The return cargo reached Penang, but the most valuable examples and blueprint copies apparently remained aboard I-30. An aircraft could have carried duplicate plans and selected weapons onward to the home islands. Japanese engineers could then have begun evaluation and production preparation before the submarine finished its voyage. When I-30 struck a British mine near Singapore, the failure to create that redundant delivery path turned one mine strike into a major technology-transfer failure.
Notable Point · 55:25-56:49
Why I-30's blueprints needed a second delivery route
Flying copies and weapon samples onward from Penang could have started Japanese evaluation sooner and prevented one mine from destroying most of the transfer.