To examine chemical transformation within stagnant air masses and the atmospheric processes acting upon such air masses, the U.S.E.P.A. sponsored a study in the summer of 1980 in the northeastern United States. Ten research aircraft and several mobile and stationary surface monitoring platforms from three EPA contractors, seven federal agencies and four universities participated in an intensive measurement program between 16 July and 15 August 1980. Pollutants of interest included SO2, NO, NOx, HC, O3, sulfate, nitrate and aerosols in general. This paper summarizes the activities of these research aircraft. The three aircraft and one helicopter operated by the contractor team logged a total of 353 flight hours during 100 missions in the program. Flights were made from Columbus, Ohio to as far east as Laconia, New Hampshire, as far south as Montgomery, Alabama, as far west as Texarkana, Arkansas, and as far north as Saginaw, Michigan. The flight patterns and data collected for each mission are documented. This summary will allow scientists who are interested in this data base to identify subsets of the data for model development.