The Bombing of Japan

The bombing campaign

On 7 December 1941, Japanese aircraft quite literally bombed the USA into World War II, by their attack on Pearl Harbour. The USA immediately declared war on Japan, but it was not until its forces had overcome Japanese strongholds, such as those in the Mariana Islands, that the Japanese mainland could be effectively targeted. With Japan in reach, a ground invasion was planned. Given how fiercely Japanese forces defended their islands and territory, it has been estimated that a ground invasion could have resulted in up to 4 million Allied casualties, including up to 800 000 fatalities, in addition to up to 10 million Japanese fatalities. Therefore, a strategic bombing campaign seemed essential in reducing the number of casualties and expediting the end of the war, primarily by targeting Japan's industrial capacity and influencing the morale of its population.

The Boeing B-29 Superfortress was introduced in May 1944, just in time to serve as the backbone of the USA's strategic bombing campaign of Japan. With its pressurised cockpit and remotely controlled turrets, the B-29 was a highly advanced bomber when compared with contemporary aircraft. The heavy, four-engined bomber was powered by four 2 200 hp Wright radial engines. It had a wingspan of 43 metres and a length of 30.2 metres, making it considerably larger than a B-17 Flying Fortress. The Superfortress was primarily armed with eight or ten .50 inch calibre machine guns and would normally carry 9 000 kg of bombs.

During 1944, B-29 raids from China continued on a comparatively small scale, whilst aircraft were moved to new airfields in the Mariana Islands. The first raid over Japan from the Marianas took place in November of that year, when more than 100 B-29s attacked Tokyo. From then on, bombing raids intensified. That said, daylight bombing raids did not produce the desired results. General Curtis LeMay, who commanded the bombing campaign, changed tactics by ordering mass firebombing attacks by night. B-29s were tasked to drop M-69 incendiary bombs from about 7 000 ft. These bombs, which have been described as 'miniature flamethrowers,’ wreaked havoc on the ground, destroying vast areas of cities by causing firestorms. At the time, Japanese cities were particularly vulnerable to this kind of attack, as many buildings were constructed from wood. The attack on the city of Kobe on 3 February 1945, provided the first truly successful example of a firebombing raid. Another attack during the following month destroyed more than 20 percent of the city. The result of these attacks on Kobe was later illustrated in the 1988 movie 'Grave of the Fireflies,’ which, despite being an animated movie, has been described as one of the greatest war films of all time.

On the nights of 9 and 10 March, more than 300 B-29s dropped more than 1 500 tonnes of incendiary bombs on Tokyo. Aircraft were stripped of guns and all unnecessary equipment to enable them to load as many bombs as possible. The raid created a massive firestorm which destroyed more than 40 km² of the city and killed more than 100 000 people, whilst leaving more than a million homeless. The heat of the firestorm boiled water in rivers and canals, melted glass and created 30 knot winds, whilst resulting updrafts caused the destruction of several overflying B-29s. It was the deadliest raid of World War II.

Similar raids caused the destruction of more than 40 percent of Japan's six largest cities. Smaller cities were also targeted. In August 1945, for example, 99.5 percent of the city of Toyama was destroyed to halt its production of steel, aluminium components and ball bearings. In order to reduce civilian casualties, leaflets warning of imminent raids were dropped over cities to warn inhabitants. Still, estimates of civilian fatalities during the campaign vary from about 250 000 to 900 000 deaths. Of course, the two most sobering displays of firepower were yet to come. On 6 and 9 August, B-29s dropped nuclear bombs on Hiroshima and Nagasaki respectively, resulting in more than 200 000 fatalities. Ironically, these horrific raids may have saved the lives of millions, as Japanese Emperor Hirohito announced his country's surrender only a few days later, effectively ending World War II.

Japanese fighters

Suffice to say that as the bombing campaign progressed, B-29s operated with near invulnerability to enemy fighters, especially when compared with bombing campaigns in Europe. Japan had relatively few fighters and relied on inexperienced pilots to defend the mainland. Land-based radar systems had a short range, so pilots had little warning to intercept American B-29s. Those who were in fact able to intercept the bomber formations had a difficult time shooting down the solidly-built B-29s. Later, with the arrival of P-51 Mustang fighter escorts, B-29 crews could conduct their raids with virtual impunity. General LeMay famously said, “It was safer to fly a combat mission over Japan than it was to fly a B-29 training mission back in the United States.” However, by the end of the war in the Pacific, Japanese fighters had managed to shoot down 74 B-29s. Let us have a look at some of these fighters:

The Nakajima Ki-43 Hayabusa (Peregrine Falcon) first flew in 1939 and saw combat through most of World War II. Operated by the Imperial Japanese Army Air Force (IJAAF), it was referred to by the reporting name 'Oscar' by the Allies. The Ki-43 lacked armour, but was highly manoeuvrable and easy to fly. As a result, more Allied aircraft were shot down by the Ki-43 than by any other Japanese aircraft type. At the end of the war, Ki-43s were used extensively in Kamikaze attacks. Almost 6 000 examples were built.

Perhaps the most famous of all the Japanese fighters, the Mitsubishi A6M Zero completed its maiden flight on 1 April 1939. By the end of World War II, about 11 000 examples had been built. With its extreme agility, the Zero was widely recognised as one of the best naval air superiority fighters in the world, particularly during the first part of the war. However, later variants were specifically developed to intercept B-29 bombers. Of course, by the end of the war, Zeros were relegated to kamikaze missions.

The IJAAF also operated the Kawasaki Ki-61 Hien (Flying Swallow), which first flew in December 1941. The Allies suspected that the sleek fighter was designed by Italians, so they assigned 'Tony' as a report name. The Ki-61 was the only Japanese fighter to be powered by an inline, liquid cooled engine. Interestingly, initial prototypes saw combat during a test flight, when their pilots were tasked to intercept B-25s participating in the famous Doolittle Raid of 1942. Production Ki-61s were frequently used to intercept B-29 bomber formations. Special Ki-61 flights were formed to attack B-29s by ramming into them, sacrificing the fighters to destroy attacking bombers. On one occasion, a Ki-61 pilot was able to return to his base and land his aircraft after ramming a B-29, despite the fact that a significant part of the aircraft's port wing was lost. By the end of the war, more than 3 000 Hiens were built.

The Kawanishi N1K Shiden (Violet Lightning) was widely regarded as the best land-based fighter in Japan's arsenal. The Allies assigned it a somewhat less glamorous report name, referring to it simply as 'George.’ Operated by the Imperial Japanese Navy Air Service (IJNAS), it was well-armoured and highly manoeuvrable, making it as capable as the best Allied fighters of the war. The Shiden first flew in 1942, but B-29 raids on Japanese factories limited production to about 1 500. This total included a naval variant which was equipped with floats for landing on water.

The IJNAS also had the Mitsubishi J2M Raiden (Thunderbolt) in its arsenal. It was designed by Jiro Horikoshi, who also developed the famous A6M Zero. Given the report name 'Jack', the Raiden completed its maiden flight in 1942. Fewer than 700 examples were built. Although it first saw combat during the Battle of the Philippine Sea, a massive battle which involved no less than 24 aircraft carriers, 12 battleships and more than 1 500 aircraft, the Raiden was designed mainly to counter the threat of B-29 bombers. However, it had limited success in that role, especially when night raids were introduced.