O2U Corsair
O2U-4 Corsair
Role Observation
National origin United States
Manufacturer Vought
Introduction 1926
Primary users United States Navy
United States Marine Corps
United States Coast Guard
Number built 580
An O2U floatplane flies over the Cavite Navy Yard, circa 1930. The seaplane tender Jason is docked at the yard, directly below the plane. Sangley Point is in the background.

The Vought O2U Corsair was 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 400 hp (298 kW) 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.

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 By 1930 they were being superseded by the O3U which was basically similar to the O2U-4, one variant of which was fitted with the Grumman float, and were manufactured until 1936.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.[1] Many of them had cowled engines and some had enclosed cockpits.

Operational history

The 600-690 hp (448-515 kW) 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 designated aircraft were built for the USN. No fewer than 141 Corsairs were still serving with the US Navy and Marines when the US entered World War II.[citation needed]

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.[1] 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 400 hp (300 kW) Wasp engine to quell 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-1 550 hp Wasp engine, some of them may have been sent to Spain.[2]

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.

Peru purchased two Vought OSUs which were designated UO-1A. Later, in 1929, 12 O2U-1 were acquired. Used first as trainers, they saw action against APRA rebels in the northern areas of the country, and against Colombian ships and aircraft during the Colombia-Peru War. None were lost due to enemy fire, but several were destroyed due to accidents. These aircraft were also used for light bombing and casualty evacuation by the US Marine Corps during the intervention in Nicaragua in the late 1920s.

Thailand used their Corsairs in the Franco-Thai War and in the Battle of Ko Chang against the French Navy.[3]

The most famous "combat" operation of this aircraft was shooting the original King Kong off of the Empire State Building.[citation needed]

The name "Corsair" was used several times by Vought's planes; the O2U, Vought SBU Corsair in 1933, F4U in 1938, and the A-7 Corsair II in 1963.


Single example taken on charge by the U.S. Army Air Corps for evaluation with serial 29-323, Wright Field Project Number P-547,[4] powered by a 450 h.p. R-1340-C engine. Destroyed in hangar fire at Wright Field, Ohio, 18 March 1930.[5]
two prototypes followed by 130 production aircraft for USN with interchangeable wheel/float landing gear and 28 aircraft for other customers. 450 hp (336 kW) Pratt & Whitney R-1340-88 Wasp engine
37 built, increased span and larger rudder
110 built (30 for export), revised wing rigging, redesigned tail surfaces and Pratt & Whitney R-1340-C engine
43 built (1 for export. Also seven civilian O2U were built), similar to O2U-3 but with equipment changes
87 built as observation seaplanes incorporating Grumman amphibious float[6][7]
29 built, strengthened airframe, Pratt & Whitney R-1690 Hornet engine
76 built, 550 hp (410 kW) Pratt & Whitney R-1340-12 Wasp engine.
65 built, Pratt & Whitney R-1690-42 Hornet engine.
test aircraft with Pratt & Whitney R-1535 engine
test aircraft converted from O3U-3 with NACA cowling and enclosed cockpits
32 built, 16 with Pratt & Whitney R-1340-12 Wasp and 16 with Pratt & Whitney R-1340-18 Wasp engines
Scout version of the O3U based on the O3U-2, 28 built[8]
Scout version of the O3U based on the O3U-4, 53 built[8]
Variant of the SU-2 with low-pressure tires, 20 built[8]
SU-2 converted as a prototype SU-4 variant with a 600 hp R-1690-42 engine, later became an SU-4.
SU-4 re-engined with a 600 hp R-1690-2 engine, 41 built[8]
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, one evaluated by the Royal Air Force
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
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.


Argentine Navy O2U Corsair
The only survivor of V-93S/SA Corsair fleet, displayed at the Royal Thai Air Force Museum
 Dominican Republic
 Germany - commercial variant (V-85G) used to deliver mail from the ocean liners SS Bremen and SS Europa
 United Kingdom
 United States

Specifications (SU-4 Corsair)

Vought O2U-2 3-view drawing from Aero Digest November 1928

Data from The Complete Encyclopedia of World Aircraft

General characteristics





  1. ^ a b Eden and Moeng 2002
  2. ^ "Corsarios Mexicanos" (in Spanish). Archived 2009-03-26 at the Wayback Machine portalaviacion.vuela.com. Retrieved: 18 January 2011.
  3. ^ Royal Thai Air Force, Bangkok, 1976: The History of the Air Force in the Conflict with French Indochina.
  4. ^ "1922-1929 USAAS-USAAC Serial Numbers".
  5. ^ Andrade, John M. U.S. Military Aircraft Designations and Serials since 1909. Earl Shilton, Leicester: Midland Counties Publications, 1979. ISBN 0-904597-22-9, page 138.
  6. ^ "New Navy Planes Land On Water Or Deck." Popular Science, February 1933.
  7. ^ "Eyes of the Fleet as seen during Maneuvers." Popular Mechanics, March 1933.
  8. ^ a b c d "Vought". Aerofiles. Retrieved: 18 January 2011.
  9. ^ Hagedorn 1993, p. 10.
  10. ^ Hagedorn 1993, p. 96.


Further reading