Brewster Buffalo was the first monoplane fighter of the US Navy. Significantly inferior to its main contemporaries, it was nevertheless used at the beginning of the Second World War due to the lack of more powerful machines and, for the same reasons, achieved some success in export.
The history of the project began on 15 November 1935, when the US Navy issued a request for proposals for a single-seat fighter to replace the Grumman F3F biplane, with a simple request: the aircraft should exceed 480 km/h.
Three firms lined up. Seversky, whose project was a navalised version of its P-35 monoplane: the XNF-1. The Grumman firm whose project, designated model G-16, was an improved version of the F3F but still in a classic biplane configuration. Brewster submitted its innovative Model B-139 which was an all-metal mid-wing monoplane with a closed cockpit. Dayton Brown, who headed Brewster’s design department, based the B-139 design on his Brewster XSBA-1 bomber.
On February 2, 1936, the Navy ordered a prototype of the Grumman G-16 biplane, under the official designation of XF4F-1, and on June 22 of the same year, a Brewster prototype. It should be noted that Brewster’s firm recovered the official designation beginning with the letter “A”, which previously designated the manufacturer General Aviation Corporation, and the prototype was accordingly designated within the Navy, XF2A-1. Seversky’s prototype was discarded, as it could not exceed 430 km/h and therefore received no official designation.During construction of the prototype, Brewster concluded that his aircraft was underpowered and changed the planned Wright XR-1690-02 and Pratt & Whitney XR-1535-92 engines for a 9-cylinder Wright R-1820-22 Cyclone air-cooled radial engine of 950 hp, the same as that fitted to the Seversky XNF-1.
Grumman’s XF4F-1 project was an effective improvement on the F3F, but its biplane design made it obsolete before it ever flew. To this end, Grumman convinced the Navy that his team had redirected its work to a monoplane. On 28 July 1936, the US Navy agreed, cancelled the XF4F-1 contract and promptly ordered a contract for Grumman’s monoplane, designated XF4F-2.
In May 1938, wind tunnel tests at Langley Field indicated that the XF2A-1’s top speed could be increased by 49 km/h by improving its aerodynamics, modifying the intakes and exhausts, the machine gun cowling and adding a cowling to cover the landing gear when raised. The prototype returned to the factory for modification and these improvements had a dramatic effect on the aircraft’s performance. The XF2A-1 now reached 490 km/h at an altitude of 4,800 metres. The aircraft now exceeded the contracted 483 km/h and was complemented by test pilots for its manoeuvrability.
Due to the engine problems of the XF4F-2 and in view of the recent improvements of the XF2A-1, the Navy opted for the Brewster design. Despite Grumman’s loss of the contract, the Navy admitted that Grumman’s project was viable, as the engine problems were not unsolvable. So in October 1938, the US Navy contracted with Grumman for an improved version called the XF4F-3, which gave birth to the famous F4F-3 Wildcat.
Brewster’s fighter had a bold look with a bulky fuselage, and was equipped with a number of significant technological innovations such as wing flaps, a fully hydraulically retractable landing gear (partially for the tailwheel), a streamlined canopy, a retractable landing hook and a fully enclosed cockpit. The most original equipment was a ventral window in the fuselage to give the pilot a certain vertical field of vision, for example for taxiing. Its structure was all metal, riveted and the control surfaces (flaps, ailerons and fin) were made of aluminium and covered with fabric.
The initial armament consisted of a mix of two machine guns, one .30 calibre (7.62 mm), another Browning M2 .50 calibre (12.7 mm), mounted in the engine cowling and firing through the propeller. The firepower was later increased with the possibility of mounting two additional .50 calibre M2s in the wings.
On 11 June 1938, the Navy ordered a first series of 54 production F2A-1s (BuNo 1386 to 1439) based on the prototype.
F2A-1, 2, 3 and 4
The production F2A-1 for the US Navy was powered by a 940hp Wright R-1830-34, but some improvements had been made over the prototype. The canopy was improved, providing a wider and more comfortable field of view. The radio mast was moved from the left side of the fuselage to the right, the wingtips were slightly modified, the ventral window was enlarged and a telescopic gun sight was installed. The first two F2A-1s were built with elliptical tail fins as on the prototype, later aircraft were fitted with triangular fins.
Brewster had misjudged the delivery time of the Navy order, and the delays began to mount. The Navy was due to receive the ordered aircraft in May 1939, but by June of that year only one aircraft was finished. It was however exhibited in New York for the World’s Fair alongside several other American military aircraft. In November 1939, 5 more F2A-1s were delivered, the Navy meanwhile being confronted with a problem of excessive carbon monoxide levels in the cockpit, which led to further modifications.
In 1940, the Navy decided to install the optional M2 machine guns in the wings of its F2A-1s, which led to a number of landing accidents due to the extra weight. Later that year, VF-3 (Fighting Squadron 3 of the USS Saratoga) traded in its F2A-1s for a more powerful version, F2A-2, so that it could send its F2A-1s back to the factory for modifications. Eight were modified to F2A-2 standards and sent for service with the VS-201 of the escort carrier USS Long Island. By mid-1941, only one aircraft remained in flying condition (Immat 1393), which was reassigned to a training unit until 1944. In June 1939, after various modifications ( three-bladed propeller, more powerful engine, modification of the fuel tanks), the F2A-2 showed better performances but had also undergone a strong increase of its weight which had affected the flying characteristics such as the manoeuvrability and the climbing rate, which were considered good for the previous versions, and the landing gear was still as fragile. The 9 F2A-2s were also rejected after testing.
But in January 1940, the US Navy ordered 108 F2A3s, a version with a longer fuselage to add a fifth tank and armour behind the cockpit, which made the aircraft even heavier.
A total of 506 were produced, the last one in May 1942.
An F2A-4 version, with a two-speed compressor and pressurised cockpit, was never built because it was too heavy.
B-239 – 44 aircraft of the F2A-1 version sold to Finland in 1939. Since 1941, when Finland fought against the Soviet Union together with Germany, due to the impossibility of buying original spare parts, some planes were equipped with captured M-63 engines. Some planes were equipped with landing gear allowing landing on snow or ice. There was also a prototype of the Finnish copy of B-239, called Humu, but the production was not started.
B-339B – planes of F2A-2 version without typical naval equipment (life raft, landing hook for aircraft carrier) designed for Belgium (40 examples). With the fall of Belgium in 1940, the majority of the planes were handed over to Great Britain, and the 6 planes on their way to Europe were located in the French estate of Martinique, where they were destroyed in order to prevent them from falling into the hands of the Vichy government.
B-339C – ordered by the Netherlands, the land-based version of the F2A-2. Due to difficulties in obtaining Wright Cyclone engines, 24 aircraft delivered to the Dutch East Indies were fitted with refurbished Wright R-1820-G105 engines (1100 hp) removed from civilian DC-3 aircraft.
B-339D – The remaining 48 B-339C for Dutch East Indies, fitted with Wright R-1820-G205 engines (1200 hp)
B-339E – 170 aircraft of the F2A-2 version bought by Britain. As these aircraft were not comparable to Luftwaffe fighters, RAF sent them to the Far East, where RAF, RAAF and RNZAF squadrons were equipped with them.
B-339-23 (B-439)- an export version of the F2A-3 ordered by the Netherlands, but fitted with the more easily available Wright R-1820-G5 engines (950 hp). By the time the planes were delivered to the Dutch East Indies, Java had been occupied by Japan, so the planes ended up in Australia, where they were first incorporated into the USAAF and later transferred to the RAAF, where 6 of them were used as reconnaissance planes and 9 served in the defence of the city of Perth. Aircraft of this version did not participate in combat.