The
Mitsubishi G4M (long designation:
Mitsubishi Navy Type 1 attack bomber: 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 Betty. Japanese Navy pilots called it
Hamaki "cigar", lit. "leaf roll") due to its cylindrical shape.
The G4M had very good performance, especially range, which was achieved by its structural lightness and an almost total lack of protection for its crew, with no armor plating or
self-sealing fuel tanks. These omissions proved to be its weakness when confronted with American fighter aircraft during the
Pacific War.