In a display unit adapted to be mounted in a cockpit of a piloted aircraft for pictorially presenting combined inflight course, altitude, and horizontal situation information relative to a selected course and altitude, the improvement comprising in combination:
- A. a horizontal situation indicator for providing heading intelligence including a window having a transparent face disposed in a plane normally related to the longitudinal axis of the cockpit, a pointer mounted for visual observation through the face of said window pictorially depicting an instantaneous heading of the piloted aircraft relative to the selected course comprising a miniature aircraft supported for rotation about an axis normally related to the plane of said window, said window having a top, the center point of the top of the window being located above the axis of the pointer when the aircraft is in a normal level flight attitude, means for driving said miniature aircraft to an oncourse position when the position of the piloted aircraft is on the selected course and the heading thereof is coincident with the bearing of the course, said on-course position being indicated by the miniature aircraft when the nose thereof is pointed toward the center point of the top of said window, and means including a drive motor connected to said pointer and a heading error signal generator connected to the drive motor for angularly displacing the pointer from said on-course position to a heading error position wherein the nose is pointed at an angle relative to a line extended between the axis of the pointer and the center point equal to the instantaneous angle defined between the bearing of the selected course and the instantaneous heading for the piloted aircraft;
- B. a course deviation bar extended downwardly from the top of said window and supported for displacement along a path extended horizontally across the face of the window, and means including a beacon signal/converter and a drive motor for displacing said bar along said path in directions and through distances corresponding to instantaneous directions and distances of the piloted aircraft relative to the selected course;
- and
- C. an altitude deviation bar extended horizontally across the window, and means including an altitude error-signal generator and a motor connected to said altitude deviation bar for displacing the altitude deviation bar vertically across the face of said window as the altitude of the aircraft deviates from a selected altitude for the piloted aircraft.