The Air Technical Intelligence Group interviewed personnel of Mitsubishi, Kawasaki and Nakajima post war and issued a series of reports on the design and development of aircraft engines from these Japanese manufacturers.
The Summaries from the Reports and links to the full A.T.I.G Reports follow:
General Design and Development of Mitsubishi Aircraft EnginesSummary: The Mitsubishi Engine Company organization, policies, procedures, and relations with the government and other engine companies were remarkably similar to those of equivalent companies in the United States. Methods of engine development and test, both experimental and production were also quite similar to American practice. The problems encountered, and in the majority of cases satisfactorily solved, were very similar to those encountered in American engineering. While previous to the war the company had relied heavily on literature published by the Allied nations for its general guidance, it displayed a surprising degree of initiative and ingenuity in meeting problems developing after this supply of information was cut off. The company displayed a dignity and a pride in its organization, its product, and its reputation and made no apologies even while admitting freely that American engines were superior. The personnel interrogated are considered well qualified to discuss all aspects of the Mitsubishi engine development. It is considered that all possible information was furnished as requested and that no reticence or attempt to withhold information were apparent. It appears that in most aspects of engine development the company was several years behind the Allied nations, but with its capable and aggressive engineering staff it would have continued to produce creditable engines had the war continued.
Kawasaki Engine Design and DevelopmentSummary: The Kawasaki company produced liquid cooled engines based on the German DB design and air cooled engines on license from Nakajima. The design efforts of the company were directed primarily toward minor modification of the basic German design and to improvements in supercharging. The design ability appeared definitely second rate and far below that of both Mitsubishi and Nakajima engineers. The company is considered of secondary importance in both production and design of aircraft engines. No features were noted that would be of interest to American designers.
Nakajima Engine Design and DevelopmentSummary: The Nakajima company as one of the two large Japanese aircraft engine manufactures corresponded very closely in policy, procedures, and methods with the Wright Aeronautical Corporation of the United States. The general pattern of the company followed that of the Wright Aeronautical Corporation from whom the company had purchased production licenses during the early 1930’s. When contact with foreign publications and information permitted, the design of Nakajima engines followed in general the leads provided by foreign development, but the company indicated a considerable degree of initiative and capability of independent thought when access to foreign information was cut off. In most respects the design of Nakajima engines was several years behind that of American engines. Although excellent performance was claimed for some of the latest experimental engines, no data was available to substantiate these claims, nor was test equipment available of sufficient accuracy to determine true altitude ratings. Several engines of each model available are being forwarded to T.A.I.C. Anacostia.
Mike
