The five papers in this issue are reports on research topics chosen by graduate students selected for awards from a nationwide competition under the fifth (1990-1991) Graduate Research Award Program on Public-Sector Aviation Issues. This program is sponsored by the Federal Aviation Administration and administered by the Transportation Research Board (TRB). Its purpose is to stimulate thought, discussion, and research by those who may become the future managers and policy makers in aviation. The papers were presented at the 71st TRB Annual Meeting in January 1992.