A6M “Zero”, Japanese Carrier Fighter


Photograph of A6M Zero launching for the Pearl Harbor attack

National Archives


Mitsubishi A6M2 Reisen "Zero" or "Zeke"


Specifications:


Crew

1

Dimensions

39'5" by 29'9" by 10'0"
12m by 9.06m by 3.05m

Wing area

242 square feet
22.4 square meters

Weight

3704-6164 lbs
1680-2796 kg

Maximum speed      

332 mph (533 km/h) at 14,930 feet (4550 meters)
282 mph (454 km/h) at sea level

Cruise speed 207 mph
333 km/h

Rate of climb

53 feet per second
16 meters per second

Service ceiling

33,800 feet
10,000 meters

Range

1162 miles (1870 km) on internal fuel
1930 miles (3100 km) with drop tank

Armament

2 7.7mm Type 97 machine guns (cowling)
2 20mm Type 99 cannon (wings) with 30 rounds per gun

External Stores

1 87-gallon (329 liter) drop tank

Fuel

183 gallons (693 liters) internal

Engines

One 950hp (708 kW) Nakajima NK1C Sakae 12 14-cylinder engine driving a three-bladed metal propeller.

Production
A total of 10,449 A6M as follows:


2

3432

903

about 6000

1

150

2

508

7

A6M1

A6M2

A6M3

A6M5

A6M6

A6M7

A6M8

A6M2-K

A6M5-K





Mitsubishi Jukogyo K.K. (Nagoya)     

Nakajima Hikoki K.K. (Ota)    

total

1939-3 to 1942-3      

722

115

837

1942-4 to 1943-3

729

960

1689

1943-4 to 1944-3

1164

2268

3432

1944-4 to 1945-3

1145

2342

3487

1945-4 to 1945-8

119

885

1004

Total

3879

6570

10449

Variants

The A6M1 used a 780hp (470 kW) Mitsubishi MK2 Zuisei 13 engine.

The M3 introduced a 1130hp (834 kW) Sakae 21. It first saw combat in the late spring of 1942.

The M5a first appeared in August 1943 and was armed with two 20mm Type 99 Mk4 with belts of 85 rounds per gun. It could carry two 60kg (132 lb) bombs.

The M5b replaced one of the 7.7mm with a 12.5mm.

The 5c replaced both cowling guns with 13.2mm and optionally mounted another 13.2mm in the fuselage.

The A6M7 was build for kamikaze use, while the A6M8c, with the 1560hp (1163 kW) Mitsubishi Kinsei 62 engine, was not produced in quantity due to destruction of the Nakajima factory.

The -K variants were two-seat advanced trainers. A total of 515 trainers were built by the Sasebo naval arsenal (236 aircraft) and by Hitachi (279 aircraft)


The legendary Zero was the terror of the Pacific for the first year or so of the war. It was just coming into mass production in 1941, and the available Zeros (roughly 400 in number) were assigned to the First Air Fleet for the Pearl Harbor raid and to the Tainan Air Group to cover the Philippines invasion. Its range and low-speed maneuverability were phenomenal, and it was faster and had a better climb rate and service ceiling than most first-generation Allied fighters. Flown by superbly trained pilots, the Zero quickly acquired an aura of invincibility in the eyes of Allied airmen.

Notable features of the design included unusually large ailerons and an integral wing. The wing was a single unit, divided into left and right fuel tanks whose large volume gave the aircraft its remarkable range. The upper surface of the center of the wing  was the floor of the cockpit. This integral design contributed structural strength and made the aircraft easy to assemble and disassemble.

Disheartened survivors of combat with Zeros reported that the aircraft engaged in elaborate acrobatics in the middle of dogfights, as if taunting the Allied fliers. These acrobatics may actually have been a means of communication or, more likely, the unorthodox hineri-komi combat maneuver taught to Imperial Navy pilots. Or they could have been exactly what the Allied pilots thought they were. Bergerud quotes Jack Fletcher:

... at that time the Japanese Zeroes all wore Seven League Boots and our aviators gave them a lot of ... respect.

However, the Zero had a number of weaknesses that became evident only after several months of combat. It was fragile, with several single-point failure points where one hit could destroy the entire aircraft. It lacked self-sealing fuel tanks, making it a firetrap. As one American flier observed, it was easily destroyed once you had it in your sights; the trick was getting it into your sights.

Other weaknesses were discovered after the Allies captured an intact Zero in the Aleutians in the summer of 1942 and performed extensive flight testing. It was found that the Zero could not maintain a steep dive, and it lost maneuverability at speeds over 300 mph or at high altitude. Also, the Zero’s large propeller generated high torque, so that its roll rate was much slower to the right than the left.

Allied pilots were instructed that they could shake a Zero off their tail with a split-S to the right. Likewise, the recommended attack procedure was a diving attack followed by a sharp turn to the right. The U.S. Navy developed cooperative tactics such as the Thatch Weave that took advantage of the better radio communications gear carried by Allied fighters. (The Zero was equipped with a very poor radio that was often removed by its pilots to save weight.)

The Zero’s armament was better on paper than in practice. Although the 20mm cannon shells packed a lot of punch, the guns had a rather low muzzle velocity, reducing their accuracy. They also had a rather low rate of fire. Perhaps this was just as well, given the ammunition load of just 30 shells per gun. Bergerud quotes Sakai Saburo, the second highest scoring Japanese ace to survive the war:

Our 20mm cannons were big, heavy and slow firing. It was extremely hard to hit a moving target. Shooting down an enemy aircraft was like hitting a dragonfly with a rifle! It was never easy to score ... our opponents were tough.
The 0.303 machine guns in the engine cowling were often ineffective against sturdy Allied aircraft.  However, the Zero had an ammunition select switch that permitted its pilots to find the range with the 0.303s, then switching on the cannon to make the kill. The Japanese quickly became aware of the weakness of the original armament, and later models (beginning with the A6M5) increased the 20mm ammunition loadout and replaced the light machine guns with more effective heavy machine guns.

The Zero remained in production throughout the war, and was produced in greater numbers than any other Japanese fighter. However, the Zero was not a match for second-generation Allied fighters, such as the Hellcat, in spite of various design refinements.

The Zero required an overhaul every 150 hours of flight time, but the Japanese often stretched this to 200 hours or more, with unhappy results.

The official Allied code name for this fighter was "Zeke," but Allied pilots usually referred to it as the "Zero," which was the Japanese name for the aircraft (Reisen). However, there was some tendency for Allied soldiers, sailors, and airmen to call any single-seat radial-engine Japanese monoplane aircraft a "Zero."

References

Bergerud (2000)

Francillon (1979)

Okumiya et al. (1956)

Prange (1982)

Sakai et al. (1957)

Wilson (1998)


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