The BARFIELD SC 063 Sight Compass is a modified version of a standby type aircraft compass used
to check the mounted aircraft compass.
1. It has been modified to indicate 180
degrees from normal, this Reversed magnetic polarity permits the operator of the Sight Compass to view the aircraft being checked from the front, making it considerably easier to transmit signals to and from the aircraft cockpit.
The compensator has been removed so the compass indicates magnetic direction at all times and is not subject to calibration offsets.
2. Combination magnifying lens and collimating sight added increase the readability of the dial and the collimating lens insures precise sighting alignment.
3. Attached to the rear of the compass is an adjustable sight lens. The lens is precisely aligned to insure that the overall accuracy of the dial does not exceed ±1 degree.
4. The Compass is mounted on a bracket, which can be attached to a monopod assembly
(supplied with the Sight Compass).
5. The Sight Compass is painted red and has a caution label attached to it to prevent
inadvertent installation in an Aircraft.
F. The SC063 Sight Compass is packaged in a protective carrying case.
A compass swing test must be performed whenever any ferrous component of the system
(i.e. flux valve compensator, or Standby Compass) is installed, removed, repaired or a
new compass is installed. Additionally a compass swing must be performed on the
1) When the accuracy of the compass is suspected
2) After any cockpit modification or major replacement involving ferrous metals
3) When compass has been subjected to shock from a hard landing or turbulence
4) After aircraft has passed though a severe electrical storm
5) After a lightning strike
6) Whenever a change is made to the electrical system
7) Whenever a change of cargo is likely to affect the compass
8) Whenever an aircraft operation is changed to a new geographic location with a
major change in magnetic deviation
9) After aircraft has been parked on one heading for over a year
10) When flux valves are replaced