Japanese officers had participated directly in Britain's wartime carrier experiments while the alliance was close. Japan's later repetition of similar design steps is presented as evidence that this privileged flow of data had weakened. The Sempill Mission officially promoted trade and passed on the aviation information it was authorized to provide. Its political and unofficial complications did not amount to unrestricted access to every British experiment. Technology transfer here depended on diplomacy and institutional permission as much as engineering expertise.
Notable Point · 36:28-37:34
The Sempill Mission carried selected aviation knowledge
Japan's need to repeat parts of Britain's carrier-development cycle shows how wartime access narrowed before the official Sempill Mission carried selected aviation knowledge to Japan.