Saab 35 Draken

The Saab 35 Draken (IPA: [²drɑːkɛn]; The Kite, ambiguous with The Dragon) is a Swedish fighter-interceptor developed and manufactured by Svenska Aeroplan Aktiebolaget (SAAB) between 1955 and 1974. Development of the Saab 35 Draken started in 1948 as the Swedish Air Force future replacement for the then also in development Saab 29 Tunnan day fighter and Saab 32B Lansen all-weather fighter. It featured an innovative but unproven double delta wing, leading to the creation of a sub-scale test aircraft, the Saab 210, which was produced and flown to test this previously unexplored aerodynamic feature. The full-scale production version entered service with frontline squadrons of the Swedish Air Force on 8 March 1960. It was produced in several variants and types, most commonly as a fighter-interceptor.

The Draken functioned as an effective supersonic fighter aircraft of the Cold War period, although it was never used in conflict. Even though the type was designed and intended as an interceptor, it was considered to be a very capable dogfighter for the era. In Swedish service, it underwent several upgrades, the ultimate of these being the J 35J model. By the mid-1980s, the SAF's Drakens had largely been replaced by the more advanced JA 37 Viggen fighter, while the introduction of the more capable Saab JAS 39 Gripen fighter was expected in service within a decade, although delayed. As a consequence of cutbacks and high maintenance costs, the SAF opted to retire the Draken during December 1999. The type was also exported to the air forces of Austria, Denmark and Finland. Danish aircraft have been exported, post-service, to the United States where they have seen use as training aircraft for test pilots.

The Swedish word "Draken" has a double meaning, translating either as "The Dragon" or "The Kite". It is said that the name was derived from the appearance of the prototype, like a paper kite, when seen from above.

The number "35" comes from the aircraft's Swedish Air Force-designation: "flygplan 35" (fpl 35), meaning “aeroplane 35”. Depending on the given role, the aircraft received a prefix to indicate its type, the most common being "J 35" to indicate "jaktflygplan" (pursuit-aircraft), the Swedish term for fighter aircraft.

As jet fighter technology developed after World War II, Sweden foresaw a need for a supersonic fighter that could intercept bombers at high altitude as well as engage other fighters. During September 1949, the Swedish Air Force, via the Swedish Defence Materiel Administration, released its recently formulated requirement for a cutting-edge interceptor aircraft that was envisioned to be capable of attacking hostile bomber aircraft in the transonic speed range. The original requirement specified a top speed of Mach 1.4 to 1.5, but this was revised upwards in 1956 to Mach 1.7 to 1.8 and then again in 1959 to Mach 2.0.

It had to be flown by a single pilot, yet be capable of conducting combat operations under all weather conditions, night or day, while operating from relatively austere airstrips, carrying all equipment needed to neutralize modern jet bombers. Although other interceptors like the US Air Force's F-104 Starfighter were being conceived at the time, this fighter would have to undertake a role unique to Sweden; the ability to operate from reinforced public roads, which were to be used as part of wartime airbases. The aircraft also needed to be refueled and rearmed in no more than ten minutes by conscripts with minimal training.

SAAB commenced work on producing an aircraft to meet these requirements. Preliminary studies found that the majority of critical issues posed by these requirements could be met with a delta wing configuration. However, to obtain an aerodynamically desirable location, the forward fuselage needed to be extended, making the aircraft too heavy. The optimum solution was thought to be a double delta wing. However, this wing configuration was new and untested, so SAAB's design staff, headed by aircraft engineer Erik Bratt, and a team of more than 500 technicians, constructed a small test aircraft to explore the behaviour of the new wing.

A sub-scale test aircraft constructed in Sweden, the Saab 210 (formally flygplan 210, "aircraft 210"), unofficially nicknamed "Lilldraken" (the little dragon), comprised a test of the double delta wing, and performed its first flight on 21 January 1952. Results produced by these test flights led to an order for three full-size Draken prototypes. On 25 October 1955, the first of these prototypes, not fitted with an afterburner, conducted its maiden flight. According to aircraft publication Flight International, an atypically intensive flight test program was conducted to define and test the type's exceptional speed, range, and complicated systems. The second prototype, equipped with an afterburner, unintentionally broke the sound barrier during its first flight while climbing.^{[page needed]}