3. Weather Radar Trouble Shooting Procedure
________________________________________
A. When the TEST mode is selected on the weather radar control panel, the entire system is energized. The receiver-transmitter circuits are tested (system transmits) for 4 seconds and then are muted. The antenna scans, and a test pattern appears on the indicator.
B. The R/T front panel contains seven annunciator lights, which in conjunction with the test pattern and fault messages on the indicator, assist in isolating faulty LRUs.
WARNING: DO NOT OPERATE WEATHER RADAR WHILE THE AIRPLANE IS BEING
_______ REFUELED OR DEFUELED AND DO NOT OPERATE IN ANY RADIATION MODE WHILE A FUELING OPERATION IS BEING CONDUCTED WITHIN 300 FEET OF A RADIATING ANTENNA OR INJURY TO PERSONNEL MAY OCCUR.
PERSONNEL MUST NOT ENTER AN AREA CLOSER THAN 50 FEET OF A RADIATING ANTENNA OR INJURY TO PERSONNEL MAY OCCUR.
C. AF 121, 122; On weather radar control panel set the mode selector switch to TEST. The test pattern should appear similar to test pattern shown in Fig. 101. In event of a fault in a line replaceable unit (LRU), a fault warning message will be displayed in yellow in the center of the display. Replace the displayed LRU.
EFFECTIVITY
AF 121, 122; SN 351-399 CONFIG 3 03 B Page 102 Sep 25/9434-43-00
FIELD C FIELD E FIELD A 4 TEST RNG COOL 10 MRK 5 0.0 CAL MIN FIELD B FIELD D FIELD F FIELD H RED
YELLOW
GREEN
3 1
FIELD C FIELD A FIELD E TEST RNG 10 COOL MRK 5 0.0 CAL MIN FIELD B FIELD D FIELD F FIELD H MAGENTA RED
YELLOW
GREEN
3 2
3 FIELD G ANT FAULT ATT FAULT IND FAULT CON FAULT R/T FAULT COOL FAULT YELLOW
4 3 2 1 AF 121,122; RNG IS 15 Figure 101 Weather Radar Test Patterns and Message Field Display FOR ILLUSTRATION PURPOSES AREAS ARE DARK (NO COLOR) SHOWN REVERSED SN 352-399 SN 351; AF 121,122
EFFECTIVITYAF 121,122; CONFIG 3 SN 351-399799B Page 103
34-43-00
Sep 25/94
INDICATOR LEGEND FIELD MESSAGE - NORMAL DISPLAY MESSAGE - MALFUNCTION DISPLAY REPLACE
A 1 '10','20','40','80','160','320' Selected range - than selected range Blank display, or a flashing number other Indicator
A 2 '15','30','60','120','240' Selected range - than selected range flashing number other Blank display, or a Indicator
B 1 '5','5','10','20','40','80' Corresponding range mark inter-val for selected range - No numbers displayed, or a number not correspond-ing to selected range Indicator
B 2 '5','10','20','40','80' Corresponding range mark inter-val for selected range - No numbers displayed, or a number not correspond-ing to selected range Indicator
C 3 Selected mode -'TEST','WX' or 'MAP' Blank display Indicator
C 4 'TEST','WX', 'TURB' or 'MAP' Selected mode - Blank display Indicator
D Antenna tilt setting -'15.0 thru 15.0 ' 'STAB' displayed in yellow (AMM 34-41-00/ Troubleshoot gation system inertial navi-Receiver/Trans-mitter or 101)
E Blank Display 'COOL' R/T Cooling fan Mount Receiver/Trans-mitter or
F (GAIN control not set to AUTO) 'CAL' displayed in blue Control panel
'CAL' displayed in yellow mitter Receiver/Trans-
SN 351-399 AF 121,122 AF 121,122; SN 351 SN 352-399
Weather Radar Indicator Failure Messages and Faulty LRU Figure 102 (Sheet 1)
EFFECTIVITY
CONFIG 3
AF 121,122; SN 351-399
799B Page 104
34-43-00
Sep 25/94
INDICATOR LEGEND FIELD MESSAGE - NORMAL DISPLAY MESSAGE - MALFUNCTION DISPLAY REPLACE
G Blank Display 'R/T FAULT' mitter Receiver/Trans-
'ANT FAULT' Antenna
'CON FAULT' switch or waveguide Control panel
'IND FAULT' - When mode position selector is in TEST Indicator
'ATT FAULT' - When mode position selector is in TEST (AMM 34-41-00/ Troubleshoot gation system inertial navi-101)
'COOL FAULT' - When mode selector is in TEST position Refer to Field E
H 3 Blue MAX 9 thru 1, MIN Out of AUTO (In MAP mode only) No message or incorrect message Control panel
H 4 Blue MAX 9 thru 1, MIN Out of AUTO (In all modes) No message or incorrect message Control panel
Weather Radar Indicator Failure Messages and Faulty LRU
Figure 102 (Sheet 2)
EFFECTIVITY
CONFIG 3 AF 121,122; SN 351-399 799B Page 105
34-43-00
Sep 25/94
D. SN 351-399; With the mode selector switch in TEST the test pattern should appear similar to test pattern shown in Fig. 101. In event of a fault in a line replaceable unit (LRU), a fault warning message will be displayed in yellow in the center of the display. Replace the displayed LRU.
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