Boeing-Stearman Model 75

Boeing-Stearman Model 75
Alan Wilson · CC BY-SA 2.0 · source
Name	Boeing-Stearman Model 75
Caption	Stearman Model 75 biplane in wartime livery
Type	Trainer aircraft
Manufacturer	Stearman Aircraft Division, Boeing
First flight	1934
Introduced	1934
Retired	varied
Primary user	United States Army Air Corps
Produced	~8,500

Boeing-Stearman Model 75 The Boeing-Stearman Model 75 is a 1930s biplane trainer produced by Stearman Aircraft, later a division of Boeing; it served as a primary trainer for the United States Army Air Corps, United States Navy, and numerous civil operators. Known colloquially as the "Stearman" or "Kaydet", it became emblematic of pilot training during the Interwar period and World War II, and many examples survive in museums, airshows, and private collections. The Model 75's rugged construction and adaptable configurations influenced later aircraft types and contributed to training programs overseen by institutions such as the Civilian Pilot Training Program.

Design and Development

Designed by Lloyd Stearman at Stearman Aircraft in the early 1930s, the Model 75 combined a fabric-covered wood-and-steel structure with a tandem open cockpit arrangement influenced by earlier designs from Travel Air and Waco Aircraft Company. Initial prototypes used radial engines supplied by Continental Motors Company, Lycoming Engines, and Pratt & Whitney, and the airframe incorporated a two-bay biplane wing cellule and fixed tailwheel undercarriage similar to contemporaneous types such as the de Havilland Tiger Moth and Avro Tutor. After Boeing acquired Stearman in 1934, production expanded at facilities including the Boeing Wichita Factory and subcontractors like Vultee Aircraft; modifications during production introduced reinforced engine mounts, updated instrument panels compatible with training syllabi from the United States Army Air Corps Flying Training Command, and naval adaptations for service with the United States Navy under designations issued by the Bureau of Aeronautics.

Operational History

Adopted by the United States Army Air Corps and designated the PT-13/PT-17 series, the Model 75 became the backbone of primary flight training throughout the 1930s and 1940s, supporting programs administered by entities such as the Army Air Forces Training Command and the Civilian Pilot Training Program. Naval versions, designated N2S, served with the United States Navy and United States Marine Corps at training stations including Naval Air Station Pensacola and Naval Air Station Corpus Christi. International operators included air arms in Canada, Australia, and Mexico, with transfers documented through wartime lend-lease arrangements overseen by United States Congress authorization. Postwar surplus sales bolstered civil aviation, with former military Model 75s appearing in air racing events like those sanctioned by the National Air Races and in film productions staged by studios such as Warner Bros. and Universal Pictures.

Variants

Several factory and field-modified variants reflect the Model 75's adaptable design. United States Army Air Corps variants included the PT-13 (equipped with a Lycoming R-680 radial), PT-17 (with a Continental R-670), and PT-18 (with a Lycoming inline prototype conversion); United States Navy variants were designated N2S-1 through N2S-5 with corresponding naval equipment and instrumentation approved by the Bureau of Aeronautics. Export and civil versions were marketed by Stearman and later Boeing to flying schools, aero clubs, and private owners; conversions for agricultural applications paralleled contemporaneous conversions by companies like Fairchild and Piper Aircraft. Aftermarket modifications by firms such as Culver and restorers in the 70s and 80s often involved engine swaps to Pratt & Whitney R-985 or modern equivalents for reliability in airshow operations.

Aircraft on Display

Examples of the Model 75 are preserved in numerous museums and collections worldwide. Notable public exhibits include aircraft displayed at the Smithsonian Institution National Air and Space Museum, the National Museum of the United States Air Force in Dayton, Ohio, the Seattle Museum of Flight, the Canadian Warplane Heritage Museum in Canada, and the Australian War Memorial in Canberra. Restored examples also appear at aviation events hosted by organizations such as the Experimental Aircraft Association and on static display at regional institutions like the San Diego Air & Space Museum and the Pima Air & Space Museum.

Specifications (Model 75)

- Crew: two (student and instructor) - Length: 24 ft 9 in (7.54 m) - Wingspan: 32 ft 2 in (9.80 m) - Height: 9 ft 10 in (3.00 m) - Wing area: 291 sq ft (27.0 m2) - Empty weight: ~1,900 lb (862 kg) - Gross weight: ~2,950 lb (1,338 kg) - Powerplant: one radial engine, commonly Continental R-670 or Lycoming R-680, 220–300 hp - Maximum speed: ~124 mph (200 km/h) - Cruise speed: ~100 mph (160 km/h) - Range: ~505 miles (813 km) - Service ceiling: ~13,200 ft (4,000 m) - Rate of climb: ~1,090 ft/min (5.5 m/s)

Category:Boeing aircraft