Recommendation ITU-R P.528: A propagation prediction method for aeronautical mobile and radionavigation services using the VHF, UHF and SHF bands. This Recommendation contains a method for predicting basic transmission loss in the frequency range 100-30 000 MHz for aeronautical services. The software implements Annex 2 of Rec P.528, the Step-by-Step method to computing propagation loss for air-to-ground paths.