Definition
The degree to which a VOR (Very High Frequency Omnidirectional Range) navigation system provides correct course guidance, typically held to a tolerance of plus or minus 4 degrees on the ground during an operational check. VOR accuracy depends on proper ground station calibration, aircraft receiver condition, signal reception quality, and the absence of terrain or structural interference along the radio path.
Plain English
How close the VOR's course information is to the truth. Pilots verify this before flying by instruments, because if the indicated course is off by more than a few degrees, the aircraft could be far from where the instruments suggest.
Context Anchor
Seen in instrument flying when checking whether the aircraft’s VOR equipment is reliable enough to use for navigation.
Derivation
VOR stands for very high frequency omnidirectional range. “Omnidirectional” means “in all directions,” which fits a VOR station because it lets aircraft determine directions around the station. “Accuracy” comes from the idea of being careful or exact; here it means how close the indicated direction is to the true usable direction.
Why Pilots Care
Unacceptable error can place the aircraft off the intended course, reducing separation from terrain or traffic.
Grounding Statement
A VOR can be working but still be slightly off, so the pilot checks that the error is small enough before using it.
Intuition Check
Do not assume “accuracy” means perfect. In this context, VOR accuracy means the indication is close enough to the correct direction to meet the allowed limit.
Example Sentence 1
Before filing IFR, the pilot performed a VOR accuracy check on the airport's designated VOT and confirmed the indication was within tolerance.
Example Sentence 2
Loss of VOR accuracy during an approach requires the pilot to switch to an alternate navigation source.