Description And Operation; Product View - SIRS Navigation KCA0101C Component Maintenance Manual With Illustrated Parts List

DESCRIPTION AND OPERATION

A. General
The compasses (Fig.1) are self-contained magnetic units, installed at eye level or
above, and give a constant indication of aircraft direction.
MOUNTING PLATE
SOCKET AND LEAD ASSEMBLY
Aircraft direction is read from the compass card against a vertical lubber line marked
on the inside of the compass bowl. A 'non-magnetic' lamp is used to light up the
compass card.
Correctors are installed above the compass bowl to reduce magnetic errors. The
complete compass can be turned to correct magnetic 'coefficient A' errors.
B. Description
The compass card is of conic section with graduation-lines marked on its outer face.
The card is attached to an assembly that includes a cobalt ring magnet and pivot.
The pivot turns in a sapphire cup that is installed in a stem assembly, which is
attached to the compass bowl by a bracket.
The compass bowl is a transparent polycarbonate moulding, painted black or grey.
The compass card is seen through a transparent window at the front of the bowl.
The document reference is online, please check the correspondence between the online documentation and the printed version.
SIRS NAVIGATION LTD
COMPONENT MAINTENANCE MANUAL
CORRECTOR KEY APERTURES
Standby Compass - General View
Figure 1
LUBBER LINE
COMPASS CARD
LAMP HOUSING
PAGE 1
34-25-21
APR 10/03