Mitsubishi Zero

The Mitsubishi A6M was a light-weight carrier-based fighter aircraft employed by the Imperial Japanese Navy from 1940 to 1945.

Variants

A6M1, Type 0 Prototypes

The first A6M1 prototype was completed in March 1939, powered by the 780 hp (580 kW) Mitsubishi Zuisei 13 engine with a two-bladed propeller. It first flew on April 1st, and passed testing in a remarkably short period of time. By September it had already been accepted for Navy testing as the A6M1 Type 0 Carrier Fighter, with the only notable change being a switch to a three-bladed propeller to cure a vibration problem.

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A6M2, Type 0 Model 11

While the Navy was testing the first two prototypes, they suggested that the third be fitted with the 940 hp (700 kW) Nakajima Sakae 12 engine instead. Mitsubishi had its own engine of this class in the form of the Kinsei, so they were somewhat reluctant to use the Sakae. Nevertheless when the first A6M2 was completed in January 1940, the Sakae's extra power pushed the performance of the plane well past the original specifications.

Related Topics:
Nakajima Sakae - Kinsei

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The new version was so promising that the Navy had 15 built and shipped to China before they had completed testing. They arrived in Manchuria in July 1940, and first saw combat over Chungking in August. There they proved to be completely untouchable by the Polikarpov I-16's and I-153s that had been such a problem for the A5M's currently in service. In one encounter 13 Zeros shot down 27 I-15 and I-16's in under three minutes without loss. After hearing of these reports the Navy immediately ordered the plane into production as the Type 0 Carrier Fighter, Model 11.

Related Topics:
Manchuria - Chungking - Polikarpov I-16 - I-153

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Reports of the Zero's performance filtered back to the US slowly. There they were dismissed by most planners, who felt it was impossible for the Japanese to build such an aircraft. Others were not so sure, and techniques were developed by Butch O'Hare to combat them just in case.

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A6M2, Type 0 Model 21

After the delivery of only 65 planes by November 1940, a further change was worked into the production lines, which introduced folding wingtips to allow them to fit on the aircraft carriers. The resulting Model 21 would become one of the most produced versions early in the war. When the lines switched to updated models, 740 Model 21's were completed by Mitsubishi, and another 800 by Nakajima. Two other versions of the Model 21 were built in small numbers, the Nakajima-built A6M2-N "Rufe" floatplane (based on the model 11 with a slightly modifed tail), and the A6M2-K two-seat trainer of which a total of 508 were built by Hitachi and the Sasebo Naval Air Arsenal.

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A6M3, Type 0 Model 32

In late 1941 Nakajima introduced the Sakae 21, which used a two speed supercharger for better altitude performance, and increased power to 1,130 hp (840 kW). Plans were made to introduce the new engine into the Zero as soon as possible.

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The new Sakae was slightly heavier and somewhat longer due to the larger supercharger, which moved the center of gravity too far forward on the existing airframe. To correct for this the engine mountings were cut down by 8 inches (200 mm), moving the engine back towards the cockpit. This had the side effect of reducing the size of the main fuel tank (located to the rear of the engine) from 518 litres to 470 litres.

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The only other major changes were to the wings, which were simplified by removing the Model 21's folding tips. This changed the appearance enough to prompt the US to designate it with a new code name Hamp, before realizing it was simply a new model of the Zeke. The wings also included larger ammunition boxes, allowing for 100 rounds for each of the 20 mm cannon.

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The wing changes had much greater effects on performance than expected. The smaller size led to better roll, and their lower drag allowed the diving speed to be increased to 360 knots (670 km/h). On the downside, manuverability was reduced, and range suffered both due to decreased lift and the smaller fuel tank. Pilots complained about both. The shorter range proved a significant limitation during the Solomons campaign of 1942.

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The first Model 32 deliveries began in April 1942, but it remained on the lines only for a short time, with a run of 343 being built.

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A6M3, Type 0 Model 22

In order to correct the deficiencies of the Model 32, a new version with the Model 21's folding wings, new in-wing fuel tanks and attachments for a 330 litre drop tank under each wing was introduced. The internal fuel was thereby increased to 570 litres in this model, gaining back all of the lost range.

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As the airframe was reverted from the Model 32 and the engine remained the same, this version received the navy designation Model 22, while Mitsubishi called it the A6M3a. The new model started production in December, and 560 were eventually produced.this company

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constructed somes examples for evaluation,armed with 30mm Type 5 Cannon,under denomination of A6M3b(model 22b).

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A6M4

The A6M4 is a subject of some debate. Most sources refer to an experimental turbocharged version of the Zero for high altitude use, but only a single mention of the A6M4 can be found in text and it does not mention much.

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A6M5, Type 0 Model 52

The A6M5 was a modest update of the A6M3 Model 22, with wings with nonfolding tips and thicker skinning to permit faster diving speeds, plus an improved exhaust system (four pipes on each side) that provided an increment of thrust.

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Subvariants included the "A6M5a Model 52a «Kou»", featuring cannon with belt feed instead of drum feed, permitting a bigger ammunition supply; the "A6M5b Model 52b «Otsu»", with an armor glass windscreen, a fuel tank fire extinguisher, and one 7.7 millimeter gun in the cowling replaced by a 13.2 millimeter Browning-pattern gun; and the "A6M5c Model 52c «Hei»", with more armor plate on the cabin's windshield (55cm) and in the pilot's seat. This version also possessed armament of three 13.2 millimeter guns (one in the cowling, one in each wing), twin 20 millimeter guns and an additional fuel tank with a capacity for 367 liters, often replaced by a 250kg bomb. The A6M5 could travel at 540 km/h and reach an height of 8000 meters in 9 minutes and 57 seconds. Other variants are the night fighter A6M5d-S(some conversion for night combat,armed with one 20mm type 99 Cannon, inclined back to Pilot's cockpit) and A6M5-K "Zero-Reisen"(model l22)tandem tranier version,also only manufactured ones seven examples by Mitsubishi.

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Several machines survived the war and are now in display all over the world in countries such as Japan (in Aichi, Hamamatsu and Shizuoka), China (in Beijing) or the UK (Duxford.)

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A6M6c

This was similar to the A6M5c, but with self-sealing wing tanks and a Nakajima Sakae 31a engine featuring water-methanol engine boost.

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A6M7, Type 0 Model 63

Similar to the A6M6 but intended for attack or Kamikaze role.

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A6M8

Similar to the A6M6 but with Mitsubishi Kinsei 62 engine, two prototypes built.

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