JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21)

Region

Country

Facility

FIR

INMAR-

SAT Se-

curity

Number

(Short Co-

des)

SATCOM Voice

(PSTN)

New York West
(WATRS) Ocean-
ic ATC (Emerg)

New York West
(KZWY)

436696

631

‐

468

‐

1495

PACIFIC

Australia

Brisbane ATC

Brisbane (YBBB)

450302

‐

3866

‐

3868

Melbourne ATC

Melbourne (YMMM)

450303

‐

9338

‐

4032

Perth TCU

Melbourne (YMMM)

450304

61-8-9476-8545

Sydney TCU

Melbourne (YMMM)

450305

‐

9556

‐

6875

Fiji

Nadi ACC/Radio

Nadi (NFFF)

452001

French Poly-
nesia

Tahiti ACC

Tahiti (NTTT)

422790

Indonesia

Jakarta ACC (su-
pervisor)

Jakarta (WIIF)

452503

Ujung Pandang
ACC

Ujung Pandang
(WAAF)

452504

Jakarta ACC-Up-
per Banda Aceh
(U-BAC)

Jakarta (WIIF)

452505

Jakarta ACC-Up-
per Indian Ocean-
ic (U-IOS)

Jakarta (WIIF)

452506

Jakarta ACC-Up-
per Pangkal Pi-
nang (U-PKP)

Jakarta (WIIF)

452507

Jakarta ACC-East Jakarta (WIIF)

452508

Japan

Fukuoka

Fukuoka (RJJJ)

443101

Korea (Re-
public of)

Incheon ACC

Incheon (RKRR)

444001

Daegu ACC

Incheon (RKRR)

444002

Myanmar

Yangon ACC

Yangon (VYYF)

450601

New Zea-
land

Auckland Oceanic Auckland Oceanic

(NZZO)

451201

ENROUTE DATA - GENERAL

321

INMARSAT SECURITY NUMBERS (SHORT CODES) AND SATCOM VOICE (PSTN)

Region

Country

Facility

FIR

INMAR-

SAT Se-

curity

Number

(Short Co-

des)

SATCOM Voice

(PSTN)

New Zealand ATC New Zealand (NZZC) 451202

Papua New
Guinea

Port Moresby
ACC

Port Moresby
(AYPM)

455301

Port Moresby
ACC (alternate)

Port Moresby
(AYPM)

455302

Port Moresby
ACC (supervisor)

Port Moresby
(AYPM)

455303

Philippines

Manila ACC

Manila (RPHI)

454801

Manila ACC (al-
ternate)

Manila (RPHI)

454802

Manila ACC (2

alternate)

Manila (RPHI)

454803

Singapore

Singapore
ATC/HF

Singapore (WSJC)

456301

Taiwan

Taipei ACC

Taipei (RCAA)

441290,
441291

Thailand

Bangkok ACC

Bangkok (VTBB)

456702

United
States

Anchorage Oce-
anic ATC (Emerg)

Anchorage Oceanic
(PAZA)

436602

Oakland Center
ATC (Emerg)

Oakland Oceanic
(KZAK)

436697

510

‐

745

‐

3415

San Francisco
Radio

Oakland Oceanic
(KZAK)

436625

ENROUTE DATA - GENERAL

322

INMARSAT SECURITY NUMBERS (SHORT CODES) AND SATCOM VOICE (PSTN)

The general information contained on the following pages is provided for use as ‘quick ref-
erence’. It has been compiled from a variety of sources. Additional information can be
found elsewhere in the Radio Aids section.

FREQUENCY BANDS

Radio frequencies lie within a relatively narrow range of the electro-magnetic spectrum between
approximately 10 kHz and 300 GHz. This range is divided into bands, more or less in accordance
with the propagation characteristics of the frequencies. These bands are:

VLF

Very Low Frequency

0 - 30 kHz

Low Frequency

30 kHz - 300 kHz

Medium Frequency

300 kHz - 3 MHz

High Frequency

3 MHz - 30 MHz

VHF

Very High Frequency

30 MHz - 300 MHz*

UHF

Ultra High Frequency

300 MHz - 3 GHz*

SHF

Super High Frequency

3 GHz - 30 GHz

EHF

Extremely High Frequency

30 GHz - 300 GHz

*200 MHz - 3 GHz is considered UHF in Aviation.

All VHF markers (FAN TYPE, OUTER, INNER and ZONE) operate on 75 MHz (75,000 KHz),
and are tone modulated as follows:
FM

Fan Marker (100 Watts)

3000 Hz

LFM

Low-Powered Fan Marker (5 Watts)

3000 Hz

Middle Marker

1300 Hz

Outer Marker

400 Hz

Station Location Marker

3000 Hz

FREQUENCY ALLOCATION

Frequency allocation is established to provide a clear channeling between the various functions
performed by aeronautical navaids and communications facilities. Although a general allocation
plan is recognized on a world-wide basis, variations may occur within certain ranges. The listing
below is intended to provide that allocation most generally used by civil operators.

RADIO DATA - GENERAL

325

GENERAL INFORMATION

NAVIGATION AIDS

190 - 535 kHz

Nondirectional Radio Beacon (low power) and Ra-
dio Range (low power).

190 - 1750 kHz

Non-directional Beacon (standard).

Marker Beacon.

108.0 - 117.975 MHz

VOR test facility (VOT).

108.0 - 111.975 MHz

ILS localizer (on odd-tenths plus twentieth frequen-
cies, 108.1, 108.3 etc.)

108.0 - 111.975 MHz

VOR (even tenths or even tenths plus a twentieth
of MHz).

111.975 - 117.975 MHz

VOR (even and odd tenths of MHz).

328.6 - 335.4 MHz

ILS glide slope.

960.0 - 1215.0 MHz

DME and TACAN.

1563.42 - 1587.42 MHz

GPS

AIRBORNE STATIONS

410 kHz

International DF (outside continental USA).

475 kHz

Working frequency exclusively for aircraft on sea
flights desiring an intermediate frequency.

500 kHz

International frequency for aircraft and ships over
the seas. Transmission on this frequency (except
for urgent and safety messages and signals) must
cease twice each hour, for three minute periods be-
ginning at 15 and 45 minutes past each hour.

3281 kHz

Lighter-than-aircraft.

117.975 - 137.0 MHz AIR TRAFFIC CONTROL OPERATIONS

The minimum separation between assignable frequencies in the aeronautical mobile (R) service
shall be 8.33 kHz.
It is recognized that in some regions or areas, 100 kHz, 50 kHz or 25 kHz channel spacing pro-
vides an adequate number of frequencies suitably related to international and national air services
and that equipment designed specifically for 100 kHz, 50 kHz or 25 kHz channel spacing will
remain adequate for services operating within such regions or areas. It is further recognized that
assignments based on 25 kHz channel spacing as well as 8.33 kHz channel spacing may con-
tinue to co-exist within one region or area.

RADIO DATA - GENERAL

326

GENERAL INFORMATION

118 - 121.4 MHz inclusive

International and National Aeronautical Mobile
Services

121.5 MHz

121.6 - 121.9917 MHz inclusive

International and National Aerodrome Surface
Communications

122 - 123.05 MHz inclusive

National Aeronautical Mobile Services

123.1 MHz

Auxiliary frequency SAR

123.15 - 123.6917 MHz inclusive

National Aeronautical Mobile Services with the ex-
ception of 123.45 MHz.

123.45 MHz

Worldwide air-to-air communications

123.7 - 129.6917 MHz inclusive

International and National Aeronautical Mobile
Services

129.7 - 130.8917 MHz

National Aeronautical Mobile Services

130.9 - 136.875 MHz inclusive

International and National Aeronautical Mobile
Services

136.9 - 136.975 MHz inclusive

International and National Aeronautical Mobile
Services
Reserved for VHF air-ground data link communica-
tions.

EFFECTIVE RANGE OF RADIO TRANSMISSION

The range of VHF transmissions is normally about 7% more than an actual line of sight, and can
be determined by the formula:

Where:
D

distance in nautical miles;

height of the aircraft station above earth;

(corresponding to an effective earth’s radius of 4/3 of the actual radius);

2.22 when h is expressed in metres; and

1.23 when h is expressed in feet.

RADIO DATA - GENERAL

327

GENERAL INFORMATION

Listed below is the appropriate range for VHF transmissions over flat terrain:

AIRCRAFT ALTI-

TUDE

RANGE (NM)

AIRCRAFT ALTI-

TUDE

RANGE (NM)

500 ft

28 NM

10,000 ft

122 NM

1000 ft

39 NM

15,000 ft

152 NM

1500 ft

48 NM

20,000 ft

174 NM

2000 ft

55 NM

30,000 ft

213 NM

3000 ft

69 NM

40,000 ft

246 NM

5000 ft

87 NM

TYPES OF SIGNAL EMISSIONS

Designation

Type of Transmissions

Characteristics Supplementary

New

Old

NON

With no modulation.

–

A1A

Telegraphy without the use of a modu-
lating audio frequency (by on-off key-
ing).

–

A2A

Telegraphy by the on-off keying of an
amplitude-modulating audio frequency
or audio frequencies, or by the on-off
keying of the modulated emission
(special case; an unkeyed emission
amplitude modulated).

–

A3A

Telephony.

Double Sideband.

R3E

A3A

Single sideband, reduced carrier.

H3E

A3H

Single sideband, full carrier.

J3E

A3J

Single sideband, suppressed carrier.

–

A3B

Two independent sidebands.

B7E

–

Two independent sidebands contain-
ing quantized or digital information.

B8E

–

Two independent sidebands contain-
ing analogueinformation.

Facsimile (by a frequency modulated
sub-carrier).

RADIO DATA - GENERAL

328

GENERAL INFORMATION

Designation

Type of Transmissions

Characteristics Supplementary

New

Old

R3C

A4A

Single sideband, reduced carrier.

J3C

–

Single sideband, suppressed carrier.

R7B

A7A

Multichannel voice-frequency telegra-
phy.

Single sideband, reduced carrier.

B9W

A9B

Cases not covered by the above, e.g.,
a combination of telephony and teleg-
raphy.

Two independent sidebands.

RADIO DATA - GENERAL

329

GENERAL INFORMATION

Information about Radio Aids published in this section is extracted from the United States
Federal Aviation Administration’s (FAA) Aeronautical Information Manual (AIM). It is provi-
ded for reference use only. The information is generally applicable around the world.
Regional variations may exist. Within the section itself, additional references may be made
to U.S. Federal Aviation Regulations (FARs). Relevant FARs can be obtained separately
from Jeppesen, or they are available directly from the U.S. FAA by mail or via the internet.

GENERAL

a. Various types of air navigation aids are in use today, each serving a special purpose. These

aids have varied owners and operators, namely: the Federal Aviation Administration (FAA),
the military services, private organizations, individual states and foreign governments. The
FAA has the statutory authority to establish, operate, maintain air navigation facilities and to
prescribe standards for the operation of any of these aids which are used for instrument flight
in federally controlled airspace. These aids are tabulated in the Chart Supplement U.S.

b. Pilots should be aware of the possibility of momentary erroneous indications on cockpit dis-

plays when the primary signal generator for a ground-based navigational transmitter (for
example, a glideslope, VOR, or nondirectional beacon) is inoperative. Pilots should disregard
any navigation indication, regardless of its apparent validity, if the particular transmitter was
identified by NOTAM or otherwise as unusable or inoperative.

NONDIRECTIONAL RADIO BEACON (NDB)

a. A low or medium frequency radio beacon transmits nondirectional signals whereby the pilot

of an aircraft properly equipped can determine bearings and “home” on the station. These
facilities normally operate in a frequency band of 190 to 535 kilohertz (kHz), according to
ICAO Annex 10 the frequency range for NDBs is between 190 and 1750 kHz, and transmit a
continuous carrier with either 400 or 1020 hertz (Hz) modulation. All radio beacons except
the compass locators transmit a continuous three-letter identification in code except during
voice transmissions.

b. When a radio beacon is used in conjunction with the Instrument Landing System markers, it

is called a Compass Locator.

c. Voice transmissions are made on radio beacons unless the letter “W” (without voice) is inclu-

ded in the class designator (HW).

d. Radio beacons are subject to disturbances that may result in erroneous bearing information.

Such disturbances result from such factors as lightning, precipitation static, etc. At night,
radio beacons are vulnerable to interference from distant stations. Nearly all disturbances
which affect the Automatic Direction Finder (ADF) bearing also affect the facility’s identifica-
tion. Noisy identification usually occurs when the ADF needle is erratic. Voice, music or erro-
neous identification may be heard when a steady false bearing is being displayed. Since
ADF receivers do not have a “flag” to warn the pilot when erroneous bearing information is
being displayed, the pilot should continuously monitor the NDB’s identification.

1-1-1

1-1-2

RADIO DATA - GENERAL

330

SECTION 1. NAVIGATION AIDS

VHF OMNI-DIRECTIONAL RANGE (VOR)

a. VORs operate within the 108.0 to 117.95 MHz frequency band and have a power output nec-

essary to provide coverage within their assigned operational service volume. They are sub-
ject to line-of-sight restrictions, and the range varies proportionally to the altitude of the
receiving equipment.
NOTE: Normal service ranges for the various classes of VORs are given in Navigational Aid
(NAVAID) Service Volumes, paragraph 1-1-8.

b. Most VORs are equipped for voice transmission on the VOR frequency. VORs without voice

capability are indicated by the letter “W” (without voice) included in the class designator
(VORW).

c. The only positive method of identifying a VOR is by its Morse Code identification or by the

recorded automatic voice identification which is always indicated by use of the word “VOR”
following the range’s name. Reliance on determining the identification of an omnirange
should never be placed on listening to voice transmissions by the Flight Service Station
(FSS) (or approach control facility) involved. Many FSSs remotely operate several omnir-
anges with different names. In some cases, none of the VORs have the name of the “parent”
FSS. During periods of maintenance, the facility may radiate a T-E-S-T code (– • ••• –) or the
code may be removed. Some VOR equipment decodes the identifier and displays it to the
pilot for verification to charts, while other equipment simply displays the expected identifier
from a database to aid in verification to the audio tones. You should be familiar with your
equipment and use it appropriately. If your equipment automatically decodes the identifier, it
is not necessary to listen to the audio identification.

d. Voice identification has been added to numerous VORs. The transmission consists of a

voice announcement, “AIRVILLE VOR” alternating with the usual Morse Code identification.

e. The effectiveness of the VOR depends upon proper use and adjustment of both ground and

airborne equipment.

Accuracy. The accuracy of course alignment of the VOR is excellent, being generally
plus or minus 1 degree.

Roughness. On some VORs, minor course roughness may be observed, evidenced by
course needle or brief flag alarm activity (some receivers are more susceptible to these
irregularities than others). At a few stations, usually in mountainous terrain, the pilot
may occasionally observe a brief course needle oscillation, similar to the indication of
“approaching station.” Pilots flying over unfamiliar routes are cautioned to be on the
alert for these vagaries, and in particular, to use the “to/from” indicator to determine
positive station passage.

(a) Certain propeller revolutions per minute (RPM) settings or helicopter rotor speeds

can cause the VOR Course Deviation Indicator to fluctuate as much as plus or
minus six degrees. Slight changes to the RPM setting will normally smooth out this
roughness. Pilots are urged to check for this modulation phenomenon prior to
reporting a VOR station or aircraft equipment for unsatisfactory operation.

1-1-3

RADIO DATA - GENERAL

331

SECTION 1. NAVIGATION AIDS

The VOR Minimum Operational Network (MON). As flight procedures and route structure
based on VORs are gradually being replaced with Performance-Based Navigation (PBN)
procedures, the FAA is removing selected VORs from service. PBN procedures are primarily
enabled by GPS and its augmentation systems, collectively referred to as Global Navigation
Satellite System (GNSS). Aircraft that carry DME/DME equipment can also use RNAV which
provides a backup to continue flying PBN during a GNSS disruption. For those aircraft that
do not carry DME/DME, the FAA is retaining a limited network of VORs, called the VOR
MON, to provide a basic conventional navigation service for operators to use if GNSS
becomes unavailable. During a GNSS disruption, the MON will enable aircraft to navigate
through the affected area or to a safe landing at a MON airport without reliance on GNSS.
Navigation using the MON will not be as efficient as the new PBN route structure, but use of
the MON will provide nearly continuous VOR signal coverage at 5,000 feet AGL across the
NAS, outside of the Western U.S. Mountainous Area (WUSMA).
NOTE: There is no plan to change the NAVAID and route structure in the WUSMA.
The VOR MON has been retained principally for IFR aircraft that are not equipped with
DME/DME avionics. However, VFR aircraft may use the MON as desired. Aircraft equipped
with DME/DME navigation systems would, in most cases, use DME/DME to continue flight
using RNAV to their destination. However, these aircraft may, of course, use the MON.

Distance to a MON airport. The VOR MON will ensure that regardless of an aircraft’s
position in the contiguous United States (CONUS), a MON airport (equipped with legacy
ILS or VOR approaches) will be within 100 nautical miles. These airports are referred to
as “MON airports” and will have an ILS approach or a VOR approach if an ILS is not
available. VORs to support these approaches will be retained in the VOR MON. MON
airports are charted on low-altitude en route charts and are contained in the Chart Sup-
plement U.S. and other appropriate publications.
NOTE: Any suitable airport can be used to land in the event of a VOR outage. For
example, an airport with a DME-required ILS approach may be available and could be
used by aircraft that are equipped with DME. The intent of the MON airport is to provide
an approach that can be used by aircraft without ADF or DME when radar may not be
available.

Navigating to an airport. The VOR MON will retain sufficient VORs and increase VOR
service volume to ensure that pilots will have nearly continuous signal reception of a
VOR when flying at 5,000 feet AGL. A key concept of the MON is to ensure that an air-
craft will always be within 100 NM of an airport with an instrument approach that is not
dependent on GPS. (See paragraph 1-1-8.) If the pilot encounters a GPS outage, the
pilot will be able to proceed via VOR-to-VOR navigation at 5,000 feet AGL through the
GPS outage area or to a safe landing at a MON airport or another suitable airport, as
appropriate. Nearly all VORs inside of the WUSMA and outside the CONUS are being
retained. In these areas, pilots use the existing (Victor and Jet) route structure and
VORs to proceed through a GPS outage or to a landing.

Using the VOR MON.

RADIO DATA - GENERAL

332

SECTION 1. NAVIGATION AIDS

(a) In the case of a planned GPS outage (for example, one that is in a published

NOTAM), pilots may plan to fly through the outage using the MON as appropriate
and as cleared by ATC. Similarly, aircraft not equipped with GPS may plan to fly
and land using the MON, as appropriate and as cleared by ATC.
NOTE: In many cases, flying using the MON may involve a more circuitous route
than flying GPS-enabled RNAV.

(b) In the case of an unscheduled GPS outage, pilots and ATC will need to coordinate

the best outcome for all aircraft. It is possible that a GPS outage could be disrup-
tive, causing high workload and demand for ATC service. Generally, the VOR
MON concept will enable pilots to navigate through the GPS outage or land at a
MON airport or at another airport that may have an appropriate approach or may
be in visual conditions.

(1) The VOR MON is a reversionary service provided by the FAA for use by air-

craft that are unable to continue RNAV during a GPS disruption. The FAA has
not mandated that preflight or inflight planning include provisions for GPS- or
WAAS-equipped aircraft to carry sufficient fuel to proceed to a MON airport in
case of an unforeseen GPS outage. Specifically, flying to a MON airport as a
filed alternate will not be explicitly required. Of course, consideration for the
possibility of a GPS outage is prudent during flight planning as is maintaining
proficiency with VOR navigation.

(2) Also, in case of a GPS outage, pilots may coordinate with ATC and elect to

continue through the outage or land. The VOR MON is designed to ensure
that an aircraft is within 100 NM of an airport, but pilots may decide to pro-
ceed to any appropriate airport where a landing can be made. WAAS users
flying under Part 91 are not required to carry VOR avionics. These users do
not have the ability or requirement to use the VOR MON. Prudent flight plan-
ning, by these WAAS-only aircraft, should consider the possibility of a GPS
outage.
NOTE: The FAA recognizes that non-GPS-based approaches will be reduced
when VORs are eliminated, and that most airports with an instrument
approach may only have GPS- or WAAS-based approaches. Pilots flying
GPS- or WAAS-equipped aircraft that also have VOR/ILS avionics should be
diligent to maintain proficiency in VOR and ILS approaches in the event of a
GPS outage.

VOR RECEIVER CHECK

a. The FAA VOR test facility (VOT) transmits a test signal which provides users a convenient

means to determine the operational status and accuracy of a VOR receiver while on the
ground where a VOT is located. The airborne use of VOT is permitted; however, its use is
strictly limited to those areas/altitudes specifically authorized in the Chart Supplement U.S.
or appropriate supplement.

1-1-4

RADIO DATA - GENERAL

333

SECTION 1. NAVIGATION AIDS

b. To use the VOT service, tune in the VOT frequency on your VOR receiver. With the Course

Deviation Indicator (CDI) centered, the omni-bearing selector should read 0 degrees with the
to/from indication showing “from” or the omni-bearing selector should read 180 degrees with
the to/from indication showing “to.” Should the VOR receiver operate an RMI (Radio Mag-
netic Indicator), it will indicate 180 degrees on any omni-bearing selector (OBS) setting. Two
means of identification are used. One is a series of dots and the other is a continuous tone.
Information concerning an individual test signal can be obtained from the local FSS.

c. Periodic VOR receiver calibration is most important. If a receiver’s Automatic Gain Control or

modulation circuit deteriorates, it is possible for it to display acceptable accuracy and sensi-
tivity close into the VOR or VOT and display out-of-tolerance readings when located at
greater distances where weaker signal areas exist. The likelihood of this deterioration varies
between receivers, and is generally considered a function of time. The best assurance of
having an accurate receiver is periodic calibration. Yearly intervals are recommended at
which time an authorized repair facility should recalibrate the receiver to the manufacturer’s
specifications.

d. Federal Aviation Regulations (14 CFR Section 91.171) provides for certain VOR equipment

accuracy checks prior to flight under instrument flight rules. To comply with this requirement
and to ensure satisfactory operation of the airborne system, the FAA has provided pilots with
the following means of checking VOR receiver accuracy:

1. VOT or a radiated test signal from an appropriately rated radio repair station.
2. Certified airborne checkpoints and airways.
3. Certified checkpoints on the airport surface.
4. If an airborne checkpoint is not available, select an established VOR airway. Select a

prominent ground point, preferably more than 20 NM from the VOR ground facility and
maneuver the aircraft directly over the point at a reasonably low altitude above terrain
and obstructions.

e. A radiated VOT from an appropriately rated radio repair station serves the same purpose as

an FAA VOR signal and the check is made in much the same manner as a VOT with the
following differences:

1. The frequency normally approved by the Federal Communications Commission is 108.0

MHz.

2. Repair stations are not permitted to radiate the VOR test signal continuously; conse-

quently, the owner or operator must make arrangements with the repair station to have
the test signal transmitted. This service is not provided by all radio repair stations. The
aircraft owner or operator must determine which repair station in the local area provides
this service. A representative of the repair station must make an entry into the aircraft
logbook or other permanent record certifying to the radial accuracy and the date of
transmission. The owner, operator or representative of the repair station may accom-
plish the necessary checks in the aircraft and make a logbook entry stating the results.

RADIO DATA - GENERAL

334

SECTION 1. NAVIGATION AIDS

It is necessary to verify which test radial is being transmitted and whether you should
get a “to” or “from” indication.

f. Airborne and ground check points consist of certified radials that should be received at spe-

cific points on the airport surface or over specific landmarks while airborne in the immediate
vicinity of the airport.

1. Should an error in excess of plus or minus 4 degrees be indicated through use of a

ground check, or plus or minus 6 degrees using the airborne check, Instrument Flight
Rules (IFR) flight must not be attempted without first correcting the source of the error.
CAUTION: No correction other than the correction card figures supplied by the manu-
facturer should be applied in making these VOR receiver checks.

2. Locations of airborne check points, ground check points and VOTs are published in the

Chart Supplement U.S.

3. If a dual system VOR (units independent of each other except for the antenna) is instal-

led in the aircraft, one system may be checked against the other. Turn both systems to
the same VOR ground facility and note the indicated bearing to that station. The maxi-
mum permissible variations between the two indicated bearings is 4 degrees.

TACTICAL AIR NAVIGATION (TACAN)

a. For reasons peculiar to military or naval operations (unusual siting conditions, the pitching

and rolling of a naval vessel, etc.) the civil VOR/Distance Measuring Equipment (DME)
system of air navigation was considered unsuitable for military or naval use. A new naviga-
tional system, TACAN, was therefore developed by the military and naval forces to more
readily lend itself to military and naval requirements. As a result, the FAA has integrated
TACAN facilities with the civil VOR/DME program. Although the theoretical, or technical prin-
ciples of operation of TACAN equipment are quite different from those of VOR/DME facilities,
the end result, as far as the navigating pilot is concerned, is the same. These integrated
facilities are called VORTACs.

b. TACAN ground equipment consists of either a fixed or mobile transmitting unit. The airborne

unit in conjunction with the ground unit reduces the transmitted signal to a visual presenta-
tion of both azimuth and distance information. TACAN is a pulse system and operates in the
Ultrahigh Frequency (UHF) band of frequencies. Its use requires TACAN airborne equipment
and does not operate through conventional VOR equipment.

VHF OMNI-DIRECTIONAL RANGE/TACTICAL AIR

NAVIGATION (VORTAC)

a. A VORTAC is a facility consisting of two components, VOR and TACAN, which provides

three individual services: VOR azimuth, TACAN azimuth and TACAN distance (DME) at one
site. Although consisting of more than one component, incorporating more than one operat-
ing frequency, and using more than one antenna system, a VORTAC is considered to be a
unified navigational aid. Both components of a VORTAC are envisioned as operating simul-
taneously and providing the three services at all times.

1-1-5

1-1-6

RADIO DATA - GENERAL

335

SECTION 1. NAVIGATION AIDS

b. Transmitted signals of VOR and TACAN are each identified by three-letter code transmission

and are interlocked so that pilots using VOR azimuth with TACAN distance can be assured
that both signals being received are definitely from the same ground station. The frequency
channels of the VOR and the TACAN at each VORTAC facility are “paired” in accordance
with a national plan to simplify airborne operation.

DISTANCE MEASURING EQUIPMENT (DME)

a. In the operation of DME, paired pulses at a specific spacing are sent out from the aircraft

(this is the interrogation) and are received at the ground station. The ground station (trans-
ponder) then transmits paired pulses back to the aircraft at the same pulse spacing but on a
different frequency. The time required for the round trip of this signal exchange is measured
in the airborne DME unit and is translated into distance (nautical miles) from the aircraft to
the ground station.

b. Operating on the line-of-sight principle, DME furnishes distance information with a very high

degree of accuracy. Reliable signals may be received at distances up to 199 NM at line-of-
sight altitude with an accuracy of better than

mile or 3 percent of the distance, whichever

is greater. Distance information received from DME equipment is SLANT RANGE distance
and not actual horizontal distance.

c. Operating frequency range of a DME according to ICAO Annex 10 is from 960 MHz to 1215

MHz. Aircraft equipped with TACAN equipment will receive distance information from a
VORTAC automatically, while aircraft equipped with VOR must have a separate DME air-
borne unit.

d. VOR/DME, VORTAC, Instrument Landing System (ILS)/DME, and localizer (LOC)/DME nav-

igation facilities established by the FAA provide course and distance information from collo-
cated components under a frequency pairing plan. Aircraft receiving equipment which pro-
vides for automatic DME selection assures reception of azimuth and distance information
from a common source when designated VOR/DME, VORTAC, ILS/DME, and LOC/DME are
selected.

e. Due to the limited number of available frequencies, assignment of paired frequencies is

required for certain military noncollocated VOR and TACAN facilities which serve the same
area but which may be separated by distances up to a few miles.

f. VOR/DME, VORTAC, ILS/DME, and LOC/DME facilities are identified by synchronized iden-

tifications which are transmitted on a time share basis. The VOR or localizer portion of the
facility is identified by a coded tone modulated at 1020 Hz or a combination of code and
voice. The TACAN or DME is identified by a coded tone modulated at 1350 Hz. The DME or
TACAN coded identification is transmitted one time for each three or four times that the VOR
or localizer coded identification is transmitted. When either the VOR or the DME is inopera-
tive, it is important to recognize which identifier is retained for the operative facility. A single
coded identification with a repetition interval of approximately 30 seconds indicates that the
DME is operative.

1-1-7

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g. Aircraft equipment which provides for automatic DME selection assures reception of azimuth

and distance information from a common source when designated VOR/DME, VORTAC and
ILS/DME navigation facilities are selected. Pilots are cautioned to disregard any distance dis-
plays from automatically selected DME equipment when VOR or ILS facilities, which do not
have the DME feature installed, are being used for position determination.

NAVAID SERVICE VOLUMES

a. The FAA publishes Standard Service Volumes (SSVs) for most NAVAIDs. The SSV is a

three-dimensional volume within which the FAA ensures that a signal can be received with
adequate signal strength and course quality, and is free from interference from other NAV-
AIDs on similar frequencies (e.g., co-channel or adjacent-channel interference). However,
the SSV signal protection does not include potential blockage from terrain or obstructions.
The SSV is principally intended for off-route navigation, such as proceeding direct to or from
a VOR when not on a published instrument procedure or route. Navigation on published
instrument procedures (e.g., approaches or departures) or routes (e.g., Victor routes) may
use NAVAIDs outside of the SSV, when Extended Service Volume (ESV) is approved, since
adequate signal strength, course quality, and freedom from interference are verified by the
FAA prior to the publishing of the instrument procedure or route.
NOTE: A conical area directly above the NAVAID is generally not usable for navigation.

b. A NAVAID will have service volume restrictions if it does not conform to signal strength and

course quality standards throughout the published SSV. Service volume restrictions are first
published in Notices to Airmen (NOTAMs) and then with the alphabetical listing of the NAV-
AIDs in the Chart Supplement. Service volume restrictions do not generally apply to pub-
lished instrument procedures or routes unless published in NOTAMs for the affected instru-
ment procedure or route.

c. VOR/DME/TACAN Standard Service Volumes (SSV).

1. The three original SSVs are shown in FIG 1-1-1 and are designated with three classes

of NAVAIDs: Terminal (T), Low (L), and High (H). The usable distance of the NAVAID
depends on the altitude Above the Transmitter Height (ATH) for each class. The lower
edge of the usable distance when below 1,000 feet ATH is shown in FIG 1-1-2 for Ter-
minal NAVAIDs and in FIG 1-1-3 for Low and High NAVAIDs.

1-1-8

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FIGURE 1-1-5

New DME Service Volumes

NOTE 1: In the past, NAVAIDs at one location typically all had the same SSV. For
example, a VORTAC typically had a High (H) SSV for the VOR, the TACAN azimuth,
and the TACAN DME, or a Low (L) or Terminal (T) SSV for all three. A VOR/DME typi-
cally had a High (H), Low (L), or Terminal (T) for both the VOR and the DME. A
common SSV may no longer be the case at all locations. A VOR/DME, for example,
could have an SSV of VL for the VOR and DH for the DME, or other combinations.
NOTE 2: The TACAN azimuth will only be classified as T, L, or H.
NOTE 3: TBL 1-1-1 is a tabular summary of the VOR, DME, and TACAN NAVAID
SSVs, not including altitudes below 1,000 feet ATH for VOR and TACAN Azimuth, and
not including ranges for altitudes below 12,900 feet for TACAN and DME.

TABLE 1-1-1 VOR/DME/TACAN Standard Service Volumes

SSV Designator

Altitude and Range Boundaries

T (Terminal)

From 1,000 feet ATH up to and including 12,000 feet ATH at radial dis-
tances out to 25 NM.

L (Low Altitude)

From 1,000 feet ATH up to and including 18,000 feet ATH at radial dis-
tances out to 40 NM.

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TABLE 1-1-1 VOR/DME/TACAN Standard Service Volumes (continued)

SSV Designator

Altitude and Range Boundaries

H (High Altitude)

From 1,000 feet ATH up to and including 14,500 feet ATH at radial dis-
tances out to 40 NM. From 14,500 ATH up to and including 60,000 feet
at radial distances out to 100 NM. From 18,000 feet ATH up to and in-
cluding 45,000 feet ATH at radial distances out to 130 NM.

VL (VOR Low)

From 1,000 feet ATH up to but not including 5,000 feet ATH at radial
distances out to 40 NM. From 5,000 feet ATH up to but not including
18,000 feet ATH at radial distances out to 70 NM.

VH (VOR High)

From 1,000 feet ATH up to but not including 5,000 feet ATH at radial
distances out to 40 NM. From 5,000 feet ATH up to but not including
14,500 feet ATH at radial distances out to 70 NM. From 14,500 ATH up
to and including 60,000 feet at radial distances out to 100 NM. From
18,000 feet ATH up to and including 45,000 feet ATH at radial distan-
ces out to 130 NM.

DL (DME Low)

For altitudes up to 12,900 feet ATH at a radial distance corresponding
to the LOS to the NAVAID. From 12,900 feet ATH up to but not includ-
ing 18,000 feet ATH at radial distances out to 130 NM.

DH (DME High)

For altitudes up to 12,900 feet ATH at a radial distance corresponding
to the LOS to the NAVAID. From 12,900 ATH up to and including
60,000 feet at radial distances out to 100 NM. From 12,900 feet ATH
up to and including 45,000 feet ATH at radial distances out to 130 NM.

d. Nondirectional Radio Beacon (NDB) SSVs. NDBs are classified according to their intended

use. The ranges of NDB service volumes are shown in TBL 1-1-2. The distance (radius) is
the same at all altitudes for each class.

TABLE 1-1-2 NDB Service Volumes

Class

Distance (Radius) (NM)

Compass Locator

50*

*Service ranges of individual facilities may be less than 50 nautical miles (NM). Restrictions to
service volumes are first published as a Notice to Airmen and then with the alphabetical listing of
the NAVAID in the Chart Supplement U.S.

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INSTRUMENT LANDING SYSTEM (ILS)

General

1. The ILS is designed to provide an approach path for exact alignment and descent of an

aircraft on final approach to a runway.

2. The basic components of an ILS are the localizer, glide slope, and Outer Marker (OM)

and, when installed for use with Category II or Category III instrument approach proce-
dures, an Inner Marker (IM).

3. The system may be divided functionally into three parts:

(a)

Guidance information: localizer, glide slope.

(b)

Range information: marker beacon, DME.

(c)

Visual information: approach lights, touchdown and centerline lights, runway
lights.

4. The following means may be used to substitute for the OM:

(a) Compass locator; or
(b) Precision Approach Radar (PAR); or

(d) Distance Measuring Equipment (DME), Very High Frequency Omni-directional

Range (VOR), or Nondirectional beacon fixes authorized in the Standard Instru-
ment Approach Procedure; or

(e) Very High Frequency Omni-directional Radio Range (VOR); or

(f) Nondirectional beacon fixes authorized in the Standard Instrument Approach Pro-

cedure; or

(g) A suitable RNAV system with Global Positioning System (GPS), capable of fix

identification on a Standard Instrument Approach Procedure.

5. Where a complete ILS system is installed on each end of a runway; (i.e., the approach

end of Runway 4 and the approach end of Runway 22) the ILS systems are not in serv-
ice simultaneously.

Localizer

1. The localizer transmitter operates on one of 40 ILS channels within the frequency

range of 108.10 to 111.95 MHz. Signals provide the pilot with course guidance to the
runway centerline.

2. The approach course of the localizer is called the front course and is used with other

functional parts, e.g., glide slope, marker beacons, etc. The localizer signal is transmit-
ted at the far end of the runway. It is adjusted for a course width of (full scale fly-left to
a full scale fly-right) of 700 feet at the runway threshold.

1-1-9

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SECTION 1. NAVIGATION AIDS

3. The course line along the extended centerline of a runway, in the opposite direction to

the front course is called the back course.
CAUTION: Unless the aircraft’s ILS equipment includes reverse sensing capability,
when flying inbound on the back course it is necessary to steer the aircraft in the direc-
tion opposite the needle deflection when making corrections from off-course to on-
course. This “flying away from the needle” is also required when flying outbound on the
front course of the localizer. Do not use back course signals for approach unless a
back course approach procedure is published for that particular runway and the
approach is authorized by ATC.

4. Identification is in International Morse Code and consists of a three-letter identifier pre-

ceded by the letter I (••) transmitted on the localizer frequency.
EXAMPLE: I-DIA

5. The localizer provides course guidance throughout the descent path to the runway

threshold from a distance of 18 NM from the antenna between an altitude of 1,000 feet
above the highest terrain along the course line and 4,500 feet above the elevation of
the antenna site. Proper off-course indications are provided throughout the following
angular areas of the operational service volume:

(a) To 10 degrees either side of the course along a radius of 18 NM from the

antenna; and

(b) From 10 to 35 degrees either side of the course along a radius of 10 NM. (See

FIG 1-1-6.)

FIGURE 1-1-6

Limits of Localizer Coverage

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6. Unreliable signals may be received outside these areas.
7. The areas described in paragraph 1-1-9 b.5 and depicted in FIG 1-1-6 represent a

Standard Service Volume (SSV) localizer. All charted procedures with localizer cover-
age beyond the 18 NM SSV have been through the approval process for Expanded
Service Volume (ESV), and have been validated by flight inspection.

Localizer Type Directional Aid (LDA)

1. The LDA is of comparable use and accuracy to a localizer but is not part of a complete

ILS. The LDA course usually provides a more precise approach course than the similar
Simplified Directional Facility (SDF) installation, which may have a course width of 6 or
12 degrees.

2. The LDA is not aligned with the runway. Straight-in minimums may be published where

alignment does not exceed 30 degrees between the course and runway. Circling mini-
mums only are published where this alignment exceeds 30 degrees.

3. A very limited number of LDA approaches also incorporate a glideslope. These are

annotated in the plan view of the instrument approach chart with a note, “LDA/Glide-
slope.” These procedures fall under a newly defined category of approaches called
Approach with Vertical Guidance (APV) described in paragraph 5-4-5, Instrument
Approach Procedure Charts, subparagraph a7(b), Approach with Vertical Guidance
(APV). LDA minima for with and without glideslope is provided and annotated on the
minima lines of the approach chart as S-LDA/GS and S-LDA. Because the final
approach course is not aligned with the runway centerline, additional maneuvering will
be required compared to an ILS approach.

Glide Slope/Glide Path

1. The UHF glide slope transmitter, operating on one of the 40 ILS channels within the

frequency range 329.15 MHz, to 335.00 MHz radiates its signals in the direction of the
localizer front course. The term “glide path” means that portion of the glide slope that
intersects the localizer.
CAUTION: False glide slope signals may exist in the area of the localizer back course
approach which can cause the glide slope flag alarm to disappear and present unrelia-
ble glide slope information. Disregard all glide slope signal indications when making a
localizer back course approach unless a glide slope is specified on the approach and
landing chart.

2. The glide slope transmitter is located between 750 feet and 1,250 feet from the

approach end of the runway (down the runway) and offset 250 to 650 feet from the
runway centerline. It transmits a glide path beam 1.4 degrees wide (vertically). The
signal provides descent information for navigation down to the lowest authorized deci-
sion height (DH) specified in the approved ILS approach procedure. The glidepath may
not be suitable for navigation below the lowest authorized DH and any reference to gli-
depath indications below that height must be supplemented by visual reference to the
runway environment. Glidepaths with no published DH are usable to runway threshold.

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3. The glide path projection angle is normally adjusted to 3 degrees above horizontal so

that it intersects the MM at about 200 feet and the OM at about 1,400 feet above the
runway elevation. The glide slope is normally usable to the distance of 10 NM. How-
ever, at some locations, the glide slope has been certified for an extended service
volume which exceeds 10 NM.

4. Pilots must be alert when approaching the glidepath interception. False courses and

reverse sensing will occur at angles considerably greater than the published path.

5. Make every effort to remain on the indicated glide path.

CAUTION: Avoid flying below the glide path to assure obstacle/terrain clearance is
maintained.

6. The published glide slope threshold crossing height (TCH) DOES NOT represent the

height of the actual glide path on-course indication above the runway threshold. It is
used as a reference for planning purposes which represents the height above the
runway threshold that an aircraft’s glide slope antenna should be, if that aircraft
remains on a trajectory formed by the four-mile-to-middle marker glidepath segment.

7. Pilots must be aware of the vertical height between the aircraft’s glide slope antenna

and the main gear in the landing configuration and, at the DH, plan to adjust the
descent angle accordingly if the published TCH indicates the wheel crossing height
over the runway threshold may not be satisfactory. Tests indicate a comfortable wheel
crossing height is approximately 20 to 30 feet, depending on the type of aircraft.
NOTE: The TCH for a runway is established based on several factors including the
largest aircraft category that normally uses the runway, how airport layout affects the
glide slope antenna placement, and terrain. A higher than optimum TCH, with the same
glide path angle, may cause the aircraft to touch down further from the threshold if the
trajectory of the approach is maintained until the flare. Pilots should consider the effect
of a high TCH on the runway available for stopping the aircraft.

Distance Measuring Equipment (DME)

1. When installed with the ILS and specified in the approach procedure, DME may be

used:

(a) In lieu of the OM;
(b) As a back course (BC) final approach fix (FAF); and

2. In some cases, DME from a separate facility may be used within Terminal Instrument

Procedures (TERPS) limitations:

(a) To provide ARC initial approach segments;
(b) As a FAF for BC approaches; and

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Marker Beacon

1. ILS marker beacons have a rated power output of 3 watts or less and an antenna array

designed to produce an elliptical pattern with dimensions, at 1,000 feet above the
antenna, of approximately 2,400 feet in width and 4,200 feet in length. Airborne marker
beacon receivers with a selective sensitivity feature should always be operated in the
“low” sensitivity position for proper reception of ILS marker beacons.

2. ILS systems may have an associated OM. An MM is no longer required. Locations with

a Category II ILS also have an Inner Marker (IM). Due to advances in both ground nav-
igation equipment and airborne avionics, as well as the numerous means that may be
used as a substitute for a marker beacon, the current requirements for the use of
marker beacons are:

(a) An OM or suitable substitute identifies the Final Approach Fix (FAF) for nonpreci-

sion approach (NPA) operations (for example, localizer only); and

(b) The MM indicates a position approximately 3,500 feet from the landing threshold.

This is also the position where an aircraft on the glide path will be at an altitude of
approximately 200 feet above the elevation of the touchdown zone. An MM is no
longer operationally required. There are some MMs still in use, but there are no
MMs being installed at new ILS sites by the FAA; and

on the glide path during a Category II ILS approach. An IM is only required for
CAT II operations that do not have a published radio altitude (RA) minimum.

TABLE 1-1-3 Marker Passage Indications

Marker

Code

Light

- - -

BLUE

•

- • -

AMBER

• • • •

WHITE

• •

WHITE

3. A back course marker normally indicates the ILS back course final approach fix where

approach descent is commenced.

Compass Locator

1. Compass locator transmitters are often situated at the MM and OM sites. The transmit-

ters have a power of less than 25 watts, a range of at least 15 miles and operate
between 190 and 535 kHz. At some locations, higher powered radio beacons, up to
400 watts, are used as OM compass locators.

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2. Compass locators transmit two letter identification groups. The outer locator transmits

the first two letters of the localizer identification group, and the middle locator transmits
the last two letters of the localizer identification group.

ILS Frequency (See TBL 1-1-4.)

TABLE 1-1-4 Frequency Pairs Allocated for ILS

Localizer MHz

Glide Slope

108.10

334.70

108.15

334.55

108.3

334.10

108.35

333.95

108.5

329.90

108.55

329.75

108.7

330.50

108.75

330.35

108.9

329.30

108.95

329.15

109.1

331.40

109.15

331.25

109.3

332.00

109.35

331.85

109.50

332.60

109.55

332.45

109.70

333.20

109.75

333.05

109.90

333.80

109.95

333.65

110.1

334.40

110.15

334.25

110.3

335.00

110.35

334.85

110.5

329.60

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SECTION 1. NAVIGATION AIDS

TABLE 1-1-4 Frequency Pairs Allocated for ILS (continued)

Localizer MHz

Glide Slope

110.55

329.45

110.70

330.20

110.75

330.05

110.90

330.80

110.95

330.65

111.10

331.70

111.15

331.55

111.30

332.30

111.35

332.15

111.50

332.9

111.55

332.75

111.70

333.5

111.75

333.35

111.90

331.1

111.95

330.95

ILS Minimums

1. The lowest authorized ILS minimums, with all required ground and airborne systems

components operative, are:

(a)

Category I. Decision Height (DH) 200 feet and Runway Visual Range (RVR)
2,400 feet (with touchdown zone and centerline lighting, RVR 1,800 feet), or (with
Autopilot or FD or HUD, RVR 1,800 feet);

(b)

Special Authorization Category I. DH 150 feet and Runway Visual Range (RVR)
1,400 feet, HUD to DH;

(c)

Category II. DH 100 feet and RVR 1,200 feet (with autoland or HUD to touch-
down and noted on authorization, RVR 1,000 feet);

(d)

Special Authorization Category II with Reduced Lighting. DH 100 feet and
RVR 1,200 feet with autoland or HUD to touchdown and noted on authorization
(touchdown zone, centerline lighting, and ALSF-2 are not required);

(e)

Category IIIa. No DH or DH below 100 feet and RVR not less than 700 feet;

(f)

Category IIIb. No DH or DH below 50 feet and RVR less than 700 feet but not
less than 150 feet; and

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SECTION 1. NAVIGATION AIDS

(g)

Category IIIc. No DH and no RVR limitation.
NOTE: Special authorization and equipment required for Categories II and III.

Inoperative ILS Components

Inoperative localizer. When the localizer fails, an ILS approach is not authorized.

Inoperative glide slope. When the glide slope fails, the ILS reverts to a non-precision
localizer approach.
REFERENCE—Jeppesen approach charts include adjustments to minimums due to
inoperative airborne or ground system equipment.

ILS Course Distortion

1. All pilots should be aware that disturbances to ILS localizer and glide slope courses

may occur when surface vehicles or aircraft are operated near the localizer or glide
slope antennas. Most ILS installations are subject to signal interference by either sur-
face vehicles, aircraft or both. ILS CRITICAL AREAS are established near each local-
izer and glide slope antenna.

2. ATC issues control instructions to avoid interfering operations within ILS critical areas

at controlled airports during the hours the Airport Traffic Control Tower (ATCT) is in
operation as follows:

(a)

Weather Conditions. Official weather observation is a ceiling of less than 800
feet and/or visibility 2 miles.

(1)

Localizer Critical Area. Except for aircraft that land, exit a runway, depart,
or execute a missed approach, vehicles and aircraft are not authorized in or
over the critical area when an arriving aircraft is inside the outer marker (OM)
or the fix used in lieu of the OM. Additionally, whenever the official weather
observation is a ceiling of less than 200 feet or RVR less than 2,000 feet, do
not authorize vehicles or aircraft operations in or over the area when an arriv-
ing aircraft is inside the MM, or in the absence of a MM, ½ mile final.

(2)

Glide Slope Critical Area. Do not authorize vehicles or aircraft operations in
or over the area when an arriving aircraft is inside the ILS outer marker (OM),
or the fix used in lieu of the OM, unless the arriving aircraft has reported the
runway in sight and is circling or side-stepping to land on another runway.

(b)

Weather Conditions. At or above ceiling 800 feet and/or visibility 2 miles.

(1) No critical area protective action is provided under these conditions.
(2) A flight crew, under these conditions, should advise the tower that it will con-

duct an AUTOLAND or COUPLED approach.
EXAMPLE: Denver Tower, United 1153, Request Autoland/Coupled
Approach (runway)
ATC replies with:

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JEPPESEN GENERAL AIRWAY MANUAL (Issue Date 1 JUL 21) - page 11