Draken SE-DXP
Year built
1960
Aircraft
Sk 35C Draken
Base
F 7 Satenas
35810/SE-DXP was originally built as a J 35A in 1960 and was delivered to the F13 “Bråvalla flygflottilj” that same year. In 1961 35810 was flown to Saab where it was converted to Sk 35C twin-seat trainer. In late 1962 the conversation was complete and the Sk 35C was delivered to the F16 “Upplands flygflottilj” and later served with the F10 “Skånska Flygflottiljen”. When retired the aircraft was transferred to the Swedish Air Force Historic Flight at Såtenäs, to be flown on the civil register as SE-DXP.
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Saab SK 35C Draken
SK 35C was the trainer version of the Draken, 25 J 35As with short tail sections were rebuilt into a twin-seated trainer version. The minor modification meant that the aircraft could easily be converted back to a J 35A standard if necessary. The trainer version lacked armament.
The Saab 35 Draken is a Swedish fighter aircraft 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 night fighter. It featured an innovative but unproven double delta wing, which lead to the creation of a sub-scale test aircraft, the Saab 210, which was produced and flown to test this previously unexplored aerodynamic feature. Saab 35 Draken entered service with frontline squadrons of the Swedish Air Force on 8 March 1960. It received the designation J 35, the prefix J standing for Jaktflygplan (Pursuit-aircraft) – the Swedish term for a fighter.
The Saab 35 Draken is known for, among other things, its many "firsts" within aviation. It was the first European-built combat aircraft with the true supersonic capability to enter service and the first fully supersonic aircraft to be deployed in Western Europe. Designwise it was one of, if not the first, combat aircraft designed with double delta wings, being drawn up in early 1950. The unconventional wing design also had the side effect of making it the first known aircraft to perform and be capable of the Cobra manoeuvre. It was probably also the second European-built aircraft to exceed Mach 2 in level flight (the first one being the very similar Dassault Mirage III); which was reached on January 14 1960.
The Draken functioned as an effective supersonic fighter aircraft of the Cold War period. 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 1980s, the SAF's Drakens had largely been replaced by the more advanced Saab 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 in December 1999. The type was also exported to the air forces of Austria, Denmark and Finland. Danish aircraft have also been exported post service to the United States where they have seen use as training aircraft for test pilots.
The Saab 35 Draken is a fighter aircraft, equipped with a distinctive double delta wing. According to Flight International, it is difficult to differentiate between the fuselage and the wing. The design anticipates what would later be known as a ‘blended wing-body. The fuselage has a circular section, and the inboard portion of the wing is a large-chord surface that extended almost to the engine intakes. It was possible to dispense with a tailplane, resulting in a clean, simple overall design. The leading edge of the inner wing was swept back 80° for high-speed performance, and the outer wing 60° for good performance at low speeds.
The cockpit of the Draken featured mostly Swedish-sourced instrumentation. Successive models introduced various improvements to the cockpit fittings, such as the revised canopy and new avionics. For export customers, the Draken was outfitted with a Ferranti-built Airpass II fire-control radar, which was effective for acquiring various air-to-air or air-to-surface targets, along with a ground-mapping mode working in conjunction with the aircraft's navigation systems. Typically, two separate radio units would be installed, along with a high-speed data link and two navigation systems. As there is no natural feedback placed upon the stick, artificial forces were generated by a q-feel system. The Draken was also fitted with a three-axis autopilot.
The fuselage of the Draken consisted of two sections, front and rear, joined by bolts. The forward section, which was integral with the intake ducts and neighbouring wing structure, accommodates the fire-control radar, cockpit, nose undercarriage, integral fuel tanks and various systems. The rear portion, which was manufactured as a single piece alongside the rest of the inner wing, contained the engine and afterburner, bag-type fuel tanks, armament, main landing gear, and other systems. The flight control surfaces consisted of a rudder, along with inboard and outboard elevons, the outer sections being fitted with mass-balance weights. Each surface was operated by a tandem hydraulic jack, which was connected to separate circuits. As a weight-saving measure, the hydraulic systems would operate at a line pressure of 210 kp/cm2 (20.6 MPa), which would be greater than double the pressure used in the earlier Saab 29 Tunnan.
Propulsion was provided by a single Svenska Flygmotor RM6B/C turbojet engine, a licence-built model of the Rolls-Royce Avon 200/300 engine. A ram turbine, positioned under the aircraft's nose, provided emergency power, while the engine also featured a built-in emergency starter unit. In order to reduce its landing distance when required, the Draken was equipped with a drogue parachute. The principal armament was carried externally, up to four AIM-9 Sidewinder air-to-air missiles were carried on hardpoints beneath the wings and fuselage; alternative payloads include a variety of bombs and rockets, along with provisions for the installation of a pair of 30 mm cannons, located within each of the inboard wing panels. In place of the cannons, additional fuel tanks could be fitted in the same space. For aerial reconnaissance missions, a variety of camera pods could be carried underneath the fuselage.
Due to a lack of knowledge on the then historically unproven design of the J 35's double delta wing, the plane had a lot of problems at the start of its service life. The unstable design of double delta wings made it difficult to land early versions of the J 35 as they had to be manually stabilized during landing. The design also allowed the plane to enter what's called "super stalls"; which simplified can be described as an uncontrollable stall that appears on planes with specific wing configurations when pulling high alpha numbers. Due to this pilots on the J 35 were trained to prevent super stalls from happening. However out of this training came what is today known as the Cobra manoeuvre, which starts with an entry into a controlled super stall by pulling high alpha and then quickly pulling negative alpha to counter it. This basically makes the plane a full-body air brake for a few seconds, which heavily drops the speed.
The Swedish Air Force is the first known air force to have discovered and developed this manoeuvre. The Swedish named the manoeuvre Kort parad, meaning short parade, most likely referring to the way the plane stands up during the manoeuvre. Its primary use was to train a pilot to counter super stalls, however, it also saw a secondary use as a combat manoeuvre to make a pursuing enemy fighter overshoot.
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