The single best treatment of the American Air Service in World War I. -- America and World War I From April to November 1918, the American Air Service grew from a poorly equipped, unorganized branch of the U.S. Expeditionary Forces to a fighting unit equal to its opponent in every way. Hostile Skies details the actual battle experiences of the men and boys who made up the service squadrons at the front -- Raoul Lufbery, Elliot Springs, Fiorello La Guardia, and, of course, Eddie Rickenbacker.