How often must a VOR be checked?

• A. Within 90 days
• B. Within 30 days
• C. Within 6 months
• D. Within 1 year

Answer: (B)

Keeping the VOR receiver accuracy current is essential because you rely on that signal for precise instrument navigation. The check proves that the VOR indication you see on your cockpit indicator matches the actual VOR signal within the allowed tolerance, so you won’t be misled by drift or a failing receiver.

In the United States, to use a VOR for IFR navigation, the VOR receiver must be checked within the preceding 30 days. This relatively short interval helps catch issues promptly, before they affect a flight. There are several valid ways to perform the check, such as using a VOT (VOR test facility) signal, checking against a known VOR radial at a published checkpoint, or conducting an airborne check with a certified facility. Keeping this check current is what ensures the VOR remains a reliable navigation source for IFR operations.

Longer intervals, like 90 days, 6 months, or a year, do not satisfy the regulatory requirement and could leave the navigation equipment out of tolerance during flight.