The Mitsubishi J2M Raiden is a single-engine land-based fighter aircraft used by the Imperial Japanese Navy Air Service in World War II.
The J2M was designed by Jiro Horikoshi, creator of the A6M Zero, to meet the 14-Shi official specification.
It was to be a strictly local-defence interceptor, intended to counter the threat of high-altitude bomber raids, and thus relied on speed, climb performance, and armament at the expense of manoeuvrability.
The J2M was a sleek, but stubby craft with its oversized Mitsubishi Kasei engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with an extension shaft.
Teething development problems stemming from the Kasei engine cooling system, and the main undercarriage members led to a slowdown in production.
A continual set of modifications resulted in new variants being introduced with the ultimate high-altitude variant, the J2M4 Model 34 flying for the first time in August 1944.
It had a 1,420 hp Kasei 23c engine equipped with a turbocharger (mounted in the side of the fuselage just behind the engine) that allowed the rated power to be maintained up to 9,100 m (29,900 ft).
Two upward-aimed, oblique-firing (aimed at seventy degrees) 20 mm cannons, mounted in the German Schräge Musik style, were fitted behind the cockpit with the four wing cannons retained.
Unresolved difficulties with the turbo supercharger caused the project to be terminated after only two experimental J2M4s were built.
Variants
J2M1 Prototype
Fitted with the 1,044 kW (1,400 hp) Mitsubishi MK4C Kasei 13 14-cylinder air-cooled radial engine and armed with two 7.7 mm (.303 in) Type 97 machine guns in the upper fuselage and two wing-mounted 20 mm Type 99 Model II cannon.
J2M2 Model 11
Powered by 1,379 kW (1,850 hp) Mitsubishi MK4R-A Kasei 23a 14-cylinder radial engine, same armament as the J2M1.
J2M3 Model 21
Armed with two wing-mounted 20 mm Type 99 Model II cannon and two wing-mounted 20 mm Type 99 Model I cannon.
J2M3a Model 21A
Armed with four wing-mounted 20 mm Type 99 Model II cannon.
J2M4 Model 32
Prototype fitted with the 1,357 kW (1,820 hp) Mitsubishi MK4R-C Kasei 23c engine.
J2M5 Model 33
High altitude variant powered by 1,357 kW (1,820 hp) Mitsubishi MK4U-A Kasei 26a engine with mechanically driven supercharger, giving increased high-altitude speed at the expense of range.
Two 20 mm Type 99 cannon in fuselage, two 20 mm Type 99 Model II cannon in wings.
J2M5a Model 33A
Armed with four wing-mounted 20 mm Type 99 Model II cannon.
Wing cannon were harmonized in trajectory and ballistics with each 200 rpg.
J2M6 Model 31
Chronologically earlier than J2M4 and J2M5 this version was based on J2M3.
Had wider cockpit and improved bubble canopy later used in J2M3 built since July 1943.
J2M6a Model 31A
Chronologically earlier than J2M4 and J2M5 this version was based on J2M3a.
Had a wider cockpit and improved bubble canopy later used in J2M3a built since July 1943, One J2M6a was built.
J2M7 Model 23A
J2M3 powered by Kasei 26a engine, a few built.
J2M7a Model 23A
J2M3a powered by Kasei 26a engine, a few built.
Specifications
Crew
1
Length
9.945 m (32 ft 8 in)
Wingspan
10.8 m (35 ft 5 in)
Height
3.81 m (12 ft 6 in)
Wing area
20.05 m2 (215.8 sq ft)
Empty weight
2,839 kg (6,259 lb)
Gross weight
3,211 kg (7,079 lb)
Powerplant
1 × Mitsubishi MK4R-A Kasei 23a,
14-cylinder air-cooled radial piston engine,
1,300 kW (1,800 hp) for take-off
1,174 kW (1,575 hp) at 1,800 m (5,906 ft)
1,051 kW (1,410 hp) at 4,800 m (15,748 ft)
Propellers
4-bladed constant-speed metal propeller
Performance
Maximum speed
587 km/h (365 mph, 317 kn) at 5,300 m (17,388 ft)
Cruise speed
351 km/h (218 mph, 190 kn)
Range
1,898 km (1,179 mi, 1,025 nmi)
Service ceiling
11,700 m (38,400 ft)
Time to altitude
6,000 m (19,685 ft) in 6 minutes 14 seconds
Wing loading
171.3 kg/m2 (35.1 lb/sq ft)
Power/mass
0.391 kW/kg (0.238 hp/lb)
Armament
2x 20 mm (0.787 in) Type 99 Mark 2 machine gun inboard wing-mounted with 190 rpg
2x Type 99 Mark 1 machine gun outboard wing mounted with 210 rpg
2× 60 kg (132 lb) bombs
Or
2 × 200 l (53 US gal; 44 imp gal) drop tanks or a larger central drop tank.
