Required Navigation Performance (RNP) is like Area Navigation (RNAV), but RNP requires onboard navigation performance monitoring and alerting capability to ensure that the aircraft stays within a specific containment area.
Required navigation performance (RNP) approaches improve safety and provide better access to runways that are not equipped with precision approach and landing aids.
There are several different levels of RNP. Examples of RNP levels used for an approach include RNP 0.1, RNP 0.3, and RNP 1.0 (There are also RNP 4.0 and RNP 10.0 levels that apply in the en route environment). "A performance value of RNP 0.3, for example, assures that the aircraft has the capability of remaining within 0.3 nautical miles to the right or left side of the centerline 95 percent of the time."
There are 3 types of RNP Approaches: RNP, RNP AR, and A-RNP.
This specification supports GNSS approach applications down to the approach minima. RNP APCH applies only to approaches with straight final approach segments. During RNP APCH operations, the 95 percent lateral accuracy requirements for both the lateral total system error and the along-track error are:
1 NM for operations in the initial and intermediate segments and for the missed approach.
0.3 NM for operations on the final approach segment down to the LNAV or LNAV/VNAV approach minima.
Based on the horizontal alert limit (HAL) extracted from the final approach segment data block (FASDB) on the final approach segment down to the LPV or LP approach minima.
This specification supports approaches to airports where limiting obstacles exist and/or where significant operational efficiencies can be gained, and includes advanced functional elements.
Aircrews are required to have additional training and authorization to fly an RNP AR APCH procedure. For aircraft operating on RNP AR APCH procedures, both lateral total system error and the along-track error must each be within the applicable accuracy for at least 95 percent of the total flight time:
0.1 NM to 1.0 NM for the initial, intermediate, and missed approach segments.
0.1 to 0.3 NM for the final approach segment.
The FAA titles all RNP AR instrument approach procedures (IAP) as “RNAV (RNP) RWY XX.” Internationally, operators may find RNP AR IAPs titled “RNP RWY XX (AR).” All RNP AR procedures will clearly state “Authorization Required” on the procedure chart.
This specification builds upon other specifications with the addition of advanced functional elements such as radius-to-fix legs and scalable RNP.
A-RNP can be applied to oceanic/remote, en-route, terminal area (SIDs and STARs), and approach operations.
A system qualified and approved for A-RNP is considered to have met the requirements of RNAV 5, RNAV 1, RNAV 2, RNP 2, RNP 1, and RNP APCH in full.
For operations in airspace or on routes designated as A-RNP, both the lateral total system error and the along-track error must each be within the applicable accuracy (0.3 NM to 2.0 NM) for at least 95 percent of the total flight time.
A-RNP eligible aircraft are NOT automatically eligible for RNP AR APCH, as RNP AR eligibility requires a separate determination process and special FAA authorization.
At the highest level, all four of these conditions must be met:
The pilot must have specialized training and be approved for RNP-AR operations.
The aircraft itself must be certified for RNP-AR operations by the FAA.
The avionics must be certified for RNP-AR operations.
The navigation database must be certified and approved for RNP-AR procedures. A normal navigation database does not include RNP-AR procedures.
| RNP Level | Typical Application | Primary Route Width (NM) - Centerline Boundary |
|---|---|---|
| 0.1 to 1.0 | RNP AR Approach Segments | 0.1 to 1.0 |
| 0.3 to 1.0 | RNP Approach Segments | 0.3 to 1.0 |
| 1 | Terminal and En Route | 1.0 |
| 2 | En Route | 2.0 |
| 4 | Projected for oceanic/remote areas where 30 NM horizontal separation is applied | 4.0 |
| 10 | Oceanic/Remote areas where 50 NM lateral separation is applied. | 10.0 |
Refer to the images below to see which Garmin navigators are compatible with the different RNP approach specifications.
This information is also available in the attached document, Garmin Performance-Based Navigation Capabilities.
