TM 1-1500-204-23-4
Figure 4-21. Compass Rose
influence on compass so that flight conditions are
simulated as nearly as possible.
(c)
Compass
rose
method
of
compensating. A compass rose is often used to obtain
the magnetic headings when an aircraft compass is
being compensated. This method of swinging the
compass is desirable, provided that care is exercised in
aligning the
aircraft with various headings. All equipment used in
the vicinity of the compass rose must be nonmagnetic
materials. Use the following procedures to compensate
compass.
1
Place aircraft on compass rose, as
shown in figure 4-21, and head toward magnetic north.
Record compass reading in column 2, line 1 of DD Form
1613 (Pilot Compass Correction Card) as shown in
figure 4-22. Assume that the compass reading is 8
degrees.
2
Turn aircraft to the east magnetic
heading and record compass reading in column 2, line
3, of DD Form 1613. Assume that the reading is 86
degrees.
3
Turn aircraft to the south magnet
heading and record compass reading in column 2, line
5, of DD Form 1613. Assume that reading is 176
degrees.
4
Turn aircraft to the west magnetic
heading and record compass reading in column 2, line
7, of DD Form 1613. Assume that compass reading is
278 degrees.
5
Fill in the column headed DEV; if
aircraft COM P is greater than the actual heading, DEV
number will be positive; if aircraft COMP is smaller than
the actual heading, DEV number will be negative. All
additions and subtractions are algebraic.
Compensating
Residual
Computation Table
Swing
Swing
Comp
Actual
Aircraft
Actual
Aircraft
Actual
Rose
Head (M)
Comp. (C) Dev.
Head (M)
Comp. (C)
C to M
Head (M)
M to C
N
000
000
008
+8
000
002
-2
000
+2
NE
045
045
046
-1
045
+1
E
090
090
086
-4
090
092
-2
090
+2
SE
135
135
135
0
135
0
S
180
180
176
-4
180
182
-2
180
+2
SW
225
225
224
+1
225
-1
W
270
270
278
+8
270
272
-2
270
+2
NW
315
315
315
0
315
0
COL NO.
(1)
(2)
(2)-(1)
(3)
(4)
(3)-(4)
(3)
(4)-(3)
Figure 4-22. DD Form 1613 (Compass Correction Card)
4-27
