FAA Explains the VOR MON Program

I’ve provided many updates on the FAA program to decommission about one-third of the VOR network in the Continental U.S. That VOR Minimum Operational Network (MON) will leave 589 VORs in operation by FY2030.

FAA recently hosted a webinar to update aviators on the program. You can watch the video below.

Here’s a link to the most recent update on the VOR MON:

Latest on VOR Decommissioning (May 2021)

See also:

  • Next Round of VOR Shutdowns
  • Update on VOR Decommissioning
  • FAA Releases List of VORs to be Shut Down
  • VOR Status–Another Update
  • VOR Decommissioning: October 2020 Update

    FAA continues its program to decommission about 307 (34%) of the VORs in the continental U.S. Some 589 VORs (with enhanced service volumes) will remain operational when the minimum operational network (MON) program is complete, now scheduled for FY2030.

    At the October 2020 session of the Aeronautical Charting Meeting, Ernesto Etienne, VOR MON Lead Engineer at FAA, provided an update on the program to date.

    For more information about the MON program, see: Updated VOR Retention List, Next Round of VOR Shutdowns, VOR Status–Another Update, Minimum Operational Network (MON) Airports.

    As of September 20, 2020, FAA had shut down 82 VORs. In Phase 2 of the program, which runs through FY2030, another 225 navaids will be decommissioned.

    The 82 VORs discontinued as of September 30, 2020 are in this list (PDF).

    Through the end of calendar year 2020, the following navaids are scheduled to be shut down (to see these VORs on a chart at SkyVector, click the links).

    Five (5) VORs planned for discontinuance – November 5, 2020:

    • (FAH) Falls, in Sheboygan, WI
    • (LNR) Lone Rock, in Lone Rock, WI
    • (MKG) Muskegon, in Muskegon, MI
    • (RBA) Robinson, in Robinson, KS
    • (UKN) Waukon, in Waukon, IA

    Three (3) VORs planned for discontinuance – December 31, 2020:

    • (EWO) New Hope, in New Hope, KY
    • (ITH) Ithaca, in Ithaca, NY
    • (URH) Texoma, in Durant, OK

    Updated VOR Retention List

    FAA is in the midst of a years-long program to decommission about one-third of the VORs in the National Airspace System (NAS). Most of the VORs on the shutdown list are in the eastern two-thirds of the continental U.S. The remaining network, known as the Minimum Operational Network (MON), will still contain nearly 600 VORs.

    Planned VOR Network

    The latest list of VORs that FAA intends to keep (dated June 2020) is available as a Microsoft Excel worksheet on the FAA website, here.

    More information about the plans to decommission VORs is available at the following posts:

    Minimum Operational Network (MON) Airports
    Next Round of VOR Shutdowns
    VOR Status–Another Update

    VOR Status–Another Update

    FAA provided another update on its plans to reduce the VOR network at the October 2018 meeting of the Aeronautical Charting Meeting. The latest Very High Frequency Omnidirectional Range (VOR) Minimum Operational Network (MON) Program update (PDF) includes the following key details:

    • 311 VORs (about 30 percent) will be shut down by 2025
    • 585 VORs will remain operational
    • Most of the VORs to be deactivated are in the East (133) and Central (163) regions; in the West, only 15 navaids are on the list to be turned off.
    • As of September 2018, 34 VORs, VOR/DME, and VORTACs have been shut down.
    • At the end of 2018, 34 of the 74 Phase 1 VORs have been shut down.
    • FAA plans to enhance the service volume of remaining VORs from 40 nm to 70 nm beginning at 5000 AGL. The enhanced VORs will be classified as VOR Low (VL) and VOR High (VH).  Documents such as the AIM will be updated as the enhancement program gets underway. The illustration below shows the coverage that the enhanced VORs will provide at or above 5000 AGL.


    As I’ve noted in several previous posts (e.g., here), the VOR MON program is designed to provide backup to GNSS (GPS). Specifically, within the contiguous United States the MON program will support conventional navigation in the event of a GPS outage by ensuring that pilots can:

    • Tune and identify a VOR at an altitude of 5,000 feet above site level and higher
    • Conduct VOR navigation through a GPS outage area
    • Navigate to a MON airport within 100 nautical miles to fly an Instrument
      Landing System (ILS), Localizer (LOC) or VOR instrument approach without
      GPS, DME, Automatic Direction Finder (ADF), or radar
    • Navigate along VOR Airways, especially in mountainous terrain, where
      Minimum En-route Altitudes (MEAs) make direct-to navigation impracticable

    MON airports (i.e., those with conventional instrument procedures as described above) will be identified on en route charts, FAA Chart Supplements, and included in the National Airspace System Resource (NASR) Subscriber File data set for developers of electronic charts, apps, and so forth.

    The FAA’s detailed policy for the transition was outlined in the Federal Register, here. More information about the program to reduce the VOR neworks is available at AOPA, here.

    Here’s the list of next round of VORs scheduled to be shut down. I have provided links to the navaids at SkyVector.com so that you can see each location on a sectional chart. Note that in each case, several nearby VORs will remain in service:

    BUU (BURBUN) Burlington, WI – Nov. 8, 2018
    RUT (RUTLAND) Rutland, VT  – Nov. 8 2018
    VNN (MT VERNON) Vernon, IL – Nov. 8, 2018
    TVT (TIVERTON) Tiverton, OH  – Nov. 8, 2018
    CSX (CARDINAL) St. Louis, MO – Jan. 3, 2019
    ISQ (SCHOOLCRAFT CO) Manistique, MI – Jan. 3, 2019
    MTO (MATTOON) Mattoon, IL – Jan. 3, 2019
    ORD (CHICAGO O’HARE) Chicago, IL – Jan. 3, 2019
    RID (RICHMOND) Richmond, IN – Jan. 3, 2019
    FRM (FAIRMOUNT) Fairmont, MN – Feb. 28, 2019
    GNP (GLENPOOL) Tulsa, OK – Feb. 28, 2019
    LSE (LA CROSSE) La Crosse WI – Feb. 28, 2019
    MTW (MANITOWOC) Manitowoc, WI – Feb. 28, 2019
    GTH (GUTHERIE) Guthrie, TX – Apr. 25, 2019
    HUB (HOBBY) Hobby, TX – Apr. 25
    CZQ (CLOVIS) Clovis, in Fresno, CA – Apr. 25, 2019

    List of Next VORs to be Decommisioned

    FAA has published a list of the next VORs to be decommissioned as part of its plan to establish a minimum operational network (MON) of the ground-based navigation aids. The list is part of a news item at AOPA that explains the process.

    Most of the 35 VORs on this list are in the eastern two-thirds of the continental U.S. Only one, ECA, is in the West, near Stockton, CA.

    You can find more background the FAA’s plan to decommission VORs  at BruceAir, here.


    Charting Proposal for VORs Under NextGen

    The FAA continues its plans to overhaul the nation’s airspace as part of the NextGen system, which relies on GPS/WAAS instead of the current network of ground-based navaids. Part of the plan includes shutting down about 50 percent of the VORs currently in use to create a minimum operational network (MON).

    For more information about plans to shut down VORs and reorganize enroute navigation, start at this post here at BruceAir.

    The FAA hosts the Aeronautical Charting Forum, a semi-annual gathering of experts to discuss improvements and changes to the charts that pilots and others rely on. A proposal for the April 2015 meeting includes a document that describes a suggested change in how VORs are depicted on charts, and the text also includes more details about how the national airspace system (NAS) and navigation will change under performance-based navigation (PBN), which is an enhanced version of today’s area navigation (RNAV) concept.

    The following paragraph provides background for discussion:

    The VOR MON program (AJM-324) is discontinuing the service of approximately half of the VOR facilities in the NAS. In parallel, the PBN Policy and Support Group (AJV-14) is planning to implement a new PBN Route Structure, which will provide “Structure where necessary and Point-to-Point where structure is not needed.” The PBNRS will generally remove most Victor Airways and Jet Routes east of the Western Mountainous region of the CONUS. Q-Routes will be published where needed, particularly in high traffic density airspace east of Chicago to New York, Atlanta, etc. T-Routes will provide structure primarily around Metroplex areas, special use airspace, and for terrain avoidance in mountainous terrain areas. The rest of the NAS will likely fly point-to-point using RNAV.

    The document then describes how VORs that are part of the MON but which are not points along named airways might appear on aeronautical charts.

    As this new strategy is implemented, many of the VORs retained for the MON will not have any VOR Airways associated with them, but pilots will need to use them to navigate VOR-to-VOR. Therefore a charting scheme is needed.

    The VOR MON Concept of Operations includes a proposed scheme for charting the MON VORs which is depicted in the figure below. The approach is to use feeder routes showing the MEA, course, and distance to each adjacent MON VOR.

    Here’s the figure:


    I plan to comment on the use of MON, used to distinguish VORs that are part of the MON and not associated with airways from other navaids. I think the use of a three-letter abbreviation will cause confusion when printed near a VOR symbol that is also associated with a three-letter identifier.

    If you have comments, direct them to the ACF.