The report describes recent aircraft sampling programs to measure nonmethane organic carbon (NMOC) levels aloft in the upwind vicinity of several U.S. cities during the morning period of 0600 - 0900 A.M. The cities studied included Dallas-Ft. Worth, Tulsa, Atlanta, Birmingham, Philadelphia, and New York City. Individual hydrocarbon compounds were measured using gas chromatographic procedures. The organic carbonyl compounds were collected on silica packed SEP-PAK cartridges impregnated with 2,4-dinitro phenyl hydrazine (DNPH) and analyzed by HPLC. The data collected will be used in photochemical ozone models, such as OZIPP, to determine ozone control strategies.