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SESK: Stuff Everyone Should Know · sesk.info/ifr-vor-30-days

To use a VOR for IFR navigation, how recently must it have been operationally checked?

Within the preceding 30 days.

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  1. Within the preceding 90 days
  2. Within the preceding 12 calendar months
  3. Within the preceding 30 days ✔

Why: 91.171 requires an IFR aircraft's VOR system to have been checked within the preceding 30 days and found within tolerance, or to be maintained under an approved procedure.

Huh, didn't know that: The person doing the check must log the date, place and bearing error and sign the aircraft log or other record.

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Pilot write-up: "Friction locks cause throttle levers to stick." Mechanic: "That's what friction locks are for."
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References

Answer: Within the preceding 30 days. 91.171 requires an IFR aircraft's VOR system to have been checked within the preceding 30 days and found within tolerance, or to be maintained under an approved procedure.

  1. 14 CFR 91.171 VOR equipment check for IFR operations www.law.cornell.edu/cfr/text/14/91.171
    within the preceding 30 days
    Checked 2026-10-10.

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