Subscriber question:
"It’s my understanding that I still need to do 30-day VOR checks to have legal VOR backups for my IFR GPS. But now there are no test stations or official checkpoints near my home base. What am I supposed to do?" —Ely S.
Bruce:
“Yes, VOR checks are still required for navigation under IFR, especially if you fly with a non-WAAS GPS, which requires working VORs in the panel, even if you never look at them. Although the FAA plans to decommission 306 VORs by September 30, 2030, 590 navaids will remain operational, most with enhanced service volumes. VORs aren’t going away. And they are the backbone of the Minimum Operational Network (MON), which would get you on the ground during a widespread, prolonged GPS system outage in IMC.
Now to the VOR test required by 91.171—probably the most frequently overlooked IFR regulation. Using a VOT signal, or a certified VOR equipment checkpoint on an airport, is easy. The Chart Supplement for your area lists VOTs and ground checkpoints under “VOR Receiver Checkpoints and VOR Test Facilities” in Section 4. Tune the VOT, or taxi to the VOR checkpoint on the ramp or taxiway and confirm that the CDIs or bearing pointers are within 4 degrees of the specified radial.
If you’re in range of a VOR at an airport without a ground checkpoint, you can also accomplish a dual VOR receiver check by tuning both radios to the navaid and centering the CDIs (or noting the bearing pointer indications). The displayed courses must agree within ± 4 degrees. The dual receiver check also works in the air. This method can be a good excuse for a lunch flight to get within range of a navaid.
If you have only a single VOR receiver, you can also do an airborne check. Unfortunately, few certified airborne checkpoints are still listed in the Chart Supplement. The FAA Flight Check teams that validated specific airborne checkpoints apparently now are too busy certifying some 12,000 RNAV and conventional instrument approach procedures, and other routes.
But if you can join a Victor Airway, follow the updated airborne check procedure described in the AIM. When you’re established along the centerline, find a prominent ground point, preferably more than 20 nautical miles from the VOR, and maneuver directly over that point at a ‘reasonably low altitude.’ Verify that the OBS or bearing pointers are within ± 6 degrees of the charted airway course.
After you complete a VOR check, you must record the results, including the date, place, and bearing errors— but don’t clutter the airframe logbook with years of tests. Instead enter the details in a small notebook or in a digital record. You need to keep those records only long enough to show compliance within the preceding 30 days.”
Another way to land under IFR without GPS is an ASR approach. Find out how.
When was the last time you used a VOR for navigation (even if just for practice)?