The present document specifies certain minimum technical performance requirements of Aircraft Earth Station (AES) equipment with both transmit and receive capabilities for provision of aeronautical mobile satellite service, in the frequency bands. The AES has the following characteristics: - These AESs are equipment for installation on aircraft. - The AESs transmit in the 14,00 GHz to 14,50 GHz band receive within the range from 10,70 GHz to 12,75 GHz ("14 GHz"), referred to as "14 GHz AES" in the present document, are operating in one or more frequency ranges of the Fixed-Satellite Service and Mobile-Satellite Service. - The AESs transmit in the 12,75 GHz to 13,25 GHz band receive within the range from 10,70 GHz to 12,75 GHz ("13 GHz"), referred to as "13 GHz AES" in the present document, are operating in one or more frequency ranges of the Fixed-Satellite Service.