|FIGHTER||Virtual Aircraft Museum / Sweden / Saab|
To produce Sweden's first turbo jet-powered fighter, Svenska Aeroplan adapted its Saab-21 design to accept the installation of a de Havilland Goblin gas turbine. This seemed a simple way to gain experience with this form of powerplant and, at the same time, extend the performance capability of the proven Saab-21 design; however, it was to prove rather more difficult a process than had been anticipated. The first requirement was for the aft fuselage nacelle to be widened to accept the new engine and the tailplane moved to the top of the fin to be clear of the jet efflux. It was also decided that because of the higher performance of this aircraft some structural strengthening was essential, and as there was no longer any need to be concerned about propeller ground clearance the landing gear struts were shortened. In this form the first Saab-21R prototype was flown initially on 10 March 1947, but almost two years elapsed before all development-problem fixes had been finalised, the first deliveries of production aircraft starting during February 1949.
The original Saab-21 production order had been for 120 aircraft, but because of delay in its development a contemporary programme for the specially-designed turbojet-powered Saab-29 was well advanced, with a result that the Saab-21R order was reduced to only 60 aircraft. These were produced as the J21RA with a 1361kg thrust de Havilland Goblin 2 engine, and J21RB with a licence-built Goblin turbojet, 30 of each being built.
After comparatively short service in the fighter role, all were converted as attack aircraft, redesignated A21R and A21RB respectively, and carrying 10 100mm or five 180mm Bofors rocket projectiles, or 10 80mm anti-tank rockets.