# Japanese light bombers and reconnaissance aircrafts



## gekho (Jun 24, 2011)

Light bombers carried a relatively light bomb load but were suitable for tactical missions requiring rapid response and flexibility. Most were single engine aircraft with a crew of two or three. Dive bombers specialized in accurate attacks with bombs against high-valued land or naval targets. Torpedo bombers, as the name implies, were naval aircraft specializing in delivering torpedoes against shipping, but they could also be employed as horizontal bombers against ground targets. A few light bombers, particularly in Japanese service, were capable neither of carrying torpedoes nor of maintaining the steep dives characteristic of dive bombers. These are listed below. In addition to the other qualities desirable in a light bomber, a carrier bomber had to have a low enough landing speed to operate off a short flight deck, enough resistance to corrosion to endure salt air, and a sturdy undercarriage for hard landings on flight decks. These requirements did not constrain carrier bomber design as severely as they did carrier fighter design. In fact, it was rare for land-based light bombers to be as successful as carrier bombers. As Bergerud points out, ships are valuable targets, and a combat attrition rate that is acceptable when attacking shipping may not be acceptable for ground support missions. 

Reconnaissance aircraft are aircraft designed to gather intelligence, usually by visual observation, aerial photography, or radar. While almost any aircraft had significant reconnaissance capability, the ideal reconnaissance aircraft was capable of flying high and fast to avoid interception by fighters and had a long range. Combat capability was much less important. Strategic reconnaissance missions were flown by long-range aircraft with high-resolution photographic equipment. Of these, the best was probably the Japanese Ki-46 Dinah, whose combination of speed, service ceiling, and range made it nearly the ideal reconnaissance aircraft. Allied fighter pilots found it extremely difficult to intercept, and Dinahs participated in the photoreconnaissance of Malaya and the Philippines before the war and on missions over Ulithi and Okinawa in its final months. The closest Allied equivalent was the reconnaissance version of the British Mosquito, which because it was made largely of plywood had a low radar cross-section, making it arguably the first stealth aircraft.


----------



## gekho (Jun 24, 2011)

The KDA-2 was designed by Richard Vogt to meet a Japanese Army requirement for a reconnaissance biplane to replace the Salmson 2. Three prototypes were built by Kawasaki in 1927. Following testing the aircraft was ordered into production as the Army Type 88-1 Reconnaissance Biplane. The aircraft was of all-metal construction, with a stressed skin forward fuselage, had unequal-span wings and a slim angular fuselage, cross-axle tailwheel landing gear and was powered by a 447 kW (600 hp) BMW VI engine. An improved version (the Type 88-II) was developed with an improved engine cowling and a revised tail unit. By the end of 1931, a total of 710 (including the three prototypes) had been built by both Kawasaki and Tachikawa (187 of the total).

Between 1929 and 1932, a bomber version was built as the Type 88 Light Bomber, differing in having a strengthened lower wing and an additional pair of centre-section struts. Bomb racks were located under the fuselage and lower wings. A total of 407 were produced. A transport variant was developed as the KDC-2 with room for a pilot and four passengers in an enclosed cabin. Only two KDC-2s were built and one of was tested on floats. Both reconnaissance and bomber versions saw action with the Imperial Japanese Army Air Force in Manchuria, and a few were still in service in 1937 during fighting at Shanghai.


----------



## gekho (Jun 24, 2011)

Developed from the KDA-6 private venture reconnaissance prototype, the Kawasaki Ki-3 was designed by German engineer Richard Vogt, who later became chief designer for Blohm und Voss. The first Ki-3 flew in March 1933 and featured an unusual annular cowling with a nose radiator, but production aircraft had a more normal chin radiator. It entered Japanese Army service as the Type 93, 203 being built by Kawasaki and a further 40 by Tachikawa. It was a rugged aircraft, but the Ki-3's liquid-cooled engine was a constant source of trouble. The Ki-3 first saw service with the 6th Composite Air Regiment in Korea. The type, which was Japan's last biplane bomber, saw action in China.


----------



## gekho (Jun 24, 2011)

Extensively test-flown in 1934, the Nakajima Ki-4 sesquiplane had divided landing gear with streamlined wheel spats, and accommodated pilot and observer in tandem open cockpits, the pilot just below a cut-out in the trailing edge of the upper wing. The Ki-4 went into production and service in 1935 as the Army Type 94 Reconnaissance Aircraft Model 2 which dispensed with the wheel fairings and had a redesigned tail unit. Production continued for several years, some aircraft being licence-built by Tachikawa among the total of 516.

The Type 94 was used widely in China by the Japanese army on direct co-operation duties, in close support of the ground forces. It was armed with up to four 7.7mm machine-guns and could carry 50kg of light bombs. A number were still in service in the supply and liaison role in 1941. The Japanese army tested two Ki-4s as seaplanes, one with twin floats and the other with one main and two stabilising floats. A landplane was used for flotation bag tests to check buoyancy in the event of an emergency put-down on water. Powered by a 477kW Ha-8 radial engine, the Type 94 could attain a speed of 300km/h. Wing span was 12.00m and maximum take-off weight 2500kg.


----------



## gekho (Jun 24, 2011)

In December 1923, Eiji Sekiguchi, chief designer of the aircraft department of Kawanishi Kikai Setsakuho (Kawanishi Machinery Manufacturing Works), started design of a new high speed transport floatplane to equip Nippon Koku KK (Japan Aviation Co. Ltd.), an airline subsidiary of Kawanishi. Sekiguchi designed a single-engined sesquiplane (i.e. a biplane with the lower wing much smaller than the upper wing) of all-wooden construction. Seating for four passengers was provided in a enclosed cabin, while the aircraft's two pilots sat in individual open tandem cockpits aft of the passenger cabin. The aircraft was powered by a single Maybach Mb.IVa water-cooled inline-engine providing 305 hp (228 kW), an engine type usually used to power Zeppelins or R-planes (Riesenflugzeuge like the Zeppelin-Staaken R.VI), received as part of Germany's reparations to Japan after the end of the First World War.

The first example of the new aircraft, the K-7A Transport Seaplane was completed in November 1924, demonstrating both good performance and handling. A further nine K-7As were built by the time production ended in 1927, together with a single example of the K-7B Mail-Carrying Aircraft, a modified version that could be operated either on floats or with a tailwheel undercarriage.


----------



## gekho (Jun 24, 2011)

The army's Mitsubishi Ki-15 (and its counterpart in the navy, the C5M) became the most popular Japanese reconnaissance plane during the period just before World War II and during the early stages of the war itself. The project was begun in the summer of 1935 at the request of army technical authorities, with the first prototype appearing in May of 1936. The new reconnaissance plane made its operational debut during the second Sino-Japanese war. It proved to be an excellent plane and was hard to intercept. Because of its high performance, the plane attracted the interest of naval authorities, who at the time did not have modern reconnaissance planese. In 1938 the navy ordered a number of these aircraft for its own use, to be designated as C5Ms. However, only about 50 of the total 489 examples made of this type were to be navy C5Ms, with the vast majority used as army Ki-15s. The Ki-15s and C5Ms (which the Allies gave the codename of "Babs") remained on front-line duty throughout 1942. Then they were gradually withdrawn and reassigned to training and liaison duty.


----------



## vikingBerserker (Jun 24, 2011)

Another great thread!


----------



## gekho (Jun 25, 2011)

In May 1936 the Imperial Japanese Army issued its specification for a light bomber required to supersede the Mitsubishi Ki-2 and Kawasaki Ki-3 then in service. The Mitsubishi Ki-30 prototype that resulted was of cantilever mid-wing monoplane configuration with fixed tailwheel landing gear, the mam units faired and spatted, and powered by a 615kW Mitsubishi Ha-6 radial engine. Flown for the first time on 28 February 1937 this aircraft performed well, but it was decided to fly a second prototype with the more powerful Nakajima Ha-5 KAI radial engine. This aircraft showed some slight improvement in performance but, in any case, exceeded the army's original specification, so there was no hesitation in ordering 16 service trials aircraft. These were delivered in January 1938 and, two months later, the Ki-39 was ordered into production.

First used operationally in China during 1938, the Ki-30s proved to be most effective, for in that theatre they had the benefit of fighter escort. The situation was very much the same at the beginning of the Pacific war, but as soon as the Allies were in a position to confront unescorted Ki-30s with fighter aircraft they immediately began to suffer heavy losses and were soon relegated to second-line use. The Allied codename 'Ann' was allocated to the Ki-30, but few were seen operationally after the opening phases of the war. A total of 704 had been built when production ended in 1941, 68 manufactured by the First Army Air Arsenal at Tachikawa, and many of these ended their days in a kamikaze role during the closing stages of the war.


----------



## gekho (Jun 25, 2011)

The Ki-32 light bomber was an all-metal mid-wing monoplane powered by a single 708kW Ha-9-IIb liquid-cooled engine. Its wide-track fixed cantilever undercarriage featured open-sided wheel fairings. Wing and tail surfaces were finely tapered. The two-man crew were accommodated beneath a long raised canopy. Armament comprised one fixed cowling 7.7mm Type 89 machine-gun and another of the same type on a flexible mounting operated by the observer. An internal bomb bay accommodated a 300kg offensive load, supplemented by 150kg of bombs on external racks.

Eight 1937 prototypes were followed by 846 series aircraft built up to May 1940 and designated Army Type 98 Light Bomber. They saw extensive war service in China, flying with seven Sentais during 1938-9 and participated in the fierce fighting over the Khalkin Gol and at Nomonhan against Soviet forces during 1939. Among the Type 98's final operational sorties were successful bombing raids on Hong Kong prior to its surrender in December 1941. The type was coded Mary by the Allies.


----------



## gekho (Jun 25, 2011)

First flown in prototype form on 20 April 1938, the Tachikawa Ki-36 was a cantilever low-wing monoplane of all-metal basic structure, covered by a mix of light alloy and fabric. Landing gear was of fixed tailwheel type, the main units enclosed in speed fairings, and power was provided by a 336kW Hitachi Ha-13 radial engine. The two-man crew was enclosed by a long 'greenhouse' canopy and both men had good fields of view, that of the observer being improved by clear-view panels in the floor. The type was ordered into production in November 1938 as the Army Type 98 Direct Co- Operation Plane. Generally similar to the prototypes, the type was armed with two 7.7mm machine guns and introduced the more powerful Hitachi Ha-13a engine. When construction ended in January 1944, a total of 1,334 had been built by Tachikawa (862) and Kawasaki (472).

The handling characteristics and reliability of the Ki-36 made the army realize that it was ideal for use as an advanced trainer, resulting in development of the Ki-55, intended specifically for this role and having armament reduced to a single forward- firing machine-gun. Following the testing of a prototype in September 1939, the army ordered this aircraft as the Army Type 99 Advanced Trainer; when production was terminated in December 1943 a total of 1,389 had been built by Tachikawa (1,078) and Kawasaki (311).

Both versions were allocated the Allied codename 'Ida', and the Ki-36 was first deployed with considerable success in China. However, when confronted by Allied fighters at the beginning of the Pacific War it was found to be too vulnerable, being redeployed in China where it was less likely to be confronted by such aircraft. It was also considered suitable for kamikaze use in the closing stages of the war, being modified to carry internally a bomb of up to 500kg.


----------



## gekho (Jun 25, 2011)

One of the best-looking Japanese aircraft of World War II, the Mitsubishi Ki-46 was designed to meet an Imperial Japanese Army requirement of 1937 for a higher performance reconnaissance aircraft to supersede the Ki-15. A cantilever low-wing monoplane with retractable tailwheel landing gear, powered by two 671kW Mitsubishi Ha-21-l radial engines, the two-seat Ki-46 prototype was flown for the first time in late November 1939. Early testing showed that maximum speed of the Ki-46 was some 10% below specification, but as its speed and overall performance was better than in-service army and navy aircraft the type was ordered into production as the Army Type 100 Command Reconnaissance Plane Model 1 (Ki-46-l), later allocated the Allied codename 'Dinah'. Early operational problems with the Ki-46-l resulted in production of the improved Ki-46-ll with 805kW Mitsubishi Ha-102 engines, this powerplant giving a maximum speed slightly in excess of the original specification. The Ki-46-ll was the major production version, with more than 1,000 built, a number of which were converted later into three-seat radio/navigation trainers under the designation Ki-46-ll KAI. Subsequent variants included the faster and improved Ki-46-III of which 609 were built, a small number being converted later as Ki-46-lll KAI fighter interceptors and Ki-46lllb ground-attack aircraft. Ki-46-IV prototypes, with 1119kW Mitsubishi Ha-112-ll Ru turbocharged engines to give improved high altitude performance, were under test when the war ended.

In service from the beginning to the end of the Pacific war, the Ki-46 proved to be an important aircraft for the Japanese army, but the growing capability and number of Allied fighters resulted in unacceptably high losses of Ki-46-IIs. However, the improved performance of the Ki-46-lll meant that this version was virtually free from interception until the final stage of the war. Production of all versions totalled 1,742, all built by Mitsubishi.


----------



## Wayne Little (Jun 25, 2011)

Cool!


----------



## vikingBerserker (Jun 25, 2011)

Excellent!


----------



## Gnomey (Jun 25, 2011)

Good stuff!


----------



## gekho (Jun 26, 2011)

The Mitsubishi Ki-51 (Army designation "Type 99 Assault Plane". Allied nickname "Sonia") was a light bomber/dive bomber in service with the Imperial Japanese Army during World War II. It first flew in mid-1939. Initially deployed against Chinese forces, it proved to be too slow to hold up against the fighter aircraft of the other Allied powers. However, it performed a useful ground-attack role in the China-Burma-India theatre, notably from airfields too rough for many other aircraft. As the war drew to a close, they began to be used in kamikaze attacks. Total production was around 2,385 units. Charles Lindbergh, flying a P-38 Lightning shot down a Ki-51 after a vigorous dogfight in which the much slower Ki-51 utilized its low speed maneuverability and made a fight of it.


----------



## gekho (Jun 26, 2011)

In 1932, the Imperial Japanese Navy issued a requirement for a new carrier-borne attack aircraft. Aichi, Mitsubishi and Nakajima responded to this requirement and each built a prototype. Neither of these aircraft were deemed satisfactory, and the service thus issued in 1934 a new requirement, 9-Shi, for a more capable aircraft to replace the obsolescent Yokosuka B3Y. The B4Y was designed by Sanae Kawasaki at the First Naval Air Technical Arsenal at Yokosuka. Regarded only as an interim type, the Navy wanted a torpedo bomber offering performance comparable to the Mitsubishi A5M monoplane fighter. The result was a biplane with fixed landing gear and an all-metal structure with metal or fabric skin. To speed development and production, the B4Y utilised the wings from the Kawanishi E7K. The B4Y1 was also the first Navy carrier attack aircraft to utilize an air-cooled engine, as the prototype that was equipped with the Nakajima Hikari 2 radial engine performed better than its opponents. The crew of three occupied two cockpits. The pilot in the open front cockpit and the other two crewmen, (navigator and radio operator/gunner), in the enclosed rear cockpit.

On 12 December 1937 3 B4Y1s were involved in the Panay incident during a Japanese attack on the United States Navy gunboat Panay while she was anchored in the Yangtze River outside of Nanjing. Although primarily used as a carrier-based aircraft, the B4Y1 was also used as a land-based bomber on occasion. In 1940, the Nakajima B5N replaced the B4Y1 as the primary carrier attack aircraft, though the B4Y1 did remain in service as an advanced trainer, and flew from Hōshō and Unyō until 1943. Before its replacement, the B4Y1 had flown during the Second Sino-Japanese War and did serve at the Battle of Midway during June 1942, where eight of them were operated from Hōshō[2]. It was one of these planes from Hōshō which took photographs of the burning Hiryū on 5 June 1942.


----------



## gekho (Jun 26, 2011)

The D1A came out of the Imperial Japanese Navy's need for an advanced carrier-based dive bomber, and in late 1934 the IJN ordered the finalisation of the Aichi AB-9 design which was produced as the early model D1A1. However, the D1A1 was not designed by Aichi Tokei Denki Kabushiki Kaisha aircraft company, but by Ernst Heinkel Flugzeugwerke at the request of the Aichi company. The initial version designed by Heinkel was the He 50, a similar model equipped with floats instead of landing gear. The subsequent model, the He 66 was provided to Aichi who immediately began production of it as the D1A1.The design of the D1A was based on the He 66 and was designed as a biplane constructed of metal, with a fabric covering, a fixed landing gear and a conventional type tail landing skid. Original models had 365 kW (490 hp) engines and it was not until later models that more powerful 433 kW (580 hp) engines were included in the construction. 

The D1A was primarily used in the Second Sino-Japanese War and up to the time Japan entered World War II in 1941. At the beginning of the Pacific War, all of the remaining D1A1s were decommissioned and most of the D1A2s were retired from the front lines and served primarily in training units. The exception was 68 of the D1A2 model that operated as a second-line support until being retired in 1942.


----------



## gekho (Jun 26, 2011)

First appearing in 1931 the H4H1 was a twin-engined high-wing monoplane flying-boat. Powered by two 500hp (597kW) Hiro 91-1 engines strut-mounted above the wing it was produced by the Kawanishi company and entered service in 1933. An improved version of the design, the H4H2, followed into production two years later. The H4H2 has re-designed twin fins and rudders and was powered by two 800hp (597kW) Myojo radial engine. A total of 47 of both versions was produced. Both the H4H1 and H4H2 remained in front-line naval service through the 1930s.


----------



## vikingBerserker (Jun 26, 2011)

Excellent!


----------



## Gnomey (Jun 26, 2011)

Nice shots!


----------



## gekho (Jun 27, 2011)

The "Glen" was used for several Japanese reconnaissance missions during the Pacific War. It also has the distinction of being the only aircraft to drop bombs on the United States mainland during World War II, in an incident known as The Lookout Air Raid. On 9 September 1942 , Chief Warrant Officer Nobuo Fujita, a pilot in the Japanese Imperial Navy, and his crewman, Petty Officer Shoji Okuda, surfaced in submarine I-25 off the coast of Oregon near Brookings. His tiny seaplane had folding wings and was transported in a small hangar attached to the deck of the submarine. The bombs - 76 kg (168 lb) incendiaries intended to cause forest fires - caused no injuries or real damage. A total of 126 planes were produced.

Reactions: Bacon Bacon:
1 | Like List reactions


----------



## gekho (Jun 27, 2011)

The E2N was developed in the 1920s for the Imperial Japanese Navy as a short range reconnaissance floatplane suitable for catapult launch from cruisers and battleships. It was a wooden twin-float sesquiplane, carrying a crew of two in open cockpits and having folding wings. This layout gave better downwards view than the monoplanes proposed by Aichi and Yokosuka, and the design was selected becoming Japan's first locally-designed shipboard reconnaissance aircraft. The E2N served with the Navy as the Type 15 Reconnaissance Floatplane (一五式水上偵察機). 80 examples were produced between 1927 and 1929 by Nakajima and Kawanishi; of these, two were bought for civil fishery patrol duties. The Navy machines were withdrawn from front-line units in the 1930s, being replaced by the Nakajima E4N, and either being reassigned to training duties or sold to civil buyers.


----------



## gekho (Jun 27, 2011)

The first prototype of this equal-span biplane reconnaissance aircraft appeared in 1930 as the Type 90-2 Reconnaissance Floatplane, company designation NZ. Intended for navy service as the Nakajima E4N1, it had twin flpats and an uncowled Kotobuki radial engine. This first prototype, however, was rejected in favour of the NJ or Navy Type 90-2-2 Reconnaissance Floatplane. This was a complete redesign, with a single main float and twin wingtip stabilising floats. It closely resembles the US Vought O3U-1 Corsair biplane and, like it, was intended for shipboard use and catapult launching. Powered by a 336kW Nakajima Kotobuki radial engine, the Type 90-2-2 had a maximum speed of 222km/h and 85 went into service with the Japanese navy as the E4N2 between 1931 and 1933, a version with fixed wheel landing gear going into service as the E4N2-C; 67 of the latter were completed. In 1933 nine of the E4N2-C landplanes were converted as night mail carriers, for use between the main islands of Japan. Designated P-1, the mail carrier was a single-seater with the pilot accommodated in an enclosed cockpit.


----------



## Gnomey (Jun 27, 2011)

Nice stuff!


----------



## gekho (Jun 28, 2011)

The E8N was developed as a replacement for the same company's E4N and was essentially an evolutionary development of the earlier type, with revised wings of lesser area and taller tail surfaces. Seven prototypes were constructed, under the company designation MS, first flying in March 1934. These were duly engaged in comparative trials against competitors from Aichi and Kawanishi. The MS was ordered into production, designated Navy Type 95 Reconnaissance Seaplane Model 1 in October 1935.[2] A total of 755 E8Ns were built by Nakajima and Kawanishi, production continuing until 1940. It was subsequently shipped aboard all the capital ships then in service, 16 cruisers and five seaplane tenders.

It was used successfully in the Second Sino-Japanese War not only for reconnaissance, but also for dive-bombing and artillery spotting. One E8N was purchased in early 1941 by the German Naval Attache to Japan, Vice-Admiral Wenneker, and dispatched on board KM MUNSTERLAND to rendezvous with the German auxiliary cruiser Orion at Maug Island in the Marianas. The meeting occurred on 1 FEB 1941, and Orion thus became the only German naval vessel of the Second World War to employ a Japanese float plane. Some aircraft remained in service with the fleet at the outbreak of the Pacific War but they were soon replaced by more modern aircraft such as the Aichi E13A and the Mitsubishi F1M, being reassigned to second-line duties.


----------



## gekho (Jun 28, 2011)

Roughly equivalent to the American Curtiss SOC Seagull observation float biplane, the smaller Mitsubishi F1M was of more compact and neater design, its development starting about two years later in 1934. First flown in June 1936, the F1M1 embodied all the efforts of its designers to achieve an exceptionally clean aerodynamic shape, including low-drag float mountings, single interplane struts and all-metal construction, only the control surfaces being fabric-covered. The early aircraft displayed poor water handling and a lack of in-flight directional stability, however, but after fairly extensive alterations the production F1M2 emerged as a thoroughly efficient aircraft, acceptable in all respects.

Initial production by Mitsubishi, which got under way in 1938, amounted to 524 aircraft before it was transferred to the 21st Naval Air Arsenal (Dai-Nijuichi Kaigun Kokusho) at Sasebo, where a further 590 were built. In due course the F1M2 equipped all but one of the K-Maru (6,900-ton) and S-Maru (7,200/8,300-ton) classes of converted merchant seaplane tenders, as well as numerous battleships and cruisers of the Imperial Japanese Navy. Codenamed 'Pete' by the Allies, FlM2s were present at the Battle of Midway, two aircraft being launched from the battleship Kirishima (but being lost when the Japanese scuttled the sorely-crippled ship at the end of the Battle of the Solomons). The giant superbattleships Musashi and Yamato each carried several 'Petes' to spot for their 460mm main gun armament at the time of the Marianas battles, but none was used in earnest; instead the Musashi succumbed to American bombs and torpedoes in the Sibuyan Sea; the Yamato, bent on a suicide mission to Okinawa, followed her to the bottom on 7 April 1945.

Nevertheless 'Pete' seaplanes were widely used throughout the Pacific war, accompanying every seaborne landing by Japanese forces, providing gunnery spotting during preliminary bombardment by supporting warships and subsequently serving as covering fighters (and even dive-bombers) once the assault forces were ashore. It was also flown on convoy escort duties with the many supply convoys sailed by the Japanese during the mid-war period. In the last stages of the war, the type was committed to the unequal task of defending the Japanese homeland from the devastating American raids, serving alongside 'Rex' and 'Rufe' seaplane fighters with the Otsu Kokutai in 1945.


----------



## gekho (Jun 28, 2011)

In 1932 the Imperial Japanese Navy requested the Kawanishi Aircraft Company to produce a replacement for the companies Kawanishi E5K. The resulting design, designated the Kawanishi E7K1, was an equal span biplane powered by a 462kW (620hp) Hiro Type 91 W-12 liquid-cooled inline engine. The first aircraft flew on 6 February 1933 and was handed over the navy for trials three-months later. It was flown in competition with the Aichi AB-6 which was designed to meet the same 7-Shi requirement. The E7K1 was ordered into production as the Navy Type 94 Reconnaissance Seaplane (九四式水上偵察機) and entered service in early 1935. It became a popular aircraft, but was hindered by the unreliability of the Hiro engine. Later production E7K1s were fitted with a more powerful version of the Hiro 91, but this did not improve the reliability. In 1938 Kawanishi developed an improved E7K2 with a Mitsubishi Zuisei 11 radial engine, it first flew in August 1938 and was ordered by the Navy as the Navy Type 94 Reconnaissance Seaplane Model 2. The earlier E7K1 was renamed to Navy Type 94 Reconnaissance Seaplane Model 1.

The type was used extensively by the Japanese Navy from 1938 until the beginning of the Pacific War, when E7K1 were relegated to second-line duties. The E7K2 continued in front-line service until 1943 and both versions were used in Kamikaze operations in the closing stages of the war.


----------



## vikingBerserker (Jun 28, 2011)

Excellent info


----------



## ppopsie (Jun 29, 2011)

Thanks! Great stuff. The serial photos of the Kawanishi E7K in the middle are official IJN photographs but none of the type designation or service name as well as the other technical details were attached, and captioned only as "A newest naval recon-plane." This is an example of how the military before and during WW2 informed of the general public as "subordinate citizens."


----------



## gekho (Jun 30, 2011)

The Aichi M6A Seiran is the only aircraft to have been designed as a submarine-based attack aircraft and to have entered service, although its only military operation was ended prematurely by the end of the Second World War. The idea of building large submarines capable of carrying attack aircraft across the Pacific first emerged late in 1941, and originated with Admiral Isoroku Yamamoto. The design of the I-400 class submarines was completed by March 1942, and in June 1942 it was decided to build 18 of these submarines, each of which would be able to carry three aircraft to any point on the planet. Yamamoto had planned to use these submarines to attack the east coast of the United States, but he was killed in April 1943, only three months after the first submarine – I-400 – was laid down at Kure. Work would eventually begin on five of the submarines, of which three would be completed, but only the first two would ever go to sea. Three M6A Seiran attack aircraft were to be carried in a long watertight cylindrical hanger built into the submarine’s superstructure, with the wings folded back against the fuselage and the floats detached. 

Aichi were ordered to produce a prototype for the special attack aircraft early in 1942. The new aircraft had to fit within the small submarine hanger, have detachable floats and folding wings, and be capable of being launched by catapult. The floats would be used on training missions, but would be detached on operations. The surviving aircraft would ditch close to their submarines, and the crew would swim back to safety. Aichi’s first response was to attempt to modify the D4Y1 Suisei (‘Judy’), which they were then producing in large numbers, but this effort failed, and a completely new aircraft had to be developed. The new aircraft looked similar to the Judy, but had a rather more simple structure, to compensate for the limited space on the submarine. It used the Aichi Atsuta Type 32 engine, a licence-built version of the Daimler Benz DB-601A that was never entirely reliable. It would carry a crew of two – pilot and radio operator/ observer/ rear gunner. The folding wings were hydraulically operated, and eventually four trained men could get the aircraft ready for flight in seven minutes.

The M6A prototype made its first flight on 8 December 1943. A number of problems with the design were discovered, and eventually eight prototypes were completed before the aircraft was considered satisfactory. Eighteen production M6A1 aircraft were built between October 1944 and July 1945, only enough to equip a third of the submarines originally planned. Two M6A1-K training aircraft were produced, with retractable landing gear in place of the floats. These aircraft were given the popular name Nanzan meaning either “Southern Mountain” (the intended meaning) or “Difficult Delivery”. 

By 1943 the target for the M6A had changed from American cities to the lock gates at the Atlantic end of the Panama Canal. Two I-400s and two standard fleet submarines (I-13 and I-14) would carry ten aircraft (three each on the I-400s and two each on the other submarines) to a position to the south west of the canal. The aircraft would then cut across the top of South American and dive bomb the lock gates. Work on this plan reached a very advanced stage, and the mission was timetabled for the autumn of 1945, but just before it was due to take place the operation was cancelled in favour of an attack on US Task Force 38, at Ulithi Atoll. This time the submarines left port. I-400 actually reached the rendezvous point off Ulithi Atoll on 16 August and was preparing to launch its M6A1s on the following morning, but at 21.00hrs that evening the Japanese Sixth Fleet formally confirmed the news of the Japanese surrender. The two I-400 class submarines made their way most of the way back to Japan before surrendering to the Americans, having never launched their M6A1s in anger.


----------



## gekho (Jun 30, 2011)

In June 1937, The Imperial Japanese Navy issued a specification to the Aichi, Nakajima, and Kawanishi companies calling for a two-seat reconnaissance floatplane of monoplane configuration to replace the aging Kawanishi E7K2 three-seat twin-float seaplane. The three manufacturers responded with three prototype designs designated E12A, E12N, and E12K, respectively. But even as these three designs were being created, a new specification was issued calling for a larger, three-seat monoplane reconnaissance seaplane, with higher speed and longer range for convoy escort duty. Three additional designs were created by the engineering teams of the companies involved, intending to compliment rather than replace earlier designs. These were designated Aichi E13A, Nakajima E13N, and Kawanishi E13K. Aichi was the only one to build both of its designs with Nakajima deciding to concentrate on the two-seat version while Kawanishi concentrated on the three-seat version.

Kishiro Matsuo's design team created both the E12A and the E13A, the latter being merely a larger and more powerful version of the former. The first E13A was completed in late 1938 add powered by a 1,080 hp (805 kW) Mitsubishi Kinsei 43 14-cylinder air-cooled radial (which was retained throughout the life of the type). During manufacturer's test flights, it became plain that the E13A was superior to the smaller E12A. Not withstanding its larger size and heavier weight, it was much more stable and manoeuvrable, and also had far better performance. By this time, the Navy had decided they wanted a three-seat aircraft and not a two-seater, so development of the two-seat E12A and E12N was halted. Service test pilots flew the prototype E13A in competition against two prototype E13Ks built by Kawanishi. In December 1940, the E13A was formally declared the winner and was accepted for production as the Navy Type 0 Reconnaissance Seaplane Model 11, or E13A1 Model 11. Aichi built 133 E13A1s through early 1942, when they were ordered to concentrate on building the Yokosuka-designed D4Y carrier dive bomber and recon plane. At that time, primary builder of the E13A became the Watanabe Tekkosho (Watanabe Ironworks Company Limited) which in 1943 was re-organized as Kyushu Hikoki KK (Kyushu Airplane Company Limited). Total aircraft production was 1,418 aircraft. Aichi Tokei Denki KK building 133 aircraft from 1939-42, Watanabe/Kyushu building 1,237 aircraft from 1942-45 and Dai-Juichi Kaigun Kokusho (11th Naval Air Arsenal) building 48 aircraft from 1940-42.

The Aichi E13A1 made its combat debut over China in the autumn of 1941. Operating from the catapults of cruisers and seaplane tenders, aircraft of this type made air attacks on the Canton-Hankow Railroad, and also flew anti-shipping patrols along the China coast. Its next combat sorties were flown over Hawaii, launched from the cruisers Tone, Chikuma, and Kinugasa. Aichi E13A1s flew reconnaissance over the area of Pearl Harbour shortly before the attack, pinpointing the positions of the American ships in the harbour and noting that all was quiet, and the Americans were not on alert. From then on, E13A1s were committed wherever the Japanese Navy was operating. Flying from either ships or shore bases, as required, the E13A1 was quite successful as long as Allied fighter opposition was limited, despite its poor fuel and crew protection and its pitiful defensive armament (a single 7.7 mm (0.303 in) machine gun in the rear cockpit). It could carry either one 551 lbs (250 kg) bomb under the fuselage between the floats, or four wing-mounted 132 lbs (60 kg) bombs or depth charges. Its maximum endurance was almost fifteen hours, giving it a useful range for patrol and reconnaissance missions. In addition to limited bombing strikes and long-range patrol sorties, the "Jake" as she was code-named, also was used for staff transport, air-sea rescue, anti-shipping attack, and, later in the war Kamikaze attacks.

For nearly four years, the Jake was built without any changes from the original prototype. In November 1944, two new subtypes were introduced, differing externally from the regular E13A1 only by the additions of a propeller spinner for the three-bladed propeller, and two extra pairs of inward-sloping bracing struts for the twin underwing floats. The E13A1a Model 11A received improved radio equipment, while the E13A1b Model 11B was fitted with an air-to-surface search radar, with antennae protruding from the fuselage sides and from the wing leading edges. Either of these versions could be fitted with exhaust flame dampers for night operations, and for anti-shipping attack (usually against surfaced submarines or PT boats), a single flexible Type 99 20 mm cannon, firing downwards and forwards from the fuselage belly, could be mounted, as well. Some Jakes were also fitted with an aerial magnetic submarine detection device, called Jikitanchiki, which required the aircraft to fly at a very low 30-40 ft (9-12 m) above the sea's surface to get any decent results.

Due to the theatre the Japanese operated in and the vast expanses of ocean it encompassed, long range seaplanes were crucial to the Japanese war effort. The Aichi E13A served from Pearl harbour to some of the last Kamikaze attacks of the war. Although easy fodder for Allied fighters the Aichi E13A and its crews performed their missions well throughout the Pacific War.


----------



## gekho (Jun 30, 2011)

The Aichi E16A originated from a 1939 specification for an replacement for the Aichi E13A, which at that time had yet to be accepted by the Imperial Japanese Navy Air Service (IJNAS).[2] Disagreements about the requirements in the 14-Shi specification prevented most manufacturers from submitting designs, but in 1941 a new 16-Shi specification was drafted by the IJNAS around the Aichi AM-22 design which had already been made by Aichi engineers Kishiro Matsuo and Yasuhiro Ozawa.[2] The first AM-22, which first got the experimental designation Navy Experimental 16-Shi Reconnaissance Seaplane and later the short designation E16A1, was completed by May 1942 and was a conventional, low-wing monoplane equipped with two floats and had the unusual (for a seaplane) feature of being equipped with dive brakes, located in the front legs of the float struts, to allow it to operate in a secondary role as a dive bomber.


----------



## gekho (Jun 30, 2011)

In mid-1938 the Japanese Imperial Navy requested a twin-engine fighter designed to escort the principal bomber used at the time, Mitsubishi G3M "Nell". The operating range of the standard Navy fighter, the Mitsubishi A5M "Claude", was only 1,200 km (750 mi), insufficient compared with the 4,400 km (2,730 mi) of the G3M. Moreover, at the time, the potential of the "Zero", then still under development, remained to be evaluated, stressing the need for a long-range escort fighter. In March 1939, Mitsubishi and Nakajima began the development of a project 13-Shi. The prototype left the factory in March 1941 equipped with two 843 kW (1,130 hp) Nakajima Sakae 21/22, 14-cylinder radial engines. There was a crew of three, and the aircraft was armed with a 20 mm Type 99 cannon and six 7.7 mm (.303 in) Type 97 machine guns. Four of these machine guns were mounted in a powered turret, the weight of which reduced the performance of the aircraft considerably. Because of the sluggish handling, being used as ae escort fighter had to be abandoned. Instead, production was authorized for a lighter reconnaissance variant, the J1N1-C, also known by the Navy designation Navy Type 2 Reconnaissance Plane. One early variant, the J1N1-F, had a spherical turret with one 20 mm Type 99 Model 1 cannon mounted immediately behind the pilot. In 1943, Commander Yasuna Kozono（小園 安名） of the 251st Kokutai in Rabaul came up with the idea of installing 20 mm cannons at 30 degree angle in the fuselage. Against orders of central command which was skeptical of his idea, he tested his idea on a J1N1-C as a night fighter. The field-modified J1N1-C KAI shot down two B-17s of 43rd Bomb Group attacking air bases around Rabaul on 21 May 1943.

The Navy took immediate notice and placed orders with Nakajima for the newly designated J1N1-S nightfighter design. This model was christened the Model 11 Gekko (月光, "Moonlight"). It required only two crew and like the KAI, had a twin 20 mm pair of Type 99 Model 1 cannon firing upward in a 30° upward angle and a second pair firing downward at a forward 30° angle, placed in the fuselage behind the cabin, similar to the German Schräge Musik configuration, but also in a ventral mode-the original German Schräge Musik mount was strictly upward-firing only. Development of both Japanese and German night fighters were independent of each other. This arrangement was effective against B-17 Flying Fortress bombers and B-24 Liberators, and its existence was not quickly understood by the allies who assumed the Japanese did not have the technology for night fighter designs. Early versions had nose searchlights in place of radar. Later models omitted the two lower-firing guns and added one 20 mm cannon to face upward as with the other two (J1N1-Sa Model 11a). Other variants without nose antennae or searchlight added a 20 mm cannon to the nose.

The J1N1-S was used against B-29 Superfortresses in Japan, though the lack of good radar and insufficient high-altitude performance handicapped it, since usually only one pass could be made against the higher-speed B-29s. However, some skillful pilots had spectacular successes, such as Lieutenant Sachio Endo, who was credited with destroying eight B-29s and damaging another eight before he was shot down by a B-29 crew, Shigetoshi Kudo (nine victories), Shiro Kuratori (six victories), and Juzo Kuramoto (eight victories); the last two claimed five B-29s during the night of 25–26 May 1945. Another Gekko crew shot down five B-29's in one night, but these successes were rare. Many Gekkos were also shot down or destroyed on the ground. A number of Gekkos were relegated to "Tokko" missions, the Japanese term for kamikaze attacks, using 250 kg (550 lb) bombs attached to the wings.


----------



## Gnomey (Jun 30, 2011)

Good stuff!


----------



## vikingBerserker (Jun 30, 2011)

Excellent!


----------



## gekho (Jul 3, 2011)

Although not a particularly powerful, or technologically advanced aircraft the Aichi D3A Val managed to come as a shock to the Americans when it spearheaded the attack on the American Fleet at Pearl Harbour on 7th December 1941. For the year following Pearl Harbour the Val (protected by Zero fighters) ruled supreme devastating Allied shipping in the South-West Pacific and Indian oceans. This was to last only until it started to come across well defended ships and better Allied fighters and by 1943 the Val had had its day and was no longer feared. The initial shock was mainly due to very poor allied intelligence which had virtually no information on Japanese aircraft and grossly underestimated them. The 'Val' gained its code name from the American system of naming enemy fighters after short boys names, trainers after trees and giving girl's names to bombers. The Val was designed by Tokuhishiro Goake and had an elliptical wing, and no internal bomb storage it also had non retractable landing gear much like the German Stuka dive bomber. Since it was intended as a carrier aircraft the tips of the wings folded for storage. The prototype first flew in 1938 with carrier trials in 1940 and flew operationally during missions in China and Indo-China a fact missed by US intelligence. At Pearl Harbour 126 Val dive bombers took part and the Japanese had over 250 in service by mid 1942. By this period losses were heavy and by 1944 only kamikaze suicide versions were in frontline service. Around 1,495 were finally produced.


----------



## gekho (Jul 3, 2011)

In mid-1936, the Japanese Navy issued the 11-Shi specification for a monoplane carrier-based dive bomber to replace the existing D1A biplane currently in service. Aichi, Nakajima and Mitsubishi all submitted designs, and Aichi and Nakajima were both asked for two prototypes each. The Aichi design started with low-mounted elliptical wings inspired by the Heinkel He 70 Blitz. It flew slowly enough that the drag from the landing gear was not a serious issue, so fixed gear were used for simplicity. The aircraft was to be powered by the 529 kW (710 hp) Nakajima Hikari 1 nine-cylinder radial engine. The first prototype was completed in December 1937, and flight trials began a month later. Initial tests were disappointing. The aircraft was underpowered and suffered from directional instability in wide turns, and in tighter turns, it tended to snap roll. The dive brakes vibrated heavily when extended at their design speed of 370 km/h (200 kn), and the Navy was already asking for a faster diving speed of 240 kn (440 km/h). The second aircraft was extensively modified prior to delivery to try to address the problems. Power was increased by replacing the Hikari with the 626 kW (840 hp) Mitsubishi Kinsei 3 in a redesigned cowling, and the vertical tail was enlarged to help with the directional instability. The wings were slightly larger in span and the outer sections of the leading edges had wash-out to combat the snap rolls, and strengthened dive brakes were fitted. These changes cured all of the problems except the directional instability, and it was enough for the D3A1 to win over the Nakajima D3N1.


----------



## gekho (Jul 3, 2011)

In December 1939, the Navy ordered the aircraft as the Navy Type 99 Carrier Bomber Model 11 (kanjō bakugekiki, usually abbreviated to 艦爆 kanbaku). The production models featured slightly smaller wings and increased power in the form of the 746 kW (1,000 hp) Kinsei 43 or 798 kW (1,070 hp) Kinsei 44. The directional instability problem was finally cured with the fitting of a long dorsal fin, and the aircraft actually became highly maneuverable. Armament was two forward-firing 7.7 mm (.303 in) Type 97 machine guns, and one flexible 7.7 mm (.303 in) Type 92 machine gun in the rear cockpit for defense. Normal bombload was a single 250 kg (550 lb) bomb carried under the fuselage, which was swung out under the propeller on release by a trapeze. Two additional 60 kg (130 lb) bombs could be carried on wing racks located under each wing outboard of the dive brakes.

The D3A1 commenced carrier qualification trials aboard the Akagi and Kaga during 1940, while a small number of aircraft made their combat debut from land bases over China. Starting with the attack on Pearl Harbor, the D3A1 took part in all major Japanese carrier operations in the first 10 months of the war. They achieved their first major success against the Royal Navy during their Indian Ocean raid in April 1942. Val dive bombers scored over 80% hits with their bombs during attacks on two heavy cruisers and an aircraft carrier during the operation. During the course of the war, Val dive bombers had to frequently combine their attacks upon enemy warships with the IJN Kate torpedo plane; consequently enemy vessels were often sunk by a combination strike of bombs and torpedoes. However, there were occasions when just the Vals would make the attacks, or at least score the sinking hits. 

As the war progressed, there were instances when the dive bombers were pressed into duty as fighters, their maneuverability being enough to allow them to survive in this role. In June 1942, an improved version of the D3A powered by a 969 kW (1,300 hp) Kinsei 54 was tested as the Model 12. The extra power reduced range, so the design was further modified with additional fuel tanks to bring the total tankage to 900 L (240 US gal, giving it the range needed to fight effectively over the Solomon Islands. Known to the Navy as the Model 22, it began to replace the Model 11 in front-line units in autumn 1942, and most Model 11s were then sent to training units. When the Yokosuka D4Y Suisei became available, the D3A2s ended up with land-based units or operating from the smaller carriers, which were too small to handle the fast-landing Suisei. When American forces recaptured the Philippines in 1944, land-based D3A2s took part in the fighting, but were hopelessly outdated and losses were heavy. By then, many D3A1s and D3A2s were operated by training units in Japan, and several were modified with dual controls as Navy Type 99 Bomber Trainer Model 12s (D3A2-K). During the last year of the war, the D3A2s were pressed back into combat for kamikaze missions.


----------



## vikingBerserker (Jul 4, 2011)

Excellent!


----------



## Gnomey (Jul 5, 2011)

Good stuff!


----------



## gekho (Jul 6, 2011)

When the Pacific War exploded in all its fury on December 7, 1941, the Nakajima B5N2 carrier torpedo bomber was the best in service with any of the world’s navies. One hundred and forty-four aircraft of this type participated in the Pearl Harbor attack as torpedo and level bombers, and they crippled the American Pacific Fleet’s battleship force. During the following twelve months, carrier-based B5N2s were to participate in sinking three American aircraft carriers, while land- and carrier-based B5N2s supported Japanese amphibious landings on all fronts. But by 1944, the Kate, as it was code-named by the Allies, was plainly obsolete, and so it finished out the war in second-line units, mainly as an anti-submarine patrol plane. The Japanese Navy never regarded its B4Y1 biplane torpedo bomber (a contemporary of the essentially similar Fairey Swordfish) as anything other than a stop-gap type, because they wanted a monoplane torpedo bomber with performance more compatible with that of the Mitsubishi A5M carrier fighter (which see). They issued, in 1935, a specification calling for a single-engined monoplane “carrier attack bomber” (as the Japanese termed torpedo bombers). The requirements called for: (1) a wingspan of less than 52 ½ ft. with provision for hydraulic wing folding to reduce the plane’s span to no more than 24 ft. 7 9/32 in.; (2) an armament of one 1,764-lb. torpedo and a single rearward-firing 7.7mm machine gun for protection; (3) a maximum speed of 207 mph at 6,560 ft.; (4) a normal endurance of 4 hours or a maximum of 7 hours at 155 mph; (5) a normal crew of three; and (6) either a Nakajima Hikari or Mitsubishi Kinsei radial engine.

Katsuji Nakamura’s design team at Nakajima created a beautifully clean low-wing monoplane with a hydraulically-operated retracting undercarriage. The large wing folded upwards, and the hinging points were so arranged that the wingtips overlapped one another when folded above the cockpit. When compared to the large wing, the fuselage seemed oddly small, but it was kept relatively short at 33 ft. 9 ½ in. to fit on the Navy’s standard carrier elevators. Other innovations on the Type K, as the company named its creation, were Fowler flaps and a variable-pitch propeller. Powered by the Nakajima Hikari 2 nine-cylinder radial engine, the prototype, given the official designation B5N1, first flew in January 1937. Hydraulic-system difficulties marred the initial flight tests, but the troubles were soon fixed, and the JNAF was particularly pleased with the B5N1’s speed, which at 230 mph exceeded the requirement by a comfortable margin.But they were worried that the many technical innovations being introduced by the new aircraft would make it excessively hard to maintain under operational conditions. Nakajima accordingly simplified the second prototype, changing the Fowler flaps to more conventional types and replacing the hydraulic wing-folding mechanism with a manual one. It also had a newer Hikari 3 engine with a constant-speed propeller-the first ever fitted to a production Japanese naval plane of any type-and integral wing fuel tanks with increased capacity. In this form the B5N1 easily won the competition with Mitsubishi’s B5M1, and it went into production in November of 1937 as the Navy Type 97 Carrier Attack Bomber Model 11 (B5N1 Model 11).

Carrier qualification trials were carried out at the same time the new bomber was flying its first combat missions in China in the spring of 1938. Armed with bombs, the B5N1 was used as a single-engined level bomber, in a fashion similar to a twin-engined machine. The observer, who was seated between the pilot and the rear gunner/radio operator, was also the bombardier during these missions; he would aim the bombs using a pair of small folding doors in the floor of the fuselage to see his target. Covered by A5M fighters, the B5N1 was a success despite its lack of protection for the crew and fuel and its modest defensive armament of a single 7.7mm machine gun. No major modifications were necessary for China operations, and the only minor change made was to add a mast antenna to replace the trailing antenna. But the JNAF was aware that there would be other opponents than the Chinese, and so in 1939 they instructed Nakajima to develop a better-performing variant of the B5N1. The B5N2 Model 12, or Type 97 Carrier Attack Bomber Model 12, first flew in December 1939; it was externally similar to the older variant aside from its engine, a Nakajima Sakae 11 fourteen-cylinder radial. A tighter-fitting cowling was used, to improve pilot view and reduce drag, and a small hub was fitted to the propeller to further reduce drag and improve the engine cooling. Oddly the B5N2 was not much faster than the B5N1 in spite of the 36% increase in power, but the Navy was pleased, as the Sakae was more reliable than the Hikari, and the B5N2 would fly most of its missions over long stretches of water.


----------



## gekho (Jul 6, 2011)

By the time of the Pearl Harbor attack, the B5N2 had totally replaced the B5N1 in all front-line units, both land- and carrier-based. Commander Mitsuo Fuchida was the aerial commander for the Hawaiian Operation; he flew in a B5N2 as observer/bombardier, and was also lead bombardier of the 49 Kates used as level bombers in the first wave. All of the B5N2 level bombers carried a single 1,653-lb. bomb made from a remanufactured armour-piercing shell. The 40 planes earmarked for the actual torpedo attack were led by Lt. Cdr. Shigeharu Mutara, considered the finest torpedo bomber pilot in the Imperial Navy if not the world. His planes were carrying a specially modified torpedo for use in shallow harbours like Pearl; the idea had been gleaned from study of the British attack on Taranto, Italy, in December 1940, where Swordfish torpedo bombers had sunk or crippled a number of Italian battleships. Stupidly, the United States had ignored the lessons of Taranto, and had disdained using torpedo nets at Pearl; they paid heavily for their neglect. Between the high-level bombers and the torpedo planes, the US Navy lost two battleships sunk outright, three more sunk but recoverable with difficulty, and three damaged heavily (the Pennsylvania, in dry dock, was damaged by dive bombers and strafing fighters). But that did not end the B5N2’s career. In the furious carrier battles of 1942, the Nakajima torpedo bomber played a prominent role in sinking the American carriers Lexington, Yorktown, and Hornet. But in all those battles losses were very heavy; Lt. Cdr. Murata, for example, was killed in the Battle of Santa Cruz, shot down by US Navy fighter ace Lt. (j.g.) Stanley “Swede” Vejtasa. Murata was just one of seven kills Vejtasa scored that day, October 26, 1942 (in 1969, Vejtasa, as a captain, was commander of Miramar NAS, and was one of the founders of the “Top Gun” training program).

The Kate did most of its later combat flying from land installations, figuring prominently in the Solomons, Marianas, and Philippines campaigns. Its last carrier-based engagement was the Battle of the Philippine Sea in June 1944. Insufficient performance, and poor crew and fuel-tank protection, contributed to staggering losses in all these campaigns, and so the Kate was relegated to second line and training units by the end of 1944. But the B5N2 found a new lease on life because it still had excellent long range endurance; it was used for maritime reconnaissance and anti-submarine patrol, in areas where Allied fighters were unlikely to be encountered. The B5N2 gave Japanese convoys desperately needed escort against the depredations of Allied submarines. Some B5N2s were fitted with a primitive form of ASV (Air-to-Surface-Vessel) radar, with antennas fitted along the rear fuselage sides and the wing leading edges, and others were given Jikitanchiki magnetic airborne submarine detection gear. The most war-weary B5N2s joined B5N1s in service as trainers, target-tugs, and even tow planes for gliders. One thousand, one hundred and forty-nine B5Ns were built, 669 by the parent company Nakajima between 1936 and 1941, 200 by Aichi in 1942-43, and 280 by the Naval Air Arsenal at Hiro in 1942-43. The B5N Kate enjoyed a brief status as the finest torpedo bomber in the world, and helped bring Japan to its pinnacle as an Empire; but eventually, its increasingly poor performance and protection left it outclassed, and it finished its operational life as a supernumerary, a spear-holder, as it were.


----------



## vikingBerserker (Jul 6, 2011)

Excellent!


----------



## gekho (Jul 7, 2011)

At a time when the triumphs of the B5N were still almost three years in the future, the Japanese navy issued a specification for a replacement, recognizing that only limited overall design improvement of the B5N could be achieved in the B5N2. Accordingly design went ahead in 1939 of the Nakajima B6N and, despite the navy's preference for the Mitsubishsi Kasei radial, a Nakajima Mamoru was selected for the prototype which flew early in 1941. Superficially the B6N Tenzan (heavenly mountain) resembled the earlier aircraft, but the much increased power and torque of the big engine and four-blade propeller was found to impose considerable directional stability problems, demanding that the vertical tail surfaces be offset to one side. Flight trials dragged on, and were further delayed by troubles during carrier acceptance tests; then Nakajima was ordered to stop production of the Mamoru engine, so modifications had to be introduced to suit installation of the Kasei. In due course B6N1 aircraft (of which only 133 were built) were embarked in the carriers Shokaku, Taiho, Hiyo, Junyo and Zuikaku, and took part in the great Battle of the Philippine Sea of June 1943, many being lost when the three first-named carriers were sunk. In that month production started of the slightly improved B6N2 (of which 1,133 were produced before the end of the war), but the heavy losses among Japanese carriers resulted in the 'Jill' being largely deployed ashore, particularly after the Battle of Leyte Gulf. Thereafter many BSNs were consigned to the kamikaze role.


----------



## gekho (Jul 7, 2011)

Early experience in the Pacific war showing the need for a long-range carrier-based reconnaissance aircraft, Nakajima was instructed in early 1942 to develop an aircraft to meet this Imperial Japanese Navy requirement. It resulted in an airframe similar to that of the company's B6N, the fuselage incorporating camera ports and observation windows, with power provided by a 1358kW Nakajima Homare 11 radial engine. The first prototype flew on 15 May 1943, its performance being disappointing with the Homare 11 engine, and 18 more prototype/pre-series aircraft followed, some with the more powerful Homare 21 engine, before the type was ordered into production in early 1944 as the Navy Carrier Reconnaissance Plane Saiun (Nakajima C6N1). Allocated the Allied codename 'Myrt' when it entered service in the summer of 1944, the Saiun (painted cloud) was fast enough to enjoy almost complete immunity from interception by Allied fighters. A total of 463 had been built' when production ended in August 1945, the total including a small number of C6N1-S two-seat night-fighter conversions from C6N1 aircraft, and one C6N2 prototype with a 1476kW Homare turbocharged engine.


----------



## vikingBerserker (Jul 7, 2011)

Great info!


----------



## Gnomey (Jul 7, 2011)

Good stuff!


----------



## Wayne Little (Jul 10, 2011)

Excellent!


----------



## gekho (Jul 22, 2011)

In 1933, the Imperial Japanese Navy (IJN) issued a requirement for an experimental large flying boat. Kawanishi submitted two designs for monoplane flying boats, including the "Type Q" with four engines and the "Type R" with three. The IJN puzzled over these submissions for a time, then issued a revised specification in early 1934. Kawanishi replied with a new design, the "Type S", evolved from the two earlier submissions. The Type S was accepted, and the first of four prototypes of the "H6K1", as the IJN designated it, performed its initial flight on 14 July 1936, with Katsuji Kondo at the controls. Service trials began at the end of the month. The second and third prototypes followed in 1937 and the fourth in 1938. The H6K1 was designed by a team under Yoshio Hashiguchi and Shizuo Kikuhara, leveraging off data provided by a Kawanishi group that had visited Short Brothers in the UK. It was a neat prewar flying boat design of metal construction, with some similarities to the US Consolidated PBY Catalina, but arguably more attractive and certainly bigger. The initial prototype had a streamlined hull, a strut-mounted wing with four Nakajima Hikari 2 nine-cylinder air-cooled radial engines with 625 kW (840 HP) each, and a twin-fin tail. It carried a crew of nine. The H6K1 had light defensive armament of three guns, consisting of a single 7.7 millimeter (0.303 caliber) Type 92 machine gun in a power-driven dorsal turret, and the same weapon on flexible mounts in nose and tail. Offensive armament consisted of two 800 kilogram (1,764 pound) torpedoes mounted on the wing bracing struts, or up to a total of 1,000 kilograms (2,200 pounds) of bombs using a similar carriage scheme.

Some changes in the design were made during prototype evaluation. The first, third, and fourth prototypes were brought up to full operational fit, re-engined with Mitsubishi Kinsei 43 radials with 745 kW (1,000 HP) each, and delivered to the IJN in January 1938. They were given the designation "H6K1 Type 97 Flying Boat Model 1". These three aircraft were followed by ten basically identical full production aircraft, which were designated "H6K2", and then two machines built as VIP transports and designated "H6K3". The H6Ks performed operational missions in the Japanese war in China. The main production version was the "H6K4", which went into service in 1941. A total of 127 was built. The major changes in this variant were increased fuel capacity and improved armament. The hand-held 7.7 millimeter Type 92 gun in the nose was retained, but the dorsal turret was replaced by another hand-held 7.7 millimeter gun and the tail position was "up-gunned" to a Type 99 Model 1 20 millimeter cannon. A glass blister was fitted on each side of the rear fuselage, with each blister featuring a Type 92 machine gun on a flexible mount. Offensive weapon load remained as before.

There were actually two subvariants or "blocks" of the H6K4. Initial production was the "H6K4 Model 2-2", which retained the Kinsei 43 engines of its predecessors. From August 1941, production moved to the "H6K4 Model 2-3", fitted with uprated Kinsei 46 radials with 798 kW (1,070 HP) each. Later on, they would both be referred to as "Model 22", with no distinction for the powerplants. 64 H6K4s were in service with the IJN when the Pacific War broke out in December 1941. The type saw considerable action, particularly in the South Pacific, even conducting bombing raids on Rabaul and the Dutch East Indies. The H6K4 had extreme range and endurance, able to undertake 24-hour patrols. The Allies gave the machine the codename "Mavis", in accordance with the doctrine that gave Japanese fighters male names and other Japanese aircraft types female names.


----------



## gekho (Jul 22, 2011)

At the same time the type's predecessor, the Kawanishi H6K, was going into service in 1938 the Navy ordered the development of a larger, longer-ranged patrol aircraft under the designation Navy Experimental 13-Shi Large-size Flying Boat. The result was a large, shoulder-winged design that is widely regarded as the best flying boat of the war. Despite this, initial development was troublesome, with the prototype displaying terrible handling on the water. Deepening of the hull, redesigning of the planing bottom and the addition of spray strips under the nose rectified this. Two further prototypes -actually pre-production aircraft- joined the development program in December 1941. The IJNAF accepted the first production version as the H8K1, Navy Type 2 Flying Boat, Model 11, of which 14 would be built. The improved H8K2 variant soon appeared, and its extremely heavy defensive armament earned it deep respect among Allied aircrews. The H8K2 was an upgrade over the H8K1, having more powerful engines, slightly revised armament, and an increase in fuel capacity. This was to be the definitive variant, with 112 produced. 36 examples of a dedicated transport version, the H8K2-L, were also built, capable of carrying 62 troops. This aircraft was also known as Seiku (晴空, "Clear Sky"). The side defensive blisters, ventral defensive hatch, and dorsal turret were discarded. To increase the available space within the aircraft, its hull tanks were removed, thus reducing its range.

The H8K entered production in 1941 and first saw operational use on the night of 4 March 1942 in a second raid on Pearl Harbor. Since the target lay out of range for the flying boats, this audacious plan involved a refuelling by submarine at French Frigate Shoals, some 550 miles north-west of Hawaii, en route. Two planes from the Yokohama Kokutai (Naval Air Corps)[8] attempted to bomb Pearl Harbor, but, due to poor visibility, did not accomplish any significant damage. H8K2s were used on a wide range of patrol, reconnaissance, bombing, and transport missions throughout the Pacific war. The H8K2 was given the Allied code name "Emily"


----------



## gekho (Jul 24, 2011)

The requirement for a large torpedo/ dive-bomber for operation from a new, larger class of aircraft carrier caused the Imperial Japanese navy to draw up in 1941 the specification of an aircraft to replace the Nakajima B6N and Yokosuka D4Y. As this specification called for an internal bombload of up to 500kg, or the carriage of a 800kg torpedo externally, coupled with high maximum speed and long range, a powerful engine was essential. The navy selected what was virtually an experimental powerplant for this task: the Nakajima Homare 11 twin-row radial developing around 1342kW. Aichi began work on this requirement, and its AM-23 prototype flew in mid-1942. This large aircraft, then designated Navy Experimental 16-Shi Carrier Attack Bomber (Aichi B7A1), was a mid-wing monoplane of inverted gull-wing configuration, a layout selected so that the main units of the retractable tail-wheel landing gear, mounted at the 'elbows' of each wing, would be as short as possible. A section of each outer wing panel folded for carrier stowage. The fuselage and tail unit were conventional, the former providing enclosed accommodation for a crew of two.

As might have been anticipated, the combination of problems from the air-frame, coupled with the teething troubles of the new engine, meant that it was almost two years before the type was ordered into production as the Navy Carrier Attack Bomber Ryusei (Shooting Star), or Aichi B7A2. Apart from nine prototype B7A1s, only 80 examples were completed by Aichi before its factory was destroyed in the serious earthquake of May 1945; an additional 25 were built by the Navai Air Arsenal at Omura. By the time these aircraft entered service, when they were allocated the Allied codename 'Grace', the Japanese navy no longer had any carriers from which they could operate, with the result that they saw only limited use from land bases.


----------



## gekho (Jul 24, 2011)

During 1942 Watanabe designed an ASW aircraft to meet an Imperial Japanese Navy requirement for a specialized aircraft in this category. Designated Kyushu Q1W, this was a cantilever mid/low-wing monoplane with retractable tailwheel landing gear, and powered by two Hitachi GK2C Amakaze 31 radial engines. Operated by a crew of three, the Q1W was planned to use an advanced search radar, but this failed to materialize and instead the Q1W had to make do with an earlier and somewhat ineffective radar complemented by MAD (magnetic anomaly detection) equipment. First flown in September 1943, the Q1W1 was ordered into production in early 1944 as the Navy Patrol Plane Tokai (eastern sea), later allocated the Allied codename 'Lorna'. It proved to be unsuccessful in operational service, too slow and too vulnerable to attack by Allied fighters, and only about 150 had been built by the time the Pacific war ended.


----------



## gekho (Jul 24, 2011)

Well-proportioned and purposeful in appearance, the Yokosuka D4Y possessed an excellent performance and owed much of its concept to the German He 118, for whose manufacturing rights Japan negotiated in 1938. Designed as a fast carrier-based attack bomber and powered by an imported Daimler-Benz DB 600G engine, the D4Y1 was first flown in December 1941; D4Y1-C reconnaissance aircraft were ordered into production at Aichi's Nagoya plant, the first of 660 aircraft being completed in the late spring of 1942. The first service aircraft were lost when the Soryu was sunk at Midway. Named Suisei (comet) in service and codenamed 'Judy' by the Allies, many D4Yls were completed as dive-bombers, and 174 Suiseis of the 1st, 2nd and 3rd Koku Sentais were embarked in nine carriers before the Battle of the Philippine Sea. However, they were intercepted by American carriers, and suffered heavy casualties without achieving any success. A new version with 1044kW Aichi Atsuta 32 engine appeared in 1944 as the D4Y2 but, in the interests of preserving high performance, nothing was done to introduce armour protection for crew or fuel tanks, and the sole improvement in gun armament was the inclusion of a 13.2mm tramable gun (replacing the previous 7.92mm gun) in the rear cockpit. This version suffered heavily in the battle for the Philippines. Problems of reliability with the Atsuta (DB 601) engine led to adoption of a Kinsei 62 radial in the D4Y3, and this engine was retained in the D4Y4 which was developed in 1945 as a single-seat suicide dive-bomber. A total of 2,033 production D4Ys was completed.


----------



## gekho (Jul 24, 2011)

The P1Y was designed by the Yokosuka Naval Air Technical Arsenal to Navy specification 15-Shi, calling for a fast bomber with speed matching the Zero, range matching the G4M, a 907 kg (2,000 lb) bombload, and the ability to dive-bomb as well as carry torpedoes. As the result, the construction suffered from excess complexity, difficulty of manufacture, and poor serviceability. Problems with the availability of enough reliable Nakajima Homare engines led to their replacement by the Mitsubishi Kasei in the P1Y2-S night-fighter version. The streamlined design of the Ginga is attributed to Miki Tadanao, an engineer who, after World War II, went on to create a similar aerodynamic design for Japan's earliest `bullet trains` (Shinkansen), while working with the Japan National Railways(JNR).

The first flight was in August 1943. Nakajima manufactured 1,002 examples, which were operated by five Kokutais (Air Groups), and acted as land-based medium and torpedo bombers from airfields in China, Taiwan, Marianas, Philippines, Ryukyu, Shikoku, and Kyūshū. During the last stages of the war the P1Y was utilized as a kamikaze aircraft against the United States Navy during the Okinawa Campaign in Operation Tan No. 2. A night fighter version, the P1Y2-S Kyokko (極光, "Aurora"), with Mitsubishi Kasei engines, was equipped with radar and Schräge Musik-style upward-firing -- as well as forward-firing -- 20 mm cannon. A total of 96 were produced by Kawanishi, but due to inadequate high-altitude performance against B-29s, many were converted back to Ginga bombers.


----------



## Wayne Little (Jul 24, 2011)

Excellent pics!


----------



## vikingBerserker (Jul 24, 2011)

I agree, and another excellent thread!


----------



## Gnomey (Jul 25, 2011)

Good stuff!


----------



## Wayne Little (Jul 27, 2011)

Bring on some more...!


----------



## TimEwers (Jul 28, 2011)

Great thread But what I want to know is what color were the early kates like up to battle of midway time frame? were they green or the same as the Val's and Zero's?.


----------



## tony french (Dec 11, 2011)

gekho said:


> Extensively test-flown in 1934, the Nakajima Ki-4 sesquiplane had divided landing gear with streamlined wheel spats, and accommodated pilot and observer in tandem open cockpits, the pilot just below a cut-out in the trailing edge of the upper wing. The Ki-4 went into production and service in 1935 as the Army Type 94 Reconnaissance Aircraft Model 2 which dispensed with the wheel fairings and had a redesigned tail unit. Production continued for several years, some aircraft being licence-built by Tachikawa among the total of 516.
> 
> The Type 94 was used widely in China by the Japanese army on direct co-operation duties, in close support of the ground forces. It was armed with up to four 7.7mm machine-guns and could carry 50kg of light bombs. A number were still in service in the supply and liaison role in 1941. The Japanese army tested two Ki-4s as seaplanes, one with twin floats and the other with one main and two stabilising floats. A landplane was used for flotation bag tests to check buoyancy in the event of an emergency put-down on water. Powered by a 477kW Ha-8 radial engine, the Type 94 could attain a speed of 300km/h. Wing span was 12.00m and maximum take-off weight 2500kg.


 
Dear Gekho, Beautiful photos of a beautiful plane and its pilots. The beauty of the wings, their generous area, the dihedral and general proportions make the Ki-4 an excellent flying peanut scale subject. I have searched the net but cannot find a drawing or 3 view. Would you be so kind to help me if you can. Tony French


----------



## gekho (Dec 12, 2011)

tony french said:


> Dear Gekho, Beautiful photos of a beautiful plane and its pilots. The beauty of the wings, their generous area, the dihedral and general proportions make the Ki-4 an excellent flying peanut scale subject. I have searched the net but cannot find a drawing or 3 view. Would you be so kind to help me if you can. Tony French



Ok, I am working on it.

Reactions: Like Like:
1 | Like List reactions


----------



## niabcd (Jan 16, 2012)

Ki-4 3-view,

How about this one?


----------



## proton45 (Feb 4, 2012)

Nice collection of photo's, and great topic.


----------



## Johnny .45 (Jan 7, 2015)

I know this is an old post, but my OCD compels me to mention that that last photograph on the Nakajima B5N post appears to be a B6N, not a B5N. It has the distinctive large over-cowling intake, the bulbous cowling, large spinner and what appears to be a forward-swept aerial mast, all of which are features of the Nakajima B6N, the successor to the B5N.


----------



## johnbr (Aug 30, 2017)

Kawanishi H8K Emily flying boat

Reactions: Informative Informative:
1 | Like List reactions


----------



## Old Wizard (Aug 31, 2017)




----------



## Wayne Little (Sep 1, 2017)

Good one.


----------



## johnbr (Jan 8, 2019)

*B6N2 *

Reactions: Like Like:
1 | Winner Winner:
1 | Like List reactions


----------



## Wurger (Jan 8, 2019)




----------



## Crimea_River (Jan 8, 2019)

Source?


----------



## Gnomey (Jan 23, 2019)

Good shots!


----------



## johnbr (Oct 16, 2019)

*Japanese Nakajima B5N torpedo bombers 
WWII planes



*

Reactions: Winner Winner:
2 | Like List reactions


----------

