Required Navigation Performance

Required Navigation Performance (RNP) is an ICAO specification that defines the navigation accuracy an aircraft must achieve to operate within a defined airspace or execute a specific instrument procedure. Unlike RNAV (which specifies equipment capability), RNP requires onboard performance monitoring and alerting — the system must confirm that it is achieving the required accuracy and alert the crew if it cannot.

Common RNP values include:

• RNP 4: ±4 NM accuracy — used for oceanic and remote continental operations
• RNP 2: ±2 NM — en-route and terminal operations
• RNP 1: ±1 NM — terminal area and arrival/departure procedures
• RNP 0.3: ±0.3 NM — approach procedures (RNP APCH)
• RNP AR 0.1: ±0.1 NM — Authorization Required approaches for curved paths in mountainous terrain (e.g., Queenstown, Innsbruck)

RNP approaches enable access to airports surrounded by terrain where traditional straight-in approaches are not possible, and allow curved paths that avoid noise-sensitive areas. They are a cornerstone of Performance-Based Navigation (PBN).