It's been nearly 38 years since Philippine Airlines unveiled the first fully flat bed on a commercial jet in the shape of slim, bunk-style "Skybeds" on the first class upper deck of its Boeing 747.
원문출처 : http://www.cnn.com/travel/article/singapore-airlines-double-bed-suites/index.html
원문출처 : http://www.cnn.com/travel/article/singapore-airlines-double-bed-suites/index.html