An FAA wind-direction indicator is out of tolerance when it differs from another indicator on the same sensor by how many degrees?

An FAA wind-direction indicator is out of tolerance when it differs from another indicator on the same sensor by how many degrees?

• A. 5 degrees
• B. 3 degrees
• C. 4 degrees
• D. 6 degrees

Answer: (A)

Redundancy in wind direction readings is checked by having two indicators on the same sensor and comparing them to catch drift or misalignment. They must stay in close agreement, because wind direction readings drive runway use and other critical operations. The standard is that the two indicators should agree within four degrees; if their readings differ by five degrees, that difference is out of tolerance and the sensor needs maintenance or recalibration. In practice, a 3 or 4 degree difference is acceptable, while a difference of 6 degrees would also be out of tolerance, but the threshold defined for this item is five degrees as the point at which action is required.

Redundancy in wind direction readings is checked by having two indicators on the same sensor and comparing them to catch drift or misalignment. They must stay in close agreement, because wind direction readings drive runway use and other critical operations. The standard is that the two indicators should agree within four degrees; if their readings differ by five degrees, that difference is out of tolerance and the sensor needs maintenance or recalibration. In practice, a 3 or 4 degree difference is acceptable, while a difference of 6 degrees would also be out of tolerance, but the threshold defined for this item is five degrees as the point at which action is required.