The Mitsubishi Experimental 7-Shi Carrier Attack Aircraft was an unsuccessful aircraft designed in an attempt to replace the Type 89 Carrier Attack Aircraft (B2M).
In April 1932 Mitsubishi and Nakajima were both asked to design a carrier based attack aircraft to replace the B2M, a Blackburn design that had only been officially accepted by the Navy in March 1932, and which remained in production until 1935. The B2M had a steel and aluminium framework with a fabric covering, a top speed of 142mph (as the B2M2, the main production version) and was a single-engine two-bay biplane.
The Experimental 7-Shi Carrier-Attack aircraft (Mitsubishi designation 3MT10) was designed by Hajima Matsuhara, Mitsubishi's chief designer. It was a two-bay biplane similar in size and overall design to the earlier B2M. Its Rolls-Royce Buzzard II-MS engine gave it 200-300hp more power, but loaded weight also increased by nearly 2,000lb and its top speed was only 132mph. The 3MT10 had a wood and metal framework, with a fabric covering.
Its range was similar to the B2M, and its climb rate was the same as on the B2M. The 3MT10 could use two different sets of wings, one with a surface area of 48.8 square meters and the second with an area of 57 square meters.
The only prototype was completed in October 1932. It was delivered to the Navy during 1933, but lost power during take-off in February 1934 and was destroyed in the resulting crash. No further aircraft were built, but the project had given Mitsubishi valuable experience of designing their own aircraft. The Mitsubishi B4M1 Experimental 9-Shi Carrier Attack Aircraft was closely related to the 7-Shi.
Engine: Rolls-Royce Buzzard II-MS twelve cylinder V water-cooled engine
Span: 48ft 3.5in
Length: 33ft 1in
Height: 12ft 8.75in
Empty weight: 5,732lb
Loaded weight: 9,700lb
Max speed: 132mph
Climb Rate: 12 minutes to 9,843ft
Endurance: 12 hours
Armament: One fixed forward firing 7.7mm machine gun, twin flexibly dorsal mounted 7.7mm machine guns
Bomb load: One Type 91 torpedo or one 1,984lb bomb