Stearman NS-1

The Stearman NS-1 was the U.S. Navy's first version of the trainer that would become world-famous as the Kaydet biplane. Ordered in 1934, it was the Navy designation for the Stearman Model 73, an open-cockpit, tandem-seat biplane of welded steel-tube and wood-and-fabric construction built for primary flight training. Rather than buy new engines, the Navy fitted the NS-1 with surplus 220-horsepower Wright J-5 Whirlwind radials it already held in stock, giving the type its "N" (no specified engine) suffix.

About 61 were delivered between 1934 and 1936. Forgiving and durable, the NS-1 introduced Navy cadets to the demands of military flying and proved the basic Stearman design that, after Boeing's takeover of the company, blossomed into the enormous PT-13/PT-17/N2S Kaydet family of World War II. It was the modest but important starting point of one of aviation's most prolific trainers.