Some years after the beginning of the Cold War, Sweden saw the need of a capable interceptor aircraft that could protect the country from transonic bombers carrying nuclear bombs. This demanded a radar-equipped fighter aircraft with supersonic speed, very high rate of climb, great range and endurance and of course the capacity of the necessary weapon load. It demanded also STOL (Short-Take-Off-and-Landing) capability to be able to operate from ordinary roads during dispersed operations according to the standard of the Swedish Air Force.

The choice fell on an layout with a slender fuselage and a double-delta wing. This kind of wing would give good performances at high speed through the inner, extremely swept part. The outer, less swept part would combine this with good characteristics at subsonic speeds. The thick inner wing, integrated with the fuselage,  granted a large fuel capacity and good space for landing gear and fixed armaments. It also made the construction very rugged. The first of the prototypes took to the air in October 1955. The deliveries of the first production variant, J 35A, began in 1959.

This platform was of course very suitable for a reconnaissance aircraft. In 1960, the development of the reconnaissance version, the S 35E, started. The prototype was a modified J 35D. This variant had a stronger engine than the earlier Drakens - the Rolls Royce Avon 300 (RM 6C) - delivering at thrust  of 7.880 kp with the reheat activated.

The narrow nose part of the Draken was of course a challenge for the engineers. The French company OMERA/Segid developed a new camera (Swedish designation SKa 24 = Seriekamera 24). The camera could be fitted with objectives of five different focal lengths for different purposes. Five cameras were fitted in the nose - four SKa 24s and one camera of the older type SKa 16. Two SKa 24s were fitted in the wings instead of the automatic guns of the fighter version. The Swedish manufacturer Jungner delivered the camera sight.

For missions in darkness, a new IR-reconnaissance system was also developed, fitted in a pod under the fuselage. The system was developed by EG&G in USA with cameras (SKa 34) from the Swiss maker Vinten.

Totally 60 S 35E were delivered to the Air Force 1965-1967. 29 were rebuilt J 35D:s, the other 31 were brand new aircraft.

Mission at both high or low altitudes could be flown without changing the camera installation. The aircraft could fly at supersonic speed at low altitude, which became the standard tactics on the return flight from the target. Four drop tanks of 2.100 litres each made this possible.

The aircraft lacked armament, but later electronic countermeasure equipment  was installed.

Top: S 35E # 35928 code F 21-57 at Kallax in June 1973. Photo via Lars E. Lundin, Västervik. 

Below: S 35E # 35922 code F 21-52 at Kallax in June 1973. Photo via Lars E. Lundin, Västervik.

© Lars Henriksson

Updated 2010-07-17