Boeing-Stearman Model 75

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Model 75 "Stearman"
Kaydet
Boeing Stearman N67193.jpg
Boeing Stearman N67193 in USN markings
Role Biplane Trainer
Manufacturer Stearman Aircraft / Boeing
Introduction 1934
Number built 9,800
Unit cost
$11,000

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.[1] 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[edit]

WAVE in a Boeing Stearman N2S US Navy training aircraft.
US Navy N2S-2 at NAS Corpus Christi, 1943.
US Navy NS-1s of the NAS Pensacola Flight School, 1936.
Boeing Stearman E75 (PT-13D) of 1944.
Boeing Stearman (PT-13) of the Israeli Air Force.
US Navy N2S ambulance at NAS Corpus Christi, 1942.
Boeing Stearman PT-17, Museum of Historical Studies Institute of Aerospace in Perú - Lima.

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[edit]

Post-War usage[edit]

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[edit]

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.[2]
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.[3]
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 (160 kW) Lycoming radial engine. Temporary designation XPT-943 for evaluation.[4]
Model 73
Initial production version. 61 built for US Navy as NS plus export variants.[3]
Model 73L3
Version for Philippines, powered by 200 hp (150 kW) R-680-4 or R-680C1 engines. Seven built.[5]
Model A73B1
Seven aircraft for Cuban Air Force powered by 235 hp (175 kW) Wright R-760 Whirlwind. Delivered 1939–1940.[5]
Model A73L3
Improved version for Philippines. Three built.[6]
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.[7]

Operators[edit]

 Argentina
Argentine Navy received 16 Model 76D1s 1936 to 1937[8]
 Bolivia
 Brazil
Brazilian Air Force
 Canada
Royal Canadian Air Force received 300 PT-27s under Lend Lease.[9]
 Republic of China
Republic of China Air Force received 150 PT-17s under Lend-Lease,[10] and 20 refurbished aircraft post war.[11]
 Colombia
Colombian Air Force
 Cuba
 Dominican Republic
 Greece
 Guatemala
 Honduras
 Iran
Imperial Iranian Air Force[citation needed]
 Israel
Israeli Air Force[citation needed]
 Mexico
Mexican Air Force[citation needed]
 Nicaragua
Nicaraguan Air Force[citation needed]
 Paraguay
Paraguayan Air Force[citation needed]
 Peru
Peruvian Air Force[citation needed]
 Philippines
Philippine Army Air Corps[citation needed]
Philippine Air Force[citation needed]
 United States
US Army Air Corps/US Army Air Forces[citation needed]
US Marine Corps[citation needed]
United States Navy[citation needed]
 Venezuela
Venezuelan Air Force[citation needed]

Survivors[edit]

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

Brazil
Colombia
  • Two PT-17 remaining in active service for display, the FAC-62 and FAC-1995.
Israel
Peru
Mexico
  • 3 Pt-17 at the Air College for exhibition
United States
Uruguay
  • PT-17 (CX-AKC). Model A 75 NL PT 17 - SN 75-3-119 / 7 Dec 1942 ("Slat" Magazine #26 jun/jul 1998)

Specifications (PT-17)[edit]

Line drawings for the N2S/PT-13.

Data from United States Military Aircraft since 1909[15]

General characteristics

Performance

See also[edit]

Aircraft of comparable role, configuration and era

References[edit]

Notes
  1. ^ National Museum of the United States Air Force gives the figure 10,346 but this includes the equivalent airframes in manufactured spare parts.
  2. ^ NMUSAF fact sheet: Stearman PT-13D Kaydet. Retrieved 18 May 2010.
  3. ^ a b Bowers 1989, pp.252-253.
  4. ^ Bowers 1989, pp. 251–252.
  5. ^ a b Bowers 1989, p. 253.
  6. ^ Bowers 1989, p. 254.
  7. ^ Taylor 1965, p. 178.
  8. ^ Bowers 1989, p. 268.
  9. ^ Bowers 1989, p. 265.
  10. ^ Bowers 1989, p. 262.
  11. ^ Bowers 1989, pp. 260–261.
  12. ^ United States Air Force Museum 1975, p. 21.
  13. ^ http://www.ae.msstate.edu/rfrl/pages/stearman.html
  14. ^ http://neam.org/index.php?option=com_content&view=article&id=905 "Stearman PT-17 (Model 75) 'Kaydet'"
  15. ^ Swanborough and Bowers 1963, p. 443.
Bibliography
  • Avis, Jim and Bowman, Martin. Stearman: A Pictorial History. Motorbooks, 1997. ISBN 0-7603-0479-3.
  • Bowers, Peter M. Boeing Aircraft since 1916. London:Putnam, 1989. ISBN 0-85177-804-6.
  • Phillips, Edward H. Stearman Aircraft: A Detailed History . Specialty Press, 2006. ISBN 1-58007-087-6.
  • Swanborough, F.G. and Peter M. Bowers. United States Military Aircraft since 1909. London:Putnam, 1963.
  • Taylor, John W. R. Jane's All The World's Aircraft 1965–66. London: Sampson Low, Marston & Company, 1965.
  • United States Air Force Museum. Wright-Patterson AFB, Ohio: Air Force Museum Foundation. 1975. 
Videography
  • Stearman, Lloyd. Stearmans, You Gotta Love Them. Lap Records, 2005. (NTSC Format)

External links[edit]