What is the approach phase RNP requirement?

The approach phase RNP (Required Navigation Performance) requirement is specified as 0.3 NM. This value reflects the accuracy necessary for aircraft to safely navigate during approach phases of flight, particularly in the context of precision approaches using Area Navigation (RNAV) procedures. An RNP of 0.3 NM indicates that the aircraft's actual flight path can deviate within 0.3 nautical miles from the intended path, allowing for a safe margin as the aircraft approaches the runway.

This requirement is designed to ensure that, especially in highly crowded airspaces or during low visibility conditions, aircraft can accurately and consistently maintain their intended flight path, reducing the risks of deviation that could lead to unsafe situations. The 0.3 NM standard is particularly critical in environments where terrain, other aircraft, or obstacles present an increased risk during approach.

In contrast, the other options represent less stringent RNP requirements that would not provide the same level of precision needed for safe approaches in these sensitive phases of flight.