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Navigation Aids

(b) Database Requirements. The onboard

navigation data must be current and appropriate for

the region of intended operation and should include

the navigation aids, waypoints, and relevant coded

terminal airspace procedures for the departure,

arrival, and alternate airfields.

(1) Further database guidance for terminal

and en route requirements may be found in AC

90-100, U.S.  Terminal and En Route Area

Navigation (RNAV) Operations.

(2) Further database guidance on Required

Navigation Performance (RNP) instrument approach

operations, RNP terminal, and RNP en route

requirements may be found in AC 90-105, Approval

Guidance for RNP Operations and Barometric

Vertical Navigation in the U.S. National Airspace


(3) All approach procedures to be flown

must be retrievable from the current airborne

navigation database supplied by the equipment

manufacturer or other FAA−approved source. The

system must be able to retrieve the procedure by name

from the aircraft navigation database, not just as a

manually entered series of waypoints. Manual entry

of waypoints using latitude/longitude or place/bear-

ing is not permitted for approach procedures.

(4) Prior to using a procedure or waypoint

retrieved from the airborne navigation database, the

pilot should verify the validity of the database. This

verification should include the following preflight

and inflight steps:

[a] Preflight:

[1]  Determine the date of database

issuance, and verify that the date/time of proposed

use is before the expiration date/time.

[2]  Verify that the database provider

has not published a notice limiting the use of the

specific waypoint or procedure.

[b] Inflight:

[1]  Determine that the waypoints

and transition names coincide with names found on

the procedure chart. Do not use waypoints which do

not exactly match the spelling shown on published

procedure charts.

[2]  Determine that the waypoints are

logical in location, in the correct order, and their

orientation to each other is as found on the procedure

chart, both laterally and vertically.


There is no specific requirement to check each waypoint

latitude and longitude, type of waypoint and/or altitude

constraint, only the general relationship of waypoints in

the procedure, or the logic of an individual waypoint’s


[3]  If the cursory check of procedure

logic or individual waypoint location, specified in [b]

above, indicates a potential error, do not use the

retrieved procedure or waypoint until a verification of

latitude and longitude, waypoint type, and altitude

constraints indicate full conformity with the

published data.

(5) Air carrier and commercial operators

must meet the appropriate provisions of their

approved operations specifications.

[a] During domestic operations for com-

merce or for hire, operators must have a second

navigation system capable of reversion or contin-

gency operations.

[b] Operators must have two independ-

ent navigation systems appropriate to the route to be

flown, or one system that is suitable and a second,

independent backup capability that allows the

operator to proceed safely and land at a different

airport, and the aircraft must have sufficient fuel

(reference 14 CFR 121.349, 125.203, 129.17, and

135.165). These rules ensure the safety of the

operation by preventing a single point of failure.


An aircraft approved for multi-sensor navigation and

equipped with a single navigation system must maintain an

ability to navigate or proceed safely in the event that any

one component of the navigation system fails, including the

flight management system (FMS). Retaining a FMS-inde-

pendent VOR capability would satisfy this requirement.

[c] The requirements for a second

system apply to the entire set of equipment needed to

achieve the navigation capability, not just the

individual components of the system such as the radio

navigation receiver. For example, to use two RNAV

systems (e.g., GPS and DME/DME/IRU) to comply

with the requirements, the aircraft must be equipped

with two independent radio navigation receivers and

two independent navigation computers (e.g., flight

management systems (FMS)). Alternatively, to

comply with the requirements using a single RNAV

system with an installed and operable VOR