The Boeing Company The International Civil Aviation Organization (ICAO) is building a worldwide IPv6-based Air Traffic Management (ATM) service known as the Aeronautical Telecommunications Network with Internet Protocol Services (ATN/IPS). Aircraft connect to the ATN/IPS via an IPv6 Air/ Ground (A/G) interface that provides a nexus for control and data messages exchanges over all available aviation wireless data links. This document discusses the use case that motivates a new IPv6 interface abstraction.