The design of the 90 Scandia was quite similar to the DC-3. The most distinct visible difference was that the 90 had tricycle landing gear while the DC-3 had a tailwheel. The Scandia also had a quite different vertical stabilizer shape, and numerous more subtle differences. The 90 had to compete with the many surplus DC-3s available on the market at the same time, making sales difficult. Development started in February 1944. Takeoff weight was specified at about 11,600 kg, with a range of about 1,000 km. The prototype Saab 90 (Scandia) first flew in November 1946. It was capable of seating 24–32 passengers, with low-speed capability. It was to be fitted with Pratt & Whitney R-2000 engines. The Scandia project was initiated in 1944 by a supposed need (after World War II) for an aircraft carrying 25–30 passengers for a distance of up to 1000 km. Main design objectives were: safety; two engines; long life; economic operation. The wing was shaped, using NACA profiles, to provide good stalling characteristics. Low wing design was chosen since it provided: Less structural weight Better safety in an emergency landing Possibility for one continuous flap. The wing was built in three pieces. The centre section with engine mounts, and left and right sections which were bolted to the centre section, immediately outboard of the engine nacelles. The fuselage diameter was chosen to allow for four seats per row. This configuration gave a capacity of 32 passengers. A configuration with wider and more comfortable seats, three seats per row, carrying a total of 24 passengers was also offered. The prototype (90.001) was equipped with 1,450 bhp (1,080 kW) Pratt & Whitney Twin Wasp R2000 engines (changed to 1,650 bhp (1,230 kW) P&W Twin Wasp R2180 on the production version). The entire aircraft was built of metal except for the rudders which were fabric-covered metal frames. A total of 18 units were built.
