That year, Stinson introduced SM-1 (Stinson Monoplane model 1), a high-wing monoplane ... cockpit biplane flights in ORA’s ...

Like several military utility airplanes of the era, including Pipers, Aeroncas, and Taylorcrafts, the Sentinel was developed from a popular civilian model, in this case, the Stinson 105 Voyager.

Each successive model came with improvements such as more powerful engines and redesigned controls. Production was brisk and Stinson built more than 5,000 108s before Piper acquired the company in ...