Hiyo (Flying Falcon)

The Hiyo was the second of two Junyo class aircraft carriers produced by modifying two semi-completed passenger liners. She entered service too late to take part in the battle of Midway, and her unreliable engines meant that she missed the battle of the Santa Cruz Islands.

During her short career the Hiyo received a number of modifications. When built she carried 24 25mm AA guns in eight triple mountings. Early in 1943 four more triple mountings were added, bringing the total to 36 guns, and before the battle of the Philippine Sea she was given another four triple mountings and twelve single mountings, giving her a total of 60 25mm guns in 16 triple and twelve single mountings.

She was also equipped with radar, being given a Type 21 radar set mounted on the island in the autumn of 1942, a second Type 21 set in 1943 and a Type 13 radar set in 1944.

During the battle of the Philippine Sea of June 1944 the Hiyo was part of Rear-Admiral T. Joshima’s B Force. She survived the fighting of 19 June intact, but during the American twilight attack of 20 June she was hit by two aircraft torpedoed. Massive internal explosions followed, probably because of leaking fuel vapour, and she soon sank.

Displacement (standard)


Displacement (loaded)


Top Speed







719ft 6in max


12 5in/40 Dual Purpose guns in double mountings
24 25mm anti aircraft guns

Crew complement



24 June 1941


31 July 1942

Sunk at Philippine Sea

20 June 1944

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How to cite this article: Rickard, J (27 November 2008), Hiyo (Flying Falcon) , http://www.historyofwar.org/articles/weapons_hiyo.html

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