AIM 

4/20/23 

NOTE

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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 

typically 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. 

2. 

The TACAN azimuth will only be classified as T, L, or H. 

3. 

TBL 1

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1

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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. 

TBL 1

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1

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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 distances 
out to 100 NM. From 18,000 feet ATH up to and including 45,000 feet ATH at ra-
dial 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 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 radial dis-
tances 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

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2. The distance (radius) is the same at all altitudes for 

each class. 

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