Definition
A Required Navigation Performance level specifying that the aircraft must be able to remain within 0.3 nautical miles either side of the intended flight path for at least 95% of the flight time, with onboard performance monitoring and alerting if that accuracy cannot be maintained. RNP 0.3 is commonly used for helicopter approach segments and certain low-altitude RNP routes.
Plain English
The aircraft's navigation system must keep it within three-tenths of a mile of the planned track, and it must warn the pilot if it can't.
Context Anchor
Seen on instrument procedures, especially GPS-based approach procedures and navigation system displays that show the required accuracy for a route or approach segment.
Derivation
The number 0.3 refers to the lateral accuracy requirement in nautical miles. RNP itself comes from 'Required Navigation Performance' — a performance-based standard rather than a description of specific equipment. The lower the number, the tighter the required accuracy.
Why Pilots Care
Determines whether the aircraft is authorized to fly a given RNP procedure, directly affecting runway access in low-visibility conditions.
Grounding Statement
RNP 0.3 is about how tightly the aircraft must stay on the intended path, not about altitude, visibility, or engine performance.
Intuition Check
Do not read RNP 0.3 as a weather minimum or altitude limit. It is a navigation accuracy requirement measured in nautical miles.
Example Sentence 1
The approach into the mountain heliport required RNP 0.3 capability, so the crew confirmed the avionics were certified before accepting the clearance.
Example Sentence 2
With RNP 0.3 approval, the aircraft could fly the curved arrival path without relying on ground-based navigation aids.