Design and developmentIn the aftermath of the Second World War, it was decided that Sweden needed a strong air defense built around the newly developed jet propulsion technology. Project "JxR" began in the final months of 1945 with two proposals from the SAAB design team led by Lars Brising. The first, codenamed R101, was a cigar-shaped aircraft somewhat similar to the American P-80 Shooting Star. The winning design however was the "barrel" design, codenamed R1001, which proved to be both faster and more agile. SAAB J29 "Tunnan" on display at Swedish Airforce Museum, Linkoping SAAB J29F "Tunnan" 29666/T on display at Soderhamn /F15 Aviation Museum, Soderhamn AirportThe original R1001 was designed around a mostly straight wing, but after the Swedish engineers had obtained some German research data on swept-wing designs, the prototype was altered to incorporate a 25 degree sweep, first tested on a modified Saab Safir (designated Saab 201). A member of the Saab engineering team had been allowed to review German aeronautical documents stored in Switzerland. These files captured by the Americans in 1945 clearly indicated delta and swept-wing designs had the effect of "reducing drag dramatically as the aircraft approached the sound barrier."  The SAAB 29 prototype flew for the first time on 1 September 1948. It was a small, chubby aircraft with a single central air intake, a bubble cockpit and a very thin swept-back wing. The test pilot was an Englishman, Robert A. "Bob" Moore, who went on to become the first managing director of Saab GB Ltd, UK, set up in 1960. Moore described the aircraft as "on the ground an ugly duckling – in the air, a swift." Because of its rotund appearance, The Saab J 29 was quickly nicknamed "Flygande Tunnan" ("The Flying Barrel"). A total of 661 Tunnans were built from 1950 to 1956, making it the largest production run for any SAAB aircraft.  Operational history Saab Tunnan on display at the Swedish Armed Forces' Airshow 2010The J 29 was one of the first production fighters with a swept-back wing. It was fast and agile. The Tunnan set the world speed record on a 500 km (310 mi) closed circuit in 1954 at 977 km/h (607.05 mph). Two S 29C (reconnaissance variant) additionally set an international speed record of 900.6 km/h (559.4 mph) over a 1,000 km (620 mi) closed-circuit course in 1955. In the 1950s, the Swedish Air Force, Flygvapnet, primarily using the J 29, was ranked as the fourth most powerful air force in the world. The crash record in early service was poor, mainly due to the inexperience with swept-winged aircraft and the lack of a two seat, dual control Tunnan trainer variant: this mean that SAF fighter pilots could only be trained using two seat variants of the de Havilland Vampire (a straight-winged jet), before going solo in a Tunnan. The fighter version was retired from active service in 1965, but some aircraft were used for target towing up to 1974. The last official military flight was completed in August 1976 at the 50th anniversary air show of the Swedish Air Force. A total of 30 Tunnans were sold to Austria in 1961 where they remained in service until 1972.