Jim Collins on How Boeing Leapfrogged McDonnell Douglas
(p. 202) Wisely, through the 1940s, Boeing had stayed away from the commercial sphere, an arena in which McDonnell Douglas had vastly superior abilities in the smaller, propeller-driven planes that composed the commercial fleet. In the early 1950s, however, Boeing saw an opportunity to leapfrog McDonnell Douglas by marrying its experience with large air-(p. 203)craft to its understanding of jet engines.
Collins, Jim. Good to Great: Why Some Companies Make the Leap. And Others Don't. New York: HarperCollins Publishers, Inc., 2001.