In December 1943, the only real facilities available to land in weather conditions of extremely poor visibility were FIDO and a system known as SBA (Standard Beam Approach).
FIDO, the Fog Investigation and Dispersal Operation, was at that time only installed at three airfields:— the PFF stations RAF Graveley and RAF Downham Market, and RAF Fiskerton close to Lincoln.
On 16 December, Graveley was stood down for operations, but due to the terrible conditions elsewhere a number of aircraft converged there hoping to land using FIDO. READ MORE