The Stearman (Boeing) Model 75 is a biplane, of which at least 9,783 were built in the United States during the 1930s and 1940s as a military trainer aircraft. 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, as a basic trainer for 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 civil market. In the immediate post-war years they became popular as crop dusters and as sports planes.

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.

Operational history
Post-War usage
After World War II, the thousands of PT-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-13Initial 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 instrumention.
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
(a.k.a. X70) The Wright Field XPT-943 based on the Stearman 6 Cloudboy.
Stearman 73
Civil production of the NS and PT-13.
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.

Specifications (PT-17)
General characteristics
* Crew: two, student and instructor
* Length: 24 ft 9 in (7.54 m)
* Wingspan: 32 ft 2 in (9.81 m)
* Height: 9 ft 8 in (2.95 m)
* Wing area: 298 sq ft (27.7 m²)
* Empty weight: 1,931 lb (878 kg)
* Max takeoff weight: 2,635 lb (1,198 kg)
* Powerplant: 1× Continental R-670-5 seven-cylinder air-cooled radial engine, 220 hp (164 kW)

Performance
* Maximum speed: 135 mph (117 knots, 217 km/h)
* Cruise speed: 96 mph (83 knots, 155 km/h)
* Service ceiling: 13,200 ft (4,024 m)
* Climb to 10,000 ft (3,050 m): 17.3 min.

Source: Wikipedia.org.

P.S.: This is the only Stearman flying here in South America, specifically in my country.