TM 1-1500-204-23-4
Figure 4-23. B-16 Master Sighting Compass Alignment Method.
NOTE
When using the Attitude and Heading
Reference System (AHRS) or the
Inertial Navigation System, locate the
aircraft away from magnetic buildings,
materials and other structures.
(f)
Checking compass while flying. The
compass may be checked for deviation while flying by
comparing the compass heading with a known heading.
NOTE
Do not compensate compass while in
flight.
(g)
Calibrator set method of compensating. A
more precise method for checking the compass is
reflected in TM 11-4920-292-15. It may be used if
desired and necessary test equipment is available.
(4)
Replacement criteria. Line maintenance on
magnetic compasses consists primarily of compass
swinging,
replacing
burned
out
light
bulbs,
and
replacement of defective compasses. Compasses will
be replaced for any of the following:
·
Clouded or discolored liquid
·
Illegible card markings, fading, or loss
of luminous paint
·
Failure of card to rotate freely in a
horizontal plane when aircraft is in a
normal flying position
·
Cracked bowl, broken mounting frame,
or broken lugs
·
Erratic action, or failure of compass to
respond
after
proper
efforts
to
compensate
·
Lubber line loose or misaligned
·
Air visible in bowl of compass
·
If the total deviation of the eight
headings exceeds 8 degrees
p.
Remote Indicating Compass. Remote indicating
compass
compensation,
testing,
and
replacement
criteria are explained in the following paragraphs.
4-29
