AIM
12/2/21
TBL 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 distances
out to 25 NM.
L (Low Altitude)
From 1,000 feet ATH up to and including 18,000 feet ATH at radial distances
out to 40 NM.
H (High Altitude)
From 1,000 feet ATH up to and including 14,500 feet ATH at radial distances
out to 40 NM. From 14,500 ATH up to and including 60,000 feet at radial dis
tances out to 100 NM. From 18,000 feet ATH up to and including 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 includ
ing 45,000 feet ATH at radial distances 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 including 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 ra
dial 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.
TBL 1
−
1
−
2. The distance (radius) is the same at all
NDBs are classified according to their intended use.
altitudes for each class.
The ranges of NDB service volumes are shown in
TBL 1
−
1
−
2
NDB Service Volumes
Class
Distance (Radius) (NM)
Compass Locator
15
MH
25
H
50*
HH
75
*Service ranges of individual facilities may be less than 50 nautical miles (NM). Restrictions to service
volumes are first published as a Notice to Air Missions and then with the alphabetical listing of the NAVAID
in the Chart Supplement U.S.
1
−
1
−
9. Instrument Landing System (ILS)
2.
The basic components of an ILS are the
localizer, glide slope, and Outer Marker (OM) and,
a. General
when installed for use with Category II or Category
1.
The ILS is designed to provide an approach
III instrument approach procedures, an Inner Marker
path for exact alignment and descent of an aircraft on
(IM).
final approach to a runway.
1
−
1
−
10
Navigation Aids