Hudson Air Depot - Mitsubishi A7M Reppu (Sam)

In 1942, the Japanese Navy ordered Mitsubishi to begin design studies for a successor to the A6M “Zero” carrier naval fighter. This new aircraft would have to be faster, more heavily armed and just as maneuverable as the Zero. The first prototype A7M1 flew on May 6,1944 powered by a Nakajima NK9 (Homare 22) engine. This engine couldn’t provide the power that the A7M required to meet the Navy’s specification demands. Disappointing tests caused the Navy to halt the program. Mitsubishi continued to work on it. The prototype A7M2 flew on October 13, 1944 with a Mitsubishi MK9 (Ha-43) engine. Results were encouraging enough for the Navy to re-instate the A7M to production status. Unfortunately in December, 1944, an earthquake and the B-29 bombing of critical factory locations meant that the A7M would not be ready to fight before war’s end. Only a handful of airframes were completed before Japan surrendered in August of 1945.

By mid 1942, the Imperial Japanese Navy had been dealt several serious set-backs. The Battle for the Coral Sea between May 4th and 8th against the US Navy was fought to a draw. Each side lost one carrier. More important, was the fact that the rest of the Japanese operation was cancelled. More serious than that was the Battle of Midway between June 4th and 7th. This battle resulted in a massive defeat for Japanese carrier power. The loss of 4 carriers, aircraft and highly experienced flight crews put the Navy at a disadvantage that it never recovered from. The Mitsubishi A6M Zero fighter was beginning to show its weaknesses. The Allies developed techniques to blunt the superior maneuverability of the Zero. Its lack of internal protection was beginning to cost the now less experienced pilots dearly. In 1943, the Allies were beginning to bring new, more powerful aircraft into action. In 1942, the Japanese Navy planners anticipating this, ordered Mitsubishi to begin designing the next generation of carrier fighter. Once again Jiro Horikoshi assembled his design team. His team had been successful with the A5M (Claude) and the world famous A6M Zero. The Navy required an aircraft that would push the industry to its limits. The specification called for higher speed, heavier armament and stronger structure and protection with the same maneuverability as the A6M. The design knew this would require more powerful engines.

At this time, the Japanese aircraft engine industry was suffering a similar problem as their German counter parts. Many promising aircraft designs required more powerful engines and the aircraft engine manufacturers were having problems developing them. The Mitsubishi A7M design called for an engine in the 2,000+ HP range. Nakajima was working on their NK9 engine and Mitsubishi itself was working on their MK9. The war was not going well and the Navy was anxious to get the Reppu into service. They ordered Mitsubishi to use the Nakajima NK9 (now known as the Homare 22) be used on the A7M1 prototype. The NK9 engine was supposedly closer to being ready for production than the MK9. It was rated at 2,000 HP. Jiro Horikoshi didn’t believe this and protested but lost. The prototype was redesigned which caused costly time delays. The prototype made its first flight on May 6,1944. From the beginning, tests showed that this combination was not going to meet the Navy’s requirements. The Homare 22 power output dropped dramatically at medium altitude. The program was ordered to halt on July 30th. Mitsubishi asked for and was given permission to continue testing. They developed a second prototype, the A7M2, powered by their Mitsubishi MK9 (now called Ha-43). This aircraft flew on October 13th. After review, the A7M2 was ordered into production. Unfortunately by this time the aircraft industry was under severe pressure from the USAAF strategic bombing campaign and production schedules were being disrupted at every turn. On December 9,1944 an earthquake centered in the Nagoya region heavily damaged several factories and disrupted the transportation infrastructure. The results were that the total production was less than ten. Prototypes of the A7M1 and A7M2 were completed and a number of production airframes were started. (numbers vary based on the reference source). The A7M3 version was on the drawing board. The Allies found only one mostly complete A7M Reppu after the surrender in the fall of 1945.

A successful version of the Reppu would have been a formidable adversary for the Allies. Armed with 4 20mm cannons and comparable structure to its counterparts, Sam would have given Japanese Navy pilots the chance to win again. In some ways, the Sam would have been similar to the FW190D in the Luftwaffe. Many German pilots felt the FW 190 Dora gave them a fighter equal to Allied fighters at the end of the war in Europe. Veteran Japanese pilots would have probably felt the same way. In reality, the overall quality of Japanese pilots had fallen so low that even a superior fighter would not have made a difference in the overall outcome. So, the Reppu/Sam is relegated to PAC ’46.

I have several kits I’m working on at the same time. I felt the need to grab a kit out of the stash and put it together OOB. I decided to do a Japanese aircraft because I haven’t done one in ages. I think the last Japanese airplane I built was a Monogram 1/48 Mitsubishi Zero back in the 20th century. With some brief research I picked the Fine Molds Mitsubishi A7M2 Reppu. It was to replace the A6M Zero but didn’t. (re:historical notes) It was given the Allied reporting name “Sam”. This was my first Fine Molds kit.

The kit is molded in a very hard gray plastic. The instructions are Japanese with clear assembly diagrams. The clear parts include a one-piece canopy, a decent looking gunsight and bullet proof panel. The decal sheet looks OK with separate white and red circles but the white portions look slightly yellowish. Could be contrast to the light blue backing paper. Tail codes for three aircraft prototypes are included. The only equipment option is a long range drop tank. Surface details are good. The engine made up well with just careful painting. The cockpit is fairly well detailed. All I added were seat belts. Wheel wells are represented well. IAS: The fuselage half part #B2 had one mold sink mark behind the cockpit on the rear section. The tires have major molding marks on the tire sides. The wing section is one piece. The fit between the fuselage and the tailing edge of the wing section part #A3 was very poor. There was a gap that measured in at an 1/8 inch! I filled this gap with stretched sprue. There was a mold sink mark right on top of the engine cowling, part #C3, above the upper air intake. Once again I start a kit hoping to just go right thru and end up with months of work to get it to look correct. I’ve now spent several weeks sanding to make the wings and fuselage look like they belong to the same airframe. Note: Several references with three view drawings of the A7M show the horizontal tail surfaces to be rounded like the Zero and several show the surfaces squared off. This kit has squared off tail surfaces. There was only a little gap work to do on the horizontal tail surfaces. IAS: The radio mast part #B21 is supposed to mount on the rear decking of the cockpit and pass thru a hole in the canopy. The mast can not be mounted at the correct angle if the locating tab is used. I removed it. Unfortunately, this makes the mast very difficult to anchor. Every slight touch knocked the mast out of position.

The Reppu is painted following the same style as the late war Zero. I used Testors Model Master Imperial Japanese Army/Navy Green #2116 on upper surfaces and Imperial Navy Sky Gray #2117 on the lower. I painted the entire cowling Testors Flat Black #1746 in the Zero style. The prop is Flat Black. The spinner is Humbrol Chestnut Brown # MC22 The greenish gray cockpit interior is actually Testors RLM 02 #2092 which matched to the D.Thorpe IJN color chart for interior colors. Landing gear pieces were painted with Floquil Gun Metal # F110108, Testors Chrome Sliver #1790 and Aluminum #1181.The wheel well and gear doors and tailhook slot are painted Chrome Silver with a thinned wash of Testors Sapphire #1539 over sprayed. The ID stripe on the wing leading edge is Model Master Deep Yellow #2118. I used Humbrol Crimson Red #20 and Midnight Blue #15 for formation lights. The kit decal sheet does not offer stencil details. I decided to display the Sam as being delivered to a Sentai before unit markings were applied. Being a late war delivery, I used the kit Hinomaru markings without the white surround, late war Zero 52 style. The decals were applied using the Micro Sol/Set system. The color density is good. The upper and lower wing decals lay down perfectly, but both fuselage decals dried with slight wrinkles. I shaved the wrinkles down with an #11 X-Acto blade and then put a very light coat of Future over the decals. The whole airframe was then worked over with Testors #1160 Dullcoat. Exhaust effects were created with Floquil #F110119 Graphite and #F110017 Weathered Black.

A simple base was created using a piece of styrofoam and actual beach sand. The sand was anchored with a 50/50 mix of water and Elmer’s glue shot thru an airbrush. The sand was colored with light washes of Testors #1745 Insignia White and Floquil #N/A Concrete.

Overall, I was greatly disappointed by the poor fit of the major airframe sections and the unfortunate location of molding dimples. Except for a few weeks of sanding, the kit falls together. Normally I weather the finish at the end of the painting process by dry-brushing. This time I experimented with a technique I’ve seen several other modelers use. I sprayed the leading edges of the airframe and several of the access panels with Aluminum # 1181 and sealed them with Future.Then I sprayed the basic colors on. Before I Future for decals I will rub some areas and chip others to allow the silver to show through. Hopefully this will give a better scale weathering effect.

This kit was displayed at the Hobby Emporium (Tyngsboro, MA) Model Expo on July 16, 2011 to demonstrate the various techniques used to build this kit.

Bibliography:

Crown Series Zero Fighter

Author: Robert C. Mikesh

Pub: Wings & Anchor / Zokeisha Publications

ISBN: 0-517-54260-9

Japanese Naval Air Force Camouflage and Markings World War II

Author: Donald W.Thorpe

Pub: Aero Publishers

ISBN: 0-8168-6583-6

Air International Vol.33 Issue 3 Fighters A to Z

Author: Air International Staff

ISSN: 0306-5634