On 16/17 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.
FIDO dispersed the lethal cloud and fog by means of fire. Vast pipes, carrying thousands of gallons of petrol, had been manufactured with fine holes from which a jet of petrol spurted forth when the pumps were in operation. To fire up each section of the system, a man manually set alight to the first burner and then ran like hell when the entire section ignited with a whoosh. The heat dispersed the fog and cloud, and the glow of the flames provided a flarepath.
Due to the terrible landing conditions at other PFF airfields close to Graveley, several aircraft went to try to land there with or without the aid of FIDO, amongst them those of the Deverill, Scott, and McLennan crews, all of which suffered multiple casualties.
The report on FIDO for that night indicates that no aircraft were able to land with its aid.