In 1942, Japanese technicians and mechanics rebuilt three damaged B-17s, one "D" and two "E" series, using parts salvaged from abandoned B-17 wrecks in the Philippines and the Java East Indies. The three bombers, which still contained their top-secret Norden bombsights, were ferried to Japan where they underwent extensive technical evaluation by the Giken, the Imperial Japanese Army Air Force's Air Technical Research Institute (Koku Gijutsu Kenkyujo) at Tachikawa's air field. The "D" model, later deemed an obsolescent design, was used in Japanese training and propaganda films. The two "E"s were used to develop air combat tactics for use against B-17s; they were also used as enemy aircraft in pilot and crew training films. One of the two "E"s was photographed late in the war by US aerial recon. It was code-named "Tachikawa 105" after the mystery aircraft's wingspan () but not correctly identified as a captured B-17 until after the war. No traces of the three captured Flying Fortresses were ever found in Japan by Allied occupation forces. The bombers were assumed either lost by various means or scrapped late in the war for their vital war materials.
in 1942 japanese technicians and mechanics rebuilt three damaged b-17s one "d" and two "e" series using parts salvaged from abandoned b-17 wrecks in the philippines and the java east indies the three bombers which still contained their top-secret norden bombsights were ferried to japan where they underwent extensive technical evaluation by the giken the imperial japanese army air force's air technical research institute (koku gijutsu kenkyujo) at tachikawa's air field the "d" model later deemed an obsolescent design was used in japanese training and propaganda films the two "e"s were used to develop air combat tactics for use against b-17s; they were also used as enemy aircraft in pilot and crew training films one of the two "e"s was photographed late in the war by us aerial recon it was code-named "tachikawa 105" after the mystery aircraft's wingspan () but not correctly identified as a captured b-17 until after the war no traces of the three captured flying fortresses were ever found in japan by allied occupation forces the bombers were assumed either lost by various means or scrapped late in the war for their vital war materials