The Vought Corsair; Forgotten Original

June 19, 2024

We’ve all heard about the Vought Corsair, right? A legendary fighter and attack aircraft, the Corsair carved its reputation in multiple campaigns of the Second World War, and in the skies of several wars afterwards. And it is often listed, with proper justifications, as one of the greatest combat aircraft of all time.

Which means everyone and his dog has written about it and so I very much doubt I can ever class it as a Forgotten Aircraft…well, apart from the Goodyear-built variants, but I have already covered those.

But what is nowadays overlooked is the first Vought Corsair, the O2-and-O3U’s.

And that is a little surprising because in their day they were hugely successful designs that saw masses of service.

Vought had begun making aircraft for the US Navy all the way back in 1917, supplying VE-7 trainers and fighters. The company continued refining its designs, achieving what were for those lean post-war years good sales to the Navy. So, when in 1925 that service required a new aircraft to serve in what today we would describe as a multirole capacity, they turned to Vought.

In 1926 Vought presented their answer – the O2U, which would soon be reclassified as the O2U-1 as the aircraft went through rapid development. After trialing two prototypes the Navy ordered an initial batch of one hundred and thirty O2Us in 1927, which were soon supplemented by additional orders for the follow on O2U-2-through-4, as well as a number for foreign export.

Glorying under their new name of “Corsair”, the O2U’s proved to be an excellent, capable and flexible aircraft that served as Scouts (i.e. fighters), attack and observation aircraft. A single bay, two-seat biplane with wings of almost equal span, the O2Us had the Pratt & Whitney Wasp engine that produced 450hp and gave the first models a top speed of 151 mph (243 km/h).

Construction was of a metal framework with the fuselage skinned from the engine bay back to behind the pilot seat in metal alloy whilst the rear fuselage and wings where fabric covered. Additionally, the undercarriage could either be twin wheel or switched out for floats, allowing the Corsair to serve on land, off carriers or as the observer aircraft for battleships and cruisers.

Armament in the O2U’s was initially only a single Browning .30-calibre gun mounted in the top wing, a Lewis gun on a flexible mounting for the observer in the rear and a payload of four 116 lb (53 kg) or ten 30 lb (14 kg) bombs under the lower wings.

And the O2’s were thrown into combat in extremely short order. Despite only being ordered in 1927 in January 1928 one of the very first of the type in service was showing not just the capabilities of the O2U, but giving a demonstration of an element of airpower capability that today we take for granted but which was revolutionary.

The US Marine Corps had deployed in the Central American country of Nicaragua in 1926, where they quickly became embroiled in an increasingly bitter fight with revolutionaries led by August Sandino, one of the many so-called “Banana Wars”.

The Marine Air Corps would famously go on to be an early demonstrator of the use of direct air support for ground forces in Nicaragua, with their use of what we now call close-air-support (CAS) being instrumental in the Marines winning several engagements. Marine O2U’s would prove very successful in this role, being used as dive bombers by the Marines against Nicaraguan forces, helping to create attention to this type of aerial attack and spurring further development around the world.

But early 1928 saw the Marines use airpower – and the Corsair – in another fresh innovation. On the 30 December, 1927, Sandino guerrillas ambushed a force of Marines in the town of Quilali in mountainous northern Nicaragua. The Marines sustained several casualties and were essentially cut off from outside support.

Except there was one flying leatherneck who, along with his O2U, thought differently.

Flying into the middle of the firefight 1st Lt. Christian F. Schilt was able to land his aircraft, one of the first delivered O2Us, directly into the middle of the besieged Marines.

Between the 6-and-8 January he flew into the middle of the town under heavy fire a total of ten times, flights with which he was able to deliver 1,400 lb (635kgs) of critical medical supplies, a new commanding officer and evacuate eighteen wounded Marines to safety. Considering that his aircraft was about 32 feet wide (9.75m) and his landing zone was only 100 feet (30m) in width, all with Sandino troops shooting at him, that required some pretty cool flying. Somewhat understandably Schilt received the Congressional Medal of Honor for his actions.

When you think about it, this demonstration was effectively a foreshadowing of a major role that US Marine Corps airpower conducts today. While much is remembered of the lessons the USMC learnt in the use of close air support during what is known as their ”small war” period, the use of airpower to supply and fly in and out personnel in contact is a prime factor in the today’s Marines, as well as modern militaries generally.

But to return to the Corsair, the new aircraft was obviously a great improvement on the aging World War One era aircraft that formed much of the US Navy’s air fleet and so the aircraft was subject to several follow-on orders in 1928.

First was the O2U-2, which featured larger wings and tail. This was followed by the -3, which had revised rigging on the wings and improved tail, and the -4, which had some further equipment changes. These aircraft also had different models of the Wasp engine as that too was worked on and improved and in total 379 production aircraft were built, mainly serving with the US fleet , where they were nicknamed “the eyes of the Navy”, and with the Marines but also with a fair number of Corsairs going to export customers.

The ongoing success of the Corsair and the rapid pace of improving technologies, especially in engines, meant that in 1930 Vought developed a new model, the O3U, at the request of the Navy.

The first of these, the O3U-1’s, were equipped with Grumman floats which featured retractable wheels to give the aircraft amphibious capability and the eighty-seven built served as the primary observation aircraft for the US Navy’s cruisers and battleships.

They were followed in short order by the O3U-2’s  which had modifications made to the airframes to take the larger and more powerful Pratt & Whitney Hornet engine. The O3U-2’s where soon largely redesignated as the SU-1 and were considered two-seater fighters, being transferred the Marines.

The SU-1’s were followed by the O3U-3, which once again were for naval use primarily as spotters but were fitted with the more powerful Pratt & Whitney  Wasp -12 which produced 550hp, and then by the O3U-4’s. Fitted with Hornet engines, producing 700hp, these were given to the Marines once again as fighters, designated as the SU-2-and-3, the latter of which had low-pressure tires for rough field operations.

The final US examples were the single XO3U-5, which had a Twin Wasp Junior engine, and the ultimate variant, the O3U-6, which reverted to the Wasp but had a NACA cowling and enclosed cockpit.

All this evolution of the Corsair took place essentially over a ten-year period, with the production line in the US closing in 1937, and up until 1939 it was the standard US Navy observation aircraft. Despite rapidly being replaced by more advanced aircraft after this date, over one hundred and forty Corsairs were still in service when the US entered the Second World War in December 1941.

Even after replaced they continued to see use, conducting patrols with the US Coast Guard and serving as trainers until 1945.

However, it isn’t just their considerable usage with the United States military for which the Corsair should alone be remembered. Because like it’s more famous descendent, the Corsairs saw a mass of action with other nations as well, with the flexibility of the basic design allowing Vought to fit improved engines, armament and capabilities into the aircraft, tailoring it to specification.

As a result, the Corsair was exported to Argentina, Brazil, Peru, Mexico, Cuba, the Dominican Republic, China and Thailand. Evaluation examples were even purchased by the British, Japan and Germany, and all these custom orders meant that there are a myriad of different designations and specs for the Corsair.

And as the 1920’s and 30’s were turbulent times these aircraft were often in the thick of the action. In South America they were used by Peru against anti-government guerillas, before being used to attack Colombian forces and warships during the short wat fought between the two countries in 1932-33.

In Mexico the urgent delivery of twelve O2 Corsairs in 1929 was critical in revitalizing the Mexican Air Force and in putting down a major rebellion by General José Gonzalo Escobar which represented a severe threat to the central government. So impressed were the Mexicans that they obtained a production license, and the Corsair proved an important type in the expanding Mexican Air Force.

In 1938 Mexican Corsairs, this time the much-improved V-99M export model, were used to help quell another rebellion, and there are unconfirmed reports that some of these aircraft were subsequently shipped to Spain for use by Republican forces fighting in the civil war there.

One of the most prolific military users of the aircraft was China, who purchased sixty-three export variants of both the O2 and O3. These reputedly first saw use against the Japanese in 1932 during the January 28 Incident, and then again from 1937 onwards when the Second Sino-Japanese War broke out, though I suspect that they didn’t last long considering their age and the capabilities of opposing Japanese aircraft.

The final foreign customer to use their Corsairs in combat was Thailand, with whom the aircraft saw action in a little-known conflict with France of all country’s!

The fall of France in 1940 meant that that country’s colonial possessions in Indo-China were now essentially no longer protected by the might of the French Empire and so the Thai’s sought to redress old wrongs committed on them by taking back territories they had been forced to cede to France in the past. This conflict, which was waged between October 1940 and January 1941, saw a considerable amount of air power used by both sides in supporting their respective ground and naval forces, as well as bombing each other’s military facilities.

And the most common type in use was the Vought V-93S, with around seventy of these aircraft flying with the Royal Thai Air Force, making up around half their active strength.

The V-93S was an export variant of the O3U-6 which the Thai’s also built under license at their own factory, where they replaced the indigenous Paribatra in production, and which probably represented the peak of the type in service. Equipped with a Hornet engine that produced 675hp, the V-93S also had an armament of initially two then increased to four 8mm machine guns, one in each wing, plus the standard single Lewis gun for the observer and the wing mounted bombs.

Naturally the V-93’s saw considerable usage in the war with French Indo-China, including being credited with achieving the first air-to-air kill for the Thai Air Force when in November 1940 a Corsair and two Curtiss Hawk IIIs intercepted a French bomber escorted by six Morane-Saulier MS.406 fighters. Despite the disparity in numbers and capability one of the -406’s was credited as shot down during the ensuing battle.

Despite losses in this conflict, as well as more that followed in the later Japanese invasion and then from Allied bombing throughout the rest of the Second World War, Corsairs went on to serve until 1950 with the Thai’s. As a result, we now have a single original example of this, the first model of Corsair, lovingly maintained at the Royal Thai Air Force Museum in Bangkok, which I believe is the sole survivor of the  580 Corsairs I’s built, as well as also, from what I understand, being the oldest surviving example of a Vought aircraft anywhere.

As a final note, I also feel I should clarify one important engagement that the Vought Corsair did not take part in. O3U’s are often credited for being the aircraft used in the epic battle with a certain giant ape over the Empire State Building in 1933’s King Kong.

But they are not. In fact, the live shots were Stearman C-3’s, while the models used in the battle shots are more like Curtiss Falcons.

However, though the Vought Corsair was not responsible for dispatching the furry menace, that doesn’t  detract from the record of what was a remarkable aircraft with a remarkable service history; an aircraft moreover, that was an important stepping-stone for the developments that aeronautic and aero engine design were taking in the fifteen years prior to the start of World War Two.

Plus, by demonstrating the potential of air power not just in aerial combat, but also in assisting ground forces both with close-air support and logistic and personnel transport directly into the hottest parts of the combat zone, the Corsair really was a pioneer in showing the flexibility that air power would bring to future warfare.


The Beardmore W.B.XXVI – When You Build Everything Else, You Might as Well Build a Fighter!

“Super Corsair” – The Goodyear F2G

Worthy of a Prince; The Royal Siamese Air Service Paribatra (Boripatra)

The Washington B.1; Britain’s B-29

The Washington B.1; Britain’s B-29

In my previous article about the Short Sperrin, I explained how one of the things that killed any chance of that aircraft getting into service was the acquisition by the British of surplus B-29’s from the United States. And generally in the histories, that’s all you...

Dave Eubank of the Free Burma Rangers

Dave Eubank of the Free Burma Rangers

Was lucky to be able to pin down Dave and get an hour or so from his busy schedule to talk about his remarkable life and the situation in Myanmar (Burma).

The Short SA.4 Sperrin; Britain’s Back-Up, Back-up Nuclear Bomber

The Short SA.4 Sperrin; Britain’s Back-Up, Back-up Nuclear Bomber

The V-Bombers; Britain’s cool and quirky answer on how to drop atom bombs on the Soviet Union. This trio of aircraft not just represented Britain’s entry into the nuclear power’s club, they also demonstrate the evolving ideas and technologies that were developing in...

Decomposing Behemoth; The Convair XC-99

Decomposing Behemoth; The Convair XC-99

You know, quite a few people have said to me: “Hey Ed, you should cover the Convair B-36 bomber. That’s a Forgotten Aircraft.” And truth be told, I probably will do something on the B-36 one day, because it really was such a beast. I mean, look at in in comparison to...

Engineering Division TP-1/XCO-5; The US Army’s Final Fighter

Engineering Division TP-1/XCO-5; The US Army’s Final Fighter

I’ve written in the past about the US Navy’s Naval Aircraft Factory, which was created in 1917 to help design and build aircraft suitable for maritime use. Indeed, I’ve already covered one of their most famous and enduring creations, the NAF N3N. The reason for the...