The Mitsubishi Zero Aircraft

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Among many of my fascinations as a child and now adult, has been equipment utilized in wars... specifically aircraft.

I truly love the UK's Spitfire and the American P-51 Mustang and Germany's Messerschmitt-109. For Japan, it begins and ends with their infamous A6M Zero.

Manufactured by Mitsubishi (yes, that Mitsubishi), the A6M Zero was a scourge during the first two years of the Pacific War (1941 and 1942) as it was more than a match for anything it fought, as it had superior firepower, range and maneuverability (though the US F6F Hellcat helped end that reign).

One of the key reasons the Allies took such heavy loses during the early stages of the Pacific Theater of WWII was the fact Allied leaders heavily underestimated Japan's ability to build a top-flight aircraft. It was an arrogance that cost many a fighter his life.

When the U.S. first encountered the Zero at Pearl Harbor in 1941, the Zero was not a new plane, but western experts expertly shrugged off reports that Japan possessed a world-class warplane as the notion that Japan could produce a superb combat craft was an alien concept to the West.

Despite the rhetoric of its leaders, Allied pilots knew that even if they themselves were better pilots than their Japanese counterparts (not always a given, of course...), the Japanese A6M Zero was a well-designed aircraft that allowed its pilots to gain a superior advantage.

For the Japanese, the A6M Zero became more of a symbol of its military might than any other piece of hardware in the war until the atomic bombs... though I suspect the might of the German Panzer tanks was also right up there, close to the Supermarine Spitfire of England. And just remember... I was born in England, named after one of the Princes and derive my humor from that country.

Let's take a closer look at the A6M Zero, which was actually known as the Reisen in Japan. Keep in mind that the crux of this article as about the A6... though I will try and provide some background on its development from other planes.

So... if the Japanese call the plane 'Reisen', why does everyone call it the Zero? Well, Reisen comes from the official Japanese designation of the plane as a Rei Shiki Sento Ki (shortened to Reisen), a Navy-type Zero Carrier-based Fighter... and yet, it was an Allied code-name for the plane—Zeke—that stuck. No kidding. People during the war called the plane a Zeke more often than a Zero.

Brits in Malaysia and Singapore knew the planes as Navy Noughts, as 'nought' means 'zero'.

The A6M (M is for Mitsubishi, 6 = the sixth generation of the A plane from the company) fighter first flew in April of 1939 and was built until the war's end in 1945.

With the Japanese Navy calling the shots about the type of plane they needed for further annexation of Asia, they said they wanted a fighter that was viable on an aircraft carrier, lighter in weight, fast, maneuverable and have superior range, climb rate and armament—essentially, they wanted the best possible killing machine out there.

A Japanese Navy Mitsubishi A6M2 Zero fighter (tail code A1-108) takes off from the aircraft carrier Akagi, on its way to attack Pearl Harbor during the morning of December 7, 1941. The aircraft was flown by PO2c Sakae Mori, 1st koku kantai, 1st koku sentai, and flew with the second wave.

Just to be up front, the A6M Zero delivered all of that... but it in order to achieve its speed, light weight, climb rate and maneuverability, designers gave it a low-powered engine... but at the beginning of the war, that was not an issue. The plane also omitted armor protection for the pilot, did not use self-sealing fuel tanks, and building lightweight wings as an integral part of the fuselage.

When the requirements for the plane were first presented in 1937, both Mitsubishi and the Nakajima Aircraft Company must have sucked a lot of air through their collective teeth as they thought the demands were impossible. While Nakajima withdrew, Mitusibishi continued, and appointed Horikoshi Jiro (surname first) the project leader.

The design of the A6M Zero was derived from the A5M Type 96 fighter that was actually the world's first monoplane (one level of wings only) aircraft carrier fighter. The Allied nickname for it was Claude.

Horikoshi used the A5M design team (with a few additions)—(all Japanese names are surname first): Sone Yoshitoshi and Tojo Teruo performed the calculations, Sone and Yoshikawa Yoshio did the structural work, Inoue Denichiro and Tanaka Shotaro designed the engine installation, Hatakenaka Yoshimi worked on the armament and ancillary equipment, and Kato Sadahiko and Mori Takeyoshi were responsible for landing gear and related equipment.

For the engine, the Mitsubishi MK2 Zuisei 13 featuring 875 horsepower was first chosen. They also used the lightweight duraluminu for lightweighting purposes.

Now, as you might expect from Japan, the best defense is an excellent offense, and so it was for the Zero, as the chief specification for it was that it be used ONLY for attack purposes... which is why there was no armor protection for the pilot and safe-sealing fuel tanks... in other words... if you were stupid enough to get hit, you were probably going to explode in flames. That's not just me saying that, but obviously the designers and Japanese military thinking that.

Guns:

• two Oerlikon 20mm cannon (Type 99) in the wings;
• two 7.7mm machine guns (Type 97 ) in the fuselage.

A 20mm Oerlikon wing gun from a Japanese Zero.

Construction of the first prototype began later that year and was completed in March 1939. With no provision for armor, lightness of airframe, and lack of heavy fittings, the prototype Type 0 weighed only 4,380 pounds (1986.7 kilograms) compared to the prototype Spitfire's 5,332 lbs (2418.6 kg).

Light weight and modest power gave it long range and good performance, but meant that substantially heavier and more powerful engines could not be fitted without extensive redesign. As an offensive, rather than a defensive weapon the Zero's very success contained the seeds of its own downfall.

The prototype was declared ready for tests at Mitsubishi's Nagoya factory on March 16, 1939. Engine tests were run on the 18th, and the next day it was towed by an ox-cart to the airfield at Kagamigahara in Gifu-ken.

Test pilot Shima Katsuzo (surname first) lifted off on April 1, 1939, and later after correcting perceived braking and vibration problems, official tests of the A6M1 took place and a second, identical prototype was built.

Apart from its lack of outright speed—304 miles per hour (489.2 kilometers per hour) instead of the required 315mph (507 kph)—all requirements were met, and the A6M1 was officially accepted by the Navy on the September 14, 1939 and received the military designation of A6M1 Type 0 Carrier-borne Fighter. The Reisen. The Zero.

Further modifications to the Zero would eventually be made, but initially, the A6M first saw combat in China in the late summer of 1940.

After the delivery of only 65 aircraft by November 1940, a further change was worked into the production lines, which introduced folding wingtips to allow them to fit on aircraft carriers. It's my opinion that the small wing tips folding up—rather than more of the wing was the minimum required for the planes to be stored below deck on an aircraft carrier, as well as to clear the hangar to the deck lift.

The resulting Model 21 would become one of the most produced versions early in the war. These were the planes that attacked Pearl Harbor (known as Operation AI in Japan).

Folding wings on a Japanese Zero.

When Japan attacked Pearl Harbor, Hawaii (the American base—and thus considered American territory was in the country of Hawaii... not yet a State) on December 7, 1941, a total of 125 Zero aircraft from six Japanese aircraft carriers participated. I won't even suggest that this sneak attack was fair... but even if American fighters could have got their planes off the ground to combat the enemy, it still wouldn't have been a fair fight. The Zero was a deadly quick plane.

Because everyone was needed by Japan in the war effort, Mistubishi and Nakajima Aircraft Company built the Zero, with 740 model 21s from Mitsubishi and 800 by Nakajima.

Nakajima also built the A6M2-N floatplane called the 'Rufe' that was another version of the Model 21, while Hitachi (yes, that Hitachi) and the Sasebo Naval Air Arsenal constructed 508 two-seat trainer planes, the A6M2-K.

Japanese Zero 'Rufe' floatplanes at Bouganville in the South Pacific.

Other models soon appeared as Japan tried to keep its superiority by correcting design flaws it found - namely the poor horsepower from the engine:

• A6M3 Model 32: had a 1,130 horsepower Sakae 21 engine; got rid of the folding wingtip section, giving a clipped wing. To retain the center of gravity positioning with the heavier Sakae 21 engine, it was moved back, which caused its own problems - a reduced fuel tank volume and thus less time in the air.
• A6M3 Model 22: Adding the original folding-tip wing to the Model 32 engine/body combination, and adding a 12-gallon fuel tank in each wing to regain lost range. By the time the Model 22 reached production, the Model 52 was approaching operational status; thus the Model 22, appearing in combat after the Model 32, had a short operational life with only 560 built late in 1942 and early 1943.
• A6M5 Model 52: Similar to the Model 32, but with some weight saving measures in the wing structure, heavier gauge wing skins to allow higher dive speed, individual exhaust stacks for additional thrust.

Eventually the West caught up with Japan and its Zero.... but it was because they learned the same things that Zero designer Horikoshi Jiro did: light weight, minimum armor, non-self-sealing tanks. All things that would allow American fighters to catch up or gain the upper hand. The advantage the Japanese had with the superior plane was lost, as the Americans had similar planes, but now they had developed tactics for combating the pesky Zero... which was to avoid getting into a one-on-one dogfight.

Horikoshi Jiro is the designer of the Japanese Zero.

The key was use the better guns against the Zero and perform hit and run diving attacks, which would light up the weak armored Japanese plane. Part of the run and gun attack was achieved thanks to their planes having extremely powerful engines that gave them more speed along with the firepower advantage.

Japan in an effort to keep up created a 1,150 horsepower engine (too little an increase) and added more horsepower and self-sealing tanks—it added weight making it less nimble—degrading the overall combat performance.

As the war dragged on, the Americans were buoyed by more experienced pilots going up, while Japan's skill level went down... and by October of 1944, during the Battle for the Philippines, the Divine Wind - the Kamikaze attacks U.S. ships using the Zero equipped with just enough fuel for a one-way flight and dive and crash into a U.S. naval ship.

By the time WWII ended, the number of Zero aircraft built was:

• 3,879 by Mitsubishi;
• 6,215 by Nakajima;
• 844 additional trainers and floatplanes;
• 10,938 Zero planes TOTAL

Now... if you are like me, you might have seen photos of the Zero in various color schemes. I had always thought it was a white-grey color—based on the first model kit I had built 35 years ago.

Apparently there is a science to figuring out the color scheme, and I'm going to leave it to the experts: HERE, and I bet we still won't find the proper answer, as I found two other illustrations similar to the one below with far different color schemes shown!

That's all for now. If you know of any errors and can provide corrections - I'm all ears. I'm hardly an expert on this plane, though I do have a bent towards pioneer aviation and will soon be starting up a fact blog on some of the earliest flying machines, including balloons, zeppelins, possibly a Chinese rocket chair, and of course aeroplanes and other craft that may or may not actually have made it up into the wide, blue yonder. I really am.

Cheers
Andrew Joseph