Saab flew in 1945 the prototype of the Saab-91 Safir, a three-seat cabin monoplane of cantilever low-wing configuration which had retractable tricycle landing gear and was powered by a 97kW de Havilland Gipsy Major 1C inline engine. Successful testing led to the first production version, the Saab-91A, which differed primarily by having the more powerful de Havilland Gipsy Major 10 engine. Swedish airforce interest in this aircraft as a primary trainer led to a prototype powered by a 142kW Avco Lycoming O-435-A flat-six engine, first flown on 18 January 1949. This was adopted by the Flygvapen as a standard trainer under the designation Sk 50, built by Saab with the same powerplant as the Saab-91B It could be equipped to carry guns, practice bombs or rockets, and served also with the air forces of Ethiopia and Norway; in a pure training sub-variant this version was also adopted by a number of European airlines.
The Saab-91C, first flown in September
having four-seat accommodation. The final production version was the Saab-91D, which introduced a number of improvements, including a new Avco Lycoming O-360-A1A engine, disc brakes and other advanced equipment that offered weight saving. When production ended a total of about 320 Safirs had been built, and examples had been sold to operators in some 20 countries.
