The Nakajima Ki-43 Hayabusa (Peregrine Falcon) was a World War II fighter aircraft used by the Imperial Japanese Army Air Force. The Allied code name for the Hayabusa was the Oscar. While the Zero was widely used by the Imperial Japanese Navy, the Hayabusa was the fighter most widely-used by the army.
Hayabusa in Days of Infamy
The Hayabusa was first brought to the Hawaiian Islands at the Army's request in the wake of the US bomber raid by Colonel Jimmy Doolittle (much to the Navy's chagrin). However, the Hayabusa didn't see much combat other than air patrolling for most of the war.
During the second American attempt to retake the islands the Hayabusa was forced into combat after the Navy was defeated and much like the Zero, the light armor and less-than-effective self-sealing fuel tanks, caused high casualties in combat. Its armament of two machine guns also proved inadequate against the more heavily armored American Hellcat, and many were shot down.
Many in the Japanese Navy looked down their noses at the Hayabusa mainly because it was an army plane but many also admitted that the Hayabusa was a far more reliable fighter than the otherwise superior Hien.