Compilation of papers summarizing some recent NASA research on manned military aircraft. I. VTOL aircraft - State of the art

During the last few years a large number and wide variety of VTOL aircraft types have been studied; some of them promising, some not so promising. The purpose of this paper is to summarize briefly the state of the art in this field and to indicate which of the types are most promising, to bring out applications where they are best suited and to indicate what is needed in the way of additional research and development.