56-101-01200 Revision G
Page 12
A. Set the compensator for zero effect by matching the dots on the compensator screws with the
fixed dots on the case.
B. Align the Aircraft as nearly as possible (not to exceed 5 degrees error) to magnetic north (0°).
C. Turn the N-S screw to cause the Aircraft Compass to read the same as the Sight Compass.
D. Align the Aircraft as nearly as possible (not to exceed 5 degrees error) to magnetic east (90°).
E. Turn the E-W screw to cause the Aircraft Compass to read the same as the Sight Compass.
CAUTION:
IF THE N-S SCREW IS INADVERTENTLY TURNED, THE NORTH HEADING
MUST BE RECHECKED AND COMPENSATED.
F. Align the aircraft as nearly as possible (not to exceed 5 degrees error) to magnetic south (180°).
G. Turn the N-S screw to remove one-half of the error between the Aircraft Compass and the Sight
Compass.
H. Align the Aircraft as nearly as possible (not to exceed 5 degrees error) to magnetic west (270°).
I. Turn the E-W screw to remove one-half of the error between the Aircraft Compass and the Sight
Compass.
7. COMPASS SWINGING PROCEDURE
A. Prepare a worksheet similar to the one shown in Table 2 by first making a copy of the blank
worksheet as shown in Table 1 and populating it with the data recorded and calculated by
accomplishing the steps that follow.
B. Starting on any convenient 30-degree heading, align the Aircraft so that the Sight Compass
reads within 5 degrees of the desired heading.
C. Record the Aircraft Compass reading in column 2 and the Sight Compass reading in column 3
adjacent to the appropriate heading in column 1.
D. Repeat steps 7.B and 7.C for each subsequent 30-degree heading.
E. Record the difference between the readings of the Aircraft and Sight Compass readings in
column 4.
F. Add or subtract the Compass errors in column 4, to or from, respectively, the desired headings
in column 1. Enter the results in column 5. Refer to Table 2 as a guide to these calculations.
G. There should not be more than plus or minus 10° difference between any of the Aircraft
Compass readings and the Sight Compass readings. If the Aircraft Compass cannot be
adjusted to meet the requirements, install another one.
H.
Enter the values from column 5 in the “STEER” portion of the Aircraft Compass correction card.
