This paper summarizes the results of the aircraft measurements of pollutant and meteorological parameters performed during the Sulfate Regional Experiment (SURE). Two aircraft were operated for a total of six 2-week intensive studies of six sampling days each. Intensive studies were performed in August 1977, October 1977, January 1978, April 1978, July 1978 and October 1978. Over 140 sampling flights were made. Statistical methods were utilized to collapse the data obtained into a set of summary statistics and plots. Several generalizations can be made from the statistical data presentations. During the SURE aircraft flights, there were clear differences in the spatial distribution of primary (SO 2, NO x ) as opposed to slowly forming secondary pollutants (ozone, light scattering aerosols). O 3 and b scat levels were reasonably uniform over the regions sampled while SO 2 and NO x concentrations were often highly variable. Except during multiday episodes of widespread high b scat and O 3 concentrations, primary pollutants (SO 2, NO x ) were not seen above 1500 m msl in significant concentrations during SURE flights. On average, the total burden of primary pollutants within the lower 1500 m msl was similar from day to night. The vertical distribution of the pollutants, however, was much better mixed during the day than at night. The median condensation nuclei concentration within the lower 1500 m msl during midday was more than twice the median concentration during the night and early morning hours, indicating substantial photochemical formation during daylight.