(3)
The ground test procedure is contained in 34-43-00, Adjustment/Test (Operational Test).
EFFECTIVITY
AF 101-120, 123-156, 158,
159, 172-182, 185-199; SN 301-350; IB 405; GN ALL; CONFIG MD ALL; VM ALL 01 Page 14
Apr 25/95
34-43-00
WEATHER RADAR SYSTEM - DESCRIPTION AND OPERATION
________________________________________________
1. General
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A. The weather radar system presents the pilots with a topographic map type of display of moisture laden weather formations (WX) or major terrain features such as rivers, coastlines, major mountain peaks, and cities for position fixing (MAP). The weather displays permit the pilot to avoid storm penetration and the associated turbulence.
B. The weather radar system consists of receiver/transmitter units, the captain's and first officer's indicators, a control panel, waveguide, a waveguide switch, and an antenna assembly. Equipment location is shown in Fig. 1.
C. Weather radar system on/off control is provided by the mode selector switch on the control panel. The indicator has individual on/off control using the range switch in the OFF position.
D. The weather radar system consists of two identical systems, only one of which operate at one time. A waveguide switch connects the selected R/T to the antenna through the waveguide. The antenna is a flatplate array radiating antenna with two identical drive systems. A dual system control panel controls operation of the weather radar, providing R/T selection, mode selection, system self-test, receiver sensitivity adjustment (GAIN), and antenna tilt angle selection. Weather radar indicators have video brightness (BRT) control and indicator range selection.
E. The receiver/transmitter generates and transmits high energy radio frequency (rf) pulses which are radiated by the antenna. A small portion of the radiated energy is reflected back to the airplane by moisture laden clouds or by major terrain features. The reflected signals are received by the same antenna, processed by the R/T unit and displayed on the indicators. The transfer of the RF energy between the R/T unit and the antenna takes place via the waveguide. Stabilization of the antenna in pitch and roll is provided by the inertial navigation system (INS).
F. Weather radar system No. 1 operates from the essential radio bus 115-volt ac 400-Hz, single-phase, and No. 2 uses the 115-volt ac No. 2 radio bus. No dc power is required.
G. The weather radar system has a built-in operator-actuated test pattern for fault identification. The operator-actuated test causes the injection of test signals, which are used to generate a test pattern on the indicator allowing the operator to adjust the display prior to flight and to ascertain correct operation of all system components.
H. The weather radar system has a built-in operator-actuated test pattern for fault identification. The operator-actuated test causes the injection of test signals, which are used to generate a test pattern on the navigation displays allowing the operator to adjust the display prior to flight and to ascertain correct operation of all system components.
I. The interface with other systems is shown in Fig. 2 in which the INS is shown providing pitch and roll stabilization signals from INS No. 1 and No. 2.
2. Control Panel
_____________
A. The weather radar control panel is located on aft electronics control panel P8.
EFFECTIVITY
AF 121, 122; SN 351-399 CONFIG 3 01 Page 1 Apr 25/9834-43-00
SEE A (2 PLACES) RECEIVER/ TRANSMITTER
WAVEGUIDE SWITCH WAVEGUIDE SEE B ANTENNA WEATHER RADAR
SEE C CAPTAIN'S WEATHER RADAR INDICATOR
SEE D SEE C WEATHER RADAR CONTROL PANEL FIRST OFFICER'S WEATHER RADAR INDICATOR
Weather Radar System Component Location
Figure 1 (Sheet 1)
EFFECTIVITY
AF 121,122; CONFIG 3
SN 351-399799 Page 2
34-43-00
Sep 25/94
649806
BendixWX RADAR Air Transport Avionics
R/T ANT IND CONT WG SW GYRO AIR
TEST
RADAR TRANSCEIVER RTA-4A
RECEIVER TRANSMITTER CONTROL PANEL
A
ANTENNA PLANAR ARRAY
TO RECEIVER/
TRANSMITTERS
SCAN AND ELEVATION DRIVE DISABLE SWITCHES
ELECTRICAL CONNECTOR
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