An overview is given of the NCAR C-130 research aircraft flights conducted during May and July 1998 in conjunction with SHEBA and the FIRE Arctic Clouds Experiment. Instrumentation is described, as well as the flight patterns and situations sampled. Highlights of the May observations related to surface characteristics, boundary layer structure, radiation, cloud microphysics, and cloud condensation and ice forming nuclei are presented. Integration applications of the dataset to scaling issues, cloud modelling and remote sensing validation are described