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Stearman Kaydet

The Stearman Model 75 is a biplane formerly used as a military trainer aircraft, of which at least 10,626 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 United States Army Air Forces, the United States Navy as the NS and N2S, and with the Royal Canadian Air Force as the Kaydet throughout World War II.

The Kaydet was a conventional biplane of rugged construction, with a large, fixed tail wheel undercarriage, and accommodation for the student and instructor in open cockpits in tandem.

The radial engine was usually not cowled, although some Stearman operators choose to cowl the engine, most notably the Red Baron Stearman Squadron.


The U.S. Army Air Forces Kaydet had three different designations based on its power plant

Production was 2,141 in total for all models.


Initial production, R-680-B4B engine, 26 built


R-680-7 engine, 92 delivered 1937–38, Model A-75


R-680-11 engine, 255 delivered 1939–40


Six PT-13Bs were modified for instrument flying.


PT-13As equipped with the R-680-17 engine, 353 delivered, Model E-75


With a Continental R-670-5 engine, 3,519 were 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-13 with a Jacobs R-755 engine, 150 built

PT-18A Six PT-18s were fitted with blind-flying instrumentation.


Canadian PT-17: This designation was given to 300 aircraft supplied under Lend-Lease to the Royal Canadian Air Force.

The U.S. Navy had several versions, including:


Up to 61 delivered, powered by surplus 220 hp (164 kW) Wright J-5 Whirlwind



R-670-14 engine, 250 delivered to the U.S. Navy


R-680-8 engine, 125 delivered to the U.S. Navy


R-670-4 engine, 1,875 delivered to the U.S. Navy


99 U.S. Army aircraft diverted to the U.S. Navy, plus 577 newly built aircraft


R-680-17 engine, 1,450 delivered to the U.S. Navy

Stearman 70

Original prototype, powered by 215 hp (160 kW) Lycoming radial engine, temporary designation XPT-943 for evaluation

Model 73

Initial production version, 61 built for U.S. Navy as NS plus export variants

Model 73L3

Version for the Philippines, powered by 200 hp (150 kW) R-680-4 or R-680C1 engines

Model A73B1

Seven aircraft for Cuban Air Force powered by 235 hp (175 kW) Wright R-790 Whirlwind, delivered 1939–1940

Model A73L3

Improved version for the Philippines, three built

Stearman 75



Evaluated by the U.S. 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

(Or X90 and X91) the metal-frame version, became 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





24 ft 9 in (7.54 m)


32 ft 2 in (9.80 m)


9 ft 8 in (2.95 m)

Wing area

298 sq ft (27.7 m2)

Empty weight

1,931 lb (876 kg)

Max take-off weight

2,635 lb (1,195 kg)

Fuel capacity

46 US gal (38 imp gal; 170 l)


1 × Continental R-670-5,

7-cylinder air-cooled radial piston engine,

220 hp (160 kW)


2-bladed fixed-pitch propeller


Maximum speed

124 mph (200 km/h, 108 kn)

Cruise speed

96 mph (154 km/h, 83 kn)

Service ceiling

13,200 ft (4,000 m)

Time to altitude

10,000 ft (3,000 m) in 17 minutes 18 seconds

Wing loading

9.9 lb/sq ft (48 kg/m2)

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