Purpose: The purpose of this document is to define a set of standard aircraft avionics architectures that support a cost effective evolution to the fully operational CNS/ATM environment. These architectures are intended to meet near-term requirements (e.g., FANS- 1, SCAT-1, etc.) and provide growth for supporting the full CNS/ATM function set over the long-term. Airlines intend to support the near-term phased implementation of these architectures. This document represents broad airline consensus for developing avionics equipment providing CNS/ATM operating capabilities.