What is the maximum allowable error for a VOR check on the ground?

The maximum allowable error for a VOR check on the ground is ±4 degrees. This standard is important because it helps ensure that the VOR navigation system is functioning accurately, which is critical for IFR operations.

When conducting a VOR check, pilots must verify the accuracy of their VOR receiver against a known ground reference. If the error exceeds the allowable limit, it indicates that the VOR system may not provide reliable navigation data. This check is essential for maintaining safety in instrument flying, where precise navigation is crucial. Therefore, when validating a VOR system before a flight, ensuring that the error remains within this ±4 degrees parameter helps pilots trust the information given by the VOR system during their flight.