If you're planning to use your VOR receiver, the receiver must be checked within the preceding 30 days for an IFR flight (14 CFR 91.171).

This rule applies to every IFR certified airplane, regardless of size. If there's something wrong with your navigation receiver, it's better to know early on before you find yourself flying miles off-course.

Here are a few ways you can get this required check done:

• VOT Signal: With a VOT, you can check the VOR accuracy from your plane before takeoff. So what is a VOT? It's an approved VOR test signal, and it's located on an airport. Not all airports have VOTs, so you'll need to check the chart supplement to see if your airport has one. If your airport does have a VOT, here's what to do:
  • Tune your VOR to the VOT signal.
  • Set the course selector to 0 degrees, and the track indicator should be centered.
  • The TO-FROM indicator should read FROM.
  • Next, set the course selector to 180 degrees
  • The TO-FROM indicator should read TO, and the track bar should then be centered.
  • The maximum indicated bearing error is plus or minus 4 degrees.


• VOR Checkpoint: Many airports have VOR checkpoint signs that are located near a taxiway, ramp or runup area. These signs indicate the exact point on the airport where there is sufficient signal strength from a VOR to check the aircraft's VOR receiver against the radial designated on the sign. To use a VOR checkpoint, simply follow the instructions on the sign.
  • The maximum indicated bearing error is plus or minus 4 degrees.


• Dual VOR Check: This is often times the easiest check to accomplish, as long as you have 2 VOR receivers. To check dual VOR receivers against one another:
  • Tune both NAV radios to the same VOR facility.
  • Center the needles of each VOR receiver with a "TO" indication.
  • Note the indicated bearings to the station from each receiver.
  • The maximum permissible variation between the two indicated bearings is 4 degrees.


• Airborne VOR Check: VOR equipment can also be checked for accuracy in flight. To accomplish an airborne VOR check:
  • Select a VOR radial that lies along the centerline of an established VOR airway.
  • Select a prominent ground point along the selected radial preferably more than 20 nautical miles from the VOR ground facility and maneuver the aircraft directly over the point at a reasonably low altitude.
  • Note the VOR bearing indicated by the receiver when over the ground point.
  • The maximum indicated bearing error is plus or minus 6 degrees.

Recording Your VOR Check

Once your check is done, you need to record it. Here's what the FARs require:

• Each person making the VOR operational check, as specified in paragraph (b) or (c) of this section, shall enter the date, place, bearing error, and sign the aircraft log or other record. In addition, if a test signal radiated by a repair station, as specified in paragraph (b)(1) of this section, is used, an entry must be made in the aircraft log or other record by the repair station certificate holder or the certificate holder's representative certifying to the bearing transmitted by the repair station for the check and the date of transmission.

Which VOR Checks Have You Used?

Which VOR checks have you used? Tell us in the comments below.