The navy designs its own

The arsenal began in May 1913 as an aeroplane factory in the navy’s ordnance department at Yokosuka, on Tokyo Bay, and went through a string of names before becoming the Naval Air Arsenal on 1 April 1932, known as Kūgi-shō. It was the navy’s own research and design centre, and many of its designs were built in quantity by private firms. Its K5Y trainer, the orange-painted Red Dragonfly of 1933, ran to 5,770 aircraft from several makers.

Bombs on Oregon

Its E14Y submarine floatplane, of which 126 were built, has a unique distinction. On 9 September 1942 Nobuo Fujita launched from submarine I-25 off Brookings, Oregon, and dropped incendiary bombs on the forest — the only time an Axis aircraft bombed the continental United States. They did no real damage. The D4Y Suisei, first flown in December 1940 and built mostly by Aichi, was called the fastest dive-bomber of the war; 2,038 were made. The P1Y Ginga bomber, 1,002 built by Nakajima, was shaped by Tadanao Miki, who later worked on the aerodynamics of the first Shinkansen bullet trains.

The Ohka and the end

The arsenal’s most notorious design was the MXY7 Ohka, a rocket-powered piloted bomb conceived by Ensign Mitsuo Ohta and carried under a G4M bomber. Its first combat mission on 21 March 1945 was a failure; on 12 April it sank USS Mannert L. Abele. Some 852 were built, 155 at Yokosuka. On 15 August 1945, hours after the surrender broadcast, Admiral Ugaki led eleven D4Ys on a final suicide mission. The arsenal ended with the navy that owned it.

מפעלים

• Yokosuka arsenal · Yokosuka, Tokyo Bay — Temporarily at Tsukiji in 1923; 155 Ohka built here

אֲנָשִׁים

• Mitsuo Ohta · naval ensign — Conceived the Ohka in 1943
• Tadanao Miki · engineer — Shaped the P1Y; later applied the ideas to early Shinkansen trains
• Nobuo Fujita · pilot — Flew the E14Y raid on Oregon, 1942

שיאים וראשונות

• Only Axis aircraft to bomb the continental United States: E14Y over Oregon, 9 September 1942
• D4Y described as the fastest dive-bomber of the Second World War