Required Navigation Performance (RNP) operations are beginning to revolutionize the air traffic system by using airspace more efficiently. RNP airspace is restricted to aircraft with a Flight Management System that's designed to fly a specific flight plan while monitoring the accuracy of the navigation system. By ensuring that the aircraft systems and the pilot know where the aircraft is - and where it is going - aircraft can be routed closer and make better use of the airspace.

The RNP of a particular route is the allowable error in the navigation solution in nautical miles. So if a route is designated as RNP 1.0, then the navigation system must be able to keep the aircraft within 1 nautical mile of the path at all times. For some routes, where deviations from the centerline of the path could result in a crash, the RNP will be set to 0.3 nautical mile or lower. The Head-up Display can be used to easily monitor the navigation system while the pilot's attention is outside the aircraft. The HUD can show the allowable manual flying tolerance based on the estimated navigation system error. The HGS can also show the pilot the current estimate of the navigation accuracy, along with the current required navigation accuracy defined by RNP. The pilot will be alerted if the current estimate exceeds the required value for the route being flown.