麻豆传媒

Despite the many developments in aircraft technology, a key problem that remained was how to land in poor visibility.

During the Second World War, fog had been responsible for the loss of multiple aircraft returning from operations. If no airfield with clear visibility could be found to land on, the procedure was for the pilot to point the aircraft towards the sea, for the crew to bail-out by parachute over land, leaving the aircraft to subsequently crash in the sea.

FIDO, or the Fog Investigation and Dispersal Operation to give the system its full name, was devised during the Second World War to deal with this problem, dispersing fog from airfields to ensure aircraft could land safely when visibility was poor.

Developed by British civil engineer Arthur Hartley during his work as technical director at the Petroleum Warfare Department, with support from Shell, FIDO was at its heart a simple concept, with fuel burnt in rows either side of the runway to literally evaporate the fog or smog away. The system consisted of three main elements: burner lines, pumping and distribution and storage for petroleum. Pipes through which the petrol was pumped enclosed the runway in a rectangle, and through small holes at intervals in the pipes blazing petrol vapour was forced under great pressure, billowing several feet high. FIDO was tested successfully on 4 November 1942 at Moody Down, Hampshire in the south of England, when 200 yards of dense fog was cleared to a height of 80 feet. Shell Aviation was already supporting the airforce, supplying fuel and lubricants at a large number of airfields. It played a major supporting role in the further development of the FIDO system and its installation at 15 Royal Air Force airfields across the country.

The first operational use of FIDO came on 19 November 1943, when four Handley Page Halifax bombers landed successfully after a mission to Germany. Although visibility was only 100 yards, 10 minutes after the FIDO system had been lit, the visibility on the runway increased to the equivalent of two miles. FIDO became an essential tool for getting Allied aircraft safely back on the ground when fog was present. It is estimated that some 2,500 Allied aircraft landed during the war with the assistance of FIDO, undoubtedly saving the lives of many airmen and preventing the loss of many valuable aircraft.

Sources:

_{De "Koninklijke/Shell" en de Tweede Wereldoorlog, 1946.
Shell historical archives.}