Plain English Meaning

These are the official accuracy standards that tell a pilot how tightly the aircraft must stay on its planned track. The smaller the number, the tighter the required accuracy. A different level applies to each phase of flight, from ocean crossings down to final approach.

Full Definition

The set of published Required Navigation Performance (RNP) values that define the lateral navigation accuracy an aircraft must maintain for a given phase of flight. Each level is expressed in nautical miles and represents the distance, left or right of the intended track, within which the aircraft must remain for at least 95 percent of the flight time. Common standard levels include RNP 10 and RNP 4 for oceanic and operations, RNP 2 and for and , and or lower for operations.