Although superior to the Grumman F3F biplane it replaced, and the early F4Fs,[2] the Buffalo was largely obsolete when the United States entered the war, being unstable and overweight, especially when compared to the Japanese Mitsubishi A6M Zero.

Powered by a 950 hp (710 kW) single-row Wright R-1820-22 Cyclone radial engine, it had a good initial climb rate of 2,750 ft/min (840 m/min) and a top speed of 277.5 mph (446.6 km/h).

Based on the tests, improvements were made to the cowling streamlining and carburetor and oil cooler intakes, and the Buffalo's speed rose to 304 mph (489 km/h) at 16,000 ft (4,900 m) without any increase in power.

Plagued by production difficulties, Brewster delivered only 11 F2A-1 aircraft to the Navy; the remainder of the order was later diverted to the Finnish Air Force in modified form under the export designation Model 239.

A later variant, the F2A-2, of which 43 were ordered by the U.S. Navy, included a more powerful R-1820-40 engine, a better propeller, and integral flotation gear, while still lacking pilot armor and self-sealing tanks.

[18][page needed] This might reasonably have been expected with the low wing loading in earlier variants, which was comparable with the Mitsubishi A6M Zero's lb/sq ft.[19] The F2A-3 was the last version of the Buffalo to enter service with the U.S. Navy and Marine Corps.

[28] The upgraded engine and slightly reduced net weight (i.e. from the omitted armor and de-navalization) resulted in an improved power-to-weight ratio and better general performance.

[29] After delivery of the B-239E, the Finnish Air Force added armored backrests, metric flight instruments, the Väisälä T.h.m.40 gunsight, and four .50 in (12.7 mm) machine guns.

[11][31] Unfamiliar with the aircraft, he burned out the engine while flying very low at high speed; crashing on a snow-covered field, damaging the propeller and some belly panels.

This was in part due to the efforts of the Finnish mechanics, who solved a problem that plagued the Wright Cyclone engine by inverting one of the piston rings in each cylinder, which had a positive effect on reliability.

The Brewster Buffalo earned a reputation in Finnish Air Force service as one of its more successful fighter aircraft, along with the Fiat G.50, which scored an unprecedented kill-loss ratio of 33-1.

[11] The Brewsters had their baptism by fire in Finland on 25 June 1941, when a pair of Buffalos from 2/LLv24, operating from Selänpää airfield (ICAO:EFSE) intercepted 27 Soviet Tupolev SBs from 201st SBAP [N 6] near Heinola.

[38] After evaluation of claims against actual Soviet losses, aircraft BW-364 was found to have been used to achieve 42½ kills in total by all pilots operating it, possibly making it the highest-scoring fighter airframe in the history of air warfare.

The only clash with the Luftwaffe took place on 3 October 1944 when HLeLV 26 intercepted Junkers Ju 87s, claiming two, the last victories to be made by Brewster pilots in World War II.

The Brewster factory removed the Navy life raft container and arrestor hook, while adding many new items of equipment, including a British Mk III reflector gun sight, a gun camera, a larger fixed pneumatic tire tail wheel, fire extinguisher, engine shutters, a larger battery, and reinforced armor plating and armored glass behind the canopy windshield.

[11] In its original form, the B-339 had a theoretical maximum speed of 323 mph (520 km/h) at a rather unrealistic 21,000 ft (6,400 m), but fuel starvation problems and poor supercharger performance at higher altitudes meant that this figure was never achieved in combat; the B-339E was no different in this regard.

At Alor Star airfield in Malaya, the Japanese captured over 1,000 barrels (160 m3) of high-octane aviation petrol from British forces, which they promptly used in their own fighter aircraft.

[48] Moreover, according to Flight Lieutenant Mowbray Garden of 243 Squadron RAF, the Buffalos were supplied with only armour-piercing ammunition and no incendiary;[49] Japanese aircraft lacked armor and self-sealing fuel tanks in the early years of the war, a fact unknown to the Allies at the time.

However, the appearance of ever greater numbers of Japanese fighters, including markedly superior types such as the Nakajima Ki-43 "Oscar" soon overwhelmed the Buffalo pilots, both in the air and on the ground.

Another significant factor was the Brewster engine's tendency to overheat in the tropical climate, which caused oil to spray over the windscreen, usually forcing an aborted mission and greatly complicating attempts to intercept and destroy enemy aircraft.

Like Malaya and Singapore, lack of effective early warning systems greatly hampered British and AVG efforts to defend Burma from air raids.

[67] Reports of Japanese aircraft performance from the Malayan Campaign prompted Buffalo pilots in Burma to employ different tactics; according to Flight Sergeant Vic Bargh, "come in from above, or at the same level at the very least, then dive away before they got onto you, because if they did get onto you, well, you were shot down".

[69] On 13 February, the squadron moved further north to Magwe with only eight Buffalos, where they continued to carry out reconnaissance flights as well as escorting Westland Lysanders on ground attack missions.

[69] The Buffalo flew its last combat sortie with the RAF on 5 March, escorting Hawker Hurricanes and Bristol Blenheims for an attack on a Japanese airbase in Chiang Mai, Thailand.

Although reinforced by British Commonwealth Buffalo Mk I (B-339E) aircraft retreating from Malaya, the Dutch squadrons faced superior numbers in the air, usually odds of one against two or three.

[60] At Midway Island, United States Marine Corps fighter squadron VMF-221 operated a mixed group of 20 Brewster F2A-3 Buffalos and seven Grumman F4F-3 Wildcats.

[74] The squadron first saw action on 10 March 1942 when a Kawanishi H8K "Emily" flying boat was shot down by Captain James L. Neefus near Midway, the Buffalo's first kill in U.S.

[73] Second Lt. Charles S. Hughes, whose Buffalo was forced to retire at the start of the raid due to engine trouble, had a ringside view of the aerial combat: The Zeros came in strafing immediately afterward.

[81]Second Lt. Charles M. Kunz reported that after successfully downing two Val bombers, he was attacked by Japanese fighters: I was at an altitude of about 9,000 ft, and shoved over in a dive trying to shake the plane on my tail until I was about 20 feet from the water.

BW-372) flown by Lt. Lauri Pekuri was damaged by a Soviet Hawker Hurricane and crashed in 1942 on Lake Big Kolejärvi, about 31 mi (50 km) from Segezha, Russia and was rediscovered in 1998 and is now on display at the Keski-Suomen Ilmailumuseo (Aviation Museum of Central Finland).