Published online by Cambridge University Press: 18 January 2010
Ever since the introduction of the Air Almanac and the Astronomical Navigation Tables, requests have been received for information as to the errors that can arise in their use. Estimates of error, for particular combinations, were made on several occasions and, in 1947, the calculation was systematized; but the methods and results were not published. It is now probable that the Sight Reduction Tables for Air Navigation, A.P. 3270 (H.O. 249 in U.S.A.), and possibly the Air Almanac, will increasingly be used for surface navigation and it therefore seems desirable to put on record a precise statement of the errors that can arise through their use. The earlier work has accordingly been modified for the changes in the publications.