Mitsubishi J2M3 Raiden Type 21 and A6M5 Zero Type 52 Hei by Hasegawa

1/72 scale
Kit No. 1989
Retail: $40.00
Decals: Two versions for the Raiden, three versions for the Zero
Comments: Both kits feature engraved panel lines, detailed cockpits, one-piece canopies, and center line drop tanks; the Zero includes a detailed radial engine; the Raiden includes a pilot figure and choice of two propellers

History – Mitsubishi A6M5 Zero

The Mitsubishi A6M Reisen (Zero) took part in every major action to which the Imperial Japanese Navy was committed for the duration of the Pacific War, from the December 1941 attack on Pearl Harbor, to the effort to fight off waves of B-29 bombers from the Marianas Islands, to the desperate Kamikaze attacks against the U.S. Navy in the final months of the conflict. Its extreme maneuverability and exceptional range accorded the Zero legendary, almost mythic status in the early months of the war, and to this day it remains an iconic symbol of Japanese air power.

During the first six months after Pearl Harbor, the Zero had virtual air superiority throughout the Pacific, but from 1943 on, as the Allies began introducing more modern, capable fighters, in time the Zero was outclassed in terms of speed, armament, and armor protection. Losses began to mount as the conflict wore on. Often outnumbered, the IJN’s force of Zeros in various parts of the Pacific Theatre slowly withered as the need for more planes and a pipeline of trained pilots began to outstrip what Japan was capable of producing.

Mitsubishi’s A6M originated with the issuance of the Imperial Japanese Naval Staff on May 19, 1937 of a preliminary specification for a Navy Experimental 12-Shi Carrier Fighter intended to replace the Type 96 A5M Claude fighter (also a Mitsubishi design) which had recently become operational. The new specification far exceeded the A5M’s performance, and included the following:
• Maximum speed of 311 mph at 13,125 ft. (270 kt and 4,000 meters)
• Rate of climb achieving 9,840 ft. (3000 meters) in 9 minutes, 30 seconds
• Endurance of 1.5 to 2 hours at “normal rated power” or 6 to 8 hours at economical cruising speed with drop tanks
• Armament of two 20mm cannon and two 7.7mm machine guns, with provision for two 132 lb./60 kg bombs
• Radio and direction finding equipment
• Take off run of less than 230ft./70 meters with a 31mph/27 knot headwind
• Maneuverability at least equal to the A5M

From the outset, the Zero was designed for speed and maneuverability. A key requirement was to keep the aircraft’s weight down where possible. One example is the bracket made of sheet aluminum pierced with large lightening holes and riveted together to support the aileron control tube. Workers made use of lightening holes in many parts such as the pilot’s seat, and in several areas they used plywood instead of aluminum or steel as backing to reinforce the metal canopy frame and the spar that supported the ailerons and flaps in the wings.

The secret to the Zero’s maneuverability lay in part in locating the engine very close to the cockit. The entire aircraft was designed and built in such a way that the center of gravity and the aerodynamic center of lift were located as close to the cockpit as possible. In the Zero’s construction, the design team led by Jiro Hrikoshi ensured that the fittings holding it together were as small and light as possible.

The A6M5
Considered by many to be the most effective variant of Mitsubishi’s A6M family, the Model 52 was developed to again shorten the wings to increase speed and dispense with the folding wing mechanism. In addition, ailerons, aileron trim tab and flaps were redesigned. Although initially produced by Mitsubishi, most Model 52s were license-built by Nakajima at its Koizumi plant in Gunma Prefecture. The prototype was completed in June 1943 by modifying an A6M3, and was first flown in August 1943. The A6M5 had a maximum speed of 565 km/h (351 mph) at 6,000 m (20,000 ft), reaching that altitude in 7 minutes, 1 second.

A new exhaust system provided an increment of thrust by aiming the exhaust stacks aft and distributing them around the forward fuselage. The new exhaust system required “notched” cowl flaps and heat shields just aft of the stacks. The lowest exhaust stacks were approximately the same length as those immediately above them. This caused hot exhaust to burn the forward edge of the landing gear doors and heat the tires. In response, Mitsubishi began to install shorter bottom stacks.

Successive modifications continued to improve the A6M5. The wing fuel tanks had carbon dioxide fire extinguishers installed, and the radio mast was shortened. The A6M5a replaced the Type 99-2 Mark 3 20mm wing cannon, which were fed with a drum magazine, with the Type 99-2 Mark 4 belt-fed cannon, allowing the Zero to carry an additional 25 rounds per gun. The bulge in the underside of the wing for each cannon’s ammunition drum was deleted and the ejection port for spent cartridge cases was moved. Thicker wing skinning was also installed to permit higher diving speeds.

The A6M5b saw one of the 7.7mm machine guns in the nose replaced with a more powerful Browning-type 13.2mm machine gun carrying 240 rounds. The larger weapon required an enlarged opening, creating a distinctive asymmetric appearance to the top of the cowling. It is a mystery as to why both 7.7mm nose guns were not replaced; it is possible that the cowling dimensions would not accommodate two of the larger machine guns with their ammunition feed systems. Armored glass plate (with a thickness of 45mm, or 1.8 inches) was fitted to the windscreen, and a new ventral drop tank with fins was also fitted.

The late-war variant, the A6M5c, would have still heavier armament and additional armor installed. One 13.2 mm (.51 in) Type 3 machine gun was added in each wing outboard of the cannon, and the 7.7 mm gun on the left side of the cowl was deleted. Four racks for rockets or small bombs were installed outboard of the 13 mm gun in each wing. New 55 dmm (2.2 in) thick armored glass was installed behind the headrest, and an 8 mm (0.31 in) thick plate of armor was installed behind the pilot’s seat. The mounting of the central 300 L (79 US gal) drop tank changed to a four-post design, and the wing skin was thickened even further to allow for greater dive speeds. The first A6M5c was completed in September 1944. Because of its increased weight,it was used mainly for intercepting B-29s and special attack, or Kamikaze missions.

The Kit

The A6M5c Zero is injection molded in grey and consists of 71 parts on six sprues. There is a one-pice canopy with clear and definite scribing to assist in painting the canopy frame. The airframe parts bear crisply engraved panel lines and recessed rivet detail. The interiors of the fuselage halves bear no internal sidewall detail for the cockpit, which is not unusual in this scale. The cockpit consists of five parts: a seat, floor, rear armored bulkhead, control yoke, and main instrument panel. A decal is provided for the latter part, as well as for a small side panel on the left side of the cockpit.

The kit features a separate three-piece radial engine, two parts for the exhaust manifold, and a single part for the cowl, which is always nice to see as it eliminates the need to pull out the putty and sandpaper for seam-hiding. There is a choice of spinners, one of which is a bit more pointed, although the kit instructions acknowledge only one. Propeller blades are individually mounted, and for some reason there are six of them, perhaps in case of accidental breakage.

The wings are particularly detailed with boxed in wheel wells for the landing gear that include raised detail, ejector ports for shell casings from the 20mm wing cannon, and recessed rivet detail. The landing gear are basic, but do have a small amount of raised detail on their interior doors. The wheels bear injector pin marks that will have to be sanded down. There are four separately mounted barrels for the 20mm wing cannon, with a pitot tube and an antenna, to be fitted through the top rear of the canopy, completing assembly.

Markings

The kit markings are of 2022 vintage and are superior to the usual Hasegawa decals that invite replacement with aftermarket products. They show no sign of yellowing, have vivid, realistic color, and are perfectly in register. They even include a few small stencils that clearly bear Japanese characters.

Conclusion

This appears to be a detailed and trouble-free kit, in terms of construction. There will be a few parts left over for the spare box, as there are duplicate parts for the belly tank, propeller blades and spinner that likely correspond to earlier versions of the Zero. Highly recommended.

 

History – Mitsubishi J2M3 Raiden

In October 1938, with the development of Mitsubishi’s A6M Zero as a replacement for the A5M Claude well underway, the Imperial Japanese Navy Air Force began discussions with Chief Designer Jiro Horikoshi for a new design for a land-based interceptor that represented a departure for its combat aircraft: The IJNAF wanted a fighter first and foremost with high speed and a high rate of climb — maneuverability and rate of climb would come a distant second. The powerplant for this new fighter would be a manifest example of the top priority for the design: sheer power.

For nearly a year the project wallowed in limbo as Hirokoshi and his team of engineers were kept busy completing the development of the first production A6M1 Zero — the official 14-Shi specification was not drawn up until September 1939, calling for a single-seat, single engine interceptor with a maximum speed of 373 mph at 19,685 feet (600 kph at 6,000 meters). It would have to climb to 6,000 meters in less that 5 1/2 minutes, with a landing speed of no more than 81 mph (130 kph), an endurance of 45 minutes at full power, with armament identical to that of the A6M2 (two 7.7mm machine guns in the upper nose and two wing-mounted 20mm cannon), but the Navy also requested armor plate behind the pilot’s seat for the first time. The specification was silent no maneuverability requirements, and Hirokoshi was left to his own devices as to the powerplant.

Hirokoshi selected the 1430 hp Mitsubishi Kasei 14-cylinder radial engine, though it had a large frontal area and high fuel consumption.To minimize drag the Kasei 13 radial was fitted with an extension shaft and an air-driven fan allowing the use of a fully tapered cowling in a quest for aerodynamic efficiency.
A laminar flow wing and combat flaps were fitted to improve maneuverability, despite the specification’s failure to even mention this factor. Drag was further reduced by the use of a shallow, curved windscreen canopy. Problems with the engine cooling system combined with the priority given to the Zero delayed completion of the prototype unitl February 1942.

The first flight occurred at Kasumigaura on March 20, 1942 with MItsubishi test pilot Katsuzo Shima at the controls. The new plane was very stable and controllable, but technical difficulties, including problems with abililty of the main landing gear to retract, dogged the flight test program. Modifications quickly began and the Navy decided to proceed with the flight testing at Suzuka Navail Air Base. The J2M1 was severely criticized by test pilots for poor visibility out of the curved, sloping wind screen, and from the cockpit in general. The propeller pitch change mechanism was unreliable and the rate of climb did not meet the specification. The Navy ordered Mitsubishi to make additional modifications, the first of which was the installation of a conventional, flat bullet-proof wind screen.

The temperamental Kasei 13 engine and its complicated extension shaft were replaced with a Kasei 23a modified to incorporate the fan cooling system with individual exhaust stacks and water-methanol injection. The new engine allowed the length of the nose to be reduced, improving visibility for pilots, especially on landing. The modifications paid off when in October 1942 the J2M2 was accepted for production as the Navy Interceptor Fighter Raiden (Thunderbolt). Unfortunately, the bugs in the Kasei 23a engine had not all been worked out, in part because it was the first Japanese engine with a water-methanol injection system, emitting excessive smoke at full power. This was cured by adjusting both the fuel and water-methanol injection systems, but engine vibration continued unabated until engine mounted shock dampers were installed and modifications were made to the propeller.

Owing to these teething problems, by March 1943 only 14 aircraft had been delivered. Production had begun to pick up when in June 1943, a J2M2 and its pilot were lost in a crash shortly after takeoff. Mitsubishi engineers were at a loss to explain the cause. In July 1943 the same incident almost occurred again, but the pilot was able to regain control of the aircraft and land safely by quickly lowering the undercarriage. Examination of the plane revealed that the tailwheel struts had pressed against the torque tube lever once the tail wheel was retracted, jamming the controls in the dive position. A modification eliminated the problem.

The J2M3 would become the major production model of the series, having a stronger wing housing four 20mm cannons. Navy pilots still complained about poor visibility and performance, for the J2M2 had almost reached the specification requirements, which once again came in below par with the introduction of the heavier, more well-armed J2M3 Model 21. As a result, in June 1944, the Navy opted to adopt the faster Kawanishi Shinden as its main interceptor, and continue Raiden production at a reduced pace until the Mitsubishi Reppu entered production. But this did not prevent the introduction of two more variants of the Raiden that had better high altitude performance.

The most ambitious of these was the J2M4 Model 34 powered by a turbocharged MK4R-C Kasei 23c. Mounted in the fuselage behind the cockpit and fitted with a large air intake on the port side of the cowling, the turbosupercharger allowed the Raiden to maintain it rated power of 1,420 hp up to 30,185 feet (9,200 meters) instead of only 15,748 feet (4,800) meters with the standard Kasei 23 engine. Capable of speeds up to 362 mph at 30,185 feet, the J2M4 would have been a valuable addition to the interceptor force on the Home Islands fighting to stop the B-29 raids, but teething troubles with the turbosupercharger forced the project’s cancellation after only two examples were built.

While a small number of Raidens were deployed to the Phillipines, where the Americans gave them the code name Jack, they were mainly used in the defence of Japan as a bomber destroyer. In this role it enjoyed reasonable success and became popular with pilots who soon preferred it to all other figher aircraft for the bomber interceptor mission due to its relatively high performance, powerful armament and (by Japanese standards) greatly improved armor protection for the pilots. But the Raiden — fortunately for the Allies — plagued by technical problems as much as official indecisiveness over its future, never reached its full potential.

The Kit

The J2M3 Raiden is of somewhat simpler construction, having few parts but above average exterior detail. The kit is injection molded in grey plastic presented on three sprues and consists of just 31 parts, including a one-piece clear canopy and a part representing armored glass mounted inside the cockpit just above the instrument panel. This single piece reveals the purpose of the Raiden — it was primarily built as a bomber destroyer, and may be the most heavily armored fighter fielded by the Imperial Japanese Navy during World War II.

The cockpit assembly is six parts: Floor, pilot’s seat, control yoke, rear armored bulkhead, and main instrument panel, for which Hasegawa provides two decals, and the aforementioned armored glass mounted just behind the canopy windscreen. The fuselage consist of two halves and the wings are a three-part assembly.

There is clearly an option to build the kit with the landing gear up, because the main gear doors are molded as a single part and must be cut in order for the smaller doors closer to the center line of the aircraft to be cemented in place in the open position. The gear are a little more detailed than those of the Zero, and the wheels have been molded without any telltale injector pin marks. That said, the boxed in wheel wells are plain and lack any detail whatsoever.

There is a one-piece cowl and a part for the face plate of the engine to be cemented to the front of the cowl, but there is no engine itself. Modelers will have a choice between a standard four-bladed propeller, and a high-performance propeller. There is a part for a belly mounted drop tank, and unlike the Zero, this kit includes a pilot figure. Care may have to be taken with the tail wheel, which looks rather small and delicate.

Markings

Consistent with the fact that the Raiden was primarily used for the defense of the Japanese Home Islands, Hasegawa provides markings for two different aircraft of the 352nd Flying Group stationed at Omura Air Base during 1945 (the City of Omura was just over 10 miles northeast of Nagasaki, the target of the second U.S. atomic bombing in August 1945). The first aircraft was flown by Lt. j.g. Yoshihiro Aoki and bears golden yellow lightning bolt markings on its fuselage and a the number 20 on its rudder in either yellow or white (modeler’s choice). The second aircraft from the same unit bears a golden yellow horizontal band on its vertical tail and has a number 50 on its rudder in either yellow or white. Both aircraft are painted with Mitsubishi Dark Green upper surfaces and Japanese Navy Grey undersides, which to my eye has always appeared as a pale green (see Kawanishi Type 94 E7K1).

Conclusion

Being of simple construction with a modicum of detail, the J2M3 Raiden would be an excellent weekend kit.

Reference

Japanese Aircraft of the Pacific War by R.J. Francillon; Copyright 1970, Putnam & Company Limited, London.