Aichi B7A Ryusei 流星 “Grace” Build in 1/72 Scale Part I

This is the old Fujimi B7A1 kit from 1984, several boxings have been released but the same tool was used for each.  Some boxings contained a small additional sprue with a torpedo and defensive gun for the rear position.  This one is meant to be in the overall orange-yellow scheme of the second (of nine) prototype aircraft and is molded in orange.  I picked it up at a model show a while ago, it was complete but had been started.  The wings and cockpit components had been glued together but I was able to separate them before beginning construction.
The cockpit is very basic and quite crude.  Even though I intend to keep the canopy closed the transparency is large and features flat panels so much of the interior will be visible on the finished model.  I decided to install the basic equipment shapes shown in the excellent interior diagrams in Mikesh’s Monogram Guide.  This really doesn’t take that long once you get going.
One thing that was a bit tricky was the decking under the rear gun position.  It finally struck me that the shape of one of my drafting pencils was pretty close but with the curve reversed.  I taped the pencil to the bench and plunge molded the shape into some scrap plastic.  This was cut out and installed into the back part of the cockpit.
Here is the cockpit fit into the fuselage and base coated with black.  I make sure coverage is complete with this layer to represent shadows, and then spray thin layers of progressively lighter greens to pick up highlights.  The end result creates the visual effect of accentuating light and contrast, giving the cockpit depth.
Here is the interior with the paint on.  The instrument panel and console faces are printed on photographic paper, as are the seat belts.  The belts are more three dimensional than PE, and easier to bend and pose for a “casual” effect.
The Homare 12 engine is a resin replacement from Engines and Things, I added the ignition wires.  It fits, and is a big improvement over the kit part.
The kit’s wheelwells were way too shallow for my tastes, so I pried the wing halves apart and ground out the shallow “roofs”.  I leave the landing gear leg attachment points in place to make life easier on future me, you can see the difference in depth by what remains.  The sidewalls are built back up using 0.005” Evergreen card.  The excess sticking out of the wing can be easily removed with the trusty Xacto knife and a sanding block. 
The wheelwells were then detailed with Evergreen strip.  The narrow sections of the wells had three curved webbing structures, these were made with a Waldron punch set.  At the trailing edge of the wings you can see I’ve begun filling the gaps in the flaps.  Fujimi has a propensity for placing the seam lines right through the middle of the aileron fabric, which they have done on this kit and several others.  The seams can be filled if care is used, but this is an avoidable problem.

Part II here:

Aichi B7A Ryusei 流星 (Shooting Star) Grace

The Aichi B7A (Allied reporting name Grace) was a large attack aircraft designed for the Imperial Japanese Navy but came too late and in too few numbers to have an impact on the Pacific War.  It was a successful design but is obscure and remains relatively unknown.

The design was intended to replace both dive bomber and torpedo bomber types currently in IJN service.  Nine prototypes were built, the first of which flew for the first time in May 1942.  Teething problems with the new 1,800 hp Homare 11 engine delayed the program.  This is the seventh prototype, finished in a scheme of overall orange-yellow to make it easier to locate in case of a forced landing.

A gull wing design was selected to provide sufficient clearance for the four-bladed propeller, a parallel to the Chance-Vought F4U Corsair design.  The Grace was much larger than the Corsair with a 47 foot (14.4 meter) wingspan.

The wings of the B7A were equipped with a hydraulic folding mechanism just outboard of the landing gear.  With the wings folded the span was reduced to 26 feet (7.9 meters).  The ailerons could both deflect downwards up to ten degrees to function as additional landing flaps.

The B7A was intended to be the primary attack aircraft on the Taiho and Shinano, but both aircraft carriers were sunk before the Grace could enter service.  The aircraft was too large to accommodate on the surviving Japanese carriers and so was obliged to operate entirely from shore bases.  The fighter component of the air wings were intended to be composed of N1K3 Shiden-Kai (George).  This is an aircraft of the Yokosuka Naval Air Group with a Type 91 torpedo, the dual horizontal tail stripes indicate a flight leader.

The B7A could carry two 250 kg (551 pound) bombs in an internal bomb bay in the dive- or level bombing role, or one 800 kg (1,764 pound) torpedo mounted externally.  Two Type 99 cannon were mounted in the wings, along with a 7.9 mm or 13 mm machine gun mounted in the rear cockpit for defense.

The Grace was fast and maneuverable, the specification required agility consistent with the famous Mitsubishi A6M Zero fighter.  Maximum speed was 367 mph (592 kph) which was quite fast for an attack aircraft of the time and on par with several fighter types.  Handling was reported to be excellent.

The only unit which was equipped solely with the B7A was the 752nd Kokutai which operated from Katori in Chiba from February 1945.  The unit was engaged in conventional attack missions and was eventually also utilized in Kamikaze attacks.

Even after the design had been finalized, Japan’s deteriorating war situation prevented production on a meaningful scale.  The Aichi plant at Funakata produced only 89 examples (including prototypes) before it was destroyed by an earthquake in May 1945.  Another 25 were completed by the 21st Naval Air Arsenal at Omura.

After the war the B7A was one of the types returned to the United States for evaluation.  One example survives today in unrestored condition at the National Air and Space Museum Storage Facility.  The survivor is one of the 25 examples produced at 21st Naval Air Arsenal at Omura.  This 752nd Kokutai aircraft is seen being wheeled out of a hanger by American personnel after the war.

1/72 Scale N1K Kyofu / Shiden Batch Build Part VII

Finished!  This turned into a “just one more thing” build and seemed to drag on, but the first seven completions for 2020 are done and I’m generally happy with how they turned out.  The big pictures on the computer highlighted a few tweaks and touch ups which are needed but they’re mostly complete.  Here’s the list of modifications and details added, some kits required more of these than others:

  • Cockpits replaced and/or detailed.
  • Instrument panels, side consoles, and seatbelts printed on photographic paper.
  • Engines replaced and/or wired.
  • Wheelwells removed, deepened, and detailed.
  • Landing gear covers replaced with card stock.
  • Landing lights made from CD case plastic.
  • Gear down indicators made from bronze rod.
  • Vacuform or plunge molded canopies.
  • Pitot tubes made with metal tube and insect pins.
  • Beading wire brake lines.
  • Wheels replaced.
  • Turned brass cannon barrels from Master.
  • Various openings and trestle ports drilled out.
  • Trim tab actuators replaced with wire.
  • Radio aerials made from Uschi elastic line.
One of the Hasegawa Shiden-Kai with several of the added details visible.  I am always really impressed with the Master gun barrels.  They are inexpensive, sturdy, and the proper thickness – an easy way to make a noticeable improvement.  Also visible are the gear down indicators, replacement landing gear covers, vacuform canopy, and a peek at the cockpit details.
The Hasegawa Kyofu floatplanes are very nice kits.  Fit of the parts was excellent and only required a small bit of sanding to eliminate seams.  The boarding ladders and beaching gear are a nice touch.  I wanted to build the prototype because of the counter-rotating propellers.  Like everybody else, the Japanese were not able to work the bugs out of this system and they reverted to a standard three-bladed propeller for the production aircraft.
This is the foundling, the MPM kit hiding along with another kit bought at the model show and forgotten.  This is a rather crude molding, but I was pleasantly surprised that it built up well with a lot of work and replacement parts.  Tail codes are from an Aviaeology sheet (try remembering how that one’s spelled!) and the Hinomaru are masked.
The best kit of the batch is Tamiya’s N1K1.  It was easy to assemble and well detailed, typical Tamiya quality.  This was the only kit which had passable wheelwells, really all I added were surface details.  For the pedantic the only two things which could be corrected are the oil cooler support should be wider and the inner section of the wheel well should be open to the spar.  The N1K1 was the first version adapted from the Kyofu into a land-based fighter.
The Aoshima Shiden are nice kits but are often overlooked.  This is the N1K1 with the redesigned wing incorporating all four Type 99 20 mm cannon internally.  The kit has shallow wheelwells but a passable cockpit.  The clear parts are a strong point and the canopy can be posed in the open position.  The gear doors do need replacing as they are thick and molded into the landing gear legs – an odd choice for such a nice kit.
The Shiden-Kai saw the wings lowered from the middle to the bottom of the fuselage and resulted in the ultimate version of the design evolution.  These two are made from the 1977 Hasegawa kit, and have the typical Hasegawa shortcomings of their time – basic cockpit, crude engine, and laughably shallow wheelwells.  They also display a shape error concerning the width of the vertical fin, Kawanishi produced both a broad- and narrow-fin N1K2, Hasegawa’s kit splits the difference and so has to be modified to properly represent either version.  Still buildable kits with a little extra effort.


So, overall a fun build but one which took longer than anticipated.  I think the next batch will be something a little more current, hopefully one which doesn’t need as many modifications!

Completed N1K models here:

Kyushu J7W1 Shinden 震電 Magnificent Lightning

A few Canard fighter aircraft were designed during the Second World War, but only the Japanese Kyushu J7W1 Shinden was ordered into production.  While a promising design, it was a case of too little, too late and only two prototypes were completed before the end of the war.

The Shinden was intended to fulfill an Imperial Japanese Navy specification for a land based interceptor to oppose the American B-29s which were ravaging Japan.  While its range was relatively short, it carried four 30 mm Type 5 cannon in the nose, a considerable armament for the time.

Power was provided by a turbocharged Mitsubishi Ha-43 eighteen cylinder radial engine which produced 2,130 hp.  The engine was mounted behind the pilot and drove a six bladed pusher propeller via an extension shaft.  Cooling air was introduced through a series of inlets along the sides of the aircraft.  The prototype experienced engine overheating while on the ground, and vibration due to the length of the shaft connecting the engine and the propeller.

The Shinden flew for the first time on 03AUG45 with CAPT Tsuruno, head of the IJN design team, at the controls.  Even before the first flight the Navy had ordered the Shinden into production, a reflection of both the design’s promise and the desperation of Japan’s military situation.

From the beginning the Shinden was intended to be adapted to jet propulsion using an Ne-130 tubojet.  This would have solved the cooling, vibration, and torque problems associated with the Ha-43 at a stroke, but the jet engine was not ready before the war ended.

One of the Shinden prototypes was brought to America after the war for evaluation, although it does not appear to have been flown.  The U.S. Navy transferred the aircraft to the Smithsonian in 1960.  The forward fuselage is currently on display at NASM Udvar-Hazy with the rest of the components held in storage.  (NASM color photographs)

Cockpit layout of the J7W1 prototype.  

Starboard side, showing the seat adjustment lever and the American-installed fire suppression system.

Port side showing the throttle.

1/72 Scale N1K Kyofu / Shiden Batch Build Part VI

The last week was spent in a little painting (Yay!) and lots of masking (Boo!).  The canopies were dipped in Future (Klear) and then masked the old-fashioned way, with little bits of Tamiya tape.  I did have one set of masks for the Kyofu, but they were the old Eduard green vinyl type which I find to be worse than useless so they were discarded.  The canopies were attached with Superglue and any gaps filled with Perfect Plastic Putty, which I can highly recommend.  The photo is at the maximum masking stage, with the undersides sprayed in Alclad Aluminum and awaiting the upper surface colors.
The color of the Kyofu prototype is debated and you can find three interpretations called out in different references.  All sources agree that the aircraft was painted – salt water would not be kind to untreated Aluminum.  Some say the finish was Aluminum dope.  Others say it was a light gray overall, this is what Hasegawa calls out in the kit instructions.  The third option is the one I favor, which is orange-yellow.  A profile in Famous Aircraft of the World 124 shows the prototype in this finish.  The orange-yellow was used by the Japanese for trainers and prototypes, if the Rex were not in this color it would be the only exception to the rule as far as I know.  I used Floquil’s Reefer Orange for this finish.  The Hinomaru are painted Testors Insignia Red using Maketar masks.
There is also some controversy surrounding the underside colors of the land-based Shiden.  Here the choices are Light Gray Green or natural Aluminum, with some saying the earliest Shiden carried the paint.  Photographs are inconclusive, and more recent references tend to lean towards the Aluminum finish.  As the Shiden-Kai was produced at several plants there is room for either to be correct, but I leaned with the general consensus on my builds and went with Aluminum undersides.  I matched the upper surface green to an Iliad Design paint chip and used Mr. Color 15 IJN Green (Nakajima), which fit the Kawanishi chip best.  Go figure.  The wing I.D. panels are Mr. Color 58 Orange Yellow.
The operational Kyofu has Mr. Color 15 uppers and Mr. Color 128 Gray Green lowers.  The beaching dolly is in Sasebo Gray but I have no clue if this is correct as I could find no mention of colors for this anywhere.  The Hasegawa instructions call out Black but the pictures look lighter to my eye.  In any case, this is the Kyofu with painted Hinomaru under a coat of Testors Glosscoat, ready for decals.  With any luck I’ll finish these off and have the completed models done for next week!

Part VII here:

1/72 Scale N1K Kyofu / Shiden Batch Build Part V

After loads of sanding the kits are finally ready for primer.  These are the Hasegawa Shiden-Kai with the modified tails.  After primer always comes … more sanding.  Things weren’t really all that bad this time, but there were minor touch ups needed here and there.  Always glad to get to the painting stage.
This is the underside of the Tamiya Shiden.  No surprise that this is the best fitting kit of the batch, and needed the least additional work to bring it up to par.  Surprisingly it did not appear to get much attention at the time of release but it is an excellent kit.
I have left the floats off the Kyofu to help with masking and painting.  These are well engineered kits and only needed a bit of fitting work at the wing / fuselage joint on the underside.
In order to show the work done in the cockpits I intend to display the models with the canopies in the open position.  The Aoshima Shiden has parts for both an open or closed canopy, the others were cut apart.  This picture shows the sliding part of a Kyofu canopy having a thin replacement made by a technique known as “plunge molding”.  This is done by heating a piece of clear PETG over a candle flame until soft and then pushing it down over the master.
I have aftermarket decals from Kopro for most of this batch, but the Hinomaru for the Kyofu and the MPM kit were sprayed on using masks from Maketar.  The yellow wing I.D. panels were also sprayed on at this time.  The masks are a good way to go, especially for markings as simple as the Japanese insignia.
While I’m working I generally listen to podcasts.  All around good guy and friend of the blog David Knights has started recording a podcast along with Mike Baskette.  They’ve managed to put out three episodes already (which is pretty impressive), give them a listen here:

Part VI here:

Nakajima G8N Renzan 連山 (Mountain Range), Allied Reporting Name “Rita”

G8N _Renzan_01
The Nakajima G8N Renzan was developed in response to an Imperial Japanese Navy requirement for a long range land-based attack bomber.  The prototype first flew on 23OCT44 and was delivered to the IJN in January 1945.

G8N _Renzan_02
The specification called for a heavy defensive armament.  Six Type 99 20 mm cannon were mounted in powered turrets located in dorsal, ventral, and tail positions, augmented with four 13 mm Type 2 machine guns mounted  two in the nose and one in each beam position.

G8N _Renzan_03
The aircraft was powered by four Homare 24 radials rated at 2,000 hp each.  These were mounted behind gear-driven cooling fans to prevent over-heating.  The engines were turbocharged, but these were problematic and the Japanese struggled to develop reliable turbochargers during the war.

G8N _Renzan_04
Four prototypes were produced but the design never entered series production due to the deteriorating war situation.  Overall flight characteristics were reported to be good.  This is the second prototype seen after the war in a hanger at Yokosuka.

G8N _Renzan_05
The prototypes were finished in an overall orange scheme which was typical for Japanese prototypes and trainers.  Cowlings were black.  Note that the yellow wing leading edge identification panels were not applied to these aircraft.  Propellers were removed to comply with U.S. directives after the surrender.

G8N _Renzan_06_Yokosuka
The starboard side shows blast damage to the rear fuselage.  The third prototype was destroyed on the ground by U.S. Navy aircraft.

G8N _Renzan_07
After the war the fourth prototype Renzan was selected to be removed to the U.S. for evaluation.  It was transported as deck cargo along with several other types aboard the escort carrier USS Bogue (CVE-9).

G8N _Renzan_08
Cockpit layout was conventional, the aircraft carried a crew of ten.  The design was modified to allow the Ohka special attack aircraft to be carried.

G8N _Renzan_09
This is not the best quality photograph, but interior pictures of the Renzan are rare.  This is the bomb bay.  Intended bomb load was two 1,000 kg bombs, 4,400 pounds total.

G8N _Renzan_10
This is the fourth prototype being reassembled in Newark, New Jersey for evaluation.

G8N _Renzan_11
Hasegawa issued a kit of the Renzan in 1968 in 1/72 scale and has reboxed it several times.  While not a bad kit for its time, it would need a lot of work to bring up to current standards.  It’s best described as a “rivet monster” as that was the surface detailing standard of the time, but surprisingly an aftermarket set of resin exhausts have recently been released by Quickboost.

G8N _Renzan_12
After evaluation, the aircraft brought to the United States was scrapped.  None of the Renzan survive today.

1/72 Scale N1K Kyofu / Shiden Batch Build Part IV

It feels like this build has been dragging on, but with the holidays over I’ve been able to get some more time at the bench.  Seams have been sanded smooth on all the kits which is a big hurtle for me as I find sanding boring.  The monotony was broken with the assembly of the beaching gear for the floatplanes which turned out nicely.
Time to start adding some details.  The wingtip navigation lights have been cut out and replaced with a small rectangle of clear plastic from a CD case.  This is superglued in place, then filed down to the proper contour.  The Shiden had another clear light cover at the base of the rudder so three are needed for each model.
Here’s what it looks like after sanding and finishing with an 8000 grit polishing cloth.  These will be masked before painting (hopefully I won’t forget) and then coated with Future at the end of construction.
Master turned brass gun barrels are a big improvement over the molded parts and much harder to break off.  These are the Tamiya guns for the underwing gondolas compared with Master barrels and round stock sized to match the FAOW drawings.
The Aoshima Shiden has the wheelwell covers molded onto the gear legs, and these have a sprue attachment and mold seam running right down the middle.  Rather than cleaning this up, I found it easier and more accurate to saw off the covers and replace them with stock.
I’m doing something different with this batch and attaching many of the detail parts before painting.  Attaching everything now will ensure a good bond and hopefully prevent any glue from marring the finish.  The down side is I’ll have to handle things very carefully from here on out.  This is the Tamiya kit.
This is the MPM Shiden showing the extent of the replacement of the soft, flash-ridden kit details.  The gondolas are castings of the Tamiya parts, the rest are fabricated from Evergreen stock.  The sway braces for the bomb racks are made from 0.0125 inch (0.3 mm) bronze rod.  The kit drop tank was a mess so this model will be finished without one.
The top of the MPM kit.  The cockpit decking and headrest are Evergreen replacing an unusable part from the kit.  The rods sticking out from the wings are “gear down” indicators.  These were mechanically linked to the gear legs, when the gear was lowered and locked they would protrude from the upper wing surface giving the pilot a visual confirmation that his gear was down.  These were common on many aircraft types and can often be seen if you look closely at photographs.
The underside of one of the Hasegawa Shiden Kai with everything in place.  The landing gear covers were replaced on each of the kits with the exception of Tamiya’s which looked the part.  There are a few more details to attend to, but hopefully I can shoot some primer and get to painting by next week!

Part V here:

Axis Midget Submarines Book Review


Axis Midget Submarines: 1939-45 New Vanguard 212

By Jamie Prenatt and Mark Stille, illustrated by Paul Wright

Paperback, 48 pages

Published by Osprey Publishing June 2014

Language: English

ISBN-10: 1472801229

ISBN-13: 978-1472801227

Dimensions: 7.3 x 0.2 x 9.8 inches

This is a typical Osprey New Vanguard volume and follows their well-established format.  The authors have organized the presentation by nationality, with the major Axis powers of Italy, Germany, and Japan each having their own sections.  The sections detail the developmental history of the various types of small submersibles employed by each nation and then gives a brief overview of their operations.

The various designs had inherent limitations imposed by their size which influenced the scope and effectiveness of their employment and chances for success.  Several types are marginal vessels at best, and while not strictly suicide missions, the odds are decidedly against the safe return of the crews.

Italian submersibles mainly fall into a category which we would call “Swimmer Delivery Vehicles” today.  The SLC delivered two divers to an enemy harbor, where the crew would attach large mines and then hopefully evade capture.  Their most notable success was the mining of the British battleship HMS Valiant at Alexandria.  The Italians also employed CB-type mini subs in support of German Operations against the Russians at Sevastopol.

The Germans came late to the midget submarine game but developed several types in anticipation of the Allied invasion of Europe.  The vast majority of these designs were ineffective, being much more a threat to their own crews than to Allied shipping.  The one successful design was the Type XXVII Seehund which accounted for 120,000 tons of shipping.  Like most German wonder weapons, this was another case of too little too late.

The Japanese were arguably the most successful of midget submarine operators, most famously employing five “Target A” as part of the Pearl Harbor Raid.  The authors’ view is that these submarines achieved no results at Pearl Harbor, although Japanese sources maintain one did hit the USS Oklahoma.  Target A submarines were also used at Sydney Harbor, the Aleutians, the Guadalcanal campaign, the Philippines, Okinawa, and Diego Suarez.  The latter is the least well known operation but is arguably the most successful, the battleship HMS Ramillies being damaged and the tanker British Loyalty being sunk on 30MAY42.

The space constraints of this series limits the narrative to only a brief discussion of each nation’s midget submarine programs but the space is used well.  Three very interesting books could easily be written by simply expanding upon this information and covering the operations in detail.  This book provides a quick introduction to the topic which leaves the reader wanting more.  Recommended.