引用・参考資料等 https://www.quora.com/Why-does-the-US-Army-have-absolutely-no-interest-in-tilt-rotor-aircraft-like-the-V-22-Osprey-even-though-other-branches-like-the-Marines-and-Navy-have-spent-tens-of-billions-of-dollars-on-the-projecthttps://www.quora.com/Why-arent-V-22-Ospreys-more-widely-used
http://www.nicovideo.jp/watch/sm45732286
