This document sets forth design and operational recommendations concerning the human factors issues and criteria for airborne terrain separation assurance systems. The visual and aural characteristics are covered for both the alerting components and terrain depiction/situation components. The display system may contain any one or a combination of these components. Although the system functionality assumed for this document exemplifies commercial aircraft implementation, the recommendations do not exclude other fixed wing aircraft types. Because of their unique operations with respect to terrain, rotorcraft will be addressed in a separate document.