Archive digitization



Aviation and Diplomacy

Frank Piasecki

NATO 1949-2009 Projekt ekspozycji w Muzeum Lotnictwa Polskiego w Krakowie



Polish Aviation Museum

31-864 Kraków,
al. Jana Pawła II 39
phone: (12) 640 99 60,
(12) 642 40 70
e-mail: info@muzeumlotnictwa.pl



Malopolska Region


Patronage

Kraków Airport







Aeroplane: SAAB J 35J Draken

SAAB J 35J Draken
Sweden
fighter



  • Technical data


Span 9.4 m
Length 15.35 m
Take-off weight 15,000 kg
Maximum speed 2125 km/h
Ceiling 20,000 m
Range (przebazowanie) 2840 km
Armament see text
Powerplant :
1 x turbojet with afterburner RM6C, 7750 kG thrust

 

The SAAB construction team, led by Erik Bratt, entered into the first study works over a supersonic fighter by the end of 1947. Sweden had difficulties with access to German research. Different aerodynamic concepts were considered. The serious drawback in research was also the lack of a suitable aerodynamic tunnel.
In 1949, together with the Flygvapnet (Swedish Air Force), tactical and technical conditions for a new fighter were set. The aeroplane was intended to intercept supersonic enemy fighters and bombers. Its combat success was to be assured by good performance, manoeuvrability and efficient armament (including guided missiles). For night operations and use of guided missiles easier, target radar as envisaged.
Ground attack capabilities were also taken into consideration. The fighter ought to have supersonic speed and achieve a high rate of climb. Combat range should cover Sweden's entire territory. Use of alternative aerodromes as well as straight sections of road was thought of, including the ability of short take off and landing speed. Its small dimensions should make transportation by road and sheltering easy, already a feature of Swedish fighters.
Service ought to easy for ground checks and quick recreating of combat capabilities. Designers faced a serious problem of matching the contradicting factors. At that time the speed of an aircraft was achieved with the costs of its manoeuvrability, range and an increased take off and landing length. Such requirements, imposed by the Swedish military authorities, demanded a creation of such an aerodynamic configuration, which could match all the contradictions. Initially, Eric Bratt and his team adopted the "clean delta" design. By the end of 1951, after analysis, the "double delta" design had been chosen.
Such a design featured a big wing area with low drag. It allowed the plane to gain better supersonic speed flight characteristics. The use of a flowing fuselage-wing chord into a constant profile with a big lifting surface aerofoil, allowed for the placement of large capacity fuel tanks. There was also a lot of room for the undercarriage, strong armament and leading edge air intakes.
To check the correctness of the aerodynamics (and to save money), the designer applied non-conventional research methods. Initially there were cardboard flying models, then ram jet models. Finally, after the deciding authorities approved the design, work on the turbojet powered aircraft started.
The test aeroplane flew for the first time in late January 1952. This allowed for checks on the wing design, steering quality and stability. The air intakes, being an important factor, were fixed to make them more efficient for the engine. It allowed to resign from the air intake adjustment system, simplifying the aircraft's equipment.
Eventually, in May 1952, the mock-up of the fighter, J35 Draken (dragon), was shown to the public. The Rolls-Royce Avon 200 turbojet engine, which was built as the RM6 at the Volvo Flygmotor plant, powered the aeroplane. In August 1953, the SAAB Works received an order for four prototypes: one for static tests, three for flight tests.
By the end of October 1955, the first prototype took to the air for the first time. By the end of January 1956, it achieved supersonic speeds in level flight, without engaging the afterburners. In following flights it crossed the sound barrier in a climb. The next two prototypes were flown at the beginning of 1956. Now the aeroplane had to face hard air force tests. The complete program of in-flight tests came through with no serious problems, which was due to the experiments previously held. The J35 became a big technical success.
Production started after the air force tests. In 1958 the first serial J35 A was flown although the first types weren?t fully capable operationally, as they had inadequate radio equipment.
The next version, Sk 35C, flown in December 1959, was intended for pilot training. At the end of 1959, production of the J35 B started. It was the first fully equipped combat aeroplane and could be engaged into Sweden's Automatic Air Defence System, STRIL 60.
By the end of December 1960 the J35 D entered production, being significantly improved.
In June 1963 the reconnaissance plane, the S 35 E, was flown. At the beginning of the Sixties, work on the new fighter, the J35 F, started.
The J35 F featured improved cockpit equipment and a new canopy, similar to that of the S 35 E. The engine was given an improved afterburner. The aeroplane was also equipped with a new weapons control system. It was based on a new radar sight with an enlarged seeking and tracing range and a heat seeking direction finder. The number of hard points was increased to eight - two under the fuselage and six under the wings. Gunnery armament was limited to a single starboard canon. Two American Hughes air-to-air missiles, produced at SAAB, were applied to the aeroplane. The first, the RB28 (the Swedish version of the AIM-4C), had an infra-red guidance system. The second, the RB27 (American AIB-26B), was equipped with a semi-active radar guidance system (the missile was aimed at the reflected radio wave source, emitted by the radar sight of the attacking aircraft). Apart from that, Sidewinder missiles were still in use. The aeroplane could also carry bombs (2 x 500kg under the fuselage and 6 x 100kg under the wings), unguided missile launchers and/or auxiliary fuel tanks (two under the fuselage).
230 aeroplanes were produced in the F1 and F2 sub versions. The J35 F came into service in 1965. Production ended in 1977.
In total, 615 J35 Draken aeroplanes were produced.
By the end of the Seventies, the decision to modernise the J35 F was taken. It was completed between 1987-91, by overhauling 66 aircraft and changing the designation to the J35 J. The aeroplane featured improved radio equipment, utilised to co-operate with the AIM-9L Sidewinder air-to-air missile. It increased the aeroplane's fight manoeuvre capabilities. The "Draken" was the first Swedish supersonic fighter and also marked its place in world aviation history as, paving the way for new technical and aerodynamic concepts.

Back

 


Dofinansowano ze środków Ministra Kultury i Dziedzictwa Narodowego
© NeoServer 2009 -      - Polityka obsługi "ciasteczek" -