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  • This episode of Real Engineering is brought to you by Brilliant, a problem solving website

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  • In the late 19th and early 20th century the Japanese Empire was under rapid expansion,

  • fueled by a feudal born military economy and European technology.First invading the chain

  • of islands north and south of it's home island, fighting a bitter war with Russia

  • for control over Manchuria and annexing Korea all before WW1.

  • The outbreak of World War 1 gave Japan the perfect platform to expand further, alling

  • against Germany and taking control of German positions in the Pacific.

  • Making Japan the dominant power in the east Pacific, with its sphere of influence extending

  • from the Asian mainland to the mid Pacific.

  • To maintain this influence Japan had undergone rapid industrial expansion, growing from a

  • technologically primitive feudal country, and developing the third largest Navy in the

  • world, with only the United States and the British Navies challenging it.

  • With US territory in the Philippines and Hawaii, and British territory in Malaya, Hong Kong

  • and British Borneo, conflict was inevitable and tension in the Pacific was rapidly growing.

  • On September 27th 1940 Japan entered an alliance with Germany and Italy, a clear warning to

  • the Americans.

  • Enter the war in Europe, and you will face war in the Pacific.

  • This warning did not come unchallenged and the United States moved it's pacific fleet

  • from California to Pearl Harbour in Hawaii.

  • From here many of us are familiar with the story.

  • Japan capitalized on this ill advised show of force and took the United States by surprise,

  • attempting to wipe out the US Navy in the Pacific in one foul swoop.

  • A decisive victory that announced Japan to the Western world as a force to be reckoned

  • with.

  • At the height of their power in WW2 Japan seized control from Western powers in China

  • and Southeast Asia.

  • But the war machine was doomed to failure, and was destined to over extend itself.

  • Nothing illustrates the turning fate of the Japanese Empire like it's iconic fighter

  • plane the Mitsubishi A6M Zero.

  • A plane that entered world war 2 as feared and formidable advisory for any plane in the

  • pacific theatre, but slowly and surely lost its tactical advantage until it was finally

  • regulated to a dispensable resource, fitted with 250 kilogram bombs and flown straight

  • at enemy ships in a last ditch effort to protect the Empire.

  • The Zero was a thoughtfully designed plane.

  • Its designer Jiro Horikoshi, built upon the framework of his previous design the A5M,

  • the world's first carrier based monoplane.The Imperial Japanese Army challenged Mitsubishi

  • and Nakajima to both design and build successors to this plane to aid the war effort in China.

  • The plane was to have a top speed of 500 km/h, be fitted with two 7.7 mm machines guns and

  • two 20 mm cannons, incredibly heavy armaments for fighters of that era.

  • On top of all this, it was to have an operating ceiling of 10,000 metres.

  • Be capable of flying 2 hours at max speed, and 6 to 8 hours at cruising speed with drop

  • tanks attached.

  • These were fuel tanks that could be jettisoned when empty, or when an enemy was encountered

  • to increase maneuverability.

  • These specifications alone were ambitious enough, but the plane also needed to be carrier

  • based, which limited it's wingspan to 12 metres.

  • The specifications were so ambitious that Nakajima pulled their bid from the project,

  • but Jiro Horikoshi persevered.[1]

  • His design [2] was ingenious.

  • Incorporating many of the most advanced techniques of the era.

  • Thin elliptical wings minimised drag, along with state of the art flush riveting.

  • New heat treatment knowledge obtained from the Germans allowed Horikoshi to develop an

  • all metal structure.

  • It's frame entirely made from this new age hardened aluminium and he cut holes into the

  • frame where possible to reduce weight.

  • All to achieve that ambitious range requirement of the Imperial Japanese Army, but that requirement

  • forced Jiro to make some sacrifices to the planes design.

  • Favouring speed, maneuverability and range with its lightweight construction, over heavy

  • armoring.

  • It's skin was only 1.2 millimeters thick over it's thickest sections, like the leading

  • edge of the wing, and forward fuselage to just 0.5 mm thick at it's thinnest over

  • the aft sections of the plane.

  • While enemy outer skin thicknesses were not significantly thicker, the outer skin is intended

  • to be a smooth aerodynamic surface not protective armouring.

  • Typically these planes would contain thicker plate armouring over key locations like the

  • engine, fuel tank and cockpit.

  • The zero did not.

  • On top of this the zero did not employ self-sealing fuel tanks, which used several layers of rubber

  • that would swell and expand when soaked in fuel, and thus seal any holes.

  • Weight savings even came down to the cockpit size, which was smaller than most Western

  • designs, designed to fit the on average, shorter Japanese pilot.

  • The zero was designed on a doctrine of training skilled pilots with nimble, lightweight planes.

  • What use was armor if you didn't get hit, what use was armor if you didn't have the

  • range to patrol your territory.

  • The lightweight skin made it difficult to get into the plane without damaging it, so

  • the designers incorporated footholds and handles, which sat flush to the planes surface, and

  • could be released with a button when needed.

  • This mechanism seen from the inside of the plane looks like a mushroom.

  • With these rounded domes protecting an internal bag which could be inflated using a pilot

  • controlled valve which redirected air from the front air intake, so that in the event

  • of an crash landing into the sea the plane would not sink.

  • The designers of this plane clearly never intended it to be used as a disposable weapon.

  • Yet that is exactly what happened.

  • The Japanese Air Force met little airborne resistance in China, it's vastly more advanced

  • planes picked the archaic chinese bi-planes out of the sky with ease.

  • It would meet a far more formidable enemy on December 7th, 1941, when Japan attacked

  • Pearl Harbor.

  • The surprise attack aimed to cripple the US Navy and cement Japan as the most powerful

  • Navy in the Pacific.[3] A show of force to dissuade the mighty American Navy from interfering

  • with the Empire's domination of Asia.

  • An ill advised attack that had the opposite effect.

  • America entered WW2 the same day, with it two primary fighters at the time.

  • The P-40 Warhawk, and the F4F Wildcat.

  • Neither were as nimble as the A6M,and in early battles the Zero had a tactical advantage,

  • despite both planes having a higher top speed.

  • Much of this was down to the superb training of the Japanese pilots, who at the outset

  • of the war, were among the best in the world.

  • The Japanese focused on quality over quantity.

  • This slowly changed over the course of the war.

  • Skilled pilots we dying quicker than Japan could produce them, and instead Japan switched

  • it's training process into overdrive.

  • Sending hundreds of green pilots to war.

  • The final blow to the legendary plane would come when the US Navy captured an intact Zero

  • and began probing it for weaknesses.

  • [4]

  • They soon discovered three fatal flaws that would dismantle its tactical advantage overnight.

  • The Americans knew of the Zero's tendency to burst into flames, due to it's weak armouring

  • and lack of self sealing fuel tanks.

  • It only took a few shots to disable the plane, the trouble was getting into a position to

  • get those shots in.

  • With American test flights of the Zero they soon found their opening.

  • The Zero suffered from the exact same problem as early Merlin engines, which powered British

  • planes like the Spitfire and Hurricane,

  • It utilized a float carburetor, which as we discovered in one of my early videos, made

  • zero-g maneuvers impossible as it caused the float valve to open.

  • Flooding the engine and shutting it off.

  • Unlike the Merlin engines of the Spitfire however, the Zero's issues were never addressed,

  • and received little upgrades throughout the war.

  • The last nail in the coffin for the Zero came with the discovery of it sluggish nature at

  • high speeds, becoming much less maneuverable when maxed out, due to aerodynamic stiffening

  • of the ailerons.

  • Where high airspeeds made it difficult for pilots to extend the control surfaces with

  • their simple manual lever control system with no help from hydraulics.

  • With these characteristics in mind American pilots were trained on how to deal with the

  • Zero.

  • The primary rule being for Allied pilots to maintain high speed and never to try to out-maneuver

  • a Zero at low speeds.

  • With its tactical advantage gone, and no improvements to be seen, and Japan running short on skilled

  • pilots The Zero was given the role of Kamikaze bomber, along with the other outdated planes

  • of the Japanese Air Force.

  • For an island nation at war, running short on valuable raw materials, this was a desperate

  • last attempt at protecting the motherland.

  • The common story retold was that these young men were brainwashed to an absolute devotion

  • to their emperor.

  • The living god of Japan.

  • All too often, detail is lost by only listening to secondary sources.

  • The stories told directly by Japanese pilots paint a different story.

  • Letters from young pilots [6], like Captain Adachi Takuya, paint a picture of young men

  • sacrificing their lives for their loved ones.

  • Perhaps the most telling of all stories comes directly from the mouth of one of Japan's

  • most famous acesSaburo Sakai” . This is a paraphrased quote from an interview before

  • his death in 2000.

  • “A lot of Westerners looked at the kamikaze strategy with complete shock, the idea of

  • putting a kid in a plane and telling him to kill himself by crashing into the enemy.

  • But even if you don't tell him to crash into something, putting a kid with only about 20

  • hours flight time into a plane and telling him to take on U.S. pilots in Hellcats and

  • Corsairs is just as much a suicidal tactic as being a kamikaze.

  • We figured that if they're going to die anyway, the kamikaze attack will probably cause more

  • damage to the enemy for the same price in lives.But let me tell you, all that stuff

  • you read about "dying for the emperor ... Banzai!" that's all crap.”

  • It should be noted that in the same interview [7] Saburo denies the Rape of Nanjing ever

  • happened, which is essentially on par with holocaust denial, so you may want to take

  • any information from this primary source with a grain of salt.

  • These young men were often barely trained with more than a basic understanding of flight

  • mechanics, and many of them crashed into the sea well away from enemy ships, precisely

  • because they never learned to deal with the Zero's control surfaces becoming essentially

  • useless at high speeds, like in a dive.

  • Many of them died desperately pulling on their stick, not being able to overcome the force

  • of air pushing the surface back down.

  • I think it's fair to say, these young men were not solely dying out of duty for their

  • emperor, but for their family, their friends, for their country.

  • Emboldened by a culture where the group takes precedence over the individual, where suicide

  • was viewed as a reasonable and honorable choice, when faced with defeat.

  • This wasn't terrorism, as many western writers have stated.This was war.

  • The most devastating Kamikaze attack on May 11th 1945, came just two months after the

  • United States firebombed Tokyo, killing over 100,000, displacing 1 million and cutting

  • the industrial output of the city in half.

  • This bombing raid was more destructive than either of the nuclear bombs.

  • With industrial output declining, raw materials scarce, trained men few and far between and

  • their homeland under attack.

  • This culture of self sacrifice for the country made Japan a fortress that no army wanted

  • to invade.

  • Made worse by President Roosevelt's policy of unconditional surrender, which only encouraged

  • unconditional resistance, and so two young Japanese Pilots Kiyoshi Ogawa and Seizo Yasunori,

  • each piloting Zeros with 250 kg bombs attached flew to their death on that day.

  • Emerging from low cloud cover the two rookie pilots began their diving attack on the aircraft

  • carrier the USS Bunker Hill, releasing their bombs and proceeding to crash their planes

  • straight into the flight deck.

  • Both bombs penetrate d the flight deck and the resulting fires and explosions claimed

  • the lives of over 390 sailors and airmen.

  • A devastating attack, that disabled the aircraft carrier for the rest of the war, but this

  • was a rare occurrence and the vast majority kamikaze attacks failed to hit a target.

  • Either missing the target completely, or being intercepted by anti-aircraft fire and enemy

  • fighters.

  • Ultimately the Japanese were being pushed back to their native Island and the B-29s

  • that dropped the nuclear bombs in Nagasaki and Hiroshima weren't even escorted over

  • Japanese land, as the Japanese Air Force had little resources to counter an attack like

  • this.

  • Their airforce had risen and fallen alongside their empire.

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