Kōkūtai

right|thumb|300px|Kawanishi N1K|Kawanishi N1K2-J "343 A-15" of 301st Hikōtai/343rd Kōkūtai, Matsuyama air base, 10 April 1945. A kōkūtai () was a military aviation unit in the Imperial Japanese Navy Air Service (IJNAS), similar to the air groups in other air arms and services of the time. Some comparable units included wing in the British Royal Air Force, gruppe in the German Luftwaffe, and groupe in the French Armée de l'Air.

A kōkūtai could be based at land or on board aircraft carriers and could contain hundreds of men and aircraft. For example, the famous 343 Kōkūtai was a land-based fighter group while the 652nd Kōkūtai was a carrier-based bomber group. Kōkūtai were divided into smaller units called hikōtai, which were the equivalent of a squadron. Kōkūtai were usually divided into three hikōtai. In general, most pilots and aircrew in the Imperial Japanese Navy Air Service were non-commissioned officers. The word kōkūtai is abbreviated with the suffix "-ku" (空). The term "343 Ku", for example, stands for 343 Kōkūtai. In the Imperial Japanese Army Air Service (IJAAS) the equivalent unit was the sentai.