The Nakajima Ki-43 Hayabusa was a single-engine land-based tactical fighter used by the Imperial Japanese Army Air Force in World War II. The Army designation was "Army Type 1 Fighter" ; the Allied reporting name was "Oscar", but it was often called the "Army Zero" by American pilots for its side-view resemblance to the Mitsubishi A6M Zerothat was flown by the Japanese Navy.