The U. S. Air force currently invests significantly in science and technology for directed-energy weapon (DEW) systems. Key elements of this investment include high-energy lasers and high-power microwaves. Other DEW research and development efforts include: optical beam control for high-energy lasers; vulnerability and lethality assessments; and advanced non-conventional and innovative weapons. Selected Directed Energy Research and Development for U.S. Air Force Aircraft Applications is the summary of three workshop sessions convened between February and April, 2013 by the Air Force Studies Board of the National Academies' National Research Council. Representatives from the Air Force science and technology community and DEW experts from the U.S. Army, U.S. Navy, Office of the Secretary of Defense, and the Defense Advanced Research Projects Agency presented and discussed threats that DEW capabilities might defend against and assessments of foreign progress in DEW. This report examines the current status of DEW capabilities both in the U.S. and abroad, and considers future applications of DEW systems.