Evolution of the Liaison-Type Airplane, 1917-1944

This study of the liaison airplane, which was written in the Air Technical Service Command Historical Office by Capt. Irving B. Holley, Jr., is one of a series dealing with such types of aircraft as the cargo airplane, medium bomber, and heavy bomber. The history is focused primarily on the evolution of the idea of the liaison airplane as distinguished from the observation airplane, and emphasis is placed on the problems of isolating and identifying the growth of this concept rather than on the liaison airplane as a continuous engineering development. Engineering details are discussed only when they were factors that influenced and delimited the evolution of the concept. In short, the history is concerned with the gradual emergence of a clear understanding of specific tactical functions for the liaison airplane. When this had been gained, it was possible to establish engineering objectives.