Fog Investigation and Dispersal Operation

The device was developed by Arthur Hartley for British RAF bomber stations, allowing the landing of aircraft returning from raids over Germany in poor visibility by burning fuel in rows on either side of the runway.

The invention of FIDO is formally attributed to Dr John David Main-Smith, an ex-Birmingham resident and principal scientific officer of the Chemistry Department of the Royal Aircraft Establishment at Farnborough, Hampshire, and as a courtesy the joint-patent (595,907) held by the Ministry of Supply was shared by the department head Dr Ramsbottom as was normal practice at the time.

Though J. D. Main-Smith co-owned the FIDO patent, no royalties accrued from any UK civilian usage after World War II, its being too petrol-hungry.

The FIDO installation usually stored its fuel in four circular upright tanks built at the edge of the airfield with a low brick bund wall in case of leakage.

[citation needed] When fog prevented returning Allied aircraft from locating and seeing their runways to land, they would be diverted to FIDO equipped aerodromes.

RAF night bombers which were damaged on their missions were also diverted to FIDO airfields due to the need to make certain they could land when they arrived.

[citation needed] An experimental FIDO system was first tested at Moody Down, Hampshire, on 4 November 1942 and 200 yards of dense fog was successfully cleared to a height of 80 feet.

The first full scale FIDO system was installed in January 1943 and an aircraft reportedly piloted by Air Vice Marshal D. C. T. Bennet successfully landed between the flames, although not in fog conditions.