How are VOR/DME ground-check tolerances typically expressed?

• A. In radians for bearing and distance tolerance outside manufacturer specs.
• B. In degrees for bearing (VOR) and distance tolerance for DME; within manufacturer specifications.
• C. In minutes for bearing and seconds for distance.
• D. In percent tolerance for both.

Answer: (B)

VOR/DME ground-check tolerances are tied to what each instrument actually measures: the VOR provides an angle (bearing), while DME provides a distance. So the tolerance is given as an angular value in degrees for the bearing and as a distance value (usually in nautical miles) for the DME reading. Both values are specified by the manufacturer and must stay within those limits. This fits the nature of the signals—an azimuth for VOR and a range for DME—and avoids formats that don’t align with how these systems are specified. Using radians, minutes/seconds, or percent wouldn’t reflect how the tolerances are defined or applied.