The Mindset Behind the Development Process of the Imperial Japanese Army Fighter Aircraft: Part #1 "Hayabusa" & "Shoki"

Let's begin with what Francillon has to say about the "Hayabusa":

"Design work on the Hayabusa began in December 1937 when the Army, giving up their long-standing policy of awarding competitive contracts to Japanese manufacturers, instructed Nakajima Hikoki K.K. to design a single-seat fighter to supersede the Army Type 97 Fighter (Nakajima Ki-27)."

And about the "Shoki":

"Shortly after instructing Nakajima to proceed with the design of the Ki-43, the Koku Hombu gave them their specification for an interceptor fighter. In a pronounced departure from previous Japanese standards, speed and climb rate were emphasized at the expense of manoeuvrability. The Ki-44, as the project became known,..."

The English Wikipedia entries heavily rely on Francillon and basically repeat the above.

But let's see what the Japanese Wikipedia has to say about the mindset behind the development of these two fighters and the "Army Aviation Weapons Research Policies":

The Nakajima-built Type 97 Fighter (Ki-27 "Nate"), officially adopted in December 1937, featured an ambitious design—the Army's first all-metal, low-wing monoplane—despite its conservative fixed landing gear. It was an excellent dogfighter with superior climb rates and maneuverability. However, by the time the Type 97 appeared, the Bf 109 (Germany) and Spitfire (UK)—both featuring retractable landing gear—had already emerged in Europe, prompting the Army to explore the development of new fighters.

In the "Army Aviation Weapons Research Policy" for the 1937 fiscal year—formulated by the Army Aviation Headquarters while the Ki-27 was under development—single-seat fighters were defined in two categories: "machine-gun equipped" and "autocannon equipped." The aircraft developed in accordance with these specifications were the Ki-43 (for the former category) and the Ki-44 (for the latter). 

The "Army Aviation Weapons Research Policy" for the 1938 fiscal year further refined these categories into "Light Single-Seat Fighter" and "Heavy Single-Seat Fighter" and added a third: the long-range two-seat fighter based on the concept of a twin-engine multi-role fighter. 

Based on this, instructions for the research and development of both "light" and "heavy" fighters were issued to Nakajima, Kawasaki, and Mitsubishi; Nakajima’s responses were the Ki-43 (Type 1 Fighter "Hayabusa") for the light fighter category and the Ki-44 (Type 2 Fighter "Shoki") for the heavy fighter category (Chief Engineer Koyama Yasushi led the design teams for both). Aoki Kunio, an engineer on the Ki-43 design team, stated that while the "Hayabusa" was also intended to be a heavy fighter (modeled after the Bf 109), the team's lack of experience in heavy fighter development resulted in it becoming a light fighter instead. 

Although proponents of light fighters argued that the Ki-44 was unnecessary, the development process—which had previously stalled—was revitalized following lessons learned during the Nomonhan Incident in 1939. Combat experience showed that Soviet Red Air Force fighters were effectively employing "hit-and-run" tactics, creating a recognized need for a cutting-edge fighter capable of executing such attacks and pursuing high-speed aircraft like the I-16.

According to FAOW #65 the attached photo features:

"the third (aircraft number 4303) of the three Nakajima Ki-43 "Hayabusa" (Oscar) prototypes built in 1939. Its shape differs considerably from that seen in full-scale models and drawings due to modifications and upgrades made to the prototype aircraft from late autumn of 1940 to early 1941. The rear fuselage, canopy, and the position of the slightly longer antenna mast, among other things, became almost identical to the production model. However, the flaps were still of the split type, and the armament covers and muzzles remained for 7.7mm guns. The reason why only two fuselage stripes were painted on the third prototype is unknown."

But note the very unusual yellow (?) band starting from the canopy side and continuing on the wing.

Unlike the Ki-43, the Ki-44 faced delays; the Army and the manufacturers lacked experience with heavy fighters, making it difficult even to finalize basic specifications, and consequently, its development schedule was prioritized below that of the Ki-43. Before the Army had even issued its formal performance requirements, Nakajima proceeded with development by setting the Bf 109 as a benchmark. According to Aoki, the "Shoki" was intended as an insurance measure in case the "Hayabusa" was not adopted, and it possessed strong characteristics of an experimental aircraft. This nature allowed Nakajima to incorporate new technologies and concepts into the "Shoki".

Drawing on lessons from the Nomonhan Incident and research into Western aircraft trends, the Army recognized the importance of protective measures. Consequently, the Ki-44 was equipped not only with fire-resistant fuel tanks (self-sealing tanks featuring a multi-layered rubber casing to prevent leakage and ignition upon impact—a feature the Army had previously ordered Nakajima to install starting with the Ki-43 prototype) but also, for the first time on a Japanese fighter, a 13 mm thick armor plate behind the pilot's seat for protection. This armor plating covered the headrest and backrest areas, with a total weight of 60 kg.

At the initial development stage, the armament requirements called for one fixed cannon and two fixed machine guns. The configuration consisted of two 12.7 mm cannons (Ho-103 Type 1 Fixed 12.7 mm Cannon)—utilizing newly developed high-explosive ammunition—mounted in the wings, and two conventional 7.7 mm machine guns (Type 89 Fixed Machine Gun) in the nose. It also featured a retractable tailwheel, a rarity among Army aircraft.

The prototype made its maiden flight on June 4, 1940. However, due to insufficient engine performance and numerous technical issues, various improvements were implemented. However, compared to conventional fighters, it was inferior in turning performance; the large-diameter engine resulted in poor forward visibility; and its high stall speed necessitated high-speed landings. On the other hand, it demonstrated excellent accuracy in firing tests, and in mock dogfights held in the summer of 1941 against a Bf 109 E-7 imported from Germany, the Ki-44's overall performance surpassed that of the Bf 109 E. Consequently, it was deemed a valuable asset capable of countering the latest Western fighters, though it remained unpopular among many veteran pilots who favored agile dogfighting capabilities.

According to FAOW #16 the attached photo features:

"the first prototype Nakajima Ki-44 "Shoki", serial number 4401, completed in August 1940. The photograph was taken in December of the same year at Tachikawa Airfield during operational testing, and the tail section of what appears to be the second prototype is visible on the far right of the frame. Due to the lack of a suitable high-powered engine, it was equipped with the Nakajima "Ha-41" (1,250 hp), a large-diameter bomber engine, resulting in an extremely wide nose. Only the first prototype differs from the second and subsequent prototypes in its cowling shape, cowl flaps, the air outlet immediately behind them, and exhaust pipes. The paint scheme is the Army's basic gray-green, and the stripe on the rear of the fuselage indicates that it is the first prototype."

In the "Army Aviation Weapons Research Policy" for the 1940 fiscal year, the "heavy" versus "light" fighter distinctions were explicitly codified. The "Heavy Fighter" evolved into the primary, all-purpose fighter—featuring high speed, heavy armament, superior range, and robust armor protection—capable of engaging both enemy fighters and bombers. Conversely, the "Light Fighter" was relegated to the role of an auxiliary fighter, prioritizing dogfighting but accepting compromises in performance and equipment to focus primarily on combat against other fighters. 

In December 1941, Nakajima received a preliminary directive for the Ki-84 as an advanced iteration of the "Heavy Fighter"; this aircraft was later officially adopted as the Type 4 Fighter "Hayate". This aircraft emerged as the definitive, all-purpose fighter, excelling in speed, armament, armor protection, range, maneuverability, handling, and ease of production. 

In the subsequent "Army Aviation Weapons Research Policy" for the 1943 fiscal year, the distinction between "light fighters" and "heavy fighters" was abolished; the "light fighter"—already an obsolete compromise—was absorbed into the "heavy fighter" category and redesignated as the "short-range fighter" (or "Kinsen"). That same policy introduced additional categories: "long-range fighter" ("Ensen"), "high-altitude fighter" ("Kohsen"), and "night fighter" ("Yasen").

P.S. This piece should teach a lesson to those who rely only on English sources, especially antiquated ones, and completely ignore the work of Japanese aviation historians!

Nakajima Ki-44 "Shoki", 87 Sentai

A quite interesting photo from the Dutch archives has been circulating online lately, showcasing a Nakajima Ki-44 "Shoki" belonging to the 87 Sentai.

The aircraft had originally suffered a forced landing with the propeller blades bent and was found by Allied forces at the end of the war. The tail features the unit's marking, most probably in red, indicating that it belonged to the 2nd Chutai of the unit. Note that it has a white border. The individual aircraft number "72" is also applied on the bottom of the tail. Note also the iff stripe following the shape of the wind leading edge. The spinner does not seem to be the same color as the unit marking, and the aircraft doesn't seem to have any anti-glare panel; if it does, it's very faint and could have been overpainted with the top camouflage. Last but not least, note that the fuselage hinomaru has a white border, but the wing hinomaru doesn't. Some online commentators mentioned that the aircraft was flown by "Lt. Hideaki Inayama" ; nevertheless...

...Nagao-san of Lifelike Decals, has included a decal set for Inayama's aircraft in the "Nakajima Ki-44 Part 1", 48-036 set, with plenty of information. Since Inayama's plane has been, I guess, traditionally(?) been identified as carrying the number "25" and a blue diagonal band, we can safely conclude that the "Shoki" in the previous photo was not flown by Inayama but by a different pilot in the unit.

Here's another photo of the Nakajima Ki-44-II "Shoki" of the 87 Sentai seen in the top photo, taken at a later date. It had had some panels removed, perhaps by trophy hunters, the rear part of the canopy is missing and the fabric-covered rudder has deteriorated.

There are more 87 Sentai Nakajima Ki-44-II "Shoki" photos online. This one is even more interesting as it has wing hinomaru with white bands and the fuselage hinomaru surrounded by a white box! The tail marking could also be in red indicating a 2nd Chutai or in yellow showing that it belonged to the 3rd Chutai. I'm leaning towards a red, 2nd Chutai aircraft since it seems to have a white border (if it were yellow, it wouldn't need a white border). The number on the tail is probably "85" but I'm sure there will be some who disagree. In any case, we can see two details that need correcting with the Lifelike illustration of the Inayama aircraft. First, the red unit tail marking needs a white border and second, the "25" should have been repeated on the bottom of the rudder.

As for the overall color of the "Shoki" in the photo, it's anyone's guess. Perhaps brown?

A Tachikawa Ki-36 "Ida" is also in the foreground and a Mitsubishi Ki-21 "Sally" behind the "Shoki".

One more photo of a 87 Sentai Nakajima Ki-44-II "Shoki" I spotted online. This one is missing its tail number. It seems that some aircraft of the unit had their tail numbers applied a bit spaciously with half the number on the rudder and half on the tail, while other numbers were more tightly spaced, applied only on the rudder. This "Shoki" has an unusual white box surround on the fuselage hinomaru as well and, this time, it definitely belongs to the 2nd Chutai, as indicated by the unit marking in red.

Here's a brief history of the unit.

The 87 Sentai was organized on March 1, 1941, in Harbin, Manchuria (present-day Northeast China). It remained stationed in the area after the outbreak of the Pacific War, continuing training in preparation for operations against the Soviet Union.

From late 1942 to early 1943, the squadron underwent reorganisation to the Nakajima Ki-44 "Shoki" Model 2. Half were the Ki-44-II Hei equipped with two 40mm cannons.

In July, the sentai transferred to Kashiwa, Chiba Prefecture, and was soon ordered to provide air defence for the Palembang Oil Refinery.

Enjoying a period of calm and ample fuel supplies, the sentai continued its training. However, in May 1944, it was temporarily redeployed to Burma to participated in the Imphal Operation.

During engagements with P-51s and other aircraft, the unit lost a quarter of its operational aircraft and suffered six fatalities. 

Returning to Palembang, the 87 again worked to rebuild its strength during a period of relative calm and by the end of August possessed 52 aircraft. Whilst other units were successively committed to the battle in the Philippines that autumn of 1944, the 87 remained in Palembang, defending the oil refinery.

The situation finally seemed to change in January 1940, when air raids by carrier-based aircraft from a British fleet departing Ceylon occurred. The 87 Sentai engaged in aerial combat against over a hundred Avengers, Hellcats, Corsairs, and Supermarine Seafire launched from four British carriers.

The British carrier-based aircraft, bravely penetrating the air defences reinforced by barrage balloons and anti-aircraft guns,

repeatedly bombed the oil refinery, inflicting heavy damage. The sentai intercepted with full force and cooperating with anti-aircraft artillery units, claimed to have shot down 50 aircraft (British records indicate 41 aircraft lost).

Nakajima Ki-44 "Shoki" In Action, 47 Sentai - video

 A short video from the NHK collection, dated January 18, 1945, features Nakajima Ki-44 "Shoki" fighters from the 47 Sentai taking off.

Check here for more.

Japanese Airfields, Equipment & more #28 - revised

Vehicles - Starter trucks
Toyota GB. Standard equipment for fighter aircraft units was to have one starter truck per plane while for reconnaissance and bomber units the ratio was one starter truck per three planes. 
Unfortunately, there is almost nothing in Japanese sources about these vehicles, regarding type, production or any other data. Feel free to contribute.

Japanese Airfields, Equipment & more #22 - revised

Various activities at the airfield (IJAAF version). 

Kawasaki Ki-32 "Mary" light bombers are getting a check-over before the next mission. Note the Type 89 Special Twin flexible machine gun operated by the rear gunner.

Changing the tire of a Mitsubishi Ki-21 Model 2 Koh "Sally".

A last engine check of a Kawasaki Ki-48 "Lilly" and a Mitsubishi Ki-51 "Sonia" belonging to the IJAAF school at Gifu.

The Gifu Army Flying School was organised in August 1940 at Kakamigahara, Gifu Prefecture. It was disbanded in March 1942. A year later, the Gifu Rikugun Koku Seibi Gakko (Army Air Maintenance School) was organised based at Kakamigahara with three kyoiku-tai (training units).

The video from the NHK collection is dated March 1, 1944.

Changing the propeller of a Mitsubishi Ki-21 Model 2 Koh "Sally". Note the unpainted front with the red stripes and the black rear.

Changing the whole engine of a Mitsubishi Ki-21 Model 2 Koh "Sally". Note the crane mentioned in a previous post and the efforts of the crew to lift the tail to adjust the plane with the new engine.

Bringing water or tea to a newly arrived pilot with his Nakajima Ki-44 "Shoki".

Japanese Airfields, Equipment & more #11 - revised

Dining

IJNAF & IJAAF ground crews and pilots on standby often dined out at the airfield, so it wouldn't be unusual to find them sitting under the shade of an aircraft wing having a meal.

Ground crew members enjoying their food near their Mitsubishi A5M "Claude" fighters. Note the various food containers.

Pilots have just had a meal and are relaxing enjoying a cigarette. Note the buckets mentioned in a previous post and the various different chairs.

Similarly, in this video, these 87 Sentai pilots are having a meal next to their Nakajima Ki-44 "Shoki" fighters, ready for takeoff.

IJAAF & IJNAF wrecked aircraft - Clark Field, Philippines Pt.2

We will continue this series based on the two recently found ebay photos, with two Nakajima Ki-44 "Shoki" fighters.

This is the first time I have seen a photo of the aircraft in the front with the rudder missing.

They are within the red circle of the panoramic photo.

The aircraft behind the rudderless "Shoki" is this one. 

It has a hiragana "も" (mo) on its tail and various publications add that its serial number is #2143.

I think the hiragana "mo" is barely visible on the tail of the aircraft in the photo above. Based on the complete lack of damage the aircraft in both photos have, I'd say that this photo shows the same "mo" aircraft from the port side. It's a rather rare occasion when we can see both sides of a Japanese aircraft. (both photos: NARA)

In this video still, we can see the same "Shoki" but note and remember the fuselage hinomaru without a white surround.

Several other "Shoki" fighters were also present at Clark Field in the area where the TAIU set shop. Here's a different Ki-44, also with a borderless hinomaru.

In this color photo found in Bob Mikesh's "Japanese Aircraft Interiors", I believe we can see the "Shoki" in the previous still, with a yellow hiragana "さ" (sa) on the tail, squeezed between two Kawasaki Ki-45 "Toryu". 

I'm sure you're surprised with the blue-painted fuselage hinomaru, right? According to Mikesh-san:

"Since the field was occupied before the fighting on Luzon had ended, the red hinomarus of the Japanese were painted blue, so that when spotted from the air by Allied fighter pilots, they would not be mistakenly strafed by Allied aircraft."

Another explanation was that the hinomaru were painted blue to repel souvenir hunters and I would add that the deleted tail numbers on the 19 Sentai "Hien" we saw in previous posts, was something that was done for the same purpose.

Based on this photo, we can safely conclude: first that that's what happened at some time to the "mo" "Shoki" as well, therefore the borderless hinomaru, and second that it had similarly brown top camouflage, not green as mentioned in various publications and shown in color artwork.

I don't think I've ever seen any Japanese models with blue hinomaru. Leave a comment if you have.

I can't decide if this photo, from here, shows the "mo" or the "sa" Ki-44 but all the publications that feature this photo say "mo". At the same time they are unaware of the "sa" color photo, so...

The photo source mentions in the caption that this particular "Shoki" belonged to the 22nd Sentai. 

This is only mentioned in the "Emblems" book by P. Scott. 

I do not know what the source of this claim is. All Japanese publications that include the "mo" "Shoki" admit that they have no idea of the unit this particular aircraft belonged to.

In my opinion, the "mo" and "sa" hiragana on the tails, indicate that these were replacement aircraft that did not yet belong to any particular sentai, and Japanese sources (FAOW, Model Art etc) agree with that. "mo" and "sa" are numbers "33" and "45" respectively in the iroha numbering system, which would be too high for aircraft assigned to units but not for replacement aircraft brought to the Philippines from a depot.

Back to P. Scott's photo caption, the 22nd Sentai is mentioned in all Japanese publications as a unit exclusively equipped with Nakajima Ki-84 "Hayate", no other aircraft type is mentioned. Peter mentions the "red leading edge to the fin, the unit marking". It's a rather confusing statement and honestly, I can't see any "red leading edge", the tail looks evenly painted to me with one color. He also mentions the top "green finish" and agrees with R. Bueschel in that the "mo" indicates the pilot; I disagree with both statements. Perhaps Peter has seen a color photo of this aircraft and therefore can describe the top camo as green, the red edge barely visible under the green and the white "mo". Unfortunately, I'm not aware of any such color photo.

These were not the only Ki-44s found at Clark Field and brought to the TAIU area. The aircraft in the photo is not seen in the panoramic photo and belonged to the 246 Sentai.

The unit was organized on October 10, 1942, came under the 18th Hikodan, was based at Kakogawa airfield, Hyogo Prefecture, and was charged with the air defense of the Hanshin area (Osaka, Kobe). Initially, it was equipped with Nakajima Ki-27 "Nate" fighters organized in three chutai, one of which was originally the 2nd Chutai of the 13th Sentai.

In July 1944, the unit relocated to the Akeno Fighter School and exchanged their "Nates" with "Shoki" fighters. After brief and largely unsuccessful assignments to Taiwan and Kyushu, the unit was based in Itami airfield, also in Hyogo Prefecture, around August 1944. At that time the 246 Sentai had 56 Ki-44s in its strength.

Two months later, the unit relocated to Taiwan assigned to air defense duties without success.

On November 8, 1944, 20 "Shoki" of the unit advanced to Clark Field.

On December 13, a group of enemy ships had been spotted heading for Mindoro Island and orders were given for an attack to be organized. The 246 Sentai was to escort the "Kyoko-tai" suicide attack unit, equipped with Kawasaki Ki-48 "Lilly" bombers. In reality, it was a one-way mission since it was at the very edge of the Ki-44 range. Thirteen aircraft were ready but just before takeoff, new orders arrived. The unit was to relocate first to Silai Airfield at Negros Island to refuel, then meet the tokko unit. But while the "Shoki" were getting refueled there, they came under attack by six P-38s. Four Ki-44s took off immediately but the one flown by Sgt Maj Kawamoto was shot down at an altitude of only 10 meters.

The next day, ten "Shoki" of the unit were patrolling the area around Bacolod airfield, again in Negros Island, when they were suddenly jumped by no less than 30 enemy fighters. Since the Japanese fighters were at the end of their fuel supply and at a disadvantageous position, the commander of the unit, Maj Ishikawa, ordered everybody to do belly landings. All the pilots were unharmed but the planes were heavily damaged.

After that, the supply of replacement aircraft was erratic and the unit was ordered to return to Japan's mainland. In April 1945, the unit changed to Ki-84s and Ki-46-IIIs.

The same "Shoki" featured in the previous photo, revealing the plane's individual number "338" on the wheel cover. It's a well-known aircraft and the subject of numerous kits and decal sets. (photos from here)

The same "338" "Shoki" from a video still. In the background of the video we can see a Kokusai Ku-8-II glider and a "Hien" squeezed between them.

Several derelict 246 Sentai Ki-44s fighters were also gathered in the TAIU area.

In the photo from the Jeff Ethell collection, we can also barely make out the aircraft with blue hinomaru in the background on the right.

Nakajima Ki-44 "Shoki" free flight model by Doug Beardsworth

I wanted to share some photos of my "Shoki", which will be making its first contest debut later this month. The model was built from a heavily edited Diels engineering laser-cut kit. The "Shoki" is a very challenging Free flight subject, due to its very short nose and small wing. The short nose means that achieving the necessary balance point will mean adding a fair amount of dead-weight ballast to the nose. And then the small wing area means there are fewer square inches of lifting area to carry the all-up weight of the ship and ballast with its rubber motor. I’ve changed the construction from using 1/16” square stock to smaller 1/20” square stock for the fuselage stringers, and stabilizer and fin/ rudder construction. And the dihedral and stabilizer’s area have both been increased in order to improve lateral and pitch stability. 

To my mind, the "Shoki" appears more like an air racer rather than a dog fighter. It is essentially a big radial engine attached to a small airframe with a comparatively small wing. In my opinion, it “looks fast” and that fin and rudder extending well past the stabilizer only adds to the effect. And from what I’ve read, it was employed in combat in the manner of a fast, swooping and diving attacking  airplane. 

The ship is covered with Esaki Japanese tissue, and the translucent silver color was sprayed on with multiple, highly thinned coats of nitrate dope with some silver enamel added. All of the markings are cut from colored tissue or hand painted.

I have not created a spinner for this bird as yet. That will be completed once I find the correct propeller diameter and pitch that gives the best flights. So the prop is a bit provisional until I get the flight qualities dialed in. 

- Doug Beardsworth -

Nakajima Ki-44 "Shoki" - 87th Sentai - video

Yet another video from the NHK collection. The date of this one is July 27, 1944 and features Nakajima Ki-44 "Shoki" of the 87th Sentai.

The narrator says:

"The day starts and ends with combat at the air base in the India-Burma border front. The pilot enjoys a modest and quick meal at the shadow of his beloved plane, during the short time between combat. There are no words to describe the hardship of the wild eagles flying in the areas where the enemy aircraft run wild. When the order to take off is given, the immediately respond and look for the enemy. Now in the India-Burma area it's the height of the rainy season and our fierce fight is becoming even more harder. On July 7 our Burma based air units attacked the enemy airfield of Myitkyina in North Burma. 23 P-40s, 16 transporters, a total of 39 enemy aircraft were destroyed.

When one unit returns from combat, immediately another unit is taking off and yet the faces of our courageous pilots are bright. Following fierce combat the wild eagle is talking dispassionately about his aerial encounter."    

 

 

 

The 87th Sentai relocated from Sumatra's Gelumbang airfield, 50km from Palembang, to Meiktila in Burma to support the Operation U-go, the attack against Manipur in India, on May 8, 1944. The unit suffered heavy casualties with six dead and 3/4 of their operational aircraft and returned to Sumatra on May 27 to refit and recuperate. So this video was probably shot either during the time in Burma or in Sumatra. Note the monkey!

Nakajima Ki-44 "Shoki"

Two Army Type 2 Single-seat Fighters or Nakajima Ki-44 "Shoki" (Tojo) of the Rikugun Koku Seibi Gakko (Army Maintenance School) in Tokorozawa.

The aircraft in the foreground has all the surface panels of the port side removed to help with maintenance tutoring and lacks the starboard wing.

The aircraft in the background is in a more complete state. But note that both aircraft lack radio antennas. The typical tail marking of the Maintenance School is a horizontal bar with a hiragana above it. Akimoto-sensei states that the bar and the hiragana are black and indeed this is how it looks in many photos. Nevertheless there is also a number of photos where the band looks lighter than the hiragana.

Examples, in MA#329 (1989), p.61 middle, the hiragana "き" (KI) looks darker than the bar on the tail of the Ki-43 "Hayabusa" although in MA#395 (1992), p.33 top profile, illustrator Nohara Shigeru chooses to depict both as black.

Same in the photo on p.65 of Koku Fan Illustrated#80. Kawasaki Ki-61 "Hien" with hiragana "I" on the tail. And again on p.68, a Mitsubishi Ki-30 "Ann" with a brighter bar than the hiragana "HA". 

In the Schiffer publication (1970) on p.30, top photo, "Shoki"  with dark "KO" on the tail seems again to have a brighter bar. Nohara decided to depict it with a red bar in the latest Model Art #779, Profile#5 (2009) p.110 although he is unsure about the white bands around the hinomaru. 

That is exactly why color photos are so important.

Nakajima Ki-44 "Shoki"

A line-up of Nakajima Ki-44-I "Shoki" belonging to the Akeno School. The aircraft in the foreground is also featured on p. 27 of FAOW#16 and it had the number 59 painted on the wheel cover.