What is the required navigation performance for terminal phase in RNP?

The required navigation performance (RNP) for the terminal phase is specifically set at 1 nautical mile (NM). This performance level is designed to ensure that aircraft can navigate accurately and safely during the approach and landing phases, which are among the most critical parts of any flight operation.

In the terminal phase, the 1 NM requirement allows for sufficient precision while still accommodating potential variances in navigation systems. This ensures that the aircraft remains on the intended flight path and clears any obstacles in the vicinity, providing both safety and efficiency in the management of air traffic around airports, particularly in busy or crowded airspace.

It's important to note that different phases of flight have varying RNP requirements. For example, during en route or approach phases, navigation performance requirements may differ to balance operational flexibility and safety. The 1 NM standard is well established in regulatory guidelines and aligns with operational procedures for terminal operations, making it a critical point for pilots to remember during instrument flight rules (IFR) training and evaluations.