The Mitsubishi Navy Type 10 Carrier Torpedo Aircraft (1MT1N) was the only triplane to enter military service in Japan, and was produced in small numbers before being replaced by the Mitsubishi Type 13 Carrier Attack Aircraft (B1M).
The Type 10 Carrier Torpedo Aircraft was one of three aircraft designed by the British designer Herbert Smith that were accepted by the Japanese navy in 1921, alongside the Type 10 Carrier Fighter and Type 10 Carrier Reconnaissance Aircraft. Those two aircraft were very similar but the Type 10 Carrier Torpedo Aircraft was a separate design.
The aircraft was an equal-span two-bay triplane. This configuration was adopted in order to allow the aircraft to carry an 18in torpedo within the wingspan limits imposed by service on a carrier. The resulting aircraft was manoeuvrable and popular with its pilots, but it wasn't so easy to handle on the ground, a fatal flaw in a carrier borne aircraft. The aircraft also had non-folding wings, increasing the space each one needed.
The prototype was ready on 9 August 1922. Two prototypes were completed by November when they were tested by the Navy, and the type was accepted for service. Only twenty Type 10 Carrier Torpedo Aircraft were built before production switched to the Mitsubishi Type 13 Carrier Attack Aircraft.
Engine: Napier Lion 12 cylinder W water-cooled engine
Span: 43ft 6in
Length: 32ft 1in
Height: 14ft 7.5in
Empty weight: 3,020lb
Loaded weight: 5,511lb
Max speed: 130mph
Climb Rate: 13min 30sec to 10,000ft
Service ceiling: 19,685ft
Bomb load: One 18in torpedo