Hi Richard,
I just stumbled across this while digging for something else. It's an Allied report based on ULTRA and other intelligence sources, 'Intelligence on German Development of Jet Aircraft', undated, but probably from April 1945:
"[referring to late-July 1944] It is at this point that there begins a substantial flow of reports from the Japanese Naval Attache in Berlin on the subject of jet aircraft. He reported on the use of the Me.163 and Ar.234, but either thought or was told that in both instances the aircraft was the Me.262. But his subsequent reports have been substantial and highly informed, perhaps because the Germans sold the Japanese the plans fo the Me.163.
...
If it had been available considerable information could have been secured from the reports in October of the Japanese Naval Attache. Difficulties of decoding some times accounted for these delays. Sometimes vagaries of distribution contributed. In general, this material has not regularly and promptly been made available to USSTAF Intelligence.
Eventually, from this Japanese material emerged the first complete description of the Ar.234, a picture of the dispersed Messerschmitt production in South Germany, and indication of proposed substantial production, and a clear indication that the speed of the jet aircraft was causing trouble in developing tactics. Also, during October the Japanese visited Dr. Heinkel in Vienna and recieved a rather melodramatic account of his hard lot which nevertheless revealed that hte He.280 was not likely to appear, but that Heinkel had a potentially important jet engine. There were also some details of a single engine jet which were later of great interest."
Cheers,
Andrew A.
Air War Publications -
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