Jiro Horikoshi’s team was asked for speed, range, agility and two cannon on 950 hp, and decided it was possible only if every unnecessary gram went. The spar used Sumitomo’s Extra Super Duralumin, an aluminium-zinc alloy that the rest of the world would later call 7075. Nothing protected the pilot or the fuel. The result had a wing loading of 107 kg/m², about half a Bf 109’s, which is why it turned inside everything.

With a 330-litre drop tank and a lean, slow cruise technique its pilots were drilled in, a Zero could fly 3,100 km. Allied commanders in 1942 concluded there must be several times as many Zeros as actually existed, because they kept appearing where no fighter could possibly be.

Above about 400 km/h the Zero’s ailerons went heavy and its roll slowed. American pilots learned not to dogfight it: dive on it, fire, keep going, or pair up in the Thach weave so that whichever Zero followed one aircraft flew into the other’s guns. From 1943 the F6F Hellcat had twice the power and armour, and the Zero had lost its trained pilots.

The two 20 mm cannon in the wings hit hard — about 2.3 kg a second with the machine guns — but their drums held sixty rounds each, seven and a half seconds of firing, and their shells were slow and dropped quickly. After that the Zero was down to two rifle-calibre guns over the engine. Experienced pilots saved the cannon for a certain kill; inexperienced ones emptied them in the first pass.