The scope of this Vertical Flight document is limited to human behavioral technologies associated with design and/or implementation of Enhanced Synthetic Vision Systems (ESVS) in vertical flight aircraft. Any overlap into logic problems or hardware/software design shall be considered to be incidental to the human factors issues. Where the performance characteristics of specific technologies are relevant they will be identified, and where performance criteria are relevant to specific intended functions/use they will be identified. From a regulatory view, intended function (Full Flight Guidance or Information/Situation Awareness support) has a tremendous effect upon the design of an ESV System. However from a Human Engineering standpoint, the information on display must be discernible and comprehensible to the human operator in both cases and differences may be primarily in information content (required to support a specific task). The document is independent of candidate technologies and concentrates on human interface criteria. This document does not include consideration of detection and/or display of air targets or integration of systems such as TCAS.