Micubiši B2M (palubní útočný letoun typ 89)

Mitsubishi B2M - přehled verzí
Mitsubishi B2M- version overview


三菱 八九 式 艦上 攻 撃 機 - Mitsubishi Ha-chi kyū shiki kandžō kōgeki-ki/Mitsubishi Naval Onboard Bomber type 89


Allied code name: not assigned
Japanese name:?



Designation Aircraft design - description
Blackburn T.7B prototype ordered by the Japanese Navy, redesignated Mitsubishi 3MR4
Mitsubishi B2M1 mass-produced version, on which design modifications were made during production
Mitsubishi B2M2 slightly lighter and modified version from 1933





Manufacturer Production period [b/b Made pieces] ]
Blackburn Airplane and Motor Co Ltd., Brough, Yorkshire [img_6 comment = United Kingdom of Great Britain and Northern Ireland (GBR)] https://vcdns.valka.cz/images/flags/gbr.gif[/img_6] 1928 - 11. 1929 prototype Blackburn T.7B
Mitsubishi Nainenki Seizo KK, Nagoya [img_6 comment = Japan (JPN)] https://vcdns.valka.cz/images/flags/jp.gif[/img_6] 03. 1932 - 1933 unknown number of B2M1 out of a total of 205 produced
Mitsubishi Jukogyo KK, Nagoya [img_6 comment = Japan (JPN)] https://vcdns.valka.cz/images/flags/jp.gif[/img_6] 1933 - 1935 unknown number of B2M2 out of a total of 205 produced



Sources used:
Robert C. Mikesh and Shorzoe Abe, Japanese Aircraft 1910-1941, Naval Institute Press Annapolis, Maryland 21402, 1990, ISBN: 1-155750-563-2
Tadeusz Januszewski and Kryzysztof Zalewski, Japońskie samoloty marynarski 1912-1945 2, Lampart, year 2000, ISBN 83-86776-00-05
author's archive
URL : https://www.valka.cz/Micubisi-B2M-palubni-utocny-letoun-typ-89-t64760#230895 Version : 0
Type history:
As early as 1927, the Imperial Naval Air Force commissioned aircraft suppliers to submit their aircraft designs to replace the "Type 13 Airborne Assault Aircraft," abbreviated as Micubisi B1M. Although it was a good, reliable and above all versatile aircraft, which lasted in service until 1938, but Kaigun Koku Hombu wanted to ensure the development of a new, more powerful machine well in advance. The following companies, Aichi Tonkei Denki Seizo K.K., Kawanishi Kokuki K.K., Mitsubishi Nainenki Seizo K.K. (hereinafter referred to as Mitsubishi) and Nakajima Hikoki Seisakusho K.K.
The navy's technical specialists specified very precisely the requirements that the new on-board bomber had to meet. It was to be a three-seater onboard bomber with a mixed design, the dimensions were given - the range should not exceed 15.0 m, the length was set at 10.0 m and the height not 3.8 m. Designers could choose between the following types of propulsion units: Suiza (manufactured under license as Mitsubishi Type Hi), Kawasaki licensed the second BMW VI engine under consideration and the third unit was the Lorriane engine. From the performance requirements I will mention the following: the maximum speed at zero altitude should be higher than 205 km/h, the aircraft should ascend to 3,000 m in less than 15 minutes, access should be at least 6,000 m and the bomb load should keep the aircraft in the air for at least 3 hours, without a bomb load, it was supposed to be a full 8 hours. Furthermore, the length of the runway (45 m) was determined at a headwind of 37 km/h, the landing speed should not be greater than 83 km/h. The assignment did not require that it must be a purely Japanese design.


Mitsubishi was very agile and prepared three projects from different design teams.
The first project was designated 3MR3 and was worked on by Herbert Smith's team, this former British factory chief designer Sopwith Aviation Company Ltd. worked until June 1924 in the Mitsubishi factory and according to his designs the Imperial Navy acquired modern and powerful onboard machines as 1MF, 2MR a B1M. The design of the new onboard bomber was designed by Herbert Smith in England and included an Armstrong Siddeley Leopard engine in his design.
The second project was designated 3MR4, it was designed by a British factory Blackburn Airplane and Motor Car What. Ltd. (hereinafter referred to as Blackburn), the Hispano-Suiza engine was chosen for propulsion. For its construction, profiled seamless tubes and duralumin ribs in the wings were taken into account.
The third project was designed by the factory Handley Page Ltd., was designated as 3MR5, was to be powered the same engine as the previous project.


Mitsubishi management chose the 3MR4 project as the best and commissioned a prototype from Blackburn. At the same time, the Japanese factory engineer Hajjim Macuhara traveled to the British factory and was soon followed by three other engineers, Arkawa, Yui and Fukui, these three designers were to be directly involved in building a prototype named Blackburn T.7B (or also 3MT4).


The prototype was completed at the end of November 1929, flew on December 28 of the same year and already on January 3, 1930, the aircraft was placed on the ship and sent to Japan. It was a relatively attractive biplane, the lower wings had a slightly (330 mm) larger span than the upper wings, the flaps were on the upper and lower wings and on the leading edges of the upper wings were slots Handley Page. The wings themselves had an all-metal construction covered with canvas, the ribs in the wings were aluminum.The fuselage also had an all-metal frame made of seamless steel tubes and up to the level of the rear cabin was covered with aluminum panels, the rear part was covered with canvas and had watertight compartments. It was possible to install a balancing weight at the very end of the fuselage, thus balancing the aircraft if it took off as a two-seater. The chassis was adapted so that, if necessary, it was possible to mount floats, which probably never happened in practice.
Twelve-cylinder fork was chosen for the drive Hispano-Suiza Type 51-12Lbr with an output of 650 hp, the engine powered a double - bladed wooden propeller. The radiator was under the engine. The fuel system consisted of two gradient tanks, each with a volume of 168.2 liters, one 200-liter tank, located between the pilot and the fire barrier. The fourth tank was under the pilot's seat and had a volume of 381.9 l. In total, the aircraft carried 918.3 liters of fuel, if the torpedo was suspended, the fuel supply was reduced to 454 liters, if necessary for reconnaissance flights could be installed another tank 386.4 l, pumping fuel into the downcomers was performed by a pump driven by a propeller, rotated in flight by a stream of air.
The crew sat in three separate open cabins that were close together so that the crew could communicate with each other, either by sound system or handwritten messages. There was a hole in the floor in the middle cabin, which was used by the bomber to target the bombs, but it was possible to lead this way with a machine gun Lewis defending fire down under the plane.


In February 1930, the prototype was unloaded from the ship and, accompanied by Blacburn factory chief designer G. E. Petty, was transported to the Mitsubishi factory. Here, on the one hand, he underwent a thorough inspection and he was also painted red Japanese characters. Together with the designer G. E. Petty, several technicians came to Japan to oversee the start of their own production at Mitsubishi.
The Japanese did not like the arrangement of some drivers and so they adjusted them to their needs and ideas, it happened without consultation with G. E. Petty, these modifications led to the crash of the first prototype - ended up in the rice field with the chassis up. The second prototype was already built by the Mitcubiš factory, it was completed on October 31, 1930, but it was soon destroyed in an accident, this time it was a pilot's fault. The third prototype was completed on February 2, 1931 and was handed over for testing to naval pilots, who accused the engine of overheating, insufficient stability in flight and difficult landing at "three points", which was necessary for landing on board the aircraft carrier. The fourth prototype was already modified in production according to the comments and requirements of the pilots, overheating was removed by introducing a retractable cooler under the slimmer bow, instability was removed by enlarging and rounding the tail surfaces. This modified prototype was adopted by the Naval Air Force as "Onboard Assault Bomber Type 89", the abbreviated designation was B2M1.
However, the new aircraft did not gain much popularity in the operational service, it was haunted by constant problems with the engine, which did not achieve the required power, and the aircraft behaved "underpowered". Factory technicians tried to eliminate all problems and so in the years 1930 - 32 a new version of the aircraft was developed. The most striking change was the reduction of the span of the lower wing, which had the same span as the upper wing, the tail was modified and the engine was even more tightly hooded, the defensive armament was reduced to one fixed and one movable machine gun. Other changes were made to the construction of the aircraft itself, it was mainly a change of material. The result was a slight improvement in flight characteristics, especially it was possible to hang bombs under the aircraft up to a total weight of 800 kg, but the range was dramatically reduced, but for reconnaissance flights, it was possible to carry a larger amount of fuel.This new version was accepted into service under the designation "On-board attack bomber type 89-2" or also B2M2.


This type remained in the first line service until the end of 1937. It served on aircraft carriers Hóšó, Ryudo, Akagi a Kaga and took part in the fighting in China. However, his service was accompanied by many accidents, in which many crews died. The aircraft had a higher carrying capacity of bombs than the older Mitsubishi B1M, but never completely replaced it, you could say that it supplemented it. Throughout the service, he was accompanied by the previously mentioned "underpowering", which was also due to the much higher weight of both versions compared to the original prototype Blackburn T.7B. However, the production of this type did bring one advantage, Japanese designers and technicians mastered the construction of the aircraft with a skeleton of steel tubes and aluminum ribs and reinforcements, the pilots got acquainted with the Handley Page slots and their use.


The Mitsubishi factory produced a total of 205 of these aircraft in the years 1930 - 1935, several dozen of them, after being withdrawn from combat units, were used for training and a small amount was disarmed and sold to civilian companies, where they were used to transport cargo.





Sources used:
Mark R. Peattie, Sunburst: The Rise of Japanese Naval Air Power, 1909-1941, Naval Institute Press, 2007, ISBN 1-59114-664-X
Robert C. Mikesh and Shorzoe Abe, Japanese Aircraft 1910-1941, Naval Institute Press Annapolis, Maryland 21402, 1990, ISBN: 1-155750-563-2
Tadeusz Januszewski and Kryzysztof Zalewski, Japońskie samoloty marynarski 1912-1945 2, Lampart, year 2000, ISBN 83-86776-00-05
www.historyofwar.org
http://www.airwar.ru/enc/bww1/b2m.html
www.aviastar.org
ww2db.com
menstream.pl
author archive
URL : https://www.valka.cz/Micubisi-B2M-palubni-utocny-letoun-typ-89-t64760#426239 Version : 0
Discussion post Fact post
Attachments


Join us

We believe that there are people with different interests and experiences who could contribute their knowledge and ideas. If you love military history and have experience in historical research, writing articles, editing text, moderating, creating images, graphics or videos, or simply have a desire to contribute to our unique system, you can join us and help us create content that will be interesting and beneficial to other readers.

Find out more