The Mitsubishi G4M or Ichishikirikkou ("Type 1 land-based attack aircraft") was the main twin-engined, land-based bomber aircraft used by the Imperial Japanese Navy Air Service in World War II. The Allies gave the G4M the identification name of Betty. The G4M had a long range and high-speed at the time of its introduction. However, it was known for its poorly-protected fuel tanks, which caused Allied fighter pilots to give it the derisive nicknames "one-shot lighter", "flying Zippo" and "flying cigar". Similarly, pilots of the Imperial Japanese Navy called the G4M the "Type One Lighter" and Hamaki (Cigar). This was due to the fact that on many occasions, it was used for low-altitude torpedo attacks where its performance advantages were negated. The "Betty"'s relatively-large size made it a large target to shoot at, and the simplified approach path on a torpedo run to attack a ship, meant for a generally easy interception.