The early stages of the helicopter's history -- from da Vinci to Sikorsky -- are outlined, with detailed analysis of the craft's development, including the experiments of the 1940s and the first true operational use in Korea. Dj has minor edgewear and minor yellowing at edges on back panel. Gift notation on front pastedown, under dj's front flap. 8vo - over 7¾" - 9¾" tall.