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AIM

10/12/17

5−3−15

En Route Procedures

the location and include duration of the anomaly if
necessary.

(i) Any information relating to the safety of

flight.

2. When not in radar contact.

(a) When leaving final approach fix inbound

on final approach (nonprecision approach) or when

leaving the outer marker or fix used in lieu of the outer

marker inbound on final approach (precision

approach).

(b) A corrected estimate at anytime it

becomes apparent that an estimate as previously

submitted is in error in excess of 2 minutes. For

flights in the North Atlantic (NAT), a revised

estimate is required if the error is 3 minutes or more.

b. Pilots encountering weather conditions which

have not been forecast, or hazardous conditions

which have been forecast, are expected to forward a

report of such weather to ATC.

REFERENCE−

AIM, Paragraph 7−1−20 , Pilot Weather Reports (PIREPs)

14 CFR Section 91.183(B) and (C).

5−3−4. Airways and Route Systems

a. Three fixed route systems are established for air

navigation purposes. They are the Federal airway

system (consisting of VOR and L/MF routes), the jet

route system, and the RNAV route system. To the

extent possible, these route systems are aligned in an

overlying manner to facilitate transition between

each.

1. The VOR and L/MF (nondirectional radio

beacons) Airway System consists of airways

designated from 1,200 feet above the surface (or in

some instances higher) up to but not including 18,000

feet MSL. These airways are depicted on IFR Enroute

Low Altitude Charts.

NOTE−

The altitude limits of a victor airway should not be

exceeded except to effect transition within or between route

structures.

(a) Except in Alaska, the VOR airways are:

predicated solely on VOR or VORTAC navigation

aids; depicted in black on aeronautical charts; and

identified by a “V” (Victor) followed by the airway

number (for example, V12).

NOTE−

Segments of VOR airways in Alaska are based on L/MF

navigation aids and charted in brown instead of black on

en route charts.

(1) A segment of an airway which is

common to two or more routes carries the numbers of

all the airways which coincide for that segment.

When such is the case, pilots filing a flight plan need

to indicate only that airway number for the route filed.

NOTE−

A pilot who intends to make an airway flight, using VOR

facilities, will simply specify the appropriate “victor”

airway(s) in the flight plan. For example, if a flight is to be

made from Chicago to New Orleans at 8,000 feet, using

omniranges only, the route may be indicated as “departing

from Chicago−Midway, cruising 8,000 feet via Victor 9 to

Moisant International.” If flight is to be conducted in part

by means of L/MF navigation aids and in part on

omniranges, specifications of the appropriate airways in

the flight plan will indicate which types of facilities will be

used along the described routes, and, for IFR flight, permit

ATC to issue a traffic clearance accordingly. A route may

also be described by specifying the station over which the

flight will pass, but in this case since many VORs and L/MF

aids have the same name, the pilot must be careful to

indicate which aid will be used at a particular location.

This will be indicated in the route of flight portion of the

flight plan by specifying the type of facility to be used after

the location name in the following manner: Newark L/MF,

Allentown VOR.

(2) With respect to position reporting,

reporting points are designated for VOR Airway

Systems. Flights using Victor Airways will report

over these points unless advised otherwise by ATC.

(b) The L/MF airways (colored airways) are

predicated solely on L/MF navigation aids and are

depicted in brown on aeronautical charts and are

identified by color name and number (e.g., Amber

One). Green and Red airways are plotted east and

west. Amber and Blue airways are plotted north and

south.

NOTE−

Except for G13 in North Carolina, the colored airway

system exists only in the state of Alaska. All other such

airways formerly so designated in the conterminous U.S.

have been rescinded.

(c) The use of TSO−C145 (as revised) or

TSO−C146 (as revised) GPS/WAAS navigation

systems is allowed in Alaska as the only means of

navigation on published air traffic service (ATS)

routes, including those Victor, T−Routes, and colored

airway segments designated with a second minimum

9/13/18

AIM