Published online by Cambridge University Press: 28 July 2016
This paper describes some work, mainly of a theoretical nature, done at the Royal Aircraft Establishment, Farnborough, during the years 1946-1947. The immediate object of this work was to establish some general principles for the guidance of the Ministry of Civil Aviation Airfield Lighting Committee, which is the body charged with the task of deciding what visual aids shall be installed on the civil airports of this country. The work is far from completion and from the scientific point of view, this account of it must necessarily leave some loose ends, but it is felt that the method of attack and the underlying ideas may prove useful to other workers in this field. If this should prove to be the case, then international standardisation will have been brought a little nearer, and as will be made clear in this paper, this is almost as necessary for the visual aids as for the radio aids.
Page 442 note 1 Strictly speaking the meteorological visibility is the distance at which a very large dark object can just be seen in daylight. In drawing range diagrams, this is conventionally taken as the distance over which the atmospheric transmission is two per cent.
Page 447 note 2 For a detailed account of early developments in America, see paper entitled “Development of Approach and Contact Light Systems,” by F. C. Brackenridge and C. A. Douglas, which appeared in “Illuminating Engineering,” November 1945.
Page 447 note 3 See article entitled “All-Weather Flying” by F. R. Stout in the American publication “Flying” for November 1947.
Page 447 note 4 In this paper the word “divergence” is used to denote the total spread of the beam.
Page 448 note 5 See article entitled “Landing Airplanes in any Weather” by W. A. Pennow in “Westinghouse Engineer” for July 1947.