The Met. Research Flight (MRF) was a Met Office facility, which operated a well instrumented C-130 Hercules (also referred to as Mk.2 Hercules) aircraft for research purposes. The C-130 was in service from 1972 to 2001 and flew over 1800 research sorties. The large capacity and long endurance of this platform made it ideal for atmospheric research in the areas of cloud physics, atmospheric radiation, atmospheric chemistry, satellite activities, mesoscale meteorology and boundary layer studies.