The Vought O2U Corsair is a 1920s biplane scout and observation aircraft. Developed by Vought Corporation, the O2U was ordered by the United States Navy (USN) in 1927. Powered by a Pratt & Whitney R-1340 engine, it incorporated a steel-tube fuselage structure and a wood wing structure with fabric covering. Many were seaplanes or amphibians.

The O2U was the first of several Vought aircraft to bear the name Corsair. The Vought SBU Corsair of 1933, Vought F4U Corsair of 1938, and A-7 Corsair II of 1963 all also bore the name.

Design and development Two prototypes were ordered in 1926 and tested by the Navy Trial Board before the first production batches were ordered. In 1927, a total of 291 O2Us were produced. The O2U-2, -3 and -4 were ordered in 1928 with minor changes. By 1930 they were being superseded by the O3U which was basically similar to the O2U-4, one variant of which was fitted with the Grumman float, and were manufactured until 1936. A total of 289 were built.Eden and Moeng 2002 Many of them had cowled engines and some had enclosed cockpits.

Operational history The Pratt & Whitney R-1690-42 Hornet engine was used to power Corsairs designated SU-1 to SU-4. The change in designation reflected their role as scouts (their larger engines and heavier weight precluded their use as floatplanes, and USN examples were only used on wheels from either carrier decks or land bases). A total of 289 SU aircraft were built for the United States Navy. No fewer than 141 Corsairs were still serving with the US Navy and United States Marine Corps when the United States entered World War II in December 1941.

Export versions included the Corsair V-65F, V-66F and V-80F for the Argentine Navy, the V-80P for the Peruvian Air Force, and the V-85G for Germany. China purchased Corsair variants V-65C and V-92C. Brazil purchased 36 aircraft V-65B, some hydroplanes V-66B and 15 V-65F.

In March 1929, Mexico purchased 12 armed aircraft O2U-2M versions with the Wasp engine to thwart a military coup. Mexico then built 31 more units under licence, and called them Corsarios Azcárate O2U-4A. In 1937, Mexico purchased 10 V-99M equipped with the Pratt & Whitney R-1340-T1H-1 Wasp engine, some of them may have been sent to Spain."Corsarios Mexicanos" (in Spanish). portalaviacion.vuela.com. Retrieved: 18 January 2011.

China purchased the 42 export versions of O2U-1 from 1929 to 1933, and 21 export versions of O3U between 1933 and 1934 and they saw extensive bombing actions. The O2U-1 versions participated in the Central Plains War and in the January 28 Incident against Japanese targets, while the O3U versions first participated in the Battle of Pingxingguan to support the Chinese ground forces, and later against the Japanese targets in Shanghai.

In 1929 Peru replaced surviving Vought UOs with 12 O2U-1. Used first as trainers, they saw action against APRA rebels in the north of the country, and against Colombian forces during the Colombia-Peru War. None were lost due to enemy fire, but several were destroyed in accidents. These were also used for light bombing and casualty evacuation by the U.S. Marine Corps during the U.S. intervention in Nicaragua in the late 1920s.

Thailand used its Corsairs in the Franco-Thai War and in the Battle of Ko Chang against the French Navy.Royal Thai Air Force, Bangkok, 1976: The History of the Air Force in the Conflict with French Indochina.

Variants XO-28 Single example for U.S. Army Air Corps evaluation with serial 29-323, Wright Field Project Number P-547, powered by a 450 h.p. R-1340-C engine. Destroyed in a fire at in March 1930.Andrade, John M. U.S. Military Aircraft Designations and Serials since 1909. Earl Shilton, Leicester: Midland Counties Publications, 1979. , page 138. O2U-1 two prototypes followed by 130 production aircraft for USN with interchangeable wheel/float landing gear and 28 aircraft for other customers. Pratt & Whitney R-1340-88 Wasp engine O2U-2 37 built, increased span and larger rudder O2U-3 110 built (30 for export), revised wing rigging, some had redesigned tail surfaces and Pratt & Whitney R-1340-C engine O2U-4 43 built (1 for export. Also seven civilian O2U were built), similar to O2U-3 but with equipment changes O2U-4A 31 built, Mexican licensed production O3U-1 87 built as observation seaplanes incorporating Grumman amphibious float"New Navy Planes Land On Water Or Deck." Popular Science, February 1933."Eyes of the Fleet as seen during Maneuvers." Popular Mechanics, March 1933. O3U-2 29 built, strengthened airframe, Pratt & Whitney R-1690 Hornet engine O3U-3 76 built, Pratt & Whitney R-1340-12 Wasp engine. O3U-4 65 built, Pratt & Whitney R-1690-42 Hornet engine. XO3U-5 test aircraft with Pratt & Whitney R-1535 engine XO3U-6 test aircraft converted from O3U-3 with NACA cowling and enclosed cockpits O3U-6 32 built, 16 with Pratt & Whitney R-1340-12 Wasp and 16 with Pratt & Whitney R-1340-18 Wasp engines SU-1 Scout version of the O3U based on the O3U-2, 28 built"Vought". Aerofiles. Retrieved: 18 January 2011. SU-2 Scout version of the O3U based on the O3U-4, 53 built SU-3 Variant of the SU-2 with low-pressure tires, 20 built XSU-4 SU-2 converted as a prototype SU-4 variant with a R-1690-42 engine, later became an SU-4. SU-4 SU-4 re-engined with a R-1690-2 engine, 41 built One United States Navy O2U-3 evaluated by the United States Army Air Corps. Vought V-65B Export version for Brazil - 36 Vought V-65C Export version for Nationalist China Vought V-65F Export version for Argentine Navy Vought V-66B Export version for Brazil Vought V-66E Export version for United Kingdom, powered by Pratt & Whitney Wasp D.1 engine, one brought for evaluation by the Royal Air Force, delivered 1933 and discarded 1936.Jarrett 1997, pp. 28–33 Vought V-66F Export version for Brazil - 15, and Argentine Navy Vought V-80F Export version for Argentine Navy Vought V-80P Export version for Peruvian Air Force Vought V-85G Export version for Germany Vought V-92C Export version for Nationalist China Vought V-93S Export version of the O3U-6 for Thailand. Locally designated B.F.5 () as a trainer and B.J.1 () as an attack aircraft. Vought V-99M Export version for Mexico TNCA Corsario Azcárate 31 O2U-4A aircraft built under license in Mexico. Vought AXV1 A single O2U supplied to the Imperial Japanese Navy Air Service for evaluation in 1929. O1V Brazilian Navy designation of the O2U-2A. O2V Brazilian Navy designation of the V-66B.

Operators

Argentine Navy Argentine Naval Aviation

Brazilian Air Force

Chinese Nationalist Air Force Chinese Red Army - One V-65-C1 was obtained from a defection during the Long March and named "Lenin".

Cuban Air Force - received at least 14 O2U-1A and O2U-3As from 1929.Hagedorn 1993, p. 10.

Dominican Air Force - received one O2U-1 and two O2U-3SDs.Hagedorn 1993, p. 96. - commercial variant (V-85G) used to deliver mail from the ocean liners SS Bremen and SS Europa

Imperial Japanese Army Air Force

Mexican Air Force

Peruvian Air Force

Royal Air Force, one V.66E for evaluation

United States Army Air Corps one for evaluation United States Navy United States Marine Corps United States Coast Guard

Royal Thai Air Force had 70 operational aircraft at the time of the French-Thai War.

Specifications (SU-4 Corsair)

References Citations

Sources

Further reading