The
A6M came as a shock to the allied in 1941 -- this despite earlier reports of its
appearance in China. For the first time, a carrier fighter had been built that
outperformed land based aircraft. The A6M was fast, extremely maneuverable, and had an
impressive endurance. But this performance had been achieved by the light construction of
the aircraft, and this was the undoing of the type when more powerful allied fighters
appeared. Development was unable to keep up with the exigencies of the time, and most of
the 10,964 built had to fight an increasingly superior opposition.The Zero was originally conceived as a replacement for the Mitsubishi Type 96 (A5M) fighter, the first of the Japanese Navy's operational monoplanes. On October 5, 1937, the Japanese Navy furnished the Mitsubishi and Nakajima companies with its requirements for a new fighter with a maximum speed exceeding 310 m.p.h.
To the Japanese the Zero-Sen was everything that the Spitfire was to the British nation. It symbolized Japan's conduct of the war, for as the Zero fared, so fared the Japanese nation. The Zero fighter marked the beginning of a new epoch in naval aviation. It was the first shipboard fighter capable of besting its land-based opponents. It created a myth--the myth of Japanese invincibility in the air, and one to which the Japanese themselves fell victim as a result of the almost total destruction of Allied air power in the early days of the Pacific war. In its day the Zero was the world's foremost carrier-based fighter, and its appearance over Pearl Harbor came as a complete surprise to the American forces. Its successive appearance over every major battle area in the opening days of the war seemed to indicate that Japan possessed unlimited supplies of this remarkable fighter, and its almost mystical powers of maneuver and ability to traverse vast stretches of water fostered the acceptance of the myth of its invincibility in Allied minds.
The supremacy of the 'Zero', or Mitsubishi Type 0, in the Far East during 1941 and 1942 is illustrated by the story of just one engagement, on April 11,1942. Flying out of Lae airstrip in eastern New Guinea, Japanese Navy 'ace' pilot Saburo Sakai, section leader in a nine-plane formation of A6M2 fighters made for Port Moresby airfield, held by the Allies. There the formation encountered four United States Army Air Force Bell P-39D Airacobras , which were left to Sakai and his wingmen. Opening up with his 20 mm cannon before the Americans could take evasive action, Sakai dived on the two rear-most fighters and sent them both down in flames. His wingmen bagged one apiece. Within minutes the battle was over, with the Zeros hardly scathed.
Designed by Jiro Horikoshi to achieve the highest possible speed and maneuverability from a Nakajima Sakae 12 engine of only 950 hp, the Zero had a light structure and powerful armament. It was an aggressive weapon, designed to perform well in a dogfight, and against Allied aircraft of 1941-2 vintage it did just that. It mastered all opposing fighters, irrespective of whether it flew from carriers, as at Pearl Harbor, or had to operate over long distances from land bases. Even the Philippines did not escape the Zeros' scourge, as the Japanese fighter used a jettisonable fuel tank to help cover the hundreds of miles of sea between those islands and its bases on Formosa.
Unbeknown to the Allies was the fact that the ZeroSen possessed many shortcomings which were only to be revealed six months later when a virtually intact specimen was obtained. Prior to this event, any captured part of a Zero-Sen was regarded as a prize. Piece by piece Allied intelligence teams endeavored to rebuild an example of this fighter for evaluation, only to be met by failure. Then, on June 3, 1942, Flight Petty Officer Tadayoshi Koga left the flight deck of the carrier Ryujo in his Mitsubishi A6M2 Model 21 fighter as part of a task force assigned to attack Dutch Harbor in the Aleutian Islands. His Zero, which had been built only the previous February, was on its first operational mission, a mission that was also to prove its last in the service of the Japanese Navy. On his way back to the Ryujo, Koga found that two bullets had punctured his fuel supply and he informed his flight commander that he intended to land on a small island designated as an emergency landing field for crippled planes. Five weeks later an American naval scouting party discovered the Japanese fighter upside down in a marsh on the island of Aktan, its pilot dead with a broken neck.
The tables were turned when the A6M5 version of 'Zeke', as the Type 0 was known to the Allies, came up against a new generation of US Navy and Army fighters, with powerful engines and heavy protection for their pilot and fuel tanks.
Against them the Zero still basically the design which had flown first on April 1,1939 offered minimal protection for either pilot or fuel. From 1943 the Zeros fell like flies, due in part to the newly-found confidence of Allied pilots, who were by now better trained, and with improved morale after the Coral Sea and Midway victories.
The Zero was originally conceived as a replacement for the Mitsubishi Type 96 (A5M) fighter, the first of the Japanese Navy's operational monoplanes. On October 5, 1937, the Japanese Navy furnished the Mitsubishi and Nakajima companies with its requirements for a new fighter with a maximum speed exceeding 310 m.p.h., the ability to climb to 9,840 feet in 3.5 minutes, maneuverability and range exceeding any existing fighter and an armament of two cannon and two machine-guns. These demands were far in excess of any previously made of the Japanese aircraft industry and, viewing them as unrealistic, the Nakajima company withdrew from the project following a design meeting at Yokosuka on January 17,1938. Mitsubishi alone accepted the task of meeting the requirements of the 12-Shi (twelfth year of the Showa reign) project as it was known, and design work began under the direction of Jiro Horikoshi, chief designer of Mitsubishi Jukogyo K.K.
The chosen power plant was the Mitsubishi MK2 Zuisei 13 (Auspicious Star), a fourteen cylinder twin row radial of 780 h.p., later known under the unified JNAF/JAAF designation system as the Ha.31/13. This engine was selected owing to its light weight and small diameter, and a two-blade constant-speed propeller was fitted. Extreme care was given to structural weight as maneuverability was directly related to wing loading, and extensive use was made of Extra-Super Duralumin (E.S.D.), a tough, lightweight alloy developed for aircraft use by the Sumitoma Metal Industry Company. Work on the prototype progressed rapidly, and changes requested after inspections of the 12-Shi mock-up on April 17 and July 11, 1938, were progressively incorporated.
On March 16, 1939, at Mitsubishi's Nagoya plant, the first prototype was completed. Engine tests were conducted on March 18, and the aircraft was transferred to the Navy's Kasumigaura airfield for flight testing. Here, on April 1,1939, one of Mitsubishi's test pilots, Katsuzo Shima, flew the new fighter for the first time. The flight was an outstanding success, the only troubles manifesting themselves being in the wheel brakes, the oil system and a slight tendency to vibrate. Continued testing indicated that the vibration could be controlled by the use of a larger propeller of three-bladed type. The prototype was accepted by the Navy on September 14,1939, as the A6M1 Carrier Fighter, and, in the meantime, a second prototype had been completed, passing the manufacturer's flight tests on October 18, 1939, and being accepted by the Navy one week later. Both A6M1 prototypes carried two 20-mm. cannon in the wings and two 7.7-mm. guns in the fuselage upper decking.
While flight testing of the A6M1 was under way, a new power plant passed its Navy acceptance tests, the Nakajima NK1C Sakae 12 (Prosperity) of 925 h.p., which was only slightly larger and heavier than the Zuisei. The Sakae 12 (Ha.35/12) was also a fourteen cylinder twin-row radial, and the Navy decided that this engine should be installed in the third prototype which would be known as the A6M2. Flight tests with the third machine began on January 18, 1940, and it was discovered that, with its new-found power, the fighter amply exceeded the original performance requirements which had been regarded as impossible a few months earlier. Even while the final acceptance of the A6M2 as a production fighter was in the balance, the Japanese Navy requested that a number of machines be delivered for operational use in China to meet growing aerial opposition. Fifteen A6M2s were accordingly delivered for service in China and, on July 21, 1940, left Japan for the Chinese mainland--almost eighteen months before the attack on Pearl Harbor. The new fighters were enthusiastically received in China, and at the end of July the A6M2 was officially adopted as the Type O Carrier Fighter, Model 11, popularly known in Japan as the Zero-Sen (Zero Fighter). At this time, production models of Navy aircraft were assigned type numbers based on the last number of the current Japanese year, and as 1940 was the year 2600 in the Japanese calendar, the A6M series was known as the Zero.
The Type O Model 11 fighters first appeared over Chungking in August 1940. Approaching at an altitude of 27,000 feet, they shot down all the defending Chinese fighters literally before the defending aircraft knew what had hit them. They were used over many Chinese battle-areas throughout the following months, and in over a year of operational use not one ZeroSen was captured or inspected by the Chinese or American observers. As a result of the new fighter's performance, General Chennault attempted to warn the U.S.A.A.F. of the Zero's capabilities, but his warning was ignored and the new fighter remained an enigma to the western nations.
The A6M2 Model 21 was the version of the Zero employed at Pearl Harbor and throughout the Pacific during the early stages of the war. With its maximum speed of 317 m.p.h. at 16,400 feet and ability to climb to 19,680 feet in 7 minutes 27 seconds, it possessed an ascendancy over any other fighter type in the Pacific. Production of the Model 21 by Mitsubishi totaled 740 aircraft, and Nakajima also began to build this model in November 1941 at its Koizuma factory. When the war commenced on December 7, 1941, the Japanese Navy had well over four hundred Zero fighters, primarily Model 21s, available.
Some were also the first aircraft used intentionally as suicide attack planes. Modified Zeros assigned to Air Group 201 in the Philippines became the first Japanese aircraft used on planned suicide missions against American surface vessels. Air Group 201, assisted by volunteer pilots from Air Group 601 and other Navy units in the area, became the first Kamikaze (Divine Wind) suicide squadron in the Japanese Naval Air Force. The outstanding successes gained by this form of attack led to the formation of other Kamikaze units, and the bomb-carrying Zeros became the prime suicide attack bombers of the Navy.
More Zero-Sens were produced than any other wartime Japanese aircraft. Mitsubishi alone produced 3,879 aircraft of this type, Nakajima built 6,215 which, together with the 844 trainer and floatplane variants produced by Sasebo, Hitachi and Nakajima, brought the grand total of A6M series aircraft to 10,938. The Zero-Sen possessed complete mastery in the air over the Pacific until the Battle of Midway in June 1942, the actual turning point of the Pacific War although recognized by only a few at the time. The value of the fighter steadily declined and its lowest point was reached when it was selected to lead the Navy's Air Force in mass suicide--and the Japanese nation followed. The installation of the Kinsei engine brought Zero-Sen closer to Allied standards attained at that stage in the war, but the moment for decision had passed and, with it, victory for the Allies had become a foregone conclusion. The fighter that started the Pacific war was no longer able to fight it--nor was the nation that conceived it.
