The reputation of the Mitsubishi A6 Zero Fighter preceded it. Before the United States had even entered the Second World War, they had received intelligence of a near-invincible fighter aircraft.

However, just a few years later, the Zero Fighter was being used in the Japanese Kamikaze campaign and was regarded as a virtually useless aircraft. Despite the Zero’s fall from dominance, this aircraft had a significant long-term influence on the tactics and engineering of Allied aircraft.

In this video, we join journalist, author and historian Max Hastings at IWM London to find out how the Allies defeated the Mitsubishi A6 Zero and how this mighty fighter shaped the air war in the Pacific. 

The story of the Mitsubishi A6 Zero Fighter

© IWM

Voiceover: "The reputation of the Zero Fighter preceded it. Even before the US had entered the Second World War, intelligence had reached them. Rumours of a near-invincible fighter aircraft that had achieved a kill ratio of 12:1 against the Chinese in 1940. But just a few years later, the A6M Zero was being used as cannon fodder in the Kamikaze campaign, deemed a virtually useless aircraft, except as a make-shift missile. And yet despite the Zero’s fall from dominance, this aircraft had a significant long-term influence on the tactics and engineering of Allied aircraft. So how exactly did this mighty fighter shape the air war in the Pacific, and how did the Allies overcome the Zero?

In the Pacific theatre, air superiority was everything. The geography of the area was marked by immense distances and scattered islands. Air power was essential for the success of naval operations, troop deployments and supply lines, and the protection of naval fleets. The Mitsubishi A6M Zero Fighter that was developed in the late 1930s and was a product of Japan’s push for a new breed of naval fighter. Its designer, Jiro Horikoshi at Mitsubishi, was answering a brief to create an aircraft that combined speed, manoeuvrability and range, crucial for operations in the vast Pacific theatre. The aircraft made its combat debut in the skies over China in July 1940, and it was quickly clear that there was little that could match it.

On display at IWM London, there is a wreck of an A6M Zero. It was found in the Marshall Islands in the 1990s, thought to have been lost in 1943. Its fractured and fragile frame now bares little resemblance to those aircraft that once dominated the skies." 

Max Hastings, journalist, author and historian: "This was the miracle aircraft of the first half of the Pacific War. The Zero Fighter, a source of terror to British and American pilots who knew that their aircraft were completely outclassed. The Zero was an aircraft that Allied intelligence had heard about before the war, but they didn't believe it could be built. It flew faster than the Spitfire or the Messerschmitt. It had high altitude. It had a range of 1,900 miles, it could land on a postage stamp on an aircraft carrier. So, this was the dominant aircraft of the first half of the war through Pearl Harbor, through many of the early Pacific naval battles because it was a naval aircraft. In fact, the Japanese army had nothing remotely to match it."

Voiceover: "The Zero had a lightweight, aluminium alloy construction. It had large wings, but overall it was relatively small, it weighed under 2000 kg and had a powerful but lightweight engine – this combination gave it incredible agility. Its armament consisted of two cowling-mounted 7.7 mm machine guns and two wing-mounted 20 mm cannons. It also had surprisingly good range, another factor making the Zero so formidable in the early part of the war was the skill of the Japanese pilots. Japanese naval pilot training emphasised quality over quantity. Early in the war, Imperial Japanese Navy pilots went through a rigorous and often brutal cadet program. At first, criteria for selection was so strict that some years, only around 100 pilot candidates were accepted. In December 1941, the Zeros joined the surprise attack on Pearl Harbour, providing fighter escort for the bombers. The attack came as a complete shock, and the US was unable to mount a meaningful counterattack.

Only a few American fighters were able to get airborne, including P-40 Warhawks and P-36 Hawks. But they did little to counter the destructive impact of the attack. Over the next few months, Japan launched a series of campaigns in South East Asia. In the Indian Ocean Raid in April 1942, the Japanese Imperial Navy attacked British naval bases in Ceylon, now known as Sri Lanka. Although the Japanese did not locate the British Eastern fleet, they inflicted devastating damage. In these attacks, Zeros fighters came up against the Hawker Hurricane, and again proved to be fearsome adversary, frequently outmanoeuvring their opponents in dogfights. The Zero had become the most feared aircraft in the Pacific. But it had not always been this way. 

In the 1930s, American assessments of Japanese air power were consistently fairly negative. Although Japan tightened security on intelligence at the start of their war with China in 1937, reports that did reach the US were often inaccurate about Japanese capabilities. This view was also informed by a preconceived notion of Japanese technological inferiority and the opinion that Japan was incapable of designing their own aircraft, and instead relied on copies of Western innovations. It was partly this underestimation of Japanese air power, that allowed Japan to gain the upper hand so quickly in the early years of the war. By 1940, things had begun to change; the US started to recognise the threat posed by Japan. That year, President Franklin D Roosevelt moved the Pacific Fleet from the mainland to the naval base on the Hawaiian Islands as a show of American power. A few months prior to the Pearl Harbor attack, even before the United States had entered World War Two, intelligence reports had reached the Americans that spoke of the capabilities of Japan’s Zero Fighter. They began to conceive of ways they could gain the upper hand – and a big part of this would be learning tactics for fighter aircraft that would allow them to win in dogfights. 

In the summer of 1941, Lieutenant Commander John S 'Jimmie' Thach faced the prospect of his squadron confronting an enemy aircraft that was faster, more manoeuvrable, and with a greater rate of climb than his squadron’s F4F Wildcats. Although he had never flown in combat against the Zeros, he had access to the intelligence reports. Using matchsticks on a table, he developed a defensive manoeuvre, and tested it in the air the following day. The tactic involved two fighters flying together – when one was being chased, the fighters would fly in towards each other. After crossing paths, the enemy aircraft on his tail was left directly in his wingman’s path. It became known as the Thatch Weave.

The Thach Weave was first tested in combat in the Battle of Midway in the summer of 1942, and later employed in the Guadalcanal campaign – and it worked. It’s still a tactic employed in dogfights to this day. Indeed, the Battle of Midway in June 1942 proved to be a decisive engagement that marked the beginnings of a shift in the balance of power. Success at Midway dealt a severe blow to Japanese air power and the beginning of a protracted struggle for air superiority. Then in July 1942, the Allies found favour again. A relatively intact wreck of a Zero fighter was found on Akutan Island in the Aleutians by an American patrol group. It was shipped back to base and restored to airworthy condition. They began testing the aircraft immediately. The engineering, they discovered, was impressive, but test flying the aircraft exposed its weak spots. It was confirmed that at high speeds the ailerons froze up, making the aircraft struggle in rolls and dives, it also rolled to the left much easier than the right. These insights influenced the instructions given to the Allied fighter pilots, helping to give them an advantage in a dogfight. Allied pilots now had the tactics and intelligence to tackle the Zero, and crucially, alongside this, the Allied fighter aircraft were also being upgraded."  

Max Hastings: "As the war went on, first of all, the Allies themselves started to develop much better aircraft. So they got into second, third generation fighters and the Zero got stuck where it was. And then the Allies began to realise all the things that was wrong with the Zero. First of all, it was what they came to call an origami aircraft, an almost paper aircraft because in order to achieve its fantastic performance and nimbleness, it had to be incredibly light and that made it very frail, very, very vulnerable that if you hit it, it fell to pieces. Second, it didn't have much ammunition in the guns, only 60 rounds for its two cannon, and that went in eight seconds in the air. Next, it had no armour plating for the pilot, it had no armour on its fuel tanks, so you hit a fuel tank and the Zero blows up. And as Allied pilots came to realise this, and the new American, above all, a Hellcat among the US naval aircraft came into play, they started to shoot the Zero out of the sky."

Voiceover: "Grumman had been working on the successor to the F4F Wildcat since the start of the war, and the engineers were paying close attention to their biggest threat – the A6M Zero. In early 1942, Grumman’s chief designers worked closely with the US Navy and F4F pilots to design an aircraft that could win in a dogfight against the A6M. The Grumman Hellcat F6F was given superior firepower, and designed to withstand damage with better armament. The Hellcat F6F-3 was given a Pratt and Whitney R-2000 Double Wasp radial engine. It was an aircraft that was specifically designed to outperform the Zero. And on the whole, it did. In the Battle of the Philippine Sea in 1944, the Hellcat played a crucial role in the US victory, and shot down huge numbers of aircraft. The Zero was soon up against America’s latest fighters; alongside the Hellcat was the Lockheed P-38 Lightening with far superior armament, and the F4U Corsair which featured heavier armour, self-sealing fuel tanks, and a Pratt and Whitney engine with 2000 hp. The Zero’s Nakajima Sakae 12 engine lagged far behind with just 940 horsepower. Its lightweight, unarmoured construction, while beneficial for speed and agility, offered little to no protection for the pilot. The flaws of the A6M Zero had been exposed and now they were being exploited."

Max Hastings: "This wreck of a Zero in the IWM gives you a very clear idea of why the Allies came to call this 'the origami aircraft' or 'the paper aircraft'. You can see very clearly, that although this was an amazing aircraft when it was intact, that it was also an incredibly fragile one, it did not take much to shoot it out of the sky if you hit it. And what you had by the later Pacific battles in 1944-45, you had the Americans and later the British, flying much better aircraft than they'd hardly dreamed of back in 1941-42, while the Japanese were still stuck with the Zero, which looked completely outclassed on many, many Japanese pilots on the second half of the war, died in the Zeros."

Voiceover: "The Imperial Japanese Navy had requested a successor to the A6M Zero by the end of 1940, but development didn’t begin until far too late. The designers were focused on other aircraft and Japan’s limited industrial capabilities was holding them back. Development of the A7M Reppū finally got underway in 1942, but it’s first test flight didn’t come until May 1944. The second prototype, the A7M2 Reppū, was powered by a MK9A engine with 2,200 horsepower; it had four 20mm autocannon and a top speed of 390 miles per hour. It had a better climb than the A6M and great manoeuvrability. The A7M Reppū was an aircraft that the Japanese Naval pilots needed, but ultimately, only nine aircraft were ever built. The A6M Zero was given small updates - its Nakajima engine was eventually upgraded by about 150 horsepower but it wasn’t enough, it could not reach the levels of power afforded to the latest Allied aircraft. And crucially, Japan was running out of the capacity to build new aircraft, with vital resources of raw materials running low. Alongside this, the skilled pilots Japan boasted at the start of the war were also running short – further exacerbated by a chronic lack of fuel. Japan had not prepared for a protracted war. By late 1944, some new Japanese naval pilots were graduating with just 40 hours flying time, while in America, pilots continued to receive around 500 hours. 

By 1943, with superior tactics, resources, and aircraft, the Allies had decisively established air superiority. Eventually the once invisible A6M Zero became cannon fodder. With Japan facing increasing difficulties and losses, the Zero Fighter continued on the front lines of operation until the end of the war. Then, with few skilled pilots left, and an unwillingness to surrender, in October 1944, the kamikaze campaign began. The Japanese calculated that they had more chance of causing damage with a suicide attack than a conventional attack. Aircraft loaded with bombs were used as improvised missiles to target Allied ships. 

With only need for fuel for a one-way trip, the Zeros were instead loaded with a 250kg bomb. With a couple of early successes in these missions, such as the sinking of USS St Lo in the Battle of Leyte Gulf in October 1944, the campaign was quickly expanded: thousands more kamikaze attacks were made, and aircraft designed specifically for suicide missions such as the Yokosuka Ohka began to be rolled out. At the Battle of Okinawa between April and June 1945, the Japanese flew over 400 kamikaze sorties, resulting in significant damage. The single most destructive kamikaze attack was the strike on USS Bunker Hill. Two A6M Zeroes dove into the ship in quick succession. Nearly 400 men were killed in the attack and the carrier was out of action for several months. But ultimately, the kamikaze campaign did not have a significant impact on the course of the war. Just a few months later, Japan had surrendered."

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  • Japanese Mitsubishi Zero fighter plane on display in the Turning Points gallery
    © IWM (2010.220.2)

    See the wreck of the Zero

    Discover the wreck of the Mitsubishi A6M fighter at IWM London.

    Flown by the Imperial Japanese Navy and damaged during combat in 1943 over the Marshall Islands, the Japanese fighter is on display in the permanent exhibition: Turning Points: 1934 to 1945.


     

  • Visitors in the Second World War Galleries at IWM London

    Second World War Galleries

    Explore IWM London's Second World War Galleries - a permanent display of over 1,500 collection items that illustrate a global war that affected millions from around the world. 

  • Ohka kamikaze aircraft is suspended in IWM London atrium
    © IWM

    Witness the Ohka

    See the Ohka (Cherry Blossom), a single-seat aircraft flown during the Japanese kamikaze campaign towards the end of the Second World War. 

    The aircraft is on permanent display in Witnesses to War, a permanent exhibition in IWM London's Atrium.