Mitsubishi B2M

Design and development

In 1927, the Japanese company Mitsubishi commissioned the British aircraft manufacturer Blackburn Aircraft to design an aircraft, which would be built under licence by Mitsubishi if successful, to enter a competition held by the Imperial Japanese Navy for a carrier-based reconnaissance and torpedo bomber to replace its B1M. Blackburn developed a design, the Blackburn T.7B, which was an enlarged development of their Ripon, which was under development for Britain's Fleet Air Arm. The T.7B was a three-seat biplane of steel tube construction and with high aspect ratio wings fitted with Handley Page slats, powered by a 466 kW (625 hp) Hispano-Suiza 12Lbr engine.

The design was declared the winner of the competition, with a prototype (referred to as the 3MR4) being ordered from Blackburn. This first flew on 28 December 1929 at Blackburn's factory at Brough, Yorkshire, and was shipped to Japan in February 1930.

Three development prototypes were built by Mitsubishi in Japan before the aircraft was adopted as the Navy Type 89-1 Model 1 Carrier Attack Plane or Mitsubishi B2M1.

Operational history

The B2M1 entered service with the Imperial Japanese Navy in March 1932, serving aboard the carriers Akagi, Kaga and Hōshō. Modifications to improve maintainability resulted in the B2M2 or Navy Type 89-2 Carrier Attack Plane, which otherwise showed little improvement in performance over the B2M1. Production of both versions totalled 204 aircraft.

B2Ms were extensively used for high- and low-level bombing attacks against China at the start of the Second Sino-Japanese War in 1937.

Variants

Blackburn T.7B

Prototype aircraft built by Blackburn Aircraft.

Mitsubishi 3MR4

Three Japanese-built prototypes.

Misubishi B2M1

Initial production aircraft.

Mitsubishi B2M2

Improved production variant with reduced wingspan and modified tail.

Operators

 Japan

Imperial Japanese Navy

Specifications (B2M1)

Data from World Encyclopedia of Military Aircraft

General characteristics

Crew: three

Length: 10.27 m (33 ft 8 in)

Wingspan: 15.22 m (49 ft 11 in)

Height: 3.71 m (12 ft 2 in)

Wing area: 55 m² (592 ft²)

Empty weight: 2,260 kg (4,982 lb)

Loaded weight: 3,600 kg (7,900 lb)

Powerplant: 1 × Hispano-Suiza 12Lbr V-12, 485 kW (650 hp)

Performance

Maximum speed: 213 km/h (115 kn, 132 mph)

Range: 1,779 km (960 nmi, 1,105 mi)

Service ceiling: 4,500 m (14,700 ft)

Armament

Guns: 1 × forward firing 7.7 mm (.303 in) machine gun and 1 × flexible 7.7 mm (.303 in) machine gun in rear cockpit

Ordnance: 1 × 800 kg (1,764 lb) torpedo or equivalent weight of bombs