The Mitsubishi G4M or ("Type 1 land-based attack aircraft") was the main twin-engine, land-based bomber used by the Imperial Japanese Navy Air Service in World War II. The Allies gave the G4M the reporting name of Betty. The Allies usually gave Japanese fighters and floatplanes "male" names, while giving "female" names to bombers and reconnaissance aircraft. These did not come into general use until mid-1943.
The G4M had a range of over 3,700 miles achieved by structural lightness and an almost total disregard for armour protection. This proved to be its weakness when Allied opposition increased in the later stages of World War II. Allied fighter pilots called it "the one-strike lighter".
