Plain English Meaning

A flight path where the airplane's navigation system has to stay within 1 mile of the line on the chart almost all the time, and it has to tell the pilot if it can't.

Full Definition

A Required Navigation Performance (RNP) route on which the aircraft must keep its position within 1 nautical mile of the centerline for at least 95 percent of the total flight time, and must have onboard performance monitoring and alerting that warns the pilot if this accuracy cannot be met. RNP 1 routes are typically used in the terminal environment, including departures, , and transitions between and phases.