The Pilatus SB-5 was a study for a civil utility aircraft by the Studienbüro für Spezialflugzeuge at the ETH Zurich department of aircraft statics and aircraft construction.
In November 1940, the design of the SB-2, designed by the same office, was proposed to its client the Swiss Federal Office of Civil Aviation which was at the time seeking a test aircraft to evaluate criteria for airfields in mountain valleys.[1] Thus the desired aircraft would be a low-speed aircraft with STOL (Short Take-Off and Landing) performance, as well as very good climbing performance. It was not until May 1944, that the SB-2 first flew.
The SB-5 was a study for an enlarged version of the Pilatus SB-2,[2] . According to the reports of the Studienbüro delivered to the Schweizerische Flugteschnische Vereinigung, whom the Studienbüro was subordinated, design commenced in the first quarter of 1944 and was last mentioned in the first quarter of 1945 as being terminated.[3]
The Pilatus SB-5 was to be a single-engine high wing monoplane with a fixed nosewheel with a light-alloy semi-monocoque fuselage shell, accommodating 9 passengers in 3 rows of three, with an optional passenger in the co-pilots seat. Power was to have been supplied "possibly" by a Wright Cyclone[4] driving a 3-bladed propeller.