What is the dual VOR receiver check tolerance on the ground and in the air?

The dual VOR receiver check tolerance on the ground and in the air is indeed +/-4 degrees. This tolerance is established to ensure that both VOR receivers in an aircraft are functioning correctly and providing accurate navigation information.

This tolerance level is critical for maintaining safe operations while flying, as discrepancies greater than this could indicate a malfunctioning VOR receiver. On the ground, it’s often easier to perform a check using a known VOR signal, ensuring that both receivers align closely within this tolerance. In the air, the same principle applies, allowing pilots to confirm that both navigation systems are effectively synchronized, which is particularly important during instrument flight where reliance on accurate navigation is paramount.

Understanding these tolerances helps pilots maintain situational awareness and adhere to FAA or other aviation regulatory standards, ultimately enhancing safety during flight operations.