This documents defines the Installation Characteristics of an airborne radio transceiver capable of broadband wireless communication with an Airport Surface Network. The Aeronautical Mobile Airport Communications System (AeroMACS) Radio Unit (ARU) will operate in the aeronautical protected frequency of 5091 MHz to 5150 MHz, utilizing the IEEE 802.16e WiMAX protocol. It is intended to offload some of the congested narrowband VHF airport traffic used for ATS and AOC communications. ARU and Antenna Form, Fit, Function and Interfaces are described.