combat value, such that optimum fighter design required understanding the penalties the endless search for higher speed was imposing, and sometimes deliberately choosing not to accept those penalties.<ref name="Hammond, 2001, p. 78"/>

===Supersonic era===
[[File:F-16 June 2008.jpg|thumb|left|The General Dynamics/Lockheed F-16 is the archetype of the modern, advanced light jet fighter, and is in service with many nations.]]
As supersonic performance, with afterburning engines and modern missile armament, became the norm the Soviet [[Mikoyan MiG-21]], the French [[Mirage III]], and the Swedish [[Saab Draken]] entered service. The next generation of lightweight fighters included the American [[F-16 Fighting Falcon]], Swedish [[JAS 39 Gripen]], Indian [[HAL Tejas]], Korean [[FA-50]], Japanese [[Mitsubishi F-2]], Chinese [[Chengdu J-10]] and Pakistani [[CAC/PAC JF-17 Thunder]]. The high practical and budgetary effectiveness of modern light fighters for many missions is why the US Air Force adopted both the [[F-15 Eagle]] and F-16 in a "hi/lo" strategy of both an outstanding but expensive heavy fighter and a lower cost but also outstanding lightweight fighter.<ref>Hammond, 2001, p. 100.</ref> The investment to maintain a competitive modern lightweight fighter air force is approximately $90M to $130M (2013 dollars) per plane over a 20-year service life, which is approximately half the cost of heavy fighters{{citation needed|date=January 2020}} so understanding fighter aircraft design trade-offs and combat effectiveness is of national level strategic importance.

In the 1960s and 1970s, a US-based "[[Fighter Mafia]]", led by colonels [[John Boyd (military strategist)|John Boyd]], Everest "Rich" Riccione and analyst [[Pierre Sprey]] advocated for production of a 4th generation light fighter.<ref>Hammond, 2001. Chapter 5 is devoted to the F-15, and chapter 6 to the F-16.</ref> Despite heavy fighter losses in the Vietnam War, most senior US Air Force leaders still opposed the light fighter concept.<ref>Coram, pp. 290–292.</ref> After much debate, General Dynamics designed the successful F-16. Its competitor, the [[Northrop YF-17]], led to the successful [[McDonnell Douglas F/A-18 Hornet]] Navy fighter as a cheaper alternative to the F-14. The F-16 offered excellent air-to-air combat performance due partly to its fly-by-wire control system, which improved agility.<ref name="Hillaker"/> When not burdened by heavy air-to-ground weapons, the F-16 had the longest range of any US fighter at the time.<ref>Coram, 2002, pp. 260–261.</ref> The F-16 and F/A-18 later added significant weight to become multirole fighters with strong air-to-ground capabilities, pushing them towards the "middleweight" range of modern fighters.

The Soviet counterpart to the F-16 and F/A-18, the [[Mikoyan MiG-29]], was originally part of the ''Perspektivnyy Lyogkiy Frontovoy Istrebitel'' (LPFI, or "Advanced Lightweight Tactical Fighter") program.<ref>Gordon p8-9-9</ref>

[[File:F-20 flying.jpg|thumb|The [[Northrop F-20 Tigershark]] was an update of the F-5 intended for the export market, but lost out to the F-16 and never entered production.]]
In the 1980s the privately developed F-5G, later renamed the [[Northrop F-20 Tigershark]], aimed to correct weaknesses in the aging F-5 while maintaining small size and low cost. Its empty weight was {{convert|6,000|kg|lb|abbr=on}}. Its [[General Electric F404]] engine produced 60 percent more power than the F-5, and it had a higher climb rate and acceleration, better cockpit visibility, and more modern radar. [[Chuck Yeager]], test pilot and the first man to break the sound barrier, referred to the F-20 as "the finest fighter" of the mid-1980s.<ref>Yeager, Chuck and Leo Janos. ''Yeager'', Bantam Books, 1985, pp. 248–249.</ref> Despite its high performance and cost effectiveness,{{Citation needed|reason=Your explanation here|date=May 2017}} the F-20 lost out for foreign sales against the similarly capable, 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> The Tigershark was cancelled having made no sales.
[[File:IAF Tejas full size (32941198511).jpg|alt=|left|thumb|[[HAL Tejas]]]]
The [[HAL Tejas]] has an empty weight of {{convert|6,500|kg|lb|abbr=on}}, and is the lightest fighter among current production light fighters. Introduced into limited service in 2014, with 16 IOC specification aircraft delivered to January 2020, it was the lowest-cost fighter aircraft with competitive air-to-air capability in production at that time, at an equivalent cost of US$27 million. 83 Tejas MK1As are ordered, with another 100 planned, making it the lightest [[4.5 generation jet fighter|4.5 generation]] aircraft in production.<ref>{{Cite web|url=https://www.ainonline.com/aviation-news/aerospace/2019-11-17/hal-struggling-labor-costs-and-disputes|title=HAL Struggling with Labor Costs and Disputes|last=Mathews|first=Neelam|website=Aviation International News|language=en|access-date=2020-01-31}}</ref><ref>Aeronautical Development Agency http://www.tejas.gov.in/, retrieved Sept. 20, 2014.</ref> The design is similar to the Mirage III and JAS 39 Gripen, being a light tailless delta-wing single-engine fighter with ground attack capability.

The French [[Dassault Mirage 2000]] was designed for the [[French Air Force]] (''Armée de l'Air'') in the late 1970s, as a lightweight single-engine fighter. Based on the [[Dassault Mirage III|Mirage III]], it entered service in 1982, and has since evolved into a multirole aircraft.<ref>{{cite web|url=http://www.vectorsite.net/avmir2k.html |title=The Dassault Mirage 2000 & 4000 |access-date=May 19, 2012 |url-status=usurped |archive-url=https://web.archive.org/web/20110514003113/http://www.vectorsite.net/avmir2k.html |archive-date=May 14, 2011 }}</ref> In heavier multirole form, it has empty weight of {{convert|7,400|kg|lb|abbr=on}}. More than 600 were built<ref name=airvectors>Goebel, Greg. [http://www.airvectors.net/avmir2k.html "The Dassault Mirage 2000 & 4000"]. Airvectors.net, 1 January 2015.  {{webarchive |url=https://web.archive.org/web/20150428055403/http://www.airvectors.net/avmir2k.html |date=April 28, 2015 }}</ref> and it has served in the air forces of nine nations.

[[File:FA-50 Fighting Eagle First delivery 1.jpg|thumb|[[KAI T-50 Golden Eagle|KAI FA-50]]]]

[[South Korea]]'s [[KAI T-50 Golden Eagle]], designed by [[Lockheed Martin]] with [[Korea Aerospace Industries]], is based on the F-16 [[Multirole combat aircraft|multirole-fighter]].<ref>{{cite web|url=https://www.koreatimes.co.kr/www/news/nation/2008/12/205_37021.html |title=Domestic Light Attack Jets Due in 2013 |publisher=Koreatimes.co.kr |date=30 December 2008 |access-date=9 February 2015}}</ref><ref>{{cite web|url=http://www.aeroflight.co.uk/types/korea/kai/t-50/T-50.htm |title=Korean Aerospace Industries T-50 Golden Eagle |publisher=Aeroflight.co.uk |access-date=9 February 2015}}</ref> Its latest variant, the [[KAI T-50 Golden Eagle#Variants|FA-50 Fighting Eagle]], is designated as a light fighter and trainer. It uses the same air frame as the T-50 advanced trainer introduced in August 2002.<ref>{{cite web|author=John Pike |url=http://www.globalsecurity.org/military/world/rok/ktx-2.htm |title=KTX-2 Indigenous Trainer |publisher=Globalsecurity.org |date=3 July 1997 |access-date=9 February 2015}}</ref> It is now deployed with [[Republic of Korea Air Force|South Korean Air Force]] and the [[Philippine Air Force]].<ref>{{cite web|url=http://www.flightglobal.com/articles/2009/01/07/320726/south-korea-orders-kai-fa-50-light-attack-fighter-prototypes.html |title=South Korea orders KAI F/A-50 light attack fighter prototypes |publisher=Flight Global |date=7 January 2009 |access-date=9 February 2015}}</ref><ref>{{cite web|url=http://english.yonhapnews.co.kr/national/2011/06/02/29/0301000000AEN20110602003300315F.HTML |title=Air Force to deploy 20 TA-50 light attack aircraft by next year |publisher=Yonhap News |date=2 June 2011 |access-date=9 February 2015}}</ref>

[[File:Pakistan Air Force Chengdu JF-17 Gu.jpg|thumb|[[CAC/PAC JF-17 Thunder]]]]

The [[CAC/PAC JF-17 Thunder]] light fighter was developed jointly by China's [[Chengdu Aircraft Corporation]] and Pakistan's [[Pakistan Aeronautical Complex]] in the early 2000s.<ref>{{cite news|url=https://www.flightglobal.com/news/articles/chengdu-puts-back-super-7-flight-tests-169377/ |last=Sobie |first=Brendan |title=Chengdu puts back Super-7 flight tests |work=Flightglobal |date=29 July 2003}}</ref> it was inducted into the [[Pakistan Air Force]] in February 2010.<ref>{{cite web|url=http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=96657&Itemid=2 |title=Associated Press Of Pakistan – First Squadron of JF-17 Thunder inducted in PAF |publisher=App.com.pk |access-date=9 February 2015 |url-status=dead |archive-url=https://web.archive.org/web/20151222163116/http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=96657&Itemid=2 |archive-date=22 December 2015 }}</ref> At least 66 aircraft have been delivered to Pakistan. More aircraft are scheduled to be introduced in 2018. A twin-seater variant was undergoing flight testing as of late 2015.

[[File:Saab-JAS-39 at ILA 2010 05.jpg|thumb|left|The versatile Gripen is the second lightest jet fighter currently in production, and features advanced canard-delta aerodynamics.]]
The [[JAS 39 Gripen]] is a single-engine light fighter manufactured by the Swedish aerospace company [[Saab Group#Aeronautics|Saab]]. With an empty weight of {{convert|6,800|kg|lb|abbr=on}} it is the second lightest fighter in production as of 2016. Though primarily an air superiority fighter, the design has effective air-to- ground capability as well. Its delta wing offers high cruise and super-cruise (above Mach 1 without using after-burner), low wing-loading and high maneuverability. It can operate from short airstrips and {{convert|800|m|yd|abbr=on}} sections of road, can be serviced by moderately trained mechanics, and has high sortie rates. Among Western 4th generation fighters the Gripen has the lowest operating cost at about $4,700 per flight hour (as of 2012). The lowest operating cost in current range of fighters discussed above is of [[HAL Tejas]] of about $4,000.<ref>{{cite web|url=https://www.defencexp.com/explained-per-hour-operating-cost-of-iafs-fighter-jets/ |title=Per Hour Operating Cost » Indian Air Force's fighter jets |date=17 May 2021 }}</ref> Among western fighters, next best operating cost fighter is the F-16 at about $7,000 per flight hour.<ref>{{cite web |url=http://www.stratpost.com/gripen-operational-cost-lowest-of-all-western-fighters-janes |title=Gripen operational cost lowest of all western fighters: Jane's |author=Saurabh Joshi |date=4 July 2012 |website=stratpost.com |publisher=StratPost |access-date=22 September 2014}}</ref>{{efn|This Jane's reference is only considering per hour cost of fuel, airfield level maintenance, and personnel. It is not considering original development costs, per unit purchase costs, and major upgrade programs. When all costs are considered and amortized, the total per flight hour costs will approximately triple. For example, total F-16C cost is reported $22,500 per hour by the USAF as of 2013, instead of the $7000 per hour reported by Jane's in their study. See https://nation.time.com/2013/04/02/costly-flight-hours/ for fully loaded hourly operating cost of USAF aircraft as reported by the USAF.}} The Gripen has [[relaxed stability]] [[fly-by-wire]] flight controls for maximum agility, a top speed of Mach 2, a 27mm cannon, heat-seeking missiles, and radar-guided missiles.
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