Two studies were performed to investigate human factors issues associated with advanced terrain displays for transport aircraft. The first study investigated three alerting displays (plan, profile, and three-dimensional views) to aid terrain avoidance maneuver performance. Subjects flew through terrain hazard situations on a simulator, and performed escape maneuvers using a sidestick. Each display was found to have limitations, though the data suggest that plan and profile displays may augment each other when used in combination.In the second study, subjects customized terrain resolution levels on a plan view display, and used the display to check for terrain hazards. Subjects preferred the highest available horizontal resolution and 500 ft or 1,000 ft contour separation. Aircraft-relative terrain altitudes allowed faster hazard determination than altitudes relative to mean sea level.