User Guide

Series III Avionics
Pilot's Guide
Page 14
When the top (active) frequency is a localizer
station, bearing or radial cannot be displayed.
Setting the FUNCTION SELECTOR switch to BRG
or RAD will cause the letters LOC to appear on the
bottom line instead of the standby frequency. This
is a reminder that this display cannot be used for
bearing or radial data while on an ILS approach.
NOTE:
When LOC is displayed, return the
FUNCTION SELECTOR to the ON
position so that the standby frequency is
displayed instead.
The number 1 below the letters ACT represent Nav
System 1 when more than one NAV System is
installed. This number is fixed at the time of
installation.
The number 2 below the letters ACT represent Nav
System 2 when more than one Nav System is
installed. This number is fixed at the time of
installation. A blank below the letters ACT
represent either Nav System 3 (when more than 2
Nav Systems are installed) or that only one Nav
System is installed.
A FAIL annunciation appears in the lower display to
indicate failure of the VNS-41A System. Fail
messages and their meanings are:
FAIL 1: NAV synthesizer out of lock.
FAIL 2: G/S synthesizer out of lock.
FAIL 3: NAV converter A/D check fail.
FAIL 4: Non-volatile memory fail.
These annunciations are the result of a continual
system self-test, and indicate that maintenance is
required before the system may be used.