F-21A was the designation given to 25 Israel Aircraft Industries Kfir C.1 fighters that were leased by the US Navy and US Marine Corps from Israel for dissimilar air combat training.
The Dassault Mirage IIICJ had long been an important part of the Israel Defense Force/Air Force (IDF/AF), and had played a key role in establishing Israeli air superiority during the Six-Day War in 1967.
However, there was some room for improvement. There were problems with the jet engine exhaust of the Mirage IIICJ and the Cyrano II fire control radar was unreliable and hard to maintain. Even before the Six-Day War, the IDF/AF had proposed to Dassault that they should produce a cheaper version of the Mirage III without a fire-control radar. The omission of the radar and the related electronics would make it possible to carry an additional 500 liters of fuel. In addition, the Atar 9B of the Mirage IIICJ was to be replaced by the more reliable and more fuel-efficent Atar 9C. Israel placed an order for 50 of these aircraft, designated Mirage 5J.
However, at the end of the Six-Day War in 1967, the government of France under President Charles de Gaulle underwent a change in its foreign policy, and decided to embargo the delivery of the batch of Mirage 5Js that the IDF/AF had ordered and which were already built and ready for delivery to Israel. The planes were redesignated Mirage 5F, and were delivered instead to the Armee de l'Air.
Faced with a continuing threat from its Arab neighbors, Israel concluded that it could no longer be certain of a supply of combat aircraft from overseas, and decided that it had to manufacture combat aircraft on its own.
One of Israel's first efforts was the production by Israel Aircraft Industries of a copy of the Mirage 5, which was known as the Nesher (Eagle). There was some unofficial French cooperation--since Dassault was a privately-owned corporation, the French government did not block the granting of a licence to built the airframe to IAI. However, the Atar engine was another matter--SNECMA was government-owned and France stubbornly refused to allow a license to be granted. Production drawings for the Atar 9C engine were stolen by Israeli agents from the Swiss Sulzer AG factory that was building the engine under license, and many airframe production drawings were stolen by Israeli agents operating in France.
To assist the project, the IDF/AF loaned a Mirage IIIBJ (Number 88) to IAI. In order to avoid losing the unofficial French cooperation, the development of the Nesher took place under a shroud of secrecy.
The first Nesher flew in September of 1969. A total of 69 Neshers were built by IAI between May 1971 and late 1974. The first Nesher was delivered to IDF/AF squadrons in May 1971. The Nesher was available for the Yom Kippur War of October 1973, and some 40 Neshers saw action in that conflict. Unofficial sources claim 144 kills for the Neshers, but this might have included some Mirage kills as well, since the Nesher program was still highly classified and did yet officially exist. By that time, Mirages were also in service with Arab air forces--IDF/AF Neshers clased with Libyan Mirages on October 18, 1973, . To avoid identification confusion between Israeli- and Arab-piloted Mirages, the IDF/AF Mirage/Nesher aircraft were painted with large yellow/black triangles on their wings and tails.
In the late 1970s, 26 Neshers surplus to IDF/AF requirements were sold to Argentina under the export designation Dagger. At that time, the story of the Israeli-built Mirage was finally revealed to the public. Seventeen Daggers were lost during the 1982 Falklands/Malvinas war, during which they operated primarily in the fighter-bomber and antishipping roles.
It was apparent that the Atar 9C of the Mirage 5/Nesher had insufficient power, and in 1968 the IAI began to look at alternative powerplants for an upgraded version of the Nesher. Work on the project began in 1968, with one team looking at the General Electric J79 and the other concentrating on the Rolls Royce Spey. The J79 was eventually selected, primarily because it powered the F-4 Phantom that had just been ordered by the IDF/AF and perhaps more importantly because the Phantom deal included rights to the local manufacture and assembly of the J79 engines.
As a trial, the veteran Mirage IIIBJ testbed was fitted with a J79 engine, and flew for the first time on September 21, 1970. A re-engined Nesher flew in September 1971.
As a result of their design work on the re-engined Mirage IIIBJ, IAI suggested that a much more sophisticated machine could be built. The new project was named Kfir (Lion Cub). The airframe was based on that of the Mirage/Nesher, but the rear fuselage was slightly shorter and larger in diameter in order to accommodate the J79. The 11 percent greater mass flow of the J79 required the use of larger air intakes, and the higher operating temperatures of the engine required the fitting of extensive heat shielding for the rear fuselage. A large dorsal air scoop was installed at the base of the fin to supply cooling air to the afterburner. The landing gear was strengthened and provided with longer-stroke oleos. The cockpit was extensively revised, and a considerable amount of Israeli-built electronics were incorporated. The internal fuel tankage was slightly rearranged and its capacity was increased to a total of 713 gallons.
The prototype Kfir was a conversion of Nesher No. 712. It flew for the first time in June of 1973. The Kfir entered production too late for participation in the Yom Kippur War of October 1973, but IDF/AF Kfirs have been active in numerous subsequent Israeli military actions against guerilla installations in Lebanon.
The first production version was the Kfir C.1. The first IAI Kfirs were not equipped with canards, and some had a round-tipped radome for their ranging radar. They were essentially little more than J79-powered Neshers. The Kfir C.1 was fitted with the Elta EL/M-2001 fire-control radar which had look-down/shoot-down capability. The basic Kfir was produced in only relatively few numbers (27) and most were later upgraded to Kfir C.2 standards with small narrow-span fixed canards on the upper air intakes and rectangular strakes behind the ranging radar on the sides of the nose.
The first Kfirs entered service in 1974, but were not revealed to the public until April 14, 1975.
In 1985, the US Navy leased 12 Kfir C.1s from Israel for use as dissimilar air combat trainers. The Kfir C.1 in US Navy service was assigned the designation F-21A. They received the Bureau of Aeronautics serial numbers 163298/163309. The twelve F-21As went to VF-43 at NAS Oceana in 1985, where they were painted in a two-tone grey scheme. They were replaced by F-16Ns in early 1988, and were all returned to Israel in March of 1988.
The Marine Corps established its own dissimilar air combat training unit, VFMT-401, at Yuma, Arizona in August of 1987. VFMT-401 received 13 F-21As leased from Israel in 1987. These were given a non-standard serial number derived from the aircraft's three-digit construction number prefixed by 999 for bookkeeping purposes to make them compatible with Navy computer systems. Some USMC F-21As were painted in a two-tone grey scheme, whereas others retained Israeli camouflage. USMC F-21As were operated by VFMT-401 for a couple of years until being replaced in late 1989 by F-5E Tiger IIs obtained from the USAF. These F-21As were then returned to Israel, bringing the era of the F-21A in US service to an end.
The Kfir C.2 and C.7 were later versions of the design with more capable electronics, additional weapons hardpoints, and the ability to carry out multirole operations. None of these ever served in the USA. The Kfir C.2 introduced larger sweptback forplanes on the air intakes, small strakes installed ont he extreme nowe, and a new wing with a "sawtooth" on the leading edge. An improved EL/M-2001B radar was installed. The Kfir C.7 was a ground attack version with a stronger landing gear and two additional hard points.
Engine: One IAI Bedek Division-built General Electric J79-J1E turbojet, rated at 11,890 lb.s.t. dry, 18,750 lb.s.t. with afterburning. Performance: Maximum speed (clean) 1516 mph at 36,000 feet, 862 mph at sea level. Ferry range 2000 miles with one 343 US gallon and two 449 US gallon drop tanks. Combat radius 480 miles with two AAMs with one 218 US gallon and two 343 US gallon drop tanks. Initial climb rate 45,930 feet per minute. An altitude of 50,000 feet in 5 minutes 10 seconds. Stabilized supersonic ceiling 58,000 feet. Dimensions: Wingspan 26 feet 11 1/2 inches, length 51 feet 4 1/4 inches, height 14 feet 11 1/4 inches, wing area 374.6 square feet. Weights: 16,060 lbs empty, 22,961 lbs. normal takeoff, 36,376 pounds maximum takeoff. Armament: Two Rafael-built DEFA 553 30-mm cannon in the wing roots, each with 125 rounds of ammunition. Two Rafael Shafrir infrared-homing air-to-air missiles are normally carried underneath the outer wings.