Patent ID: 8155800

Claim:
An aircraft display system, comprising: a display device; and a processor in operable communication with the display device and adapted to receive at least data representative of a desired course of the aircraft, data representative of required navigation performance (RNP) for the aircraft, and data representative of estimated position uncertainty (EPU) for the aircraft, the processor configured, in response to at least these data, to render a horizontal situation indicator on the display device that includes: (i) an aircraft symbol representative of a top-down view of the aircraft, the aircraft symbol rendered at a position that is representative of actual aircraft position relative to the desired course, (ii) an EPU graphic representative of the EPU for the aircraft, the EPU graphic comprising a pair of line segments symmetrically disposed on either side of rendered aircraft symbol and separated from each other by a separation distance that is proportional to the EPU for the aircraft, one line segment always rendered left of the rendered aircraft symbol, and another line segment always rendered right of the rendered aircraft symbol, and (iii) an RNP boundary graphic representative of at least one RNP boundary for the aircraft, the RNP boundary graphic rendered at a position relative to the rendered aircraft symbol and comprising a shaded region that shades a portion of the display device outside the at least one RNP boundary.