The compass swing is a key ground operational check. The procedure identifies heading deviations within the aircraft compass. AMTs must do this to understand and correct reading variation. Barfield 101-01200 sight compass calibration can take place after performing the compass swing procedure.
Compass Swing Environment
The procedure must be performed a location that is free of magnetic interference and meets specific criteria. The manufacturer recommends establishing a stable location to perform the check. Ensure that the check point meets relevant standards.
Barfield Sight Compass Check Point Technique
- Choose an open area
- Ensure the selected area is 91.4 meters (300 feet) away from a runway, building or machinery
- Check point site should be at least 91.4 meters away from a magnetic interference
- Select a prominent reference point at least 1609 meters (1 mile) away
- Remove any personal items that could affect the sight compass
- Aim compass sight on the reference point, record readings
- Use an object to mark the observation point
- Document the check point location, distant reference point, and the observation point
The check point must not be subject to compass interference. The manufacturer recommends evaluating the location regularly, to ensure that conditions remain stable. One reason for this is that the check point may change in the future, most likely due to new construction. If possible, avoid establishing a check point in an area that may be subject to new construction.
Barfield 101-01200 Sight Compass Calibration Considerations
During the compass swing procedure, the aircraft compass is checked against the Barfield 101-01200 sight compass for accuracy. The sight compass serves as the standard for navigation. The readings of the aircraft compass are checked against those of the sight compass. The aircraft compass is adjusted to match the headings of the sight compass. Barfield 101-01200 sight compass calibration must be accurate. The check point allows AMTs to verify accuracy between scheduled calibration testing intervals.