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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