AIM 

4/20/23 

FIG 1

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3 

Lower Edge of Low and High Service Volumes (in altitude ATH) 

2. 

With the progression of navigation capabilities to Performance Based Navigation (PBN), additional 

capabilities for off

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route navigation are necessary. For example, the VOR MON (See paragraph 1

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3 f.) 

requires the use of VORs at 5,000 feet AGL, which is beyond the original SSV ranges. Additionally, PBN 

procedures using DME require extended ranges. As a result, the FAA created four additional SSVs. Two of the 

new SSVs are associated with VORs: VOR Low (VL) and VOR High (VH), as shown in FIG 1

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4. The other 

two new SSVs are associated with DME: DME Low (DL) and DME High (DH), as shown in FIG 1

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5. The 

SSV at altitudes below 1,000 feet for the VL and VH are the same as FIG 1

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3. The SSVs at altitudes below 

12,900 feet for the DL and DH SSVs correspond to a conservative estimate of the DME radio line of sight (RLOS) 

coverage at each altitude (not including possible terrain blockage). 

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8 

Navigation Aids