Saab J-35 Draken

Summary

Description

At the end of the 1940s, the Swedish aviation industry was already capable of designing high-performance aircraft. As the guarantor of Sweden's neutrality, along with the Swedish army and navy, the Swedish Air Force (Flygvapnet) already had a large number of excellent aircraft and had entered the world of jet aircraft at an early stage. The entry into service of the J-29 Tunnan was a prime example of this. However, in 1949, while the Tunnan was just entering service, Sweden decided to work on its successor. The Swedish government's request was for a single-seat supersonic interceptor (capable of reaching Mach 1.4 in level flight) that could operate in all weather conditions and from minimally prepared or unimproved runways over short distances (the latter requirement had become the norm in Sweden, with Swedish aviators expected to use parts of roads in the event of conflict). The goal was to counter possible high-altitude attacks by enemy bombers. Trials were conducted using a smaller prototype, the SAAB 210, which made its first flight on January 21, 1952. Although its engine proved to be underpowered for optimal use, the SAAB 210 allowed Swedish engineers to validate the main features of their project. This paved the way for the construction of three prototypes, initially equipped with the same RM5A engine (a licensed-produced Avon Mark 21) as the J-32 Lansen, then a Mark 43, and finally a Mark 46. At the end of 1956, the Swedish government gave its approval to SAAB, allowing them to start production and deliver the first production aircraft in the spring of 1960.

Named the J-35 Draken, the new Swedish interceptor generated a certain amount of interest. It had a highly unusual appearance, quite different from the chubby Tunnan and the sleek Lansen. The Draken had a distinctive look resulting from the choices made by its designers. Initially intended to have a delta wing, it was finally equipped with a double-delta wing design: the front portion of the wing had an angle of 80°, while the wingtips had an angle of only 57°, better suited for low speeds and the requirements of short takeoffs. The wing seemed to occupy the majority of the Draken's structure, making the front section appear even smaller than it actually was. The cockpit featured a small bubble canopy that did not offer much rearward visibility. Two oval air intakes framed the cockpit, feeding a single Svenska RM.6B turbojet engine with afterburner, and later a more powerful RM.6C (used from the J-35D onwards), both based on a Rolls-Royce Avon engine produced under license. To facilitate operations on short runways, a braking parachute and an airbrake were installed. Flight controls were assisted by hydraulic systems to reduce the fatigue of the lone pilot, who could, as a last resort, use the ejection seat. As for the radar, it evolved with each version: J-35A models were equipped with a PS-02/A radar, featuring an IFF system and a French Thomson-CSF-built fire control system, J-35B models featured a PS-03/A radar, and the later J-35F models carried a highly advanced PS-01/A radar capable of guiding RB.27 and RB.28 missiles launched from AIM-4 Falcons.

Sweden continuously made improvements to the Draken, leading to various versions.

Key versions:

• J-35A: Basic version, produced in approximately 90 units.
• J-35B: Improved version, featuring a new firing system; most J-35A models were upgraded to this standard; 73 units produced between 1962 and 1963.
• J-35D: J-35B equipped with a more powerful engine; 120 units produced between 1963 and 1964.
• J-35F: The most advanced variant, equipped with a single cannon instead of the original two, as well as the ability to fire radar-guided and infrared-guided missiles; 230 units produced between 1965 and 1972.
• J-35H: Version specifically developed for Switzerland but abandoned after Switzerland's selection of the Mirage III.
• J-35J: Modernized version of the J-35F, operated by Swedish aircraft; 76 units involved.
• Sk.35C: Two-seat training variant; 25 units produced.

The S-35E Draken was a reconnaissance variant without weapons or radar. Its modified nose housed a battery of forward, vertical, and oblique-facing cameras. Sixty units were produced, either from new airframes or converted from J-35D airframes (some S-35E models were later partially converted back to J-35D standard).

Developed by a team of engineers under the direction of Erik Bratt, the J 35 was one of the best fighters of the 1950s. It enjoyed some success in the export market, primarily in Europe (although potential contracts in South America did not materialize). Despite competition from the Mirage III, F-104 Starfighter, and Hawker Hunter, the Draken sold quite well. Its first user was naturally Sweden, which operated the majority of the nearly 640 units that were built. In 1968, Denmark selected the J-35X, an improved variant of the J-35F (with increased internal fuel capacity, increased payload capability from 4.1 to 4.5 tons, and a strengthened airframe). A total of 52 aircraft were delivered to Denmark, including 20 reconnaissance aircraft (later renamed RF-35). These aircraft served until 1993. Finland acquired 12 J-35F aircraft, later increasing the number to 48 (including all versions), with the last ones being retired in 2000. Additionally, in 1985, Austria purchased 24 second-hand J-35D aircraft from Sweden and had them upgraded to J-35O standard. The Austrian Drakens served for twenty years. Some aircraft from Denmark were acquired by the National Test Pilot School, a major civilian pilot training center located in the Mojave Desert in the United States. Other Drakens were sold to private owners and are still flying, particularly in the United States.

Technical specifications

Current operating countries

No country is operating the J-35 Draken in 2024.

All operators

Austria • Denmark • Finland • Sweden

Armament

Missiles payload:

• Air-to-Air Short-Range AIM-4 Falcon
• Air-to-Air Short-Range AIM-26 Falcon
• Air-to-Air Short-Range Raytheon AIM-9 Sidewinder

Photo of J-35 Draken

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