Thursday, March 26, 2015

202/3 Kokutai

Formed on 10 April 1941, the 3 Kokutai was originally a mix of bomber and fighters, but soon became all fighters. Roughly equivalent to a U.S. fighter Group, in top form the unit had about 45 planes. Pilots of the Imperial Japanese Navy at that time were among the world's best, only the cream of the crop accepted from flying schools, the "newest" of who had 1000 flying hours. With its "sister" unit, Tainan Kokutai, these outfits were entirely land-based.

Along with the Tainan Air Group, the 3rd Air Group was among the most distinguished naval fighter units of the entire Pacific War. The group survived the war as perhaps the sole fighter unit that was always victorious, from the beginning of the war in the Philippines, through the air battles over the Dutch East Indies, and on into the attack on Darwin (Australia).

The 202/3 Kokutai was designed for land attack (bomber) operations and was attached to the 11th Air Fleet. In July of 1941, the unit advanced to Hanoi in northern French Indochina. Then in September of 1941, the 202/3 Kokutai was reorganized into the greatest fighter unit of the Imperial Japanese Navy. With hostilities between Japan and the United States imminent, the 202/3 Kokutai was expected to play a key role as a fighter unit in the battle for air control, together with the Tainan Air Group, in the southern area of operations.

In contrast to the fact that the air groups were traditionally composed of a number of different types of aircraft, the 202/3 Kokutai was constituted only of fighters, which was the first historically speaking. The squadron allowance was also increased to fifty-four (54) operational carrier fighters with eighteen (18) aircraft in reserve. Also had nine (9) land reconnaissance planes. The actual strength on the eve of the outbreak of hostilities was forty-five (45) Zero Model 21 fighters and twelve (12) Type 96 carrier fighters.

Experimentation by its dedicated leaders showed the ability of the A6M2 to use its designed-in very long range to reach the Philippine Islands, and still retain fuel for useful combat time. This saved the use of Aircraft Carriers and freed them up for other tasks. When the 3rd and Tainan Kokutais hit the Philippines from bases in Taiwan in December 1941, no missions the likes of this were seen until the advent of the Very Long Range P 51 missions in 1945. 3 Kokutai played a major part in the December 8th disaster visited upon the P40 squadrons on Luzon, catching many on landing, low on fuel. This was the unit involved in the storied tangle with Philippine A.F. P26's, the outcome being in no doubt. Quickly, opposition was subdued, and the planes moved south to newly captured bases, to attack the Dutch East Indies. With little or no early warning, it was the same story for the Allied air forces, usually caught at disadvantage by the Zero fighters, and quickly worn down.

After the conquest of the Indies, the 3rd Kokutai took part in the summer raids on Darwin, fighting the P40's of the 49th fighter group. This was the first outfit to give them trouble, honors being about even. When the invasion of Guadalcanal caused excessive losses to the units involved, 3rd Kokutai. was sent to Rabaul as reinforcement. Here they came up against the Wildcats of Joe Foss and the Marines, their tactics and teamwork causing problems for even these veterans. In a rearrangement in November, 3rd Kokutai became 202 Kokutai all Japanese Groups getting 3 digit numbers. Summer of 1943 was spent raiding Darwin again, escorting G4M bombers on long missions. This time the opponents were Spitfire Vic’s of the 1st RAAF wing. Once again they bested their enemies, the Spitfire pilots allowing themselves to be drawn into the circling combat that was the Zero's forte.

After this campaign, the 202 Kokutai was taken off operations for a time. Split up and distributed among the Central Pacific islands, gradually the units were chewed up and dispersed, disappearing into the maw of the now Allied meat-grinder. In their prime they were a top notch outfit. Many photos of these planes at their newly won bases were published in the Japanese papers, a symbol of the Empire at full flood.

Kaneyoshi "Kinsuke" Muto
Parallel to the attack on Pearl Harbor, Japanese forces attacked the Philippines. On 8 December 1941 Muto, flying with the 3rd Air Group, took part in the attacks on Iba Airfield and Clark Airfield to eliminate the immediate threat of American air power.

Muto fought further air battles in the Java Sea, in the Solomon Islands, and in New Guinea. He fought alongside Saburo- Sakai through mid-1944 on the island of Iwo Jima, surviving to be called by Sakai "the toughest fighter pilot in the Imperial Navy."

In December 1944, Muto was posted to the Japanese Home Islands to join Captain Minoru Genda in his 343rd Air Group formed to defend against Boeing B-29 Superfortress attacks. Muto has also been identified as a tactics instructor with the Yokosuka Air Group, based at Naval Air Facility Atsugi in early 1945. There, Muto flew a powerful Kawanishi N1K-J Shiden, a type codenamed "George" by the Americans. At that time, he and his wife Kiyoki were expecting a child.

On 16 February 1945, Muto and at least nine fellow airmen scrambled to meet an incoming flight of enemy fighters. The Japanese fighters were a mixed group of Mitsubishi A6M Zeros, J2M Raidens, and Kawanishi Shidens such as the one Muto flew. The latter two types were heavily armed, each carrying four 20 mm Type 99 cannon. The enemy was a group of seven U.S. Navy Grumman F6F Hellcats flying from the aircraft carrier Bennington. The Americans were well-trained but this was their first combat, and the Japanese veteran pilots shot down four without loss to themselves. Two of the Americans were killed in action and two were taken prisoner of war.

After the squadron of Japanese pilots landed at Yokosuka, newspaper reporters wrote about Muto alone, ignoring the others in his flight. Muto was said to have fought a dozen Hellcats alone, splashing four in the ocean and chasing the others away. They compared him to the legendary Samurai swordsman Miyamoto Musashi, thrusting and attacking with a fighter aircraft rather than a sword. Muto's wife read these triumphant reports while recovering from the birth of their daughter. The story of Muto flying alone was the one related by Genda to Norman Polmar, U.S. Navy historian, and to Masatake Okumiya, Jiro Horikoshi and Martin Caidin, who co-authored the book Zero!

Muto continued to serve in combat, defending Japan against American forces such as in March 1945 when aircraft from Task Force 58 flew over Shikoku. In June he was posted to the 343rd Air Group, 301st Squadron commanded by veteran ace Naoshi Kanno. A recovered and preserved Kawanishi N1K-J Shiden, possibly flown by Muto

On 24 July 1945, over the Bungo Channel, Muto and other pilots scrambled to attack a larger group of American fighters which turned out be VF-49 Hellcats, part of Task Force 38 supporting the bombing of Kure. Greatly outnumbered, Muto was shot down and never seen again. Takashi Oshibuchi, the commander of the 701st Squadron, was also among the six veteran Japanese airmen who did not return from the violent action.

Tuesday, March 3, 2015

Kawasaki Ki-48

Imperial Japanese Army aircraft confronted by the Soviet-built Tupolev SB-2 bomber, providing support for the Chinese during 1937. were somewhat shattered by its capability, its maximum speed being such that Japanese army fighter aircraft were virtually unable to intercept except when a standing patrol found itself in a position to launch a surprise attack. Almost at once the army instructed Kawasaki to begin the design of a twin-engine light bomber of even better capability, specifying a maximum speed of about 301 mph (485 km/h). Work on what was to become known as the Kawasaki Ki-48 began in January 1938, the result being a cantilever mid-wing monoplane with conventional tail unit. retractable tail wheel landing gear and, in the type's prototype form, two 950-hp (708-kW) Nakajima Ha-25 radial engines mounted in nacelles at the wing leading edges. The fuselage provided accommodation for a crew of four (the bombardier. navigator and radio-operator each doubling as gunners) and also incorporated an internal bomb bay.

Involvement in the Ki-45 programme delayed the maiden flight of the first of four Ki-48 prototypes until July 1939, but tail flutter problems then caused further delay until the introduction of modifications. Service testing resulted in unqualified approval of the type, which was ordered into production in late 1939 under the official designation Army Type 99 Twin-engined Light Bomber Model  1A (company designation Ki-48Ia). Armament of this version comprised three 7.7-mm (0.303-in) machine-guns on flexible mounts in nose, dorsal and ventral positions, plus up to 882 lb (400 kg) of bombs, this being unchanged in the improved Ki-48-Ib that followed the Ki-48-la into production, and differed by introducing minor equipment changes and detail refinements; manufacture of these two initial versions had totalled 557 when production ended in June 1942.

Ki-48s entered service in the summer of 1940, becoming operational in China during the autumn of that year. In China their speed gave the Ki-48's almost complete immunity from enemy defences, but their deployment against Allied aircraft at the beginning of the Pacific war revealed that their superior performance was illusory. Codename 'Lily' by the Allies, this initial production version had a number of deficiencies for the different kind of operations then required, and it was fortunate for the Japanese army that an improved version was already under development. This had the company designation Ki-48-II and differed from the earlier model by introducing a slightly lengthened fuselage, protected fuel tanks, armour protection for the crew, increased bombload and more powerful Nakajima Ha-U5 engines, an advanced version of the Ha-25 which incorporated a two-stage supercharger. The first of three prototypes was completed in February 1942, and in the spring of that year the type entered production as the Army Type 99 Twin-engined Light Bomber Model 2A (company designation Ki-48-IIa). It was built also as the Ki-48-IIb which, generally similar to the Ki-48-IIa, was intended for use in a dive-bombing role, and so incorporated dive brakes in the undersurface of each outer wing panel. Final production variant was the Ki-48-IIc, also basically the same as the Ki-48-IIa, but with improved armament. A total of 1,408 Ki-48-IIs of all versions was built, to bring overall production to 1,977 including prototypes.

Unfortunately for the Japanese army, when the Ki48- II was introduced into operational service its speed was still too low and its defensive armament inadequate to provide a reasonable chance of survival against Allied fighter aircraft. Attempts to increase armament merely upped the overall weight and speed suffered proportionately: it was clear by the summer of 1944 that the day of the Ki-48 had passed, and in October it was declared obsolescent. The majority ended their days in kamikaze attacks, but some examples were used as test-beds for the experimental Ne-O turbojet engine and Kawasaki's Igo-1B radio-guided bomb.


    Four prototypes with Ha-25 engines of 708 kW (950 hp), and five pre-production aircraft, with modified tail surfaces.
    Army Type 99 Twin Engine Light Bomber Model 1A; as first series model. Produced from 1940, 557 built.
    Similar to the Ia, with changes in defensive machine gun mountings.

    * Total production of Ki-48 Ia and Ib: 557 aircraft

    Three prototypes built.
    Fitted with more powerful engines, a longer fuselage, additional armour, and larger bomb load. Produced from April 1942.
    Dive bomber version, with reinforced fuselage and dive brakes.
    Improved defensive weapons. Produced from 1943.

    * Total production of Ki-48 IIa, IIb and IIc: 1,408 aircraft

Ki-48-II KAI Kamikaze (Type Tai-Atari)
    Conversion with 800 kg (1,760 lb) of explosives and two or three pilots for kamikaze missions

    * Total production of all versions: 1,977 aircraft

    Proposed version of the Ki-48. Not built.
    Single-seat special attack version. Not built.

Kawasaki Ki-48-lIb
Type: four-seat light/dive-bomber
Powerplant: two 1,150-hp (858-kW) Nakajima Ha-115 14-cylinder radial piston engines
Performance: maximum speed 314 mph (505 km/h) at 18,375 ft (5600 m); service ceiling 33,135 ft (10100 m); maximum range 1,491 miles (2400 km)
Weights: empty 10,0311b (4550 kg); maximum takeoff 14,8811b (6750 kg)
Dimensions: span 57 ft 3 in (17.45 m); length 41 ft 10 in (12.75 m); height 12 ft 5V2 in (3.80 m); wing area 430.57 sq ft (40.00 m2)
Armament: three 7.7-mm (0.303-in) machine-guns on trainable mounts in nose, dorsal and ventral positions, plus up to 1,764 lb (800 kg) of bombs
Operator: Japanese Army

Japanese Light Bombers [1] in China

Arriving at Po-yun air base, Kuangtung, Southern China, in June, 1941, newly commissioned 2nd Lt Haruo Matsuura reported to the Sentai Commander, Lt Col Hajime Sakurai, at the Headquarters of 27th Sentai. The commander assigned Haruo to 3rd Chutai (Company), company commander of which was Capt Rokuro Seto. The 27th Sentai was originally established in Manchukuo in 1937, equipped with type 97 light bomber (Ki-30), and then type 98 light bomber (Ki-32). When Haruo arrived, the Sentai was in the process of moving its base to Tien-he airfield, which was also in Kuangtung area, and their equipment had already been changed to type 99 ground assault plane (Ki-51), much better in performance compared those two predecessors.

Ki-15 (Mitsubishi) “Karigane” (“Wild Goose”): originally developed as a private venture by Mitsubishi, with the sponsorship of Asahi Shimbun, one of the leading Japanese newspapers. Under this sponsorship the second prototype, registered to the newspaper and given the name “Kamikaze” (“Divine Wind”), in August 1937 garnered great publicity with record-setting flight from Japan to London, covering 9,900 miles in 51 hours 17 minutes. When war with China broke out just three months later, the variant under development for the Army (who had come to show interest at an early stage) was ready for action, and was one of the first Japanese bombers to be employed in the “China Incident.” The Ki-15 was a single-engined, two-seat monoplane with fixed landing gear. In its original version it carried a single 551-lb bomb at a top speed of 280 mph. An improved variant (Ki-15-II) could accommodate 1,100 lbs of bombs at speeds of close to 300 mph. In any event, the Ki-15 was originally faster than any plane possessed by the Chinese, except for the Soviet-built I-16 fighter, which it roughly matched in speed. Armament was one 7.7mm machinegun flexibly-mounted in the rear of the cockpit, and sometimes an additional 7.7mm mg fixed to fire forward. The bomb load was carried externally. The aircraft was also used in China for photo reconnaissance. A total of over 400 were built for the Army, and from 1939 the Navy received 50 of their own reconnaissance variant, the C5M (capable of just over 300 mph). One of the latter made the first sighting of the PRINCE OF WALES and REPULSE off the coast of Malaya, setting in motion the chain of events leading to their eventual sinking by Japanese Navy air units. But by the time of Pearl Harbor the Army Ki-15 was well into the process of being phased out, as its replacements had started entering service at the end of 1938, and its service was mainly limited to the China theatre.

Ki-30 (Mitsubishi): the Japanese Army undertook a comprehensive modernization plan for its air units in 1935. This program produced four basic combat types, the Ki-27 fighter, the Ki-21 heavy bomber, and the Ki-30 and Ki-32 light bombers. The Ki-30 was a single-engined, two-seat monoplane, with fixed landing gear. Like most of the new Army aircraft, it was an all-metal design, with stressed-skin construction. The Ki-30 had an internal bomb bay holding three 220-lb bombs. Armament consisted of one or two 7.7mm mgs fixed to fire forward, and one 7.7mm hand-aimed from the rear of the cockpit. Top speed was just over 260 mph. Entering service at the end of 1938, and rushed almost immediately into action over China (where it played a significant part in Japanese Army air efforts over the next three years, and, benefitting from fighter escort and scant opposition, suffered acceptably low losses), the Ki-30 was still one of the Army’s chief light bombers at the time of Pearl Harbor and throughout the great opening offensive in the Pacific and southeast Asia. It was however rather rapidly withdrawn from service in mid-1942, once these grand opening moves were successfully completed. Over 700 were built.

Ki-32 (Kawasaki): developed in competition with the Mitsubishi design that became the Ki-30, the Ki-32 was rather unusual among Japanese aircraft of the period in that it used a liquid-cooled, in-line engine instead of the radials which were preferred by most of the Japanese aircraft industry at the time. Like the Ki-30, it was a two-seat, single-engine plane, with fixed landing gear. Mounting two 7.7mm machineguns, the Ki-32 achieved a top speed of just over 260 mph while carrying up to 992 lbs of bombs. Its range was even shorter than that of the Ki-30, but what caused the most problems was engine reliability. Questions about the Ki-32’s power plant caused the Army to initially select the Ki-30 in preference to the Kawasaki design, as the radial engine was generally considered less troublesome and easier to service. However, the opening of the war with China caused the Ki-32 to be ordered into production as well. As with the Ki-30, the first examples were delivered in late 1938, and the type saw considerable service in China. Like the Ki-30, it remained in front-line use through the early months of 1942, and then was withdrawn to training duties. Although it was considered something of a second-line aircraft compared to the Ki-30, it was actually built in somewhat larger numbers, with over 850 manufactured before production ended in 1941.

Ki-48 (Kawasaki): by 1940-41 the limitations of the early Japanese Army designs of single-engined light bombers had been fully realized, and new aircraft were entering production to replace them. The early light bombers all suffered from deficiencies in range, payload, and survivability against newer fighter types, and new designs focused on improving one or more of these categories. The Ki-48 was a two-engined plane with a four-man crew. Its design and production were a direct result of the introduction of the Soviet SB-2 bomber into Chinese service—the Japanese realized that the speed of this new aircraft made it (in 1938 terms) almost immune to interception, and wished to develop something similar for their own forces. When the Ki-48 first entered service in China in 1940, it seemed to meet these standards, as, with a top speed of almost 300 mph, the opposing fighters in that theatre simply could not catch it. The Ki-48 also brought an increase in range of some 500 miles over the earlier Ki-30 and Ki-32, although its bomb load remained small— normally only 660 lbs (carried internally), although 882 lbs could be carried. Defensive armament was also still somewhat deficient, with three hand-aimed 7.7mm machineguns in the glass nose and rear-facing ventral and dorsal positions. With the first aircraft delivered in the summer of 1940, more than 550 of the original version Ki-48-I were built by June 1942, when it was replaced by the improved Ki-48-II. This had better engines, increasing speed to almost 315 mph, and also featured increased armor protection for the crew positions and fuel tanks. Later versions (beginning in 1943, mainly the Ki-48-IIc) added a second nose gun in a twin mount, and a heavy 12.7mm mg replacing the 7.7mm in the glassed-in position on top of the fuselage. These changes were still not enough to stop the aircraft from being relatively easy meat to the Allied fighters it encountered by 1942-43 over the south Pacific and Burma, and the relatively light bomb load remained a further problem. By late 1942 the Ki-48 was being increasingly relegated to night missions only in an attempt to improve its ability to survive (as for instance over Guadalcanal, where single nocturnal intruders on nuisance raids were such a common feature as to gather colourful nicknames from the Marines whose sleep they regularly disturbed). Nonetheless, the Ki-48 remained in production until 1944, for sheer lack of anything better to replace it with, and eventually over 1,950 were produced, mainly of the Ki-48-II variants.

Ki-51 (Mitsubishi): a different approach to improving the effectiveness of the Japanese Army light bombers was the development of a purpose-built dive bomber. To the disadvantage of light payloads in the Ki-30 and Ki-32 was added the problematic accuracy of level-bombing techniques, even from relatively low altitudes. The Japanese Army aircraft in China had already adopted glide-bombing techniques in an attempt to improve their ratio of hits (this was also demonstrated by a group of Ki-30’s in one of the earliest air raids on Corregidor in the Philippines). But this approach often left the attacking aircraft increasingly vulnerable to ground fire, and the often marginal improvements in bombing accuracy hardly justified the risk. The Ki-51 was therefore constructed with survivability as primary consideration. It was both highly manoeuvrable and fairly well-protected, and even when seemingly outmatched as the war progressed showed a surprising ability to elude enemy fighters. As a further bonus, the Ki-51 was designed with a short take-off and landing capability which allowed it to operate easily from crude front-line airstrips. It was in many ways an ideal ground-support plane, and the Army used it widely for most of World War II despite its deficiencies. Chief among those deficiencies was the extremely limited payload—only 440 lbs of bombs, carried externally under the wings. The Ki-51 was a single-engined two-seater, with fixed landing gear, in some respects based closely on the Ki-30 it was designed to replace. Armament consisted of two fixed 7.7mm mgs in the wings, and a third on a flexible mount in the rear of the cockpit (later in the war the rear mg was upgraded to 12.7mm calibre). Top speed was just over 260 mph. Like all the other Japanese light bombers discussed, the Ki-51 first entered service against China (in 1940). The Army relied so heavily on this plane in the close support role that in 1944 production was actually increased, and the plane was still being manufactured in 1945, a total of 2,385 being built. A few were also used for reconnaissance duties. The improved Ki-71, with retractable landing gear and a more powerful engine, was intended as a replacement, but proved only a modest improvement and never preceded beyond the prototype stage.

[1]The Japanese did not develop a dedicated single-engined ground support aircraft; the Japanese army relied on light bombers, such as the Ki-30 ('Ann'), Ki-32 ('Mary'), Ki-36 ('Ida') and Ki-51 ('Sonia'). These were all obsolescent. However, the Kawasaki Ki-45-KAI Toryu ('Nick'), although primarily designed as a twin-engined long-range fighter, turned out to be a quite useful attack aircraft. The Ki-45-KAIb version was armed with a 37 mm Type 98 tank gun, which fired the same ammunition as the Type 94 anti-tank gun (not to be confused with the less powerful Type 94 tank gun). The Type 98 was manually loaded. The Ki-45-KAIc instead carried a 37 mm Ho-203, less powerful than the Type 98 but equipped with a 15-round belt feed. The Ho-203 was later scaled up to the Ho-401 57 mm cannon, and this weapon (with 17 rounds) was installed in the attack version of the Ki-102 ('Randy') fighter, the successor of the Ki-45. Of this Ki-102b (also known as the Army Type 4 Assault Aircraft) about 200 seem to have been completed. The Ho-401 with its 520 m/s muzzle velocity was a suitable weapon for use against soft targets, but not much use against armour. Rikugun, the army aeronautical research institute, designed the Ki-93 with the Ho-402 in a belly fairing; this was also a 57 mm weapon but much larger and more powerful, firing its projectiles at 700 m/s. However, only one Ki-93 was ever flown. These Japanese aircraft were no longer as unprotected as most Japanese combat aircraft had been at the start of the conflict, but they were not heavily armoured either, the designers' priorities being performance and handling.

Nakajima G8N1 "Renzan"

Nakajima G8N1 "Renzan" (N-40) could also carry a pair of torpedoes just like Nakajima G5N "Shinzan". IJN seemed to think aircraft as additional power to the Combined Fleet, so IJN "G" series was designed to help battleships. "G" means "rikujo kohgekiki"(=land based attack plane) which can carry not only bombs but also torpedoes. As you might know, Yokosuka P1Y "Ginga" was able to do both dive-bombing and torpedo attack. But since US Navy started to use VT fuse as a defence weapon, I think it became very hard for such large planes to get closer to US ships.

A basic description would be of a four engined heavy bomber designed too late to be the Navy's first four engine bomber. Specification was issued in 1943. First prototype was flown on Oct.23, 1944. Three other prototypes were completed over the next few months. Number three was destroyed by allied aircraft and program was canceled because of material shortages. One was evaluated in US after the war. Power was four Nakajima NK9K-l Homare 24 radial engines. Aircraft were finished overall training orange with unpainted cowling with black on the leading edge of the cowls and black spinners.

Nakajima G8N1 Renzan (Mountain Range) or Rita as known by the allies: Normal crew of ten; Armament-Twin 20mm Type 99 cannon in power operated dorsal, ventral and tail turrets; two 13mm Type 2 machine-guns in a power operated nose turret and one flexible 13mm Type 2 machine-gun in each of the port and starboard beam positions. Bomb load: normal four 250kg(551 lb)bombs-maximum, two 2000kg(4,409 lb)bombs. Maximum speed 320 kt at 8,000m(368 mph at 26,245ft);Max range 4,030 nautical miles(4,639 st miles)Four G8N1's built. Some additional info...prior to the cancellation of the G8N1 bomber, the design had been modified to allow the use of this aircraft as the parent aircraft for the Ohka 33 Special Attack suicide aircraft (which was an enlarged Ohka mod.22).Powerplant for the Ohka 33 was to be a Ne-20 turbojet. Weight with Warhead listed at 800 kg (1,764 lb).

Japanese Camo 1 - Mitsubishi G3M

At the time of its appearance, the Nell was one of the world’s most advanced long-range bombers. It participated in many famous actions in World War II before assuming transport duties.

In 1934 Admiral Isoroku Yamamoto, future head of the Japanese Combined Fleet, advocated development of long-range land-based naval bombers to compliment carrier-based aviation. That year Mitsubishi designed and flew the Ka 9, an unsightly but effective reconnaissance craft with great endurance. It owed more than a passing resemblance to Junkers’s Ju 86, as that firm had assisted Mitsubishi with the design. Now a team headed by Dr. Kiro Honjo developed that craft into the even more capable Ka 15. It was a twin-engine, mid-wing design with stressed skin throughout, twin rudders, and distinctive, tapered wings. Following a succession of prototypes, it entered service in 1937 as the G3M. That year these bombers made history by launching the first transoceanic raids against the Chinese cities of Hankow and Nanking from their home island—convincing proof of Japan’s burgeoning aerial prowess. Moreover, the G3M could also function as an effective torpedo-bomber, adding even greater punch to Japanese naval aviation. By the time World War II erupted in the Pacific in December 1941, the G3M formed the bulk of Japanese naval medium bomber strength. At that time it acquired the Allied designation Nell.

Three days after Pearl Harbor, G3Ms made world headlines when a force of 60 bombers helped sink the British battleships HMS Repulse and HMS Prince of Wales off Malaysia. Several days later, Nells were among the first Japanese aircraft shot down by U.S. Navy fighters at Wake Island. The spring of 1942 then witnessed G3Ms functioning as parachute aircraft over the Dutch East Indies. Within months, however, revitalized Allied forces poured into the region, forcing the slow and under-armed Nells to sustain heavy losses. By 1942 most had ceased active combat operations and spent the rest of the war as transports. Production came to 1,048 machines.

Japanese Bombers Camo

The Japanese had a wider range of bombers. English-language terms for these aircraft derived from Western Allied identification codes, in which female names were given to bombers and male names to fighters. The Japanese Army’s Mitsubishi “Betty,” or Type-1 G4M, was famed for flaming out. It was underarmored, with almost no cockpit protection and mounted highly vulnerable fuel tanks that did not self-seal. Similar problems attended the twin-engine Mitsubishi “Sally” and “Peggy” models, with the latter appearing in small numbers from October 1944. Some thought was given to developing an interoceanic bomber called the “Fugako,” but Japan’s limited aircraft industry could not spare the needed resources. The Japanese Navy deployed several bombers, including the “Kate” torpedo bomber, “Judy” dive bomber, and “Val” altitude or level bomber.

Kawasaki Ki-48 Redux

It is a remarkable fact that the Japanese Army Air Force's first modern light twin-engined bomber, a machine produced in greater numbers monthly than any other twin-engined type by Japan's wartime aircraft industry, and one which was active throughout the Pacific War and in every area in which the JAAF was engaged, should today be one of the least-known of Nipponese operational aircraft.

Yet the Ki.48, or Type 99 Light Bomber, produced by the Kawasaki Kokuki Kogyo K.K., and known to the Allies by the singularly inappropriate code name of Lily, enjoyed such an in-auspicious career and was so completely devoid of outstanding characteristics, that it achieved neither prominence nor notoriety. Yet nearly two thousand aircraft of this type rolled off the assembly lines between mid 1939 and October, 1944.

In 1937, the JAAF issued a specification for a light bomber with longer range and greater offensive potentialities than existing single-engined aircraft. Possibly influenced in their choice of a twin-engined machine by the Bristol Blenheim, the JAAF desired increased mobility with an eye to possible operations against Russian forces on the Manchurian border. To meet the requirements of this specification, Kawasaki evolved an all-metal twin-engined mid-wing cantilever mono-plane, and the first of nine prototypes, designated Ki.48, flew in July, 1939. Initial trials indicated some instability and flutter, and early modifications were the strengthening of the rear fuselage and the raising of the horizontal tail surfaces by fifteen and a half inches. Before the end of the year quantity production of the aircraft had been initiated under the designation Type 99 Light Bomber Model 1.

The bomber was powered by two Nakajima Ha.25 fourteen-cylinder air-cooled radial engines, each rated at 1,000 h.p., for take-off, and 980 h.p. at 9,840 ft., carried four or five crew members; a defensive armament of three flexible 7.7-mm. machine guns, and an internally-housed bomb load of 660 pounds. Actual production deliveries began in July, 1940, and the Type 99 Model I (Ki.48-I) was immediately dispatched to China for operational trials. Neither the offensive potentialities nor performance of the bomber were outstanding, normal bomb load being twenty-four 33-lb. bombs or six 110-lb. bombs, and maximum and cruising speeds were 298 m.p.h. and 217 m.p.h. at 11,480 ft. respectively. Range with maximum bomb load was 1,230 miles, and with maximum fuel was 1,490 miles, an altitude of 16,400 ft. was attained in nine minutes, and empty and loaded weights were 8,929 lb. and 13,337 lb. respectively. There were minor defensive armament differences between the Ki.48-Ia and -Ib, but both stability and manoeuvrability of the bomber were poor, and improvements were obviously necessary from an early date in its career. Nevertheless, 557 Kawasaki Ki.48-I bombers were built before the first of three prototypes of the Ki.48-II made its appearance in February, 1942.

The principal differences between the Ki.48-I and -II were to be found in the engines, defensive armament and armour protection. The new model had Nakajima Ha.115 fourteen-cylinder air-cooled radials rated at 1,130 h.p. for take-off and 1,100 h;p. at 9,350 ft., the fuel tanks were protected, and 12.5-mm. and 6.5-mm. fore and aft armour protection was provided for the crew members. Initially the defensive armament remained a trio of 7.7-mm. guns, but the additional power permitted an increase in bomb load to 1,760 lb. in maximum loaded condition. Whereas the Type 99 Model 2a (Ki.48-IIa) was built as a level bomber, the Model 2b (Ki.48-IIb) was fitted with dive brakes under each wing, and was capable of dive-bombing attacks up to an angle of sixty degrees. Late production machines of this type featured a dorsal fin extension. The Model 2c (Ki.48-IIc) was essentially similar to the Model 2b apart from the addition of a single 12.7-mm. gun to the defensive armament.

Jet and Fighter variants

The Type 99 Model 2 was soon active wherever the JAAF appeared, and in 1944, four machines were modified as parent aircraft for the Kawasaki-built I-Go-lb guided missile which entered production in January, 1945, the Type 99 with bomb-bay doors removed serving as its principal carrier. One machine was modified as a flying test bed for the Ne.00, the first indigenous turbojet, and among several proposed variants which did not materialise was the Ki.81 heavy multi-seat fighter variant. Heavily armed and armoured, the Ki.81 was designed for the exclusive use of the formation leader. When production finally terminated in October, 1944, no less than 1,408 Type 99 Model 2 bombers had been built, bringing total production of all Ki.48 aircraft, including prototypes, to 1,977 machines.

The Type 99 Model 2c (Ki.48-IIc) possessed the following overall dimensions: span, 57 ft. 3 ¾ in.; length, 42 ft. 2 ¾ in.; height, 12 ft. 0 ½ in.; wing area, 430.556 sq. ft. Defensive armament comprised one 7.7-mm. machine gun with 600 rounds in the nose, two 7,7-mm. or one 12.7-mm. machine gun in the dorsal position, and one 7.7-mm. machine gun with 500 rounds in the ventral position. Alternative bomb loads comprised six 110-lb. bombs or four 220-lb. bombs, and empty and maximum loaded weights were 10,031 lb. and 14,881 lb. Performance included a maximum speed of 314 m.p.h. at 18,372 ft., the ability to climb to 16,400 ft. at maximum loaded weight in 9 min. 56 sec., a maximum ceiling of 32,800 ft., and a maximum range of 1,490 miles.

G7M1 Taizan

Facing enemy fighters and a barrage of anti-aircraft artillery fire, the crew of this G7M1 Taizan bomber nevertheless continues their torpedo run against a US carrier. A failed successor to the famous G4M “Betty”, it never made it beyond the mock-up stage. created by RonnieOlsthoorn


The G7M shown is Takahashi's version. The Japanese were investigating turboprops but the G7M as envisioned by Takahashi did not use them.

The G7M as designed by Kiro Honjo. There was a version designed first, however, by Kijiro Takahashi which was quite different from what Honjo came up with (which, basically, was a derivative of the G4M which he also worked on). Takahashi's design used two 24-cylinder, H-engines and had a nose not unlike the Heinkel He 177 (among other similar features) and used a tricycle landing gear system. The design was doomed when the needed machinery to produce the H-engines could not be imported. With Takahashi's project shelved, Honjo took over but, ultimately, even the G7M (and its competitor, the Kawanishi K-100) was canceled in favor of four-engined bomber designs.

As a note, the G7M was intended as a long range, strategic bomber, not a medium bomber like the G4M (despite its great range). In the end, the constant revisions to the G7M resulted in a design little better than the G4M which helped speed its demise.

Takahashi's design, with a lighter payload, was expected to meet the 4,598 mile range dictated by the 16-shi specification. The Dornier Do 17 couldn't even touch this kind of range. For reference, from Tokyo, Japan to Los Angeles, California is 5,478 miles.

With Takahashi's version of the G7M doomed, Honjo's version, while also estimated to be able to attain the 16-shi range, was wishful thinking. No doubt the Kaigun Koku Hombu realized to attain such a range would have resulted in a relatively worthless bomb load.

The G7M was a strategic bomber, not a heavy bomber. By strategic, we are talking about a plane capable of a very large operational radius.

Honjo's original concept for the G7M had four engines but just the mere suggestion of using four engines saw Honjo's idea squashed by the Kaigun Koku Hombu before it ever got anywhere. This is when Takahashi stepped up with his two engine design. It wasn't until the failure of the G7M1 (Honjo's two-engine design) and the K-100 to meet the 16-shi and 17-shi specifications respectively did the Kaigun Koku Hombu become more receptive to four engine bombers. Of course, by then, it was too little, too late.

Mitsubishi G7M1 "Taizan" Ground Bomber
(Type16 Experimental Ground Bomber "Taizan")
Length: 20.00m
Wing Span: 25.00m
All-Up Weight: 16,000Kg
Engine: Mitsubishi Ha42 Model 31 (2,400hp) X 4
Max Speed: 556Km/h
Range: 2,780Km
Crew: 5
Armament: 20mm Machine Gun X 2, 13mm Machine Gun X 6
Bomb: 800Kg X 1 or 500Kg X 2 or 250Kg X 6 or Torpedo X 1

Nakajima Ki-49 Donryu

The Nakajima Ki-49 was designed as a replacement for the Mitsubishi Ki-21, which was just entering service in the spring of 1938. The Japanese Army Air Staff issued the specification at that very time, calling for a bomber capable of operating without fighter escort, relying instead on heavy defensive armament and high speed to escape interceptors. A maximum speed of 311 miles per hour was requested, an improvement of about 16 % over the Ki-21. Also included in the requirements were a range of 1,864 miles, a bomb load of 2,205 pounds, and a heavy (for the time) defensive armament including one flexible 20mm cannon in the dorsal position and several flexible 7.7mm machine guns, including a proper tail turret (the first ever fitted to a JAAF bomber). Interestingly, the specification called for crew armour and self-sealing fuel tanks-a very welcome advance, considering the disdain the Japanese normally showed for aircrew and fuel-tank protection.

When Nakajima lost the bomber competition in 1937 to Mitsubishi, they had received a contract to build the Ki-21 in lieu of their own Ki-19, and the Ki-49 design team, led by T. Koyama, used the opportunity to study their competitor’s aircraft with a view toward improving on it when they designed its intended replacement. Especial attention was paid to handling, and a mid-mounted wing of low aspect ratio was selected to ensure good manoeuvrability and stable flight at low and medium altitudes.

The centre section of the wing, inboard of the engine nacelles, was wider in chord than the outer panels to accommodate six self-sealing fuel tanks, three on each side of the fuselage. This also reduced drag and allowed the nacelles to be positioned well ahead of the wing trailing edge. To improve take-off and initial climb, Fowler flaps were adopted, and they extended from the fuselage to the ailerons. In each of the outer wing panels, two more self-sealing fuel tanks and a protected oil tank were fitted. The defensive armament was a single 20mm cannon mounted flexibly in the dorsal position and a flexible 7.7mm machine gun in each of the nose, ventral, port and starboard beam, and tail positions. The bomb bay was large, extending almost the entire length of the wing centre section. All in all, the new bomber looked very impressive when it was completed and flown for the first time in August 1939.

Powered by two 950-hp Nakajima Ha-5 radials, this first example was used primarily for handling trials; service pilots were particularly impressed with the prototype’s manoeuvrability, but complained that the Ki-49 was rather underpowered when actually carrying a bombload, and was harder to fly than the Ki-21. The second and third prototypes, powered by two Nakajima Ha-41s of 1,250 horsepower, were completed and flown in the final quarter of 1939. These were followed by seven pre-production machines in 1940, and throughout that year and into the beginning of 1941, all ten Ki-49s were extensively tested. After minor modifications in protection, armament, and seating arrangements, the type was formally adopted by the Army in March 1941 as the Army Type 100 Heavy Bomber Donryu (Storm Dragon) Model 1 (Ki-49-I).

While the service tests were proceeding with the first ten examples, shocking reports were coming in from the Chinese battlefront. The Ki-21 was suffering heavy losses because the Army’s then-standard fighter, the Nakajima Ki-27, lacked sufficient range to accompany the bombers all the way to and from their targets. This created a delay in delivery of the Ki-49 to front-line units, for valuable time was wasted in trying to make a heavy escort-fighter version of the Donryu, the Ki-58.

Three prototypes were built between December 1940 and March 1941. The Ki-58 resembled the Navy’s G6M in that it had the bomb bay sealed and replaced by a ventral gondola; further armor protection was fitted, and the defensive armament was increased to no less than five flexible 20mm cannon and three 12.7mm machine guns. Fortunately, the idea was abandoned when tests of the new Ki-43 Hayabusa proved it to have the range needed to be a proper escort fighter. But further effort was diverted into the building of a “formation leader’s” aircraft, the Ki-80; two prototypes of this variant were built in October 1941, but further work on the Ki-80 was cancelled by the coming of the war. The two prototypes eventually were used as test-beds for the 2,420-hp Nakajima Ha-117 engine.

The Ki-49-I was first delivered to the JAAF in August 1941, and the first unit to receive its Donryus was the 61st Sentai in China; because of the low initial delivery rate, this group kept some of its older Ki-21s until February 1942. In that same month, the Donryu made its combat debut, in a raid on Darwin, Australia, on the 19th. Code-named Helen, it was frequently encountered over New Guinea and New Britain. But the doubts of the service-test pilots, alluded to above, were confirmed by actual combat experience. In addition to its poor handling and lack of power when fully loaded, the Ki-49’s speed, though superior to the older type, was still not fast enough to avoid interception, and its effective bomb load was lower than that of the Ki-21. On the plus side, the Donryu’s crews thought highly of its superior defensive armament and of its armour and self-sealing fuel tanks.

In the spring of 1942, it was decided to install a pair of 1,450-hp Nakajima Ha-109 radial engines in the Ki-49 in an attempt to improve its performance and handling. The oil coolers, formerly mounted on the front of the older engines, were shifted to scoops under the cowlings; otherwise, there was little change in the nacelles as the two kinds of engines were virtually identical in size. Combat experience dictated further changes, such as a new bombsight, heavier-grade armour plate, and improved self-sealing fuel tanks. After testing of two pre-production prototypes, the revised version was accepted for production as the Ki-49-IIa, and deliveries commenced in September 1942. However, it was swiftly realized that rifle-calibre machine guns were not very effective against Allied fighters, and all of the former 7.7mm guns in the nose, ventral, and tail positions were replaced by 12.7mm guns in the major production variant, the Ki-49-IIb.

Despite all the improvements made to it, the Ki-49-II never totally supplanted the Ki-21-II in service. It was the best-protected and best-armed JAAF twin-engined bomber until the Mitsubishi Ki-67 Hiryu was introduced in October 1944, but its crews were still disappointed at its performance. In particular, its low and medium-altitude speeds were still deemed unsatisfactory, and its flight characteristics were not as pleasant as those of its predecessor. When the Americans returned to the Philippines in October 1944, the Helen was very heavily engaged; they suffered massive losses until December of that year when most of the survivors were expended in suicide attacks against the US landing force at Mindoro island. Many more were used in the suicide attack role during the Okinawa campaign; for this mission all the armament was removed, the crew was reduced to the two pilots only, and the bomb load increased to 3,527 pounds.

Nakajima was baffled by the type’s continuing problems, and tried hard to improve the Ki-49; their most ambitious attempt involved creating a version featuring two examples of the most powerful fourteen-cylinder radial engine ever devised by any country, Nakajima’s own 2,420-hp Ha-117. But the Ha-117’s teething troubles could never be resolved, and only six examples of this subtype, the Ki-49-III, were built in 1943.

Despite its shortcomings, the Donryu was adapted to perform a number of additional missions besides “heavy” bomber. Some were used as troop transports (the great Navy ace Hiroyoshi Nishizawa was killed while riding as a passenger in a Helen-ironic fate!); others were field-modified as night fighters. In the night-fighter role, one aircraft worked as a “hunter” with a searchlight, and a second was the “killer”, mounting a 75mm cannon, but the Ki-49 made a disappointing night fighter as it lacked the performance needed for this role. Still others carried electronic and magnetic detection gear to act as anti-submarine patrol planes. In the end, though, the Donryu was a very disappointing aircraft, for all the effort put into making it an effective warplane. Just 819 examples of the Ki-49 and its derivatives were built, 769 by Nakajima, and 50 more by Tachikawa Aircraft Ltd., but plans to also produce it in Harbin, Manchuria, by Mansyu were not realized. Overall production ceased in December 1944, as the Army had placed its hopes in the Mitsubishi Ki-67 Hiryu.

    Prototypes and pre-series models with a 708 kW (950 hp) Nakajima Ha-5 KAI or the 1,250 hp Ha-4. The pre-series with little modifications from the prototype.
    Army Type 100 Heavy Bomber Model 1, first production version.
    Two prototypes fitted with two Nakajima Ha-109 radial piston engines.

        Army Type 100 Heavy Bomber Model 2A - Production version with Ha-109 engines and armament as Model 1.
        Version of Model 2 with 12.7 mm Ho-103 machine gunes replacing rifle calibre weapons.

    Six prototypes fitted with two 1,805 kW (2,420 hp) Nakajima Ha-117 engines.
    Escort fighter with Ha-109 engines, 5 x 20 mm cannon, 3 x 12.7 mm (0.5 in) machine guns. 3 prototypes built.
    Specialised pathfinder aircraft - 2 prototypes; employed as engine test-beds.

    Total production: all versions 819 examples (including 50 built by Tachikawa)

Nakajima Ki-49 Donryu (Helen) Technical Data

Twin-engined “heavy” bomber, of all-metal construction.

Crew of eight (two pilots, bombardier, navigator, radio operator/gunner, and three dedicated gunners) all in enclosed cockpits, main cabin, or turrets.

(First prototype) Two Nakajima Ha-5 fourteen-cylinder air-cooled radial engines, rated at 950 hp for take-off and 1,080 hp at 13,125 ft.

(Pre-production machines and Ki-49-I) Two Nakajima Ha-41 fourteen-cylinder air-cooled radials, rated at 1,250 hp for take-off and 1,260 hp at 12,140 ft.

(Ki-49-II and Ki-58) Two Nakajima Ha-109 fourteen-cylinder air-cooled radials, rated at 1,450 hp for take-off and 1,300 hp at 17,330 ft.

(Ki-48-III and Ki-80) Two Nakajima Ha-117 fourteen-cylinder air-cooled radials, rated at 2,420 hp for take-off and 2,250 hp at 16,075 ft.

(Prototypes/pre-production machines, Ki-49-I and Ki-49-IIa) One flexible 20mm cannon in the dorsal position and one flexible 7.7mm machine gun in each of the nose, ventral, beam, and tail positions.

(Ki-49-IIb and Ki-49-III) One flexible 20mm cannon in the dorsal position, one flexible 12.7mm machine gun in each of the nose, ventral, and tail positions, and one flexible 7.7mm machine gun in the port and starboard beam positions.

(Ki-58) Five flexible 20mm cannon and three flexible 12.7mm machine guns.

Normal, 1,653 lbs.; maximum, 2,205 lbs.; suicide attack, 3,527 lbs.

Dimensions, weights, and performance:

Wingspan, 67 ft. 1/8 in.;
length, 55 ft. 1 ¾ in.;
height, 13 ft. 11 5/16 in.;
wing area, 743.245 sq. ft.;
empty weight, 13,382 lb.;
loaded weight, 22,377 lb.;
maximum weight, 23,534 lb.;
wing loading, 30.1 lb./sq. ft.;
power loading, 8.9 lb./hp;
performance figures N/A.

Wingspan, 67 ft. 1/8 in.;
length, 54 ft. 1 5/8 in.;
height, 13 ft. 11 5/16 in.;
wing area, 743.245 sq. ft.;
empty weight, 14,396 lb.;
loaded weight, 23,545 lb.;
maximum weight, 25,133 lb.;
wing loading, 31.7 lb./sq. ft.;
power loading, 7.8 lb./hp;
maximum speed, 306 mph at 16,405 ft.;
cruising speed, 217 mph at 9,845 ft.;
climb to 16,405 ft., 13 min. 39 sec.;
service ceiling, 30,510 ft.;
normal range, 1,243 miles;
maximum range, 1,833 miles.