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AIM

10/12/17

1−2−5

Performance−Based Navigation (PBN) and Area Navigation (RNAV)

or avionics failure. The Aircraft Flight Manual

(AFM) or avionics documents for your aircraft

should specifically state the aircraft’s RNP eligibili-

ties. Contact the manufacturer of the avionics or the

aircraft if this information is missing or incomplete.

NavSpecs should be considered different from one

another, not “better” or “worse” based on the

described lateral navigation accuracy. It is this

concept that requires each NavSpec eligbility to be

listed separately in the avionics documents or AFM.

For example, RNP 1 is different from RNAV 1, and

an RNP 1 eligibility does NOT mean automatic RNP

2 or RNAV 1 eligibility. As a safeguard, the FAA

requires that aircraft navigation databases hold only

those procedures that the aircraft maintains eligibility

for. If you look for a specific instrument procedure in

your aircraft’s navigation database and cannot find it,

it’s likely that procedure contains PBN elements your

aircraft is ineligible for or cannot compute and fly.

Further, optional capabilities such as Radius−to−fix

(RF) turns or scalability should be described in the

AFM or avionics documents. Use the capabilities of

your avionics suite to verify the appropriate waypoint

and track data after loading the procedure from your

database.

b. PBN Operations.

1. Lateral Accuracy Values. Lateral Accuracy

values are applicable to a selected airspace, route, or

procedure. The lateral accuracy value is a value

typically expressed as a distance in nautical miles

from the intended centerline of a procedure, route, or

path. RNP applications also account for potential

errors at some multiple of lateral accuracy value (for

example, twice the RNP lateral accuracy values).

(a) RNP NavSpecs. U.S. standard NavSpecs

supporting typical RNP airspace uses are as specified

below. Other NavSpecs may include different lateral

accuracy values as identified by ICAO or other states.

(See FIG 1−2−1.)

(1) RNP Approach (RNP APCH). In the

U.S., RNP APCH procedures are titled RNAV (GPS)

and offer several lines of minima to accommodate

varying levels of aircraft equipage: either lateral

navigation (LNAV), LNAV/vertical navigation

(LNAV/VNAV), Localizer Performance with Verti-

cal Guidance (LPV), and Localizer Performance

(LP). GPS with or without Space−Based Augmenta-

tion System (SBAS) (for example, WAAS) can

provide the lateral information to support LNAV

minima. LNAV/VNAV incorporates LNAV lateral

with vertical path guidance for systems and operators

capable of either barometric or SBAS vertical. Pilots

are required to use SBAS to fly to the LPV or LP

minima. RF turn capability is optional in RNP APCH

eligibility. This means that your aircraft may be

eligible for RNP APCH operations, but you may not

fly an RF turn unless RF turns are also specifically

listed as a feature of your avionics suite. GBAS

Landing System (GLS) procedures are also con-

structed using RNP APCH NavSpecs and provide

precision approach capability. RNP APCH has a

lateral accuracy value of 1 in the terminal and missed

approach segments and essentially scales to RNP 0.3

(or 40 meters with SBAS) in the final approach. (See

Paragraph 5−4−18, RNP AR Instrument Approach

Procedures.)

(2) RNP Authorization Required Ap-

proach (RNP AR APCH). In the U.S., RNP AR

APCH procedures are titled RNAV (RNP). These

approaches have stringent equipage and pilot training

standards and require special FAA authorization to

fly. Scalability and RF turn capabilities are

mandatory in RNP AR APCH eligibility. RNP AR

APCH vertical navigation performance is based upon

barometric VNAV or SBAS. RNP AR is intended to

provide specific benefits at specific locations. It is not

intended for every operator or aircraft. RNP AR

capability requires specific aircraft performance,

design, operational processes, training, and specific

procedure design criteria to achieve the required

target level of safety. RNP AR APCH has lateral

accuracy values that can range below 1 in the terminal

and missed approach segments and essentially scale

to RNP 0.3 or lower in the final approach. Before

conducting these procedures, operators should refer

to the latest AC 90−101, Approval Guidance for RNP

Procedures with AR. (See paragraph 5−4−18.)

(3) RNP Authorization Required Depar-

ture (RNP AR DP). Similar to RNP AR approaches,

RNP AR departure procedures have stringent

equipage and pilot training standards and require

special FAA authorization to fly. Scalability and RF

turn capabilities is mandatory in RNP AR DP

eligibility. RNP AR DP is intended to provide

specific benefits at specific locations. It is not

intended for every operator or aircraft. RNP AR DP

capability requires specific aircraft performance,

design, operational processes, training, and specific

procedure design criteria to achieve the required

2/28/19

AIM