The Saab 91 Safir (Swedish for sapphire) is a three (91A, B, B-2) or four (91C, D) seater, single engine trainer aircraft. The Safir was built by Saab AB in Linköping, Sweden (203 aircraft) and by De Schelde in Dordrecht, Netherlands (120 aircraft). Development of the Safir began in 1944 as part of a plan to compensate for reductions in orders for military aircraft when the Second World War finally ended. Three major civil programmes were planned, the Type 90 Scandia airliner, the Type 91 Safir light aircraft and the Saab 92 motor car. The Safir was designed by Anders J. Andersson, who had previously worked for Bücker, where he had designed the all-wood Bücker Bü 181 "Bestmann". The Safir thus shared many conceptual design features with the Bestmann. It was primarily of metal construction, although it did have fabric-covered control surfaces. Development was slowed by the need to concentrate on more urgent military work, and by industrial action in suppliers. The Safir's first flight took place on 20 November 1945. While the prototype was first powered by a 130 hp (97 kW) four cylinder de Havilland Gipsy Major IC piston engine, the Saab 91A initial production model used a 145 hp (108 kW) Gipsy Major 10. The Gipsy-engine Safir was considered underpowered by military customers, and as a result, the Gipsy was replaced by a six-cylinder Lycoming O-435A rated at 190 hp (140 kW), with the re-engined type becoming the Saab 91B, flying on 18 January 1949. The Saab 91C, first flying in September 1953, retained the O-435 engine, but has a revised four-seat cabin. The 91D replaced the O-435 with a lighter four-cylinder Lycoming O-360-A1A engine rated at 180 hp (130 kW). As well as its primary role as a trainer/touring aircraft, the Safir was also used as an aerodynamic testbed. The first prototype was used as a platform for low speed testing of the swept wing for Saab 29 jet fighter, and was later further modified to test the wing for the Saab 32 Lansen fighter.[8] In addition, one ex-Swedish aircraft was sold to Japan, going through a variety of modifications to test high-lift devices for the Shin Meiwa PS-1 flying boat. Saab restarted production of the Safir at its Linköping factory in 1954,[6] building 25 Saab 91B-2s for Norway, 30 Saab 91Cs, all for military customers, and 99 Saab 91Ds.[10] Production continued until 1966, when the last Safir, a Saab 91C for Ethiopia, was completed. Total production was 323 aircraft including the prototype. The Safir was used by the Swedish, Norwegian, Finnish, Austrian, Tunisian, and Ethiopian air forces as a trainer aircraft, and a single aircraft was used by the Japan Defense Agency as an STOL test platform. The type remained in Norwegian and Finnish service until the late 1980s, and in Austria until 1992. While it was replaced as a trainer by the Scottish Aviation Bulldog in Sweden in 1971, it remained in use as a liaison aircraft, still being in service in 1994. Major civilian users were Air France, Lufthansa and the Dutch Rijksluchtvaartschool (RLS) on the Groningen Airport Eelde, near Groningen. Variants 91A – Original production version, powered by 145 hp (108 kW) de Havilland Gipsy Major 10 engine. Three seats. 48 built. Swedish Air Force designation Tp 91. 91B – Three seat version with 190 hp (140 kW) Lycoming O-435. 106 built by De Schelde. Swedish Air Force designation Sk 50B. 91B-D - Improved 91B. Three built by De Schelde. 91B-2 – 91B variant for Royal Norwegian Air Force with minor modifications, mainly a constant speed propeller[citation needed]. 25 built by Saab for Norway. 91C – Four seat version of 91B, with fuel tanks moved to the wings, and a constant speed propeller.[citation needed] Eleven built by De Schelde and 30 by Saab. Swedish Air Force designation Sk 50C. 91D – Four-seat version, powered by 180 hp (130 kW) Lycoming O-360 engine driving a constant speed propeller. 99 built by Saab.
