The purpose of MICROMIX was to test and improve the representation of mixed phase clouds in radiative transfer models. The FAAM BAE-146 aircraft was flown in conjunction with the Chilbolton radar facility and AMSU overpasses in order to characterise the in-situ microphysics, spatial variability of the microphysics and the radiative properties respectively. This activity was also a means of validating the microphysics retrievals that have been developed using the suite of remote sensing instrumentation at Chilbolton.