A gyro is gimbaled within a frame which is fixed within an aircraft. Roll indicia is responsive to the gyro for rotation within a display window on the frame about an axis parallel to the roll axis of the aircraft. A horizon indicating member is also responsive to the gyro for movement within the display window to remain parallel to the actual horizon during flight of the aircraft. A steering bar is movable within the display window relative to the roll indicia and the horizon indicating member in dependence upon selected flight guidance commands.
Artificial horizon indicators are precise, gyroscopic flight instruments designed to furnish an aircraft pilot with an artificial indication of an aircraft pitch and roll attitude with respect to earth. Basically, such indicators include a gyro gimbaled within a frame which is fixed to the aircraft. Roll indicia is responsive to the gyro for rotation within a display window as a part of the frame about an axis parallel to the roll axis of the aircraft. A spherically shaped horizon indicating member is also responsive to the gyro for movement within the display window to remain parallel to the actual horizon during flight of the aircraft. The spherical horizon indicating member is pivotally mounted to the frame between the gimbal axis of the gyro and the roll indicia. The coupling of a horizon indicating member to the gyro includes a two stage three pin drive to present the aircraft pilot a uniform movement of the horizon indicating member for movement of the aircraft about the pitch axis.
