The Nakajima Ki-43 Hayabusa (隼, "Peregrine falcon"), formal Japanese designation Army Type 1 Fighter (一式戦闘機, Ichi-shiki sentōki) is a single-engine land-based tactical fighter used by the Imperial Japanese Army Air Service in World War II. The Allied reporting name was "Oscar", but it was often called the "Army Zero" by American pilots because it bore a certain resemblance to the Mitsubishi A6M Zero, due to similar layout and lines, bubble canopies, and round engine cowling.