Mitsubishi 2MR8

 

The Mitsubishi 2MR8 was a Japanese short-range reconnaissance aircraft of the 1930s designed and built by Mitsubishi for the Imperial Japanese Army Air Force (IJAAF).

Its origins date back to 1930 when the IJAAF issued a requirement for a short-ranged reconnaissance aircraft which would act as a supplement for the long-range Kawasaki Type 88. Mitsubishi developed two designs, a biplane based on their 2MR and B2M reconnaissance aircraft and torpedo bomber designs respectively. The other one was the 2MR8, a high-wing parasol monoplane.

A total of four prototypes were made, the first of which was powered by a Mitsubishi A2 radial engine which yielded 320 hp of power and flew for the first time on 28th March 1931. Successive prototypes were powered by more powerful versions of such engine and, eventually, production version featured a Mitsubishi Type 92 engine which yielded 475 hp and drove a two-bladed propeller. The fourth prototype was modified to have a reduced wing area and a shorter fuselage and it was accepted by the IJAAF and ordered into production as the Mitsubishi Army Type 92 Reconnaissance Aircraft.

The production variant had wide-track divided landing gear and carrier a crew of two, a pilot and an observer in two open cockpits. It was armed with two forward-firing synchronized 7.7 mm (0.303 in) Type 89 machine guns plus and additional one or two mounted on a ring at the observer's cockpit. A total of 230 machines were manufactured at Mitsubishi's plant in Nagoya from April 1930, when the type was ordered into production until March 1934 when production ceased in favor of the Nakajima Ki-4 and the Kawasaki Ki-3, which showed better performance rates. 

In order to meet the requirements of the Japanese Ministry of Railways for a survey aircraft, Mitsubishi developed also a civilian version of the Type 92, which was known as the Hato Survey Aircraft. A single aircraft was ordered in 1935, together with a Fokker Super Universal made by Nakajima and powered by a Mitsubishi A5 engine. The Hato differed from the military version in having a glazed canopy over the rear cockpit, which was also enlarged to accomodate a crew of two, an open forward pilot's cockpit and spat-type main wheel fairings. It was delivered in March 1936 and received the civilian registration of J-AARA. 

The Type 92 entered service with the Kwangtung Army Air Corps in their reconnaissance chutais (squadrons) which were also part of the hiko rentais (air regiments of mixed composition). The usage of the Type 92 was very limited as only three hiko rentais (1st, 3rd and 7th) were equipped with the 2MR8. These were also part of the "Kanto" hiko shidan (air corps) and saw active usage during the hostilities in Manchuria in 1932, though during the latest stages, which were just some few skirmishes. They weren't keep on active service with the Kwangtung Army for much longer as they were being replaced. However, by 1937 at the beginning of the Second Sino-Japanese War, some of them were still active and in Agust-September that year, some of them were listed to have been operated in the ground support role in North-Eastern China. Anyway, by late 1937, they were completely withdrawn from the frontlines. Some disarmed machines were handed over to various organizations, such as "Aikoku-Go" a paramilitary flight school for women.

The Guangxi Clique, a warlord regime that existed in Southern China, bought also some machines in 1934 and 1935, during the brief period of peace between the two countries. They were used against the Kuomintang when these invaded and, when the Guangxi-Kuomintang War was over, some were captured by the Republic of China Air Force and were used during the earlier stages of the Second Sino-Japanese War in 1937.

All things consider, the Type 92 didn't shine as an excellent machine. However, it was the first aircraft powered by a completely Japanese engine which was not a licensed copy of a foreign engine.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_2MR8

2. https://www.valka.cz/Micubisi-2MR8-t34884

3. http://www.airwar.ru/enc/other1/2mr8.html (translated)

Further reading (in Chinese - use the translator)

1. http://cwlam2000.epizy.com/caf23.htm

Mitsubishi 1MF -Recap-

 

Note: This is a recap of the plane mentioned in the title, as we didn't like the way it was, so we've decided to put them all in a single post.

The Mitsubishi 1MF was a Japanese carrier fighter aircraft of the 1920s decade. It was designed for Mitsubishi by the British aircraft designer Herbert Smith. It was known as the "Navy Type 10 Carrier Fighter" by the Imperial Japanese Navy Air Service (IJNAS).

The Japanese shipbuilding company Mitsubishi Shipbuilding and Engineering Co. Ltd. set up a subsidiary company called Mitsubishi Internal Combustion Engine Manufacturing Co. Ltd. in the year 1920 to manufacture automobiles at the city of Nagoya. They quickly attracted the attention of the Imperial Japanese Navy (IJN) to produce three types of aircraft to operate from the aircraft carrier Hosho: a fighter (Mitsubishi 1MF), a torpedo bomber (Mitsubishi 1MT) and a reconnaissance aircraft (Mitsubishi 1MR). To design those aircraft, they hired Herbert Smith, who, at that time was unemployed, as the company he was working on, Sopwith Aviation Company, went defunct. For that purpose, Smith brought to Japan a team of 7 British engineers. 

The fighter designed, received the name of 1MF by Mitsubishi and Navy Type 10 Carrier Fighter by the IJN (referring to 1921, the tenth year of the Taisho period in Japan) and it flew for the first time in October 1921. 

The 1MF was a single-seat, single-bay biplane with unequal span-wings made entirely out of wood. It was powered by a single Hispano-Suiza 8 engine (locally produced under license as the Mitsubishi Hi) , which yielded 300 hp of power and was armed with two 0.303 vickers machine guns buried in the upper fuselage. It was fitted with a claw-type arrestor gear for use with British-style fore and aft arrestor cables. 

After flight testing, it was accepted by the IJN their standard carrier fighter. A total of 128 machines of every variant were manufactured from 1922 until 1928 when production on the type ceased. The different variants were as follows:

• 1MF1 & 1MF1A: Initial prototypes. Powered by the Mitsubishi Hi engine fitted with a car-type radiator in the nose. Only one prototype each being built in 1921. The MF1A had increased wing area.
• 1MF2: An experimental prototype with two-bay wings. Powered by the Hispano-Suiza 8 engine, produced under license in Japan and with some modifications aimed to improve cooling. The original car-type radiators were also replaced by Lamblin-style ones, placed under the nose. Flew for the first time in 1926.
• 1MF3 & 1MF3B: The most produced and successful variant. Powered by a Mitsubishi Hi-V8 (license version of the Hispano-Suiza 8F) and armed with two Vickers 0.303 in machine guns in the nose. Its production period ranges from 1923 until 1928. 
  The 1MF3B was a sub-variant modified to carry a small amount of bombs to provide ground support. This designation was probably given retroactively in 1926.
  
• 1MF4: A revised version with a modified rudder, the cockpit moved forward and two Lamblin-type coolers above the landing gear. They were manufactured in 1926.
• 1MF5 & 1MF5A: The last variant of the fighter. A small amount were either produced or converted in 1928. The 1MF5 was a revised version with minor changes made, while the 1MF5A was a trainer version with jettisonable wheeled undercarriage and underwing inflatable floats to allow for a safe ditching. The IJN handed over six 1MF5A to civilian users. 

The 1MF entered service with the IJNAS in 1923 replacing the Gloster Sparrowhawk. One 1MF3 became the first aircraft to take-off and land on Japan's new aircraft carrier Hosho on 28th February 1923. The 1MF series proved to be reliable and tough and they operated from Akagi and Kaga aircraft carriers too, when they entered service in 1927 and 1928 respectively. and continued in active service until 1930 when they were replaced by the Nakajima A1N, itself a licensed copy of the Gloster Gambet. 

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_1MF

2. https://www.valka.cz/Micubisi-1MF-t33673 (translated)

MItsubishi Ki-21, part one

 

Back in 1936, the Imperial Japanese Army issued a requirement for a new heavy bomber to replace the Mitsubishi Ki-20 and the Mitsubishi Ki-1 bombers which were clearly outdated for the time. The requirement called for a crew of at least four men, a top speed of 400 km/h (250 mph) with an endurance of at least five hours and a bomb payload of 750 kg (1.650 lb). Those technical requirements were very ambitious for the time and very few twin-engine bombers could achieve such performance numbers.

Mitsubishi and Nakajima were asked to submit their proposals, with Kawasaki's one being rejected. Mitsubishi's design was an all-metal mid-wing cantilever monoplane with a retractable landing gear, ventral bomb bay and two Mitsubishi Ha-6 radial engines. 

The first prototype flew for the first time on 18th December 1936, with the second prototype, which differed from the first one in having a long greenhouse canopy instead of a ventral turret, flying in January 1937. In the ensuing competition against Nakajima Ki-19 (Nakajima's proposal), they found to be similar in performance numbers, being the Ki-21 better in speed and endurance and the Ki-19 being better as a bombing platform and its Nakajima Ha-5 engines being more reliable. In order to make a decision, two more prototypes were ordered from both Mitsubishi and Nakajima, with Mitsubishi ordered to switch its own 825 hp Ha-6 engines for the Ha-5 ones, used by Nakajima and vice versa. That third prototype of the Ki-21 featured a glazed nose similar to the Ki-19 and revised tail surfaces. Therefore, the Ki-21 proved to be superior and was ordered into production as the "Army Type 97 Heavy Bomber Model 1A" in November 1937.

Production aircraft began to enter service in August 1938, supplementing and replacing the Fiat Br.20 Italian bombers that had been purchased as an interim measure. 

The Ki-21-Ia was used in combat for the first time during the Second Sino-Japanese War by the 60th Sentai (an unit equivalent to an aviation Group or Wing in other air forces) from autumn 1938, performing long-range unescorted missions together with the Br.20 of the 12th and 98th Sentais. The Ki-21 proved to be more reliable, robust and better suited for the long Asian distances than the Br.20. Two additional Sentais, the 58th and the 61st were deployed to Manchuria in the summer of 1939 to operate against China, with aircraft of the 61st being heavily employed against Soviet and Mongolian forces during the Nomohan incident (AKA Battles of Khalkin Gol) in June-July 1939, when the Japanese forces launched their main attack.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-21

2. https://www.valka.cz/Micubisi-Ki-21-Sally-t31499 (translated)

Mitsubishi B5M

 

In summer 1935, the Imperial Japanese Navy Air Service (IJNAS) issued a specification, 10-shi, for a carrier-based strike-bomber with torpedo capabilities. The specification called for a maximum speed of 330 km/h (205 mph) , an endurance of up to 7 hours unloaded and 4 loaded with a single torpedo plus folding wings to facilitate its usage in a carrier. Those requirements exceeded by far the performance numbers of the winner of the previous specification, 9-shi,  the Yokosuka B4Y. Regarding armament, the 10-shi called for a total payload of up to 800 kg (1.764 pounds) plus a rear-defensive machine-gun. The resulting machine had to be powered by the Mitsubishi MK8 Kinsei radial engine. 

Two old rivals, Mitsubishi and Nakajima (which eventually won the contest with the famous Nakajima B5N), were called to participate in the contest, with Yokosuka not taking part although they won the previous contest.

Mitsubishi's project for the 10-shi, received the internal designation of Ki-16 and was designed by Jiro Horikoshi, designer of the successful A5M and the more successful A6M Zero. Inspired by the Northrop 5A (a prototype for the Northrop YA-13 which was sold to the IJNAS by the USA), Horikoshi decided to adopt a fixed landing gear, relying on the success of the A5M, covering wheels with a massive cowling. He also refused the mechanical wing-folding drive the 5A had in order to not overload the engine with additional tasks. 

The B5M prototype was completed in January 1937, almost at the same time the B5N's prototype was completed. Both bombers were tested and the B5M showed a slower speed than the B5N, 355 km/h (221 mph) versus 368 km/h (229 mph) of the B5N.

During the year 1937, both airplanes were tested, with the IJNAS' high command divided between the two. On one hand they liked the good flying characteristics of the B5N, but on the other, they saw it as a very progressive machine, as it had many new characteristics for naval bombers of the time, such as retractable landing gear. So, in late 1937, they IJNAS' high command opted to adopt both designs under the same denomination, of "Type 97 Deck Attack Aircraft of the Fleet". To distinguish both bombers, "Type 97 Model 1" was the B5M and "Type 97 Model 2" was the B5N. 

Unfortunately for Mitsubishi, Nakajima was able to fix the problems of the earlier models of the B5N, while Mitsubishi didn't as they were more concentrated on improving the A5M and designing the A6M, therefore, the B5M was discontinued with only 125 machines having been built between 1936 and early 1941.

The B5M1 (an improved model with a new engine, from 1939) was powered by the Mitsubishi MK8D Kinsei-43 radial engine which, in its newest models, had a theoretical power of 1.080 hp, raising this way its top speed to 381 km/h (234 mph), making it faster than the B5N. However, the IJNAS still decided in favour of the B5N.

The first combat unit to be equipped with the B5M in late 1938 was the newly formed Suzuka Kokutai, based in Eastern Japan. This unit undertook the task of training and evaluating the B5M. 

Contrary to popular belief, the B5M was not deployed to China, as every machine was deployed in combat training units in mainland Japan and, in early 1941, they were assigned as follows:

• Oita Kokutai: 45 units
• Usa Kokutai: 63 units
• Omura Kokutai: 16 units

All those units were deployed at Kure Naval Base, in Tokyo and carried out anti-shipping patrols over the Pacific Ocean, after Pearl Harbour. 

As the IJNAS was in need of every aircraft they could count on, the B5M was rushed to many front-line units, so many B5Ms were assigned in early 1942 to the 33rd Kokutai which took part in the battle of Celebes Island, in the Dutch East Indies. It is not known the exact number of machines that served with the 33rd Kokutai, but by the time that unit was re-organized as the 932th Kokutai, in the summer of 1943, there were still many B5Ms active. 

One of them became famous when, at the hand of Captain Kino, rammed the leader of a formation of American B-24 bombers that bombed the city of Makassar.

From July to October 1942 some B5Ms were assigned to the escort-carrier Un'yo, serving in the area of Truk Atol. It seems too that some machines were retrofitted with forward-firing machine guns, however, as the war went on, the usage of both the B5M and the B5N decreased and, apart from a sporadic anti-submarine patrol, the B5M wasn't used. 

The last known usage in combat of a B5M was during the Kamikaze attacks in Okinawa during April-May 1945. 

Sources:

1. http://www.airwar.ru/enc/bww2/b5m.html (translated)

2. https://en.wikipedia.org/wiki/Mitsubishi_B5M

3. https://www.skytamer.com/Northrop_1933(Gamma5D).html (for the Northrop 5A)

4. https://www.valka.cz/Micubisi-B5M1-Mabel-t30172

Mitsubishi G3M, part three

 

The Mitsubishi G3M was a land-based medium bomber that was used for the first during the Second Sino-Japanese War of 1937 where it made great use of its long range. On 14th August 1937 forty-two G3M2 together with seven Hiro G2H and escorted by twelve Nakajima A4Ns and twelve Mitsubishi A5M fighters belonging to the 2. Rengo Kokutai (formed itself by the 12th and 13th kokutais) took off from their bases on western Japan, crossed the East China Sea and bombed the cities of Hangchow and Kwanteh, in China and performed, among other actions, terror bombings on coastal and inland targets in China, including bombings during the Battles of Shanghai and Nanjing. 

The bombers and their escorts were often engaged in combat by Curtiss Hawk III and Boeing P-26 fighters of the Chinese Air Force in the early periods of the war. As the war kept going on, the Japanese set up airfields in occupied China, where many bomber kokutais operated from in the strategic carpet bombardment campaigns of the Chinese mainland, taking advantage of its long range (4.400 km - 2.700 milles) as the distances in that war were considerably longer. Most notably, it was involved in the round-the-clock bombing of the city of Chongqing where the type took part from February 1938 until 1941 when the Pacific War started as that city was used for operative bomber training and testing of new types.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_G3M

2. https://en.wikipedia.org/wiki/Bombing_of_Chongqing

3. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

Mitsubishi G3M, part two.

 

The Mitsubishi G3M Model 11 had a crew of five, could carry up to 800 Kg (1763.7 lb) of bombs carried externally under the fuselage or a single torpedo (as the specification made by the Imperial Japanese Navy - IJN - requested) capable of sinking an armoured battleship.

Just like the Ka-15 its defensive armament consisted on two retractable dorsal turrets equipped with a single 0.303in Type 92 machine gun plus another retractable ventral one. These turrets were initially "flat topped", however, in later versions, some of them were retroactively fitted with a "cupola shaped" one, typical of the G3M2. 

It was powered by two Mitsubishi Kinsei 3 engines, rated at 898 hp each. 

Although it flew for the first time, as the Ka-15 (see our previous post) in 1935, in a flight taking off from Mitsubishi's private airfield in Nagasaki and landing at Haneda airport, close to Tokyo, it wasn't until 1937 that the G3M was employed in combat. It was employed, albeit in smaller numbers than its successor the G3M2, in the Japanese expansionists campaigns on the Chinese mainland, known as the Second Sino-Japanese War. During this campaign, the G3M1 exploited their long-range capabilities when aircraft belonging to the 1. Rengo Kokutai (a special unit) was set up together with Kanoya and Kisarazu Kokutais based at Taipei in Formosa and Omura, Kyushu and Jeju islands in western Japan, though Jeju nowadays belongs to south Korea. 

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_G3M

2. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

3. https://www.valka.cz/Micubisi-G3M1c-11C-Nell-t1283

Mitsubishi G3M, part one, Mitsubishi Ka-15

 

Back in 1935 the Imperial Japanese Navy (IJN) issued a requirement for a land-based twin-engine reconnaissance airplane. Mitsubishi presented the Ka-15, a development of their previous Ka-9/G1M1 recon airplane. The Ka-15 prototype presented some room for improvement to be used as a land-based long-range medium bomber. 

The original prototype, flew for the first time in July 1935 powered by two Hiro Type 91 radial engines which could deliver up to 750 hp of power mounted on the mid-set wings, just like in the Ka-9. 

Twenty more prototypes and pre-production Ka-15 were completed, of which three were powered by the Hiro engine and remaining 17 by either the Mitsubishi Kinsei 2 (which could deliver up to 830 hp of power) or the Mitsubishi Kinsei 3 (whose power output could reach up to 910 hp), engines which greatly boosted the bomber's performance. 

These aircraft were assigned to the IJN and received the unofficial designation of G3M1a, comprising the three original prototypes with Hiro engines and solid nose, G3M1b, to designate two prototypes powered with the Kinsei 2 engine, having solid noses and one of them having been tested with ski undercarriage for winter operations, and G3M1c for the remaining machines featuring a redesigned cockpit and a glazed nose. 

They could carry up to 800 kg of bombs externally or a single torpedo. The versions featuring a solid nose were armed with two 0.303 in Type 92 machine guns (a Japanese copy of the famous Lewis machine gun) placed inside retractable dorsal turrets. These pre-production bombers were assigned to various Kokutais (IJN's basic combat group) which used them for various service trials, however, before the completion of the first batch, the IJN ordered the much promising G3M1 Model 11, being itself a more elaborate development of the Ka-15/G3M1a-b-c.

Sources:

1. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

2. https://en.wikipedia.org/wiki/Mitsubishi_G3M

3. https://www.armedconflicts.com/Mitsbishi-Ka-15-1st-2nd-5th-and-6th-prototype-20061-15-1-2-5-a-6-t33046

Airspeed Envoy, part three

The Airspeed Envoy was a British light, twin-engined transport aircraft that was designed and built by Airspeed Ltd. in the 1930s.
The Envoy was designed by A.H. Tiltman as a twin-engine development of the earlier Courier. It used the same wooden construction outer wing panels and innovative retracting main undercarriage.
It was a twin-engined low-wing cabin monoplane entirely made out of wood with fabric-covered control surfaces. It had a rearwards retracting main undercarriage with a fixed tailwheel. It was built in three series. The series I was the initial production variant which didn't have trailing-edge flaps, with just 17 of them being manufactured. The series II featured split-flaps and just 13 of them were built. The series III was similar to series II but with detailed minor improvements and 19 of them were built. Each series was sold with a different engine choice, including the Wolseley Aries, Armstrong-Siddeley Cheetah V or Armstrong-Siddeley Lynx IVC, radial engines. Those engines were housed in a variety of cowlings, mostly short-chord Townend rings, but also wider chord cowlings with or without blisters for cylinder heads.
The prototype, registered as G-ACMT, flew for the first time on 26th June 1934 and was shown to the public at the exhibition made by the Society of British Aircraft Constructors (SBAC) at Hendon aerodrome, in London on month later, in July. Small-production scale was set-up at Airspeed's factory in Portsmouth.
It was manufactured in many variants, with the most produced ones being AS.6J Envoy III which was powered by two 345 hp Armstrong-Siddeley Cheetah IX (27 exemplars made), and AS.6E Envoy III which was powered by two 340 hp Walter Castor engines (just 5 exemplars made).
It was used by many countries:

• United Kingdom: The first production Envoy I, registered as G-ACVH, flew in October 1934 and was used as a company demonstrator. The second, belonging to the Series I, but powered by two Wolseley Aries III engines, was delivered to Lord Nuffield, in order to take part in the MacRobertson Air Race from England to Australia in 1934. However, the aircraft was damaged and it was withdrawn from the race, to be replaced by the Airspeed AS.8 Viceroy (which we made a post some days ago, check it out). One Envoy participated in the Schlesinger Air Race, from Portsmouth to Johannesburg, in South Africa, but it crashed killing the crew of two.
  At least three Envoy III were taken on charge by the Royal Air Force to serve with the No.24 Squadron. The military Envoys were used for VIP Transport duties from as early as 1937 (when the first one was officially acquired by the RAF) until 1942 when all of them were either damaged or destroyed).
• Germany: The German Luftwaffe had at least 3 Envoys. Two of them being ex-Czechoslovak, which were given to Finland in March 1942, and a captured one which was used at Fluglehrer-schule Brandenburg-Briest, a flying school. The fate of this machine is unknown but, most likely, it was destroyed during the course of the war.
• Japan: Two Envoys I were sent to Japan in 1935, one for evaluation by the Japan Air Transport Co. (NKY-KK) and one for the Imperial Japanese Navy Air Service (IJNAS), labelled as Airspeed LXM. Three months later they ordered four more Envoys and a production license was also acquired.
  Production started at Mitsubishi's factory, in Nagoya, Japan, as Mitsubishi Hinazaru-type Passenger Transport. It was initially powered by the Gasuden Jimpu radial engine, but later they were replaced by either the Armstrong-Siddeley Lynx or the Wolseley Aries III engines. Mitsubishi built eleven machines in total and they had landing flaps which weren't fitted to any other Airspeed-built Envoys. When the Jimpu-powered aircraft was tested, it all finished with a crash, killing the flight-test observer, being that the first fatality during flight testing of a Mitsubishi Aircraft. The crash was blamed upon the engines, which produced excessive drag, so a decision to switch to British engines was taken. As we said, eleven aircraft were made and all of them served with the NKY-KK, which later became Greater Japan Airways.
  Apparently at least one was given to Manchukuo Imperial Air Force.
• Manchukuo: It seems that an unknown number of Mitsubishi-built Envoys were passed on to Manchukuo National Airways, which was the paramilitary organization that acted as Manchukuo's airline. As we couldn't find graphical evidence of the Envoy serving in Manchukuo's colours, the drawing should be considered as speculative. The fate of these machines is unknown, but they were most probably, destroyed during the War.

Sources:

1. https://en.wikipedia.org/wiki/Airspeed_Envoy

2. https://en.wikipedia.org/wiki/Manchuria_Aviation_Company

3. https://www.valka.cz/topic/view/114456/Airspeed-AS-6J-Envoy

4. https://www.valka.cz/topic/view/114447/Airspeed-AS-6E-Envoy

5. https://www.ab-ix.co.uk/pdfs/airspeed_prewar.pdf

6. https://en.wikipedia.org/wiki/No._24_Squadron_RAF

Mitsubishi G1M1/Ka-9

The Mitsubishi Ka-9 was originally designed to perform aerial surveillance over the Pacific. It was the first prototype in the series of aircraft that would later be known as the Mitsubishi G3M 'Nell'. The Imperial Japanese Navy's (IJN) first ambitious attempt to produce a long range bomber was part of the Experimental 7-shi programme of 1932, which was hoped for that programme to produce a new generation of Japanese naval aircraft. However, the only successful to come out from it was the Kawanishi E7K reconnaissance seaplane, while the only land-based bomber to emerge from the programme was the Hiro G2H, which flew for the first time in 1933 which, although it had the required range, it lacked performance in many other factors like speed and, eventually only eight of them would be built in 1935.
In 1933 the head of the technical development at the Naval Aircraft Establishment was the Rear-Admiral Isoroku Yamamoto, who was convinced that the IJN needed a long-range land-based bomber to be used as a defensive weapon from bases on the scattered islands of the Japanese Empire in the Pacific Ocean. It was clear that the G2H wasn't that aircraft, so Yamamoto gave Mitsubishi in early 1933 a non-competitive contract to produce a long-range, high-speed multi-engined monoplane. No bomb load or performance figures were issued, giving Mitsubishi free reign.
Mitsubishi was chosen because in the late 1920s it had developed strong bonds with Junkers. In fact, in 1928 they had purchased a number of licences for Junkers' aircraft designs and, by the start of 1933, they had designed the Mitsubishi Ki-1, Ki-2 and Ki-20 bombers for the Imperial Japanese Army Air Force. A number of Japanese engineers, among them Sueo Honjo (who designed the Ka-9), had also received training from Junkers.
Sueo Honjo was the main chief engineer in charge of the "Navy's Project 435" or, "Experimental 8-shi reconnaissance plane". Internally at Mitsubishi it was known simply as "Ka-9".
The Ka-9 was completed on 18th April 1935 and was a twin-engined monoplane powered by two Hiro Type 91 engines which gave 650 hp of power each. It had a slim streamlined fuselage, twin vertical tails and rudders, and Junkers' double wings. On this design, a second, much smaller airfoil was mounted on the back of the main wing. The gap between the two wings increased lift, specially when the aircraft flying at a step angle, either when climbing or landing, at the expense of increased drag. It was also the first Japanese military aircraft to have retractable landing gear.
Yamamoto was among the first people to test the aircraft and was impressed by its performance. Honjo had produced an aircraft with a range of 3265 nautical milles (6047 km), better than any contemporary military aircraft. The Ka-9 was given the short designation of G1M1 by the IJN making it the first entry in a new land-based bomber sequence.
Mitsubishi were therefore rewarded with the Navy Project 79 for the Navy Experimental 9-shi land based attack plane, which would eventually emerge as the Ka-15 and accepted into IJN's service as the G3M.
The sole G1M1 was used as a testbed for Mitsubishi's 14-cylinder Shinten twin-row air cooled radial engines, which could yield the impressive amount (for the time) of 920 hp but only could increase aircraft's speed by 15 mph (24.1 km/h) and were very unreliable.

Sources:
1. http://www.historyofwar.org/articles/weapons_mitsubishi_G1M1.html
2. https://elpoderdelasgalaxias.wordpress.com/2013/07/01/mitsubishi-ka-9-name-it/
3. https://www.secretprojects.co.uk/threads/mitsubishi-ka-9-8-shi-special-reconnaissance-plane-g1m1.23519/
4. https://www.valka.cz/Micubisi-G1M1-t64820
5. https://en.wikipedia.org/wiki/Mitsubishi_G1M

Messerschmitt Bf.108, part three

The Messerschmitt Bf.108 was a German single-engine sports and touring aircraft that was used by many countries all around the globe. Among many users, it was also used by the next ones:

• Brazil: At least one was used by Viaçao Aerea Rio-Grandese (VARIG) airline during the 1930s and was most probably used as a VIP transport.
• Chile: One Bf.108 was purchased directly to Messerschmitt by the Chilean senator Carlos del Campo in the mid-to-late 1930s. After a brief period of using it as his personal transport, he sold it to LAN (Linea Aérea Nacional - National Airline) who operated the aircraft as a VIP transport and was painted with the colours depicted below. With the outbreak of World War 2, as spare parts became a problem, it was sold again to another unknown customer who kept it left to rot in a barn. In the mid 1960s some Chilean air enthusiasts tried to buy the plane but the owner sold it to some North American customer. It was then when the trace of this Bf.108 vanished. According to some people it was sent to the USA where it was repainted and restored to flying condition, while some other claim that it was repainted and shown in a museum. However, the real fate of the aircraft is still a mystery.
• Czechoslovakia: The Czechoslovak Air Force operated some ex-German exemplars after the War. They were renamed as K-70 and served with the Transport Squadron based at Prague's Kbely airbase.
• Japan: The Imperial Japanese Army Air Service bought some few Bf.108 for testing purposes. They were assigned to the Army Aviation Experimental Centre in Japan, where they were tested during the 1930s. After testing they decided to not order them and they were passed on to Manchukuo, their main puppet state in Asia.
• Manchukuo: From 1936 until 1940 the Manchukuo National Airways (MKKK) (which in spite of its name was a paramilitary organisation) used some Bf.108 ceded from Japan for light transport and reconnaissance duties. 
• Norway: It seems that some few ex-German machines were used by the Royal Norwegian Air Force during the post-war period. As we couldn't find graphical evidence, the colours should be considered speculative.
• Poland: The Polish Central Staff for the Aviation League operated some ex-German Bf.108 during the post-war period. It was also used by the Polish Internal Security Corps which was the Polish counterpart of the Soviet NKVD.

Sources:

1. https://en.wikipedia.org/wiki/Messerschmitt_Bf_108

2. http://www.warbirdalley.com/bf108.htm

3. Wydawnictwo Militaria 149 - Messerschmitt Bf-108 Taifun

4. https://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=347

Mitsubishi Ki-30, part three

The Mitshubishi Ki-30 was designed and developed in response to an Imperial Japanese Army specification issued in May 1936 for a replacement of the Kawasaki Ki-3 light bomber. The scope of the issue was to replace it with a complete indigenous bomber both in design and manufacture.
Both Mitsubishi and Kawasaki were requested to build two prototypes each by December 1936. The specification requested a top speed of 400km/h (250mph) at 3000m (9840ft) high, a normal operating altitude from 2000m (6560ft) to 4000m (13130ft) high, the ability to climb to 3000m in 8 minutes and an engine which had to be either the 850hp Mitsubishi Ha-6, the 825hp Nakajima Ha-5 or the 850 Kawasaki Ha-9IIb, all of them radial and liquid cooled. The requisition also requested a normal bomb load of 300kg (660lb), with a maximum of 450kg (990lb), one forward-firing machine gun and another rearward-firing one in a defensive position with the ability to perform 60º dives for dive bombing and a loaded weight less than 3300kg (7280lb).
The first Mitsubishi prototype flew on 28th February 1937 and was powered by the Mitsubishi Ha-6 radial engine which drove a three-bladed propeller. It was originally designed with a retractable landing gear but the wind tunnel tests showed that the gain in speed was marginal due to the landing gear's extra weight. Therefore a fixed and spatted main wheels system arrangement was chosen instead. The wing was mounted at a point above the line of the aircraft's belly to fully enclose the bomb bay within the fuselage. The pilot sat just above the leading edge of the wing and the rear gunner/radio-operator just behind the wing trailing edge, in a long canopy which gave an excellent all-around vision.
A second prototype was completed the next month, this time fitted with the slightly more powerful Nakajima Ha-5 engine. Both were completed two months behind schedule and were overweight, however, both of them met or exceded the requirement's minimum specifications. As the second prototype could achieve a top speed of 423km/h (263mph) at 4000m high, the Imperial Japanese Army Air Force placed an evaluation order of 16 exemplars. Those were delivered in January 1938 and, after passing trials, the Army ordered the Ki-30 into production in March under the designation of Army Type 97 Light Bomber.
A total of 704 Ki-30s were built. Most of them, 636, were built by Mitsubishi Heavy Industries at the city of Nagoya from February 1937 until April 1940 and the 1st Army Air Arsenal --AKA Army Air Supply Workshop-- located at the city of Tachikawa manufactured 68 exemplars from 1939 until September 1941 when production of the type ceased.
The Ki-30 was used in combat for the first time in the Second Sino-Japanse War in spring 1938. It showed enough reliability to operate in rough airfields and it was highly effective when operated escorted by fighters. This success continued in the early stages of the Pacific War and the type saw extensive use in the Invasion of the Philippines. However, once unescorted, their losses quickly mounted up and the type was withdrawn to second line duties. During 1942 they served in the China-Burma-India Theatre of War, operating from Thailand. Anyway, by the end of 1942 the type was deemed as obsolete and was relegated to training roles only. Many of them were used as kamikaze aircraft towards the end of the war.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-30
2. https://www.valka.cz/Micubisi-Ki-30-Ann-t1289
3. The Hamlyn Concise Guide To Axis Aircraft Of World War II

MItsubishi A5M, part four

The Mitsubishi A5M was also used during the early stages of the Japanese entry into World War 2. In fact, the Flying Tigers encountered unoficially the Type 96 (Mitsubishi A5M4) at Mingaladon airfield in Burma on 29th January 1942.
As obsolete as it could be in December 1941, the A5M was still in service. Some American Intelligence sources believed that the A5M still served as the Imperial Japanese Navy Air Service's main fighter when it had been replaced by the A6M Zero on the first-line aircraft carriers and with the Tainan Kökütai (Taiwan Air Group). Other Japanese carriers and Kökütais continued to use the A5M until the A6M was produced in enough quantities.
On 1st February 1942 the American carrier USS Enterprise (CV-6) launched air-strikes at Japanese naval and air-bases on Roi and Kwajalein Atolls in the Gilbert islands. During those actions, three Douglas SBD dive bombers were shot down by Mitsubishi A5M, including the aircraft of Lt.-Cdr. Halstead Hopping, CO of VS-6 Squadron. The last combat action of the A5M took place at the Battle of the Coral Sea on 7th May 1942 when two A5M together with four A6M Zeroes, belonging to the Japanese carrier Shöhö, clashed against American airplanes that had shot down their carrier.
During the closing months of the war, some A5M airframes were used for kamikaze attacks.
There were various variants of the A5M like the A5M3, which was a single regular A5M2 powered by an Hispano-Suiza 12Xcrs twelve-cylinder Vee liquid-cooled engine which delivered 602hp of power for take-off and 681hp at 12.795ft high (4.500m). It was armed with just one 20mm Hispano-Suiza HS-404 cannon mounted in the engine and firing through the propeller hub. However there were plans to install more machine guns in the wings, but, as both Imperial Japanese Navy and Imperial Japanese Army favoured radial engines against inline ones, the model was discarded and only one prototype was built in 1938.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_A5M
2. https://forum.valka.cz/topic/view/28833
3. Salamander Books - The Complete Book of Fighters

Mitsubishi A5M, part three

The most competitive adversary that the A5M faced was the Soviet Polikarpov I-16 which was a fast and heavily armed fighter that was flown both by Chinese Nationalist pilots and Soviet volunteers. The aerial battles that took place on 18th February and 29th April 1938 were the largest ones ever seen up to that time.
The battle of 29th April confronted 31 Polikarpov I-16s and 36 Polikarpov I-15bis (making it a total of 67 of them) versus 18 Mitsubishi G3M escorted by 27 A5Ms. Victory was claimed by each side, as the Sino-Soviet side claimed 11 fighters and 10 bombers (making it a total of 21) with a total of 50 airmen killed and two captured at a cost of 12 aircraft lost and 5 pilots killed. On the other hand, the Japanese claimed they only lost two G3Ms and other two A5Ms with more than 40 Chinese aircrafts shot down.
The Mitsubishi A5M2b was a version with an enclosed NACA cowling. It was manufactured from October 1937 until 1938 by Mitsubishi Heavy Industries, in Nagoya, Japan with 108 of them made and the 21st Naval Aviation Workshop manufactured 16 of them in 1939. A total of 124 of them were manufactured. It was powered by a single Nakajima Kotobuki 3, nine-cylinder air-cooled single-row radial which delivered a power of 631hp for take-off and 705hp at 9186ft high (2800m).
It was armed with two 0.303in (7,7mm) Type 89 machine guns placed at the nose and could carry a small bomb payload of 60kg (132lb).
This variant was barely used as the next main variant, the A5M4, was already pushing for being Imperial Japanese Navy Air Service's main fighter.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_A5M
2. https://forum.valka.cz/topic/view/28830
3. Salamander Books - The Complete Book of Fighters

Mitsubishi A5M, part two

Note: This post is a direct follow-up of the previous one.
The main antagonist of the Mitsubishi A5M during the Second Sino-Japanese War, was the Curtiss Hawk III that was in service with the Chinese Nationalist Air Force, but the A5M was better in almost every aspect, in spite of its weak armament.
The A5M proved to be quite effective and damage-tolerant with an excellent maneouvrability a sturdy construction and provided an excellent escort for the Mitsubishi G3M bombers, which composed the backbone of the Imperial Japanese Navy Air Service's bomber force.
The Mitsubishi A5M2a was an improved variant that was produced by Mitsubishi Heavy Industries in Nagoya from June-December 1937. Only a total of 36 of them were manufactured and they were powered by a single Mitsubishi Kotobuki KAI 3b radial engine which delivered a power of 602hp for take-off and 681hp at 3250m high (10663ft) and drove a three-bladed propeller. It was armed with two forward-firing 7,7mm (0.303in) Type 89 machine guns placed in the nose with 500 rounds each. It could also carry a small bomb load as it had a total payload of 60Kg (132lb).
It operated together with the enclosed-cockpit variant A5M2b (which will be covered in a future post) and was gradually replaced by the much better variant and, by mid-1939, there wasn't any A5M2 in active service with the Imperial Japanese Navy Air Service.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_A5M
2. https://forum.valka.cz/topic/view/28829
3. Salamander Books - The Complete Book of Fighters

Mitsubishi A5M, part one

Note: This is our last post of the year as tomorrow we start out Christmas holidays.
Back in 1934 the Imperial Japanese Navy issued a specification for an advanced fighter with a maximum speed of 350km/h (220mph) at 3000m (9840ft) high and had to be able to climb to 5000m (16400ft) in 6 and half minutes. This specification was called 9-shi and both Nakajima and Mitsubishi submitted designs.
Mitsubishi assigned the task of designing their new fighter to a team lead by Jiro Horikoshi (who designed the unsuccessful Mitsubishi 1MF10 and would also design the successful A6M Zero). The resulting design was called the Mitsubishi Ka-14 which served as the prototype for the A5M.
As the A5M won the contract, an initial production order for 75 aircraft was placed under the designation of Mitsubishi A5M1. It entered service with the Imperial Japanese Navy Air Service in 1937 and soon was involved in the aerial battles of the Second Sino-Japanese War including the ones versus the Chinese Boeing P-26C, in the world first aerial dogfight between metallic monoplanes.
The A5M1 was the first production model which was produced from 1936 (when the prototype flew for the first time) until June 1937. Seventy-five exemplars were manufactured all of them by Mitsubishi Heavy Industries in Nagoya, Japan. It was designed to operate from carriers and was powered by a single Nakajima Kotobuki 2 KAI 1 nine-cylinder air-cooled single-row radial which delivered a power of 572hp for taking off and 621hp at 1500m (4920ft) high. That engine drove a two-bladed metallic propeller.
It was armed with two fixed synchronized forward-firing 7,7mm (0,303in) Type 89 machine guns placed in the nose with 500 rounds.
The A5M1 was quickly replaced by the improved version A5M2 and, by 1938, there wasn't any active A5M1 serving with the Imperial Japanese Navy Air Service and it received the Allied reporting name of "Claude".

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_A5M
2. https://forum.valka.cz/topic/view/28828
3. Salamander Books - The Complete Book of Fighters

Mitsubishi Ka-14

Back in 1934, the Imperial Japanese Navy issued a specification calling for an advanced fighter that would reach a maximum speed of 350km/h (220mph) at 3000m (9840ft) high and that could climb to 5000m (16400ft) in 6,5 minutes. Both Nakajima and Mitsubishi competed for this specification which was called 9-shi (1934).
Mitsubishi assigned the task of designing a new fighter to a team leaded by Jiro Horikoshi, who was the original designer of the previous, albeit unsuccessful, Mitsubishi 1MF10 and would later design the famous and successful Mitsubishi A6M Zero. The resulting design received the internal denomination of Mitsubishi Ka-14. It was an all-metal low-wing fighter with a thin elliptical inverted gull-wing and a fixed undercarriage, which was chosen because the increase in performance, estimated at a 10% in drag but just at a 3% in maximum speed, arising from use of a retractable undercarriage didn't justify the extra weight.
The first prototype flew for the first time on 4th February 1935 at Nagoya, in Japan and was powered by a single 5-cylinder Nakajima Kotobuki engine which yielded a power of 596hp, and although information about its armament is unknown, most likely, it wasn't armed. During testing, problems with the engine were found, as the reducer was very faulty, as well as stability ones. Therefore they decided to test new engines on the fuselage and wing flaps on a second prototype.
The second prototype was built shortly later, in that same year, 1935, this time powered by a 3 nine-cylinder Nakajima Kotobuki radial engine which yielded 705hp of power, and, like its most direct predecessor, the first prototype, its not known if it was armed, but, most likely, it wasn't.
One year later, in 1936 a third prototype was built, this time powered by a 789hp Nakajima Hikari 1 radial engine which was followed by a fourth one, all of them used to test the different engines.
The experience gained on the Mitsubishi Ka-14, inspired the later design of the Mitsubishi A5M, which would eventually win the contract.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_A5M
2. https://forum.valka.cz/topic/view/118810

Mitsubishi Ki-15

The Mitsubishi Ki-15 was a Japanese reconnaisssance aircraft which was also used as a light attack bomber during the Second World War.
It was designed by Mitsubishi to meet a requirement from the Imperial Japanese Army Air Force of 1935 for a two-seat high-speed reconnaisssance aircraft. The design submitted by Mitsubishi was a low-wing cantilever monoplane with a fixed, spatted undercarriage which was similar to other all-metal designs of the early-to-mid 1930s like the Heinkel He.70 or the Northrop Alpha.
Initially it was powered by a single Nakajima Ha-8 radial engine which yielded 750hp of power at 4000m (13120ft) high. The first prototype made it to the air in May 1936 and testing proved succesful with the aircraft meeting all performance requirements and achieving a speed of 481km/h (299mph) showing, at the same time, good flying characteristics.
Service testing was completed without any difficulty and the type was ordered into production under the official denomination of Army Type 97 Command Reconnaisssance Plane Model 1. One year after the prototype flew for the first time, in May 1937, the first batch of 437 aircrafts was handed to the Imperial Japanese Army.
The first model, Ki-15-I, was rushed into operational service at the beginning of the second Sino-Japanese war in 1937. It proved very useful in Chinese soil, where it performed missions deep into Chinese strategic rear areas, reaching even the city of Lanzhou, located at the province of Gansu. It enjoyed a clear advantage thanks to its high speed, until the Chinese Air Force adquired the Polikarpov I-16. The Ki-15 was used in a wide variety of roles like level bombing, close support and photo reconnaissance before it was eventually replaced by the Mitsubishi Ki-30.
It's known that after the World War 2, the Chinese Communist Air Force, operated an unknown number of captured aircraft which were based in Manchuria. They were captured at the city of Harbin in June 1946 and by 1948 they were completely repaired and being used as trainers. They served in that role until 1951 when they were withdrawn.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-15
2. https://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=890

Mitsubishi Ka-8

During early 1930s the Imperial Japanese Navy showed interest in the concept of two-seat fighters, as it was popular with foreign air arms. Therefore they ordered a prototype of the Nakajima NAF-1 6-Shi two-seat fighter in 1931. Albeit the NAF-1 was unsuccessful, IJN's interest in two-seat fighters persisted and in 1933 they requested designs for carrier-based two-seat fighters both from Nakajima and Mitsubishi.
Mitsubishi submitted a design, which they named the Ka-8 and the IJN named it Mitsubishi Experimental 8-Shi two-seat fighter. It was a single-engine biplane made out of mixed wood and metal. It had duraluminum spars in its single-bay equal-span staggered wings with wooden ribs and fabric covering. Fuselage structure was made out of welded steel tube with fabric covering with pilot and gunner/observer sitting in tandem in open cockpits. It was armed with two forward-firing 0.303in Vickers machine guns plus another defensive one mounted flexibly in the rear cockpit and it also could carry a small amount of bombs under the wings.
A twin-tail was fitted and it had a fixed undercarriage. It was powered by a single Nakajima Kotobuki which delivered 580hp (430Kw) of power and was a license-built version of the Bristol Jupiter radial engine.
Two prototypes were made by Mitsubishi the first of which was completed in 1931, with both of them being delivered to the IJN later in that same year. The second prototype broke-up when performing diving tests at Yokosuka on 16th September 1934. The pilot managed to escape by parachute but the observer in the rear seat was killed. That accident caused testing of the second prototype to be abandoned, with the other contender, the Nakajima NAF-2 being also rejected and the IJN abandoning the two-seat fighter category.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_Ka-8
2. https://forum.valka.cz/topic/view/48242
3. Salamander Books - The Complete book of fighters

Mitsubishi 1MF10

Back in 1932, the Imperial Japanese Navy issued a specification both to Nakajima and Mitsubishi to find a replacement for the Nakajima A2N which was their main carrier-borne fighter.
Breaking with the biplane tradition which had been the rule until that same moment, both companies submitted monoplane designs with Nakajima submitting a navalized version of their Army Type 91 fighter which was already in service with the Imperial Japanese Army.
Mitsubishi assigned the design of its contestant to a team led by Jiro Horikoshi (the same designer of the mighty A6M Zero) who eventually created the first low-wing cantilever monoplane to be designed in Japan, the Mitsubishi 1MF10.
The Mitsubishi 1MF10 (AKA Mitsubishi Experimental 7-Shi Carrier Fighter) was made entirely out of all-metal with a monocoque duraluminium fuselage, with duraluminium wing structure covered in fabric, with an open cockpit. It was powered by a single Mitsubishi A4 14-cylinder air-cooled radial engine which yielded 780hp (580Kw) of power which drove a two-bladed wooden propeller. It had a fixed undercarriage, both main and tailwheel.
The first prototype, with the internal company name of Mitsubishi Experimental 7-Shi Carrier Fighter, flew for the first time in March 1933 and the first prototype was destroyed shortly later, in July 1933, due to a broken tail during diving tests, although the pilot successfully jumped out of the cockpit by parachute. The second prototype, which had a slightly modified undercarriage, with the main wheels and undercarriage legs faired into streamlined spats, was also destroyed in a crash when it entered an uncontrolable dive spin in June 1934 when it was being piloted by Motoharu Okamura who bailed out in time to save his life but at the cost of four fingers, jeopardizing that way his career as fighter pilot.
Although the design was advanced for its time (it was comparable to the American Boeing P-26), it wasn't accepted by the Imperial Japanese Navy because it had poor handling and it didn't meet the requirements of the specification. However, it did form the basis for more advanced designs as Horikoshi used elements of it (like the box-spar) in the later successful design like the Mitsubishi A5M fighter which had similar layout.

Sources:
1. https://en.wikipedia.org/wiki/Mitsubishi_1MF10
2. https://en.wikipedia.org/wiki/Motoharu_Okamura
3. Salamander Books - The Complete Book of Fighters

Aichi D1A

The Aichi D1A was a Japanese carrier-based dive bomber. It was created as the Imperial Japanese Navy needed an advanced carrier-bomber and therefore, in 1934 they prompted Aichi to finish their AB-9 design, which had already one prototype into service, the D1A1.
It was designed by the German Ernst Heinkel who worked on request of Aichi. Initially it was highly based on the Heinkel He.50 but it was equipped with floaters instead of a fixed landing gear, however, the prototype of the very next model, the Heinkel He.66 was sold to Aichi which they manufactured it as the Aichi D1A1.
As it was based on the export model of the Heinkel He.50, (the He.66) it was a metallic biplane with a fabric covering, a fixed landing gear and a conventional tail landind skid. Initially they were powered by either 490hp or 580hp engines but it wasn't until the second model, the D1A2 came that it was powered by the more powerful 730hp Nakajima Hikari radial engine. It had an offensive armament of two 7.7mm type 92 machine guns plus one defensive 7.7mm type 92 one. It could also carry one 250 bomb under the fuselage and 2 30kg bombs under the wings.
They mainly were used from the Second Sino-Japanese War of 1937 until Japan entered the World War 2 in December 1941. At the beginning of the Pacific War all D1A1 models were decommissioned and the remaining D1A2 were retired from the frontlines and used as advanced bomber trainers. There is, however, one exception because some of them were still being used as second-line support bombers until 1942 in mainland China. After most of them were retired they were handed to the Manchukuo's coast guard where they served most probably until the end of the war.

Sources:
1. https://en.wikipedia.org/wiki/Aichi_D1A
2. http://www.aviastar.org/air/japan/aichi_d1a.php