TM 1-1510-225-10
3C-34
(6) VOR Self-Test.
1. Select a VOR frequency on the NAV
Control (a specific frequency is not
required for test). A signal on
frequency will not interfere with the
self-test.
Rotate
the
OBS
to
approximately 0.
2. Press the TEST button on the
CTL -32.
3. The NAV flag will come into view.
4. After approximately 2 seconds, the
flag will go out of view, the HSI lateral
course
deviation
bar
will
approximately center, and a
TO
indication will display. The HSI
pointers will indicate approximately a
0° magnetic bearing.
5. The VIR-32 will return to normal
operation
after
approximately
15
seconds, even if the TEST button is
held.
(7) ILS (Localizer and Glideslope) Self-Test.
NOTE
Anytime an ILS frequency is selected, the
HSI bearing pointer will drive to park at the
3 o'clock position.
1. Select a localizer frequency on the
CTL -32 NAV Control (a specific
frequency is not required for test).
2. Press the TEST
button on the
CTL -32.
3. The NAV and GS flags will come into
view.
4. After approximately 3 seconds, the
flags will go out of view, the HSI
course deviation bar will deflect right
approximately 2/3 of full scale, and
the glideslope pointer will deflect
down approximately 2/3 of full scale.
5. The VIR-32 will return to normal
operation
after
approximately
15 seconds, even if the TEST button
is held.
(8) Marker Beacon Self-Test. The marker
beacon assembly is tested automatically when the
self-test is actuated and either a VOR or localizer
frequency is selected. Proper operation of the marker
beacon assembly is indicated by all three marker
lamps lighted (they flicker perceptibly, at a 20-Hz rate).
A 20-Hz tone will also be present in the marker audio
output.
(9) Marker Beacon Audio. Marker Beacon
Audio generally associated with an ILS, must be
source selected by the MKR BCN 1 or 2 audio
selector switches located on the audio control panel.
Sensitivity selection for marker beacon audio is
accomplished by a toggle switch placarded MKR BCN
1 & 2 HI-LO located to the right of the color radar.
CAUTION
The diagnostic routines are intended as an
extension of the self-test capability. The
pilot should first observe the deviation
indicators and associated flags for the
proper self-test responses. If a fault
condition exists, the problem may be
verified in more detail by the diagnostics.
(10) Diagnostic Display. An extensive self-test
diagnostic routine is also initiated in the VIR-32 by
pushing the TEST button on the CTL-32. The CTL-32
will modulate the active and preset display intensity
from minimum to maximum to annunciate that self-test
is in progress. If a fault condition existed prior to
actuating self-test, the CTL -32 will display the
diagnostic
code
associated
with
the
fault
for
approximately 2 seconds immediately after the TEST
button is pressed. The code will appear in the preset
display. If a fault is detected during self-test, that fault
code will also be displayed on the CTL -32 along with
the word DIAG, FLAG, or four dashes (– – – –) in the
active display. The four dashes will be displayed
along with the code 00 indicating that no faults have
been found. FLAG will be displayed along with a two-
digit code when something is abnormal but a failure
has not occurred i.e., low signal level, etc. DIAG is
displayed along with a code to indicate a failure has
been detected in the VIR-32. Completion of self-test is
indicated when either the normal frequency displays or
a fault code is displayed on the NAV control. A partial
list of diagnostic and fault codes is provided below.
The codes are listed in numerical order. The TEST
button must be pushed before any fault code can be
displayed. Refer to Table 3C-2.
(11) Normal Operation. Selection procedures
and display of the VHF NAV information is the same
as the described for TACAN. When changing VOR
frequencies, and until signal lock-on, the RMI / HSI
