引用・参考資料等 https://www.quora.com/When-did-naval-ships-start-having-helicopter-pads-How-long-did-it-take-the-US-Navy-to-change-all-their-ships-and-have-helicopter-padshttps://www.quora.com/unanswered/What-year-did-the-US-Navy-start-using-helicopters-on-ships
http://www.nicovideo.jp/watch/sm44467724
