(a)  
No. 3 INS CDU BAT light illuminates.

 (b)  
Warning alarm sounds 30 (| 10) seconds after the circuit breaker is opened.

 (7)  
Close 10 amp PWR-INS 3 circuit breaker and verify that the warning alarm ceases.

 E. Restore Airplane to Normal
 (1)  Set each INS mode selector switch to OFF position.
 CAUTION: FAILURE TO MOVE MODE SELECTOR TO OFF WILL CAUSE INS TO
_______ AUTOMATICALLY SWITCH TO BATTERY POWER WHEN POWER IS REMOVED FROM AIRPLANE.
 (2)  
Remove electrical power if no longer required. Refer to 24-22-00.

 (3)  
Remove equipment cooling if no longer required. Refer to 21-58-00.

 EFFECTIVITY

 
 ALL  10 Page 502  Apr 25/7634-41-16
 WEATHER RADAR SYSTEM - DESCRIPTION AND OPERATION
________________________________________________
 1.  General (Fig. 1 and 2)_______
 A.  The weather radar system is a navigation system which uses the reflective effect of microwave pulses on material substances to obtain a picture of conditions ahead of the airplane. Weather radar operation is based on the fact that rainfall (generally associated with storm cells) reflects a radar beam in proportion to the moisture concentration. For systems with color indicators, three colors (green, yellow, and red) are used to represent increasing levels of rainfall concentration and provides an easily identifiable picture of the rainfall areas with their associated concentrations. On systems without color indicators, the relative brightness of rainfall indications on the display is representative of the rainfall concentration. The iso-echo contour mode of operation is provided for systems without color indicators to allow the heaviest rainfall concentrations to be displayed in black and are identifiable as black spots within the normal lighted indications.
 B.  The weather radar system operates in the X-band and can penetrate relatively light intervening rainfall to detect distant storms. When the airplane is approaching a storm area, the rain gradient indicated by iso-contouring is of primary importance.
 C.  AT ALL; AZ ALL EXCEPT 281-299; LH ALL EXCEPT 082-099; IB 406-499, the weather radar system consists of two identical systems, one of which may be in use with the other system in a standby mode. Two identical receiver/transmitters (R/T) are installed on the weather radar shelf (E5) in the forward equipment area shown in figure 1. A waveguide switch connects the selected R/T to the antenna through waveguide or switches the output power into a dummy load during test. The antenna is used for both transmitting and receiving from either R/T. A single control panel controls operation of the weather radar, enabling R/T selection, mode selection, and testing. The captain and first officer have indicators with storage CRT's.
 LH 082-099; AZ 281-299; AF 157, 161, the two receiver/transmitters (R/T) are installed below the compartment floor on the centerline in the nose cargo door section. Access to the R/T's is gained through the walkway/dripshield panel in the compartment floor. The weather radar system is operable for testing and maintenance when the nose cargo door, containing the radar antenna is raised. Ground target testing of the system is limited however, due to the abnormal vertical attitude of the antenna zero reference axis. Refer to Adjustment/Test Procedures.
 D.  Weather radar system number 1 operates from the essential radio bus 115 volts ac 400 Hz, single-phase, and number 2 uses the 115 volts ac number 2 radio bus. No dc power is required.
 EFFECTIVITY

 AT ALL; AZ ALL; LH ALL;  CONFIG 1 AF 157, 161;  10 Page 1 IB406 THRU 499  Sep 25/94

34-43-00
GAIN ADJ'S 
RESET  VSWR  STAB 
ANT 
T/R 
PITCH  ROLL  HOURS 
RECEIVER  ONX M T 
TRANSMITTERS  WT  LBS 
(2 PLACES) 
SEE  A 
WEATHER  RECEIVER/TRANSMITTER FRONT PANEL 
RADAR 
ANTENNA  A 

WAVEGUIDE WAVEGUIDE

SWITCH AND DUMMY LOAD
FREIGHTERS 1
RECEIVER TRANSMITTERS (2 PLACES)
SEE A
WAVEGUIDE SWITCH AND DUMMY LOAD

WAVEGUIDE
REFLECTOMETER
WEATHER RADAR ANTENNA

PASSENGER
1 LH 082-099; AZ 281-299, AF 157,161
2 LH ALL EXCEPT 082-099 AZ ALL EXCEPT 281-299; AT ALL;IB 406-499
Weather Radar System Component Location Figure 1 (Sheet 1)
779810
EFFECTIVITY

AT ALL; AZ ALL; LH ALL; CONFIG 1
AF 157,161; IB 406-4997XA Page 2

34-43-00
Sep 25/94
 ... .XA
SEE B INDICATOR CAPTAIN'S WEATHER RADAR  SEE B INDICATOR WEATHER RADAR FIRST OFFICER'S 
　
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