The Clouds, Water Vapour and Climate programme was a five-year NERC directed mode research programme. Its overall aim was to improve our understanding of the physical processes responsible for the distribution of humidity and clouds, and their influences on climate. Projects were selected for funding through three rounds of awards, in January 1999, December 2000 and September 2001. One CWVC project, namely "The Microphysical and Radiative Properties of Mixed Phase Clouds", is based on an airborne campaign using the FAAM aircraft.