Various Classes of VORs (Service Volumes): An Overview
The Federal Aviation Administration (FAA) has recently updated the Standard Service Volumes (SSVs) for Very High Frequency Omnidirectional Range (VOR) stations. These changes aim to enhance navigation accuracy and support modernized airspace and navigation infrastructure.
Previously, there were three main types of VOR service volumes: Terminal, Low, and High. However, the FAA has now added two new types: VOR Low and VOR High, thanks to improvements in transmitter technology.
A service volume is a three-dimensional area where aircraft can reliably pick up the NAVAID's signal, free from interference. To determine a VOR's service volume, one can either view the VOR info box on an IFR low or high enroute chart or check the Chart Supplement for NAVAID info.
The new VOR High contains five layers, with the first layer beginning at 1,000 ft and ending at 5,000 ft, providing navigation up to 40 NM from the transmitter. The second layer ends at 14,500 ft and provides navigation up to 70 NM. The three remaining layers of the new VOR High remain the same as the legacy service volume.
On the other hand, the new VOR Low has two layers. The first layer begins at 1,000 ft and ends at 18,000 ft, allowing navigation to 40 NM. The second layer ends at 14,500 ft and provides reliable navigation up to 70 NM.
In the case of a VORTAC or VOR/DME, there will be two letters to decode: the first letter is the VOR's SSV, and the second letter is the other component's SSV. The SSV is identified by (T), (L), and (H) for legacy volumes and (VL) and (VH) for new service volumes.
These updates to the SSVs come from FAA aeronautical information sources or regulations published in Federal Register notices and Aeronautical Information Publications effective from specific dates, such as June 12, 2025, and later dates. For the most accurate and current SSV values, one should consult the latest FAA Aeronautical Information Manual (AIM), chart supplements, or the FAA's navigational aid documentation released with current effective dates.
In summary, the new SSVs reflect updated coverage standards for VOR stations to support modernized navigation but require direct reference to FAA official publications for exact numeric values and differences from prior standards. The modifications may involve adjustments in the radius and altitude limits of the VOR signal coverage, aiming to optimize coverage and efficiency while supporting newer navigation technologies such as RNAV and RNP procedures.
The advancements in technology have enabled the Federal Aviation Administration (FAA) to add two new types of Service Volumes (VOR Low and VOR High) for VOR stations, enhancing navigation accuracy and supporting modernized airspace and navigation infrastructure. Finance is essential, as these updates come from FAA aeronautical information sources or regulations published in Federal Register notices and Aeronautical Information Publications.
%3A%20An%20Overview){kind=link}