Required Navigation Performance

Required Navigation Performance (RNP ) is a concept of the International Civil Aviation Organization ( ICAO), which defines the required navigation performance of aircraft used for RNAV guidance in order to standardize on certain airspace and flight procedures in aviation. It is up to the pilot, with which navigation system it meets the RNP requirements.

RNP is defined as a statement about the accuracy of the navigation performance necessary for operation within a given airspace. It is expressed by the distance from the intended position (target position), to comply with the aircraft in at least 95 % of the total flight time. So RNP 4 means that all aircraft must remain on its intended position within 4 NM at least 95 % of the total flight time.