Plain English Meaning

A test signal at certain airports that lets a pilot confirm the aircraft's VOR navigation receiver is reading correctly before flying on instruments. Tune it in, and the instrument should show a specific known reading. If it does, the receiver is good to use.

Full Definition

A ground-based radio transmitter that broadcasts a single, fixed omnidirectional signal used to check the accuracy of a VOR receiver in the aircraft. When tuned to the published VOT frequency, a properly functioning VOR receiver will indicate the 360° radial FROM the station, or the 180° radial TO the station, regardless of the aircraft's actual position on the . The receiver is considered for use if the indicated is within ±4° of these values.