From the Introduction: "This special study provides a historical survey and comparison between two key elements of the joint combined arms team, indirect fire support, as provided by field artillery and mortars, and direct aerial fire support (close air support (CAS) and interdiction) provided by aerial platforms (fixedand rotary-wing aircraft). Since the beginning of modern combined arms operations in World War I, there has been a continual improvement and refinement of ground and air fire support means. But, at times, there has been controversy over the use of the respective delivery means. This study discusses the interplay and use of air and ground fire support elements in the modern period. The work begins with a brief background on the evolution of modern field artillery but is primarily concerned with the period from 1914 to the present. While it discusses all major technological and tactical innovations, the focus is clearly on the United States Army and United States Air Force. Since at least 1941, the United States has led the way in technological and organizational developments in both aviation and field artillery. The emphasis of the survey is on technological and organizational developments, structures, innovations, and techniques. The stress is not, however, on details of technology but, rather, on the capabilities that technological developments have given to the weapons or fire support systems."
Ike Skelton Combined Arms Research Library Digital Library: http://cgsc.contentdm.oclc.org/