How The British Fought Fog With Runways of Fire

During the Second World War, British pilots were fighting more than the German Messerschmitts. They were also fighting against the weather—more specifically, with fog. Fog was responsible for a large number of losses of RAF aircraft returning from bombing missions over Germany. Since most of these raids took place at night, fog would often obscure large areas of the ground making it difficult for the pilots to see the airfields and the runways. In these cases, the pilot would point his airplane towards the sea and then, while still over land, the crew would bail out by parachute leaving the aircraft to harmlessly crash into the ocean. With bombing raids involving several hundred aircraft, a significant number of bombers were lost to fog this way. An Avro Lancaster of the RAF’s No 35 Squadron takes off with FIDO petrol burners on either side of the runway at Graveley, Huntingdonshire in May 1945. Fog has always been and continue to be a serious hazard in aviation. Fog leads to poor visibility, and visibility is crucial for making a safe landing. Henry Garrett Houghton, an electrical engineer at MIT, the United States, considered fog “the greatest hindrance to the development of aviation.” He believed that combatting fog would be the first breakthrough for humans trying to use science to modify weather, and a stepping stone to controlling it. In 1934, Houghton demonstrated that fog could be removed appreciably by spraying the air with calcium chloride. For his demonstration, Houghton built an apparatus consisting of a 100-foot long pipe fitted with downward spraying nozzles that he suspended 30 feet in the air. When the fog rolled through, he sprayed the misty cloud with 2.5 gallons of calcium chloride solution per second.