The Sempill Mission was a British naval aviation technical mission led by Captain
William Forbes-Sempill. and sent to Japan in September 1921, with the objective of helping the
Imperial Japanese Navy
The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...
develop its aeronaval forces. The mission consisted of a group of 30 instructors and support staff, the mission was headed by Colonel Sempill, and stayed in Japan for 18 months.
Background
The
Imperial Japanese Navy
The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...
had closely monitored the progress of aviation of the three
Allied naval powers during World War I and concluded that Britain had made the greatest advances in naval aviation, they had also learned a good deal about naval aviation through their contacts within the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...
. In 1920, a representative had also been sent to Britain to observe air operations off the decks of . In 1921, the Japanese government formally requested that the British dispatch a naval air mission, in order to develop and to provide a professional edge to Japanese naval aviation. There were reservations on the part of the
Admiralty
Admiralty most often refers to:
*Admiralty, Hong Kong
*Admiralty (United Kingdom), military department in command of the Royal Navy from 1707 to 1964
*The rank of admiral
*Admiralty law
Admiralty can also refer to:
Buildings
* Admiralty, Traf ...
about granting the Japanese unrestricted access to British technology, yet after refusing the Japanese a total of ten times, the British government relented and sent an unofficial civil aviation mission to Japan.
Arrival of the mission
The Sempill Mission was led by
Captain William Forbes-Sempill, a former officer in the
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...
experienced in the design and testing of Royal Navy aircraft during World War I. The mission consisted of 30 members, who were largely personnel with experience in naval aviation and included pilots and engineers from several British aircraft manufacturing firms. The British technical mission left for Japan in September with the objective of helping the Imperial Japanese Navy develop and improve the proficiency of its naval air arm, the British government also hoped it would lead to lucrative an
arms deal. The mission arrived at
Kasumigaura Naval Air Station the following month, in November 1921, and stayed in Japan for 18 months. Although civilians, the Japanese granted active commissions to all members of the mission and a suitable uniform was provided.
Sempill was given the rank of a
naval captain
Captain is the name most often given in English-speaking navies to the rank corresponding to command of the largest ships. The rank is equal to the army rank of colonel and air force rank of group captain.
Equivalent ranks worldwide include ...
by the Japanese while other members of the team were given lesser ranks.
The Japanese were trained on several new British aircraft such as the
Gloster Sparrowhawk; as the mission also brought to Kasumigaura, well over a hundred aircraft comprising twenty different models, five of which were then currently in service with the Royal Air Force, including the Sparrowhawk. These planes eventually provided the inspiration for the design of a number of Japanese naval aircraft. Technicians become familiar with the newest aerial weapons and equipment-torpedoes, bombs, machine guns, cameras, and communications gear. While naval aviators were trained in various techniques such as torpedo bombing, flight control and carrier landing and take-offs; skills that would later be employed in the shallow waters of
Pearl Harbor
Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the ...
in December 1941. The mission also brought the plans of the most recent British
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...
s, such as and , which influenced the final stages of the development of the
carrier ''Hōshō''. Although ''Hōshō'' was already launched by that time, she became the first aircraft carrier laid down as such in the world when she was commissioned in 1922, one year before ''Hermes''.
Impact
By the time the last members of the mission had returned to Britain, the Japanese had acquired a reasonable grasp of the latest aviation technology and the Sempill mission of 1921–1922, marked the true beginning of an effective Japanese naval air force. Japanese naval aviation also, both in technology and in doctrine, continued to be dependent on the British model for most of the 1920s. The Imperial Japanese Navy were also aided in their quest to build up their naval forces by Sempill himself, who had later become a Japanese spy. Over the next 20 years, the British Peer provided the Japanese with secret information on the latest British aviation technology. His espionage work helped Japan rapidly develop its military aircraft and its technologies before the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
.
Notes
References
Bibliography
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External links
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{{coord missing, Japan
Military history of Japan
1921 in Japan
1921 in the United Kingdom
1921 in international relations
1921 in military history
Japan–United Kingdom relations