Mitsubishi A6M Reisen (Zero Fighter)

This fighter - by far the most famous of all Japanese aircraft - dominated the first six months of the aerial war in the Pacific, and continued in service until the end of hostilities. The Zero - allied code-name 'Zeke' - was remarkable in being the first carrier fighter to outperform its land-based equivalents. It had been designed by Mitsubishi to meet the severe demands of the 1937 Imperial Navy specification for a ship borne fighter - demands which included a speed of 500 km/h (311 mph) and an armament (powerful for the time) of two cannon and two machine-guns. The result was a small, lightly-built aircraft with outstanding maneuverability.

The first production version received a more powerful engine than the prototype and was designated the 'A6M2'. As it was first produced in 1940 - the Japanese year 5,700 - it became popularly known as the "Zero-Sen" ("Type 00 Fighter"). Two squadrons with 15 planes were sent to China in July 1940 for trials under operational conditions, and quickly eliminated all opposition. The effectiveness of the Zero was urgently and emphatically reported to Washington by General Chennault, commanding officer of the Flying Tigers, but his report appears to have gone unnoticed.

More than 400 A6M2 and A6M3 (clipped-wing) Zeros had been delivered by the time of the attack on Pearl Harbor. They had unprecedented range for a small aircraft, and their unrivaled maneuverability and powerful armament gave them decisive superiority over every opponent. This was startlingly demonstrated in the heavy Japanese carrier raids on Ceylon 5-9 April 1942, in which they were in action against British Hawker Hurricanes. These were fighters which were regarded as outstandingly maneuverable (and which had proved their superiority in this respect to the Messerschmidt Bf-109s of the German Luftwaffe). Nonetheless the Hurricanes were easily out-turned by the raiding Zeros.

Nonetheless, in the great carrier battles of Coral Sea and Midway in mid-1942, in which the Zero encountered Grumman F4F Wildcats flown by some of the US Navy's most able pilots,the weaknesses of the Japanese fighter began to show. The A6M's lack of armor and self-sealing fuel tanks, combined with the general lightness of its construction, made it exceptionally vulnerable to combat damage. At Midway many pilots were lost aboard the Japanese carriers,all four of which were set ablaze by the carrier-borne American Dauntless dive-bombers. In the protracted and bitter Guadalcanal campaign losses of aircrew mounted and the quality of Japanese pilots correspondingly declined. Allied aircraft therefore achieved increasing success against the Zero. When, on top of this, much more modern and capable US aircraft - notably the Grumman F6F Hellcat and Vought F4U Corsair - appeared in the combat areas of the Pacific, the A6M found itself outclassed.

Mitsubishi therefore tried desperately to come up with a more effective version of the Zero. These efforts resulted in the A6M5 - the variant produced in the largest numbers. However, the improvement it represented was not sufficient, and the Zero was never, after 1943, able to fight on equal terms with the best Allied aircraft. However, the A6M6c equipped with the combat-boosted Sakae 31 engine, and the A6M8c equipped with 1,560 hp Kinsei 62 engine, were in 1945 able to give considerable trouble to the F4F and FM Wildcat fighters operating from US escort carriers.

At the Battle of the Philippine Sea 220 or so of the Japanese Mobile Fleet's 430 carrier aircraft were Zeros - many of them operating as bombers. A6Ms were again in action at the Battle for Leyte Gulf, mainly as attack aircraft, and from October 1944 until the end of the War Zeros were employed in hundreds of kamikaze attacks on American warships.

By late 1944, following tremendous defeats at Midway, the Philippine Sea, and Leyte Gulf, Japan's large-deck carrier fleet was almost wiped out. Dive bombers that could operate from small flight decks were urgently needed. When the Navy directed Mitsubishi to redesign the Zero to drop bombs, the A6M7 was born. The centerline fuel tank was replaced with a bombrack that carried a single 250 kg (551 lb) bomb. The horizontal stabilizer was reinforced to withstand the stress of pulling-out from a steep dive, and hardware was installed in the wings to carry two 150-liter (40 gal) drop tanks. Production began in May 1945. Total production of the A6M came to 10,449 units.