This document sets forth the desired characteristics of the GNSS Navigation and Landing Unit (GNLU) intended for installation in all types of aircraft. The intent of this document is to provide general and specific guidance for the development and installation of the GNLU unit primarily for airline use. This Characteristic will describe the desired operational capability of the equipment, the standards necessary to ensure interchangeability, form factor, and pin assignments.

Equipment manufacturers should note that this document aims to encourage them to produce maintenance-free, high performance equipment rather than that of minimum weight and dimensions. They are at liberty to accomplish this objective by means of design techniques they consider to be the most appropriate, as their airline customers are interested primarily in the end result rather than the means employed to achieve it.

The ICAO Future Air Navigation System (FANS), Standards and Recommended Practices (SARPs) for Communications, Navigation, Surveillance, and Air Traffic Management (CNS/ATM) are currently evolving and are expected to continue to evolve over the next several years. The requirements included in this document represent a best guess at the CNS/ATM related functions which should be supported by the ARINC 756 GNLU.