NAVIGATION AND
COMMUNICATION
AIRPLANE
OPERATIONS
MANUAL
2-18-22
Page
2
Code
02
MARCH 30, 2001
3 - POWER AND MODE KNOB
OFF - Turns off the system.
STBY - For approximately 5 seconds COM and NAV frequency
displays show the number 1 followed by eights and “TX”
is annunciated.
- A short audio tone will be heard.
- A dimming self-test of the frequency displays is
performed.
- The last COM/NAV frequencies are displayed
ON - Turns on the system.
- After turning ON, the equipment performs a test. In a
few seconds a code is displayed. If the system is OK,
“00” will be displayed. In case of any detected failure, a
different code will be displayed. In this case, record the
code displayed to help the maintenance personnel to
locate the problem.
SQ OFF - Disables the VHF COM receiver squelch circuits. Use
this position to set volume control or, if necessary, to try
to receive a very weak signal that cannot operate the
squelch circuits.
4 - ANNUNCIATOR
− The TX annunciator illuminates whenever the VIR-433 is
transmitting.
5 - ACTIVE NAV FREQUENCY DISPLAY
− Displays the active Navigation (NAV) frequency (frequency to
which the equipment is tuned) and diagnostics messages.
6 - ACTIVE COM FREQUENCY DISPLAY
− Displays the active VHF Communication (COM) frequency
(frequency to which the equipment is tuned) and diagnostics
messages.
To Next Page
