Sempill Mission

The Sempill Mission was a British aeronaval technical mission led by Captain Sempill and sent to Japan in September 1921, with the objective of helping the Imperial Japanese Navy develop its aeronaval forces. The mission consisted in a group of 29 instructors, headed by Captain Sempill, and stayed in Japan for 18 months.

The Mission started training operation at the air base of Kasumigaura. The Japanese were trained on several new aircraft, such as the Gloster Sparrowhawk, in various techniques such as torpedo bombing and flight control.

The Mission also brought the plans of the most recent British aircraft carriers, such as the "HMS Argus" and the "HMS Hermes", which influenced the final stages of the development of the Japanese aircraft carrier "Hōshō". Although the Hōshō was already launched by that time, she became the first purpose-designed aircraft carrier in the world when she was commissioned in 1922, actually one year before the "Hermes".