Saab 35 Draken – Double Delta Dragon
The Saab 35 Draken (known as the “dragon” or “the kite” in Swedish) was a Swedish supersonic jet fighter and interceptor aircraft that served as the backbone of the Swedish Air Force during the height of the Cold War period from the late 1950s up until the 1980s.
Developed by the Swedish aerospace company Saab AB, the Draken was the first European-built aircraft to be designed around the delta wing configuration and be considered a supersonic aircraft. Its design enabled the J-35 to prove itself as one of the most advanced fighter aircraft of its era.
At the end of the Second World War, jet fighter technology began to rapidly advance and was intensified with the onset of the Cold War between Western NATO forces and the Soviet Union.
By the early 1950s, the Swedish Air Force was also looking to replace its ageing fleet of mostly propeller-driven fighter aircraft with a new supersonic fighter that could match the capabilities of jet fighters produced elsewhere.
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Although Sweden had remained officially neutral during the Second World War, its proximity to the Soviet Union with Northern Scandinavia essentially sitting on the dividing line between East and West and advances in aircraft technology abroad prompted Swedish defence experts to begin research into jet fighter designs that could intercept a high-altitude bomber before it reached a target.
In 1948, Saab had already developed the successful Saab J-29 Tunnan jet fighter which had in part been created in response to concerns that Sweden was falling behind other nations in terms of defence technology.
The J-29 saw action during UN peacekeeping operations in the Republic of Congo in the early 1960s and was considered an effective aircraft in terms of its safety and performance, with none being lost to enemy fire.
However, a year into the Tunnan’s service, the Swedish government was already looking to produce an updated replacement or design an entirely new airframe to keep up with other countries.
A specification was issued in 1949 with Swedish defence ministers calling for a single-seat fighter aircraft that could not only match but exceed the speed of any other aircraft then in production in any country around the world.
The specification also demanded that the new fighter have an incredible rate of climb, be able to intercept high-altitude aircraft, feature an extensive weapons payload and be able to use roads as well as runways for takeoff and landing.
The Saab aerospace company was contracted to develop the Tunnan’s successor and Erik Bratt led the design team. Bratt’s team decided to follow the double delta (or compound delta) concept which featured two pairs of delta-shaped wings, one smaller set near the front of the plane at sharp sweep angles followed by a larger wing behind.
The idea was to maximize the delta wing’s capabilities of efficient fuel use, stability at slower speeds and more room for mounting weapons.
Saab also signed an agreement to reproduce the British-made Rolls-Royce Avon jet engine under license and this was fitted to the new design.
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The double delta wing design formed the basis for the Saab 210 prototype, nicknamed Lilldraken (or Little Dragon) which completed its maiden flight in 1952. Three 210 units were produced and were essentially smaller versions of what would become the J-35 Draken. The prototype’s delta wing was deemed a success, a point which was especially proven when the second 210 unintentionally broke the sound barrier during a climb.
Production was given the green light and the first Draken model completed its maiden flight in 1955.
The Saab 35 Draken was introduced into service with the Swedish Air Force in the late 1950s, with deliveries of the first J-35 A variant taking place between 1959 and 1962. It quickly became the backbone of the Swedish Air Defense.
Despite strict export policies in Sweden, the aircraft was also sold overseas and was operated by a number of other air forces including Austria, Denmark and Finland. The Draken was used by the Swedish Air Force for several different intended roles, including air defence, ground attack, and reconnaissance.
Pilots found the aircraft to be a versatile and highly manoeuvrable fighter aircraft as intended by Saab. Its delta wing configuration gave it a strong performance at high altitudes and high speeds, and its compact size and drag chute feature allowed it to be operated from smaller military airfields.
The air force J-35 was equipped with a modern avionics suite that included a radar system, a navigation system, and a weapons control system.
As a product of the Cold War, the aircraft was also armed with a variety of air-to-air missiles, including the RB04 air-to-air missile, which was one of the first air-to-air missiles in the world to use radar homing. Other armament options included conventional bombs and two M55 ADEN 30mm cannons.
Although the 210 prototypes had used the licensed Avon engine, the production model 35 Draken was powered by a single Volvo Flygmotor RM6B turbojet engine which was capable of producing up to 15,000 pounds of thrust.
The engine was designed specifically for the aircraft and provided supersonic performance abilities, fitted with an afterburner which increased its thrust and allowed the aircraft to reach speeds of up to Mach 2.
The Draken was also equipped with a unique air intake system that reduced its radar cross-section, making it more difficult to be detected by enemy radar.
While the primary use of the 35 Draken was as an interception aircraft, it also demonstrated potential as a dogfighter thanks to its agility and speed which enabled it to keep up with or even outrun most other jet fighters in service at the time.
In 1962, Saab released the revised 35 B model which featured updated gun sights and a collision course radar system. Existing 35 A models were also converted by Saab into two-seat training aircraft.
Saab continued to revise the design further with the 35 D which returned to using the Avon engine and this was followed by the 35 E used for reconnaissance roles. The 35 E had much of its weaponry removed to make way for cameras mounted in the nosecone and more radar and tracking equipment. Although some E variants were built from scratch, others were essentially modified first-generation 35 Draken units.
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In the mid-1960s, Saab also conceived the 35 F model.
The 35 F was probably the most advanced variant of the Draken and 60 units were produced between 1965 and 1972. The F variant stripped away some of the weaponry to make way for more advanced electronics, which included an automatic control system, a Pulse-Doppler radar and air-to-air missiles supplied by Hughes Falcon.
Further updates were made to the 35 F in 1985 in order to make it compliant with new government regulations on all aircraft made in Sweden and Saab used the opportunity to modify the fuel tank to allow for longer-range flight capabilities.
Despite the 35 Draken’s groundbreaking design and excellent performance, the aircraft was known for its high operating costs. The Draken was a highly advanced fighter aircraft, and its maintenance and operating costs were significantly higher than those of other fighters of its time.
This was in part due to the complexity of its avionics suite and the delta wing configuration, which required a higher level of skilled maintenance.
Another issue with the Draken was its limited range before the 35 F’s updates. The aircraft was designed for short-range air defence missions and to pursue enemy bombers in Swedish airspace, but its somewhat limited range made it unsuitable for long-range interception missions. This was a significant drawback, as other countries were beginning to develop longer-range air defence aircraft.
In Sweden, earlier model Draken units were replaced by the more modern Saab Viggen and later the Gripen, which could perform as both an interceptor and a multi-use fighter aircraft.
Although the 35 Draken was eventually overtaken by more advanced models both in Sweden and abroad and Swedish policies of neutrality meant the Draken never saw an active combat situation to test its abilities, the 35’s innovative features kept it in service for a respectable amount of time compared to other fighter aircraft.
Austria had been the largest international operator of the Draken and kept theirs in service up until 2005. Denmark modified some of their 35 Draken units into strike and ground attack aircraft, and kept them in this role until 1993. Sweden retired all of its remaining 35 Draken units in 1999.
However, the Draken was given a new lease of life in the United States when the National Test Pilot School in the Mojave Spaceport purchased some of Denmark’s Draken units for testing and research purposes on supersonic aircraft.
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With its delta wing configuration, highly manoeuvrable design, and advanced avionics suite, the Saab 35 Draken was considered one of the most advanced fighter and interceptor aircraft of its time.
Its legacy has continued to influence the design of military aircraft around the world thanks to its effective delta wing design. Despite its high operating costs and limited range, the 35 Draken remains a highly important aircraft in the history of military aviation and can be considered one of the most innovative and advanced fighter aircraft of the Cold War era.
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- Crew: 1
- Length: 15.35 m (50 ft 4 in)
- Wingspan: 9.42 m (30 ft 11 in)
- Height: 3.89 m (12 ft 9 in)
- Empty weight: 7,865 kg (17,339 lb)
- Max takeoff weight: 11,914 kg (26,266 lb)
- Powerplant: 1 × Svenska Flygmotor RM6C afterburning turbojet engine, 56.5 kN (12,700 lbf) thrust dry, 78.4 kN (17,600 lbf) with afterburner
- Maximum speed: 2,450 km/h (1,520 mph, 1,320 kn) at 11,000 m (36,089 ft)
- Service ceiling: 20,000 m (66,000 ft)
- Rate of climb: 199 m/s (39,200 ft/min)