Terrain Orientation Theory for the visual guidance of an approach and landing is based on glide path perception dependent upon the orientation of the landing surface due to global and local features. Numerous studies have attempted to determine the primary cues used to visually guide an aircraft to landing during rich viewing conditions and during black hole or featureless terrain conditions. Research has focused on the runway and the horizon. No one model or theory however has yet to capture all aspects of the perceptual approach to landing process. Previous studies have implied the role of surface orientation and terrain but failed to manipulate conditions throughout the entire approach and landing to account for robust conclusions.