In the early years of powered flight , the National Advisory Committee on Aeronautics in the United States produced three reports describing a method of analysis of aircraft accidents . The first report was published in 1928 ; the second , which was a revision of the first , was published in 1930 ; and the third , which was a revision and update of the second , was published in 1936 . This paper describes the contents of these reports , and compares the method of analysis proposed therein to the methods used today .