Boeing-Stearman Model 75

The Stearman (Boeing) Model 75 is a biplane used as a military trainer aircraft, of which at least 8,584 were built in the United States during the 1930s and 1940s. Stearman Aircraft became a subsidiary of Boeing in 1934. Widely known as the Stearman, Boeing Stearman or Kaydet, it served as a primary trainer for the USAAF, the USN (as the NS & N2S), and with the RCAF as the Kaydet throughout World War II. After the conflict was over, thousands of surplus aircraft were sold on the civilian market. In the immediate postwar years they became popular as crop dusters, sports planes, and for aerobatic and wing walking use in airshows.

Design and development


The Kaydet was a conventional biplane of rugged construction with large, fixed tailwheel undercarriage, and accommodation for the student and instructor in open cockpits in tandem. The radial engine was usually uncowled, although some Stearman operators choose to cowl the engine, most notably the Red Baron Stearman Squadron.

Post-War usage
After World War II, the thousands of PT (primary trainer)-17 Stearmans were auctioned off to civilians and former pilots. Many were modified for cropdusting use, with a hopper for pesticide or fertilizer fitted in place of the front cockpit. Additional equipment included pumps, spray bars, and nozzles mounted below the lower wings. A popular approved modification to increase the maximum takeoff weight and climb performance involved fitting a larger Pratt & Whitney R-985 engine and a constant speed propeller.

Variants
The US Army Air Forces Kaydet had three different designations based on its power plant:
 * PT-13: with a Lycoming R-680 engine. 2,141 total all models.


 * PT-13 Initial production. R-680-B4B engine. 26 built.
 * PT-13A R-680-7 engine. 92 delivered 1937-38. Model A-75.
 * PT-13B R-680-11 engine. 255 delivered 1939-40.
 * PT-13C Six PT-13Bs modified for instrument flying.
 * PT-13D PT-13As equipped with the R-680-17 engine. 353 delivered.


 * PT-17: With a Continental R-670-5 engine. 3,519 delivered
 * PT-17A 18 PT-17s were equipped with blind-flying instrumentation.
 * PT-17B Three PT-17s were equipped with agricultural spraying equipment for pest-control.


 * PT-18
 * PT-13 with a Jacobs R-755 engine, 150 built.
 * PT-18A Six PT-18s fitted with blind-flying instrumention.


 * PT-27
 * Canadian PT-17. This designation was given to 300 aircraft supplied under Lend-Lease to the RCAF.

The US Navy had several versions including:
 * NS
 * Up to 61 delivered. powered by surplus 220 hp (164 kW) Wright J-5 Whirlwind.


 * N2S :Known colloquially as the "Yellow Peril" from its overall-yellow paint scheme.
 * N2S-1 R-670-14 engine. 250 delivered to the US Navy.
 * N2S-2 R-680-8 engine. 125 delivered to the US Navy.
 * N2S-3 R-670-4 engine. 1,875 delivered to the US Navy.
 * N2S-4 99 US Army aircraft diverted to the US Navy, plus 577 new-build aircraft.
 * N2S-5 R-680-17 engine. 1,450 delivered to the US Navy.


 * Stearman 70
 * Original prototype, powered by 215 hp Lycoming radial engine. Temporary designation XPT-943 for evaluation.


 * Model 73
 * Initial production version. 61 built for US Navy as NS plus export variants.


 * Model 73L3
 * Version for Philippines, powered by 200 hp R-680-4 or R-680C1 engines. Seven built.


 * Model A73B1
 * Seven aircraft for Cuban Air Force powered by 235 hp Wright R-760 Whirlwind. Delivered 1939–1940.


 * Model A73L3
 * Improved version for Philippines. Three built.


 * Stearman 75
 * (a.k.a. X75) Evaluated by the army as a Primary trainer. The X75L3 became the PT-13 prototype. Variants of the 75 formed the PT-17 family.


 * Stearman 76
 * Export trainer and armed versions of the 75.


 * Stearman 90 and 91
 * (a.k.a. X90 & X91) Productionised metal framed version becoming the XBT-17.


 * Stearman XPT-943
 * The X70 evaluated at Wright Field.


 * American Airmotive NA-75
 * Single seat agricultural conversion of Model 75, fitted with new, high lift wings.

Operators

 * Argentine Air Force
 * Argentine Navy received 16 Model 76D1s 1936 to 1937
 * Argentine Navy received 16 Model 76D1s 1936 to 1937


 * Brazilian Air Force
 * Brazilian Air Force
 * Brazilian Air Force


 * 🇨🇦 Canada
 * Royal Canadian Air Force received 300 PT-27s under Lend Lease.


 * Republic of China Air Force received 150 PT-17s under Lend-Lease, and 20 refurbished aircraft post war.
 * Republic of China Air Force received 150 PT-17s under Lend-Lease, and 20 refurbished aircraft post war.


 * Colombian Air Force
 * Colombian Air Force


 * Imperial Iranian Air Force
 * Imperial Iranian Air Force
 * Imperial Iranian Air Force
 * Imperial Iranian Air Force
 * Imperial Iranian Air Force
 * Imperial Iranian Air Force
 * Imperial Iranian Air Force


 * Israeli Air Force
 * Israeli Air Force


 * Mexican Air Force
 * Mexican Air Force


 * Nicaraguan Air Force
 * Nicaraguan Air Force


 * 🇵🇾 Paraguay
 * Paraguayan Air Force


 * Peruvian Air Force
 * Peruvian Air Force


 * $\phi$
 * Philippine Army Air Corps
 * Philippine Air Force


 * US Army Air Corps/US Army Air Forces
 * US Marine Corps
 * United States Navy
 * United States Navy


 * Venezuelan Air Force
 * Venezuelan Air Force

Survivors
A considerable number of Stearmans remain in flying condition throughout the world, as the type remains a popular sport plane and warbird.


 * Brazil
 * Museu Aeroespacial in Rio de Janeiro


 * Colombia
 * Two PT-17 remaining in active service for display, the FAC-62 and FAC-1995.


 * Israel
 * The Israeli Air Force maintains a single airworthy PT-17 (31) at its museum in Hatzerim.


 * Peru
 * PT-17 on display Instituto de Estudios Históricos Aeroespaciales del Perú, Miraflores, Lima.
 * Mexico
 * 3 Pt-17 at the Air College for exhibition
 * United States
 * Stearman model 70 The original prototype of the model 75 at Western Antique Aeroplane & Automobile Museum.
 * Stearman model 75 is in regular use at Chester County G. O. Carlson Airport in Coatesville, Pennsylvania.
 * PT-13D (s/n 42-17800) is on display at the National Museum of the United States Air Force in Dayton, Ohio. This aircraft is the last Kaydet produced. It was donated in 1959 by the Boeing Aircraft Company, which purchased the Stearman Company in 1938.
 * 75-3130 is on display in the hangar deck of the USS Yorktown (CV-10) at The Patriot's Point Naval and Maritime Museum in Charleston, South Carolina.
 * A PT-17 in which George H.W. Bush once flew as part of his navy training is on display at the Pacific Aviation Museum, on Ford Island, Pearl Harbor.
 * A PT-17 is on display Carolinas Aviation Museum, Charlotte, North Carolina.
 * A PT-17 is on display at Vintage Flying Museum, Meacham International Airport, Fort Worth, Texas.
 * A PT-17 (N53129) is in regular use at Mississippi State University as a research aircraft and glider tow-plane
 * PT-17 (s/n 41-8786) is on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT
 * Uruguay
 * PT-17 (CX-AKC). Model A 75 NL PT 17 - SN 75-3-119 / 7 Dec 1942 ("Slat" Magazine #26 jun/jul 1998)