carrier-type fighters, dive bombers, and torpedo bombers increasing in numbers, along with land-based twin engined medium bombers. However, by 1941 the IJN's land-based air groups were almost always composed of one type of aircraft, the exception was the Chitose air group which was based in Micronesia and was composed of both medium bombers and fighters. On November 1, 1942, all land-based identified with base names were given numerical designations. As the war in the Pacific progressed, this structure lacked flexibility and hampered front-line operations, consequently, in March 1944 the IJN's land-based air forces were restructured, and certain hikōtai were given independent numerical designations and an identity of their own outside the parent Kōkūtai. Notable Kōkūtai The 201st Kōkūtai The Tainan Kōkūtai The 343 Kōkūtai (also called Tsurugi Butai) The 601st Kōkūtai The 652nd Kōkūtai The 721st Kōkūtai The Yokosuka Kōkūtai See also Imperial Japanese Navy Air Service Imperial Japanese Navy Notes References Naval units and formations of Imperial Japan Military history of Japan ja:大日本帝国海軍航空隊