AIM
8/15/19
5
−
3
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16
En Route Procedures
en route altitude (MEA) depicted in blue and
followed by the letter G at those lower altitudes. The
altitudes so depicted are below the minimum
reception altitude (MRA) of the land
−
based
navigation facility defining the route segment, and
guarantee standard en route obstacle clearance and
two
−
way communications. Air carrier operators
requiring operations specifications are authorized to
conduct operations on those routes in accordance
with FAA operations specifications.
2.
The jet route system consists of jet routes
established from 18,000 feet MSL to FL 450
inclusive.
(a)
These routes are depicted on Enroute
High Altitude Charts. Jet routes are depicted in black
on aeronautical charts and are identified by a “J” (Jet)
followed by the airway number (e.g., J12). Jet routes,
as VOR airways, are predicated solely on VOR or
VORTAC navigation facilities (except in Alaska).
NOTE
−
Segments of jet routes in Alaska are based on L/MF
navigation aids and are charted in brown color instead of
black on en route charts.
(b)
With respect to position reporting,
reporting points are designated for jet route systems.
Flights using jet routes will report over these points
unless otherwise advised by ATC.
3. Area Navigation (RNAV) Routes.
(a)
Published RNAV routes, including
Q
−
Routes and T
−
Routes, can be flight planned for
use by aircraft with RNAV capability, subject to any
limitations or requirements noted on en route charts,
in applicable Advisory Circulars, or by NOTAM.
RNAV routes are depicted in blue on aeronautical
charts and are identified by the letter “Q” or “T”
followed by the airway number (for example, Q
−
13,
T
−
205). Published RNAV routes are RNAV
−
2 except
when specifically charted as RNAV
−
1. These routes
require system performance currently met by GPS,
GPS/WAAS, or DME/DME/IRU RNAV systems that
satisfy the criteria discussed in AC 90
−
100A, U.S.
Terminal and En Route Area Navigation (RNAV)
Operations.
(1)
Q
−
routes are available for use by RNAV
equipped aircraft between 18,000 feet MSL and
FL 450 inclusive. Q
−
routes are depicted on Enroute
High Altitude Charts.
NOTE
−
Aircraft in Alaska may only operate on GNSS Q-routes
with GPS (TSO-C129 (as revised) or TSO-C196 (as
revised)) equipment while the aircraft remains in Air
Traffic Control (ATC) radar surveillance or with
GPS/WAAS which does not require ATC radar surveil-
lance.
(2)
T
−
routes are available for use by GPS or
GPS/WAAS equipped aircraft from 1,200 feet above
the surface (or in some instances higher) up to but not
including 18,000 feet MSL. T
−
routes are depicted on
Enroute Low Altitude Charts.
NOTE
−
Aircraft in Alaska may only operate on GNSS T-routes
with GPS/WAAS (TSO-C145 (as revised) or TSO-C146 (as
revised)) equipment.
(b)
Unpublished RNAV routes are direct
routes, based on area navigation capability, between
waypoints defined in terms of latitude/longitude
coordinates, degree
−
distance fixes, or offsets from
established routes/airways at a specified distance and
direction. Radar monitoring by ATC is required on all
unpublished RNAV routes, except for GNSS
−
equipped aircraft cleared via filed published
waypoints recallable from the aircraft’s navigation
database.
(c)
Magnetic Reference Bearing (MRB) is the
published bearing between two waypoints on an
RNAV/GPS/GNSS route. The MRB is calculated by
applying magnetic variation at the waypoint to the
calculated true course between two waypoints. The
MRB enhances situational awareness by indicating a
reference bearing (no
−
wind heading) that a pilot
should see on the compass/HSI/RMI, etc., when
turning prior to/over a waypoint en route to another
waypoint. Pilots should use this bearing as a reference
only, because their RNAV/GPS/GNSS navigation
system will fly the true course between the
waypoints.
b.
Operation above FL 450 may be conducted on
a point-to-point basis. Navigational guidance is
provided on an area basis utilizing those facilities
depicted on the enroute high altitude charts.