Raiden "Thunderbolt" Model 21 - Mitsubishi J2M3)
Allied Codename: Jack
Type: Single Seat Fighter Interceptor
Powerplant: One 1,820 hp (1357 kw) Mitsubishi MK4R-A Kasei 23a 14-cylinder radial piston engine.
The choice of the engine was left up to the designer. Horikoshi had a choice between the Aichi Ha-60 Atsuta (a derivative of the Daimler-Benz DB 601A) inverted-vee 12-cylinder liquid cooled engine rated at 1185 hp for takeoff and the Mitsubishi Ha-32 Kasei Model 13 14-cylinder air cooled radial rated at 1440 hp for takeoff. Although the Aichi Tokei Denki K. K. (Aichi Clock and Electric Company, Ltd) promised a future increase of at least 15-20 percent in the power of the Atsuta engine, Jiro Horikoshi decided to select the more powerful Kasei radial despite its higher fuel consumption and larger frontal area.
Performance: Maximum speed 371 mph (597 km/h) at 19,360 ft (5900 m); cruising speed 219 mph (352 km/h) at 9,840 ft (3000 m); service ceiling 38,385 ft (11770 m).
Range: 655 miles (1055 km) on internal fuel stores.
Weight: Empty 5,423 lbs (2460 kg) with a maximum take-off weight of 8,695 lbs (3945 kg).
Dimensions: Span 35 ft 5 1/4 in (10.80 m); length 32 ft 7 3/4 in (9.95 m); height 12 ft 11 1/2 in (3.95 m); wing area 215.82 sq ft
(20.05 sq m).
Armament: Four wing mounted 20 mm cannon (comprising two Type 99 Model 1 and two Type 99 Model 2), plus two 132 lbs (60 kg) bombs or two 44 Imperial gallon (200 litre) drop tanks on external racks.
Variants: J2M1 (prototype), J2M2 (Navy Interceptor Fighter Raiden Model II), J2M3, J2M3a, J2M4 Model 34 (prototype), J2M5 (prototype designation), J2M5a, J2M6 (single experimental aircraft), J2M6a/J2M7/J2M7a (were proposed but never built).
Operators: Japanese Navy.
The high priority given by Mitsubishi to the development of the A6M Reisen (Zero Fighter) series of carrier-based fighters caused the completion of the first prototype J2M1 to be delayed until February of 1942. By this time, Dr. Jiro Horikoshi, suffering from overwork, had relinquished his post of chief designer to Kiro Takahashi. The prototype flew for the first time on March 20, 1942, with Mitsubishi test pilot Katsuzo Shima at the controls. A total of three J2M1 prototypes were built.
Although designed to a 1939 requirement, at a time when Japanese war leaders scarcely imagined a situation requiring a home defence fighter, the Mitsubishi J2M Raiden (thunderbolt) only came into its own while defending the Japanese homeland against American raids in the last year of the war. The Japanese navy's emphasis upon speed and climb rate, rather than its customary demands for range and manoeuvrability, prompted the designer Jiro Hinkoshi to adopt a squat single- engine design with long-chord radial engine cowling, laminar-flow wings and high-raked, curved windscreen. First flight of the prototype J2M1 took place on 20 March 1942, but the aircraft soon attracted criticism from navy pilots on numerous counts, not least that the view from the cockpit was inadequate. Modifications to rectify these shortcomings were delayed owing to Mitsubishi's preoccupation with the A6M. Production J2M2 fighters left the factory slowly and entered service with the 381st Kokutai late in 1943, and were followed by the J2M3 with a stronger wing stressed to mount four 20-mm cannon. The heavier armament now restricted the performance of the Raiden to the extent that it no longer met the original demands, and the J2M4 was an attempt to restore the performance by including a turbocharger. The final production variant, the J2M5 (34 built), was powered by a 1357kW Mitsubishi Kasei 26a radial. In all, 476 J2Ms were built. In acknowledgement of the fact that J2Ms could not combat the Boeing B-29s at their operating altitudes, some J2M3s were armed with two upward-firing 20mm cannon in addition to their wing guns. (The Allies selected the reporting name 'Jack' for the J2M).
The J2M1 handled well, but test pilots complained that the view from the cockpit was totally inadequate and the curvature of the windshield severely distorted forward vision, especially during landing. The propeller pitch change mechanism proved to be unreliable, and the main undercarriage members had difficulty in retracting at speeds greater than 100 mph. The ailerons tended to stiffen up at speeds above 323 mph. In addition, the speed (357 mph at 19,685 feet) and the climb rate (19,685 feet in 7.8 min) were both below those promised in the original specification. Consequently, the fourth prototype was extensively reworked into the more-powerful J2M2.
Edited by sendo5, 11 September 2012 - 09:27 AM.