AMM 41.0.0.0WEATHER RADAR SYSTEM (BENDIX RDR 1150 COLOUR) - DESCRIPTION & OPERATION 1. Description A. General The Weather Radar System, Bendix type RDR-1150 (colour), is installed to provide continuous en-route weather information. In addition to weather detection the system may be used for ground mapping. Ground mapping provides a display of prominent landmarks, rivers, lakes, etc.. The system is comprised basically of three units, a receiver/transmitter, an indicator and an antenna. B. Detail (1) Receiver/transmitter, Bendix type RT 1151A (Part Number 4001921-5101), The unit is mounted in the nose of the aircraft and is idented SB4. The receiver/transmitter consists of a magnetron, solid-state modulator, duplexer (with passive TR limiter), dualconversion IF, analogue-to-digital converter, and power supply circuits. A more detailed description of the unit is provided in the Manufacturers Manual. (2) Radar antenna and antenna drive, Bendix types AA-1212A and DA-1203A respectively. The antenna and its drive unit are located in the nose of the aircraft and are idented SB5/ 6. The antenna is a 12 inch phased array type and is connected to the receiver/transmitter via a waveguide. The drive motors, connected to the antenna, position the phased array in the aimuth and horiontal axes. Antenna stabiliation is in accordance with pitch and roll signals from the Flight Director System, and the tilt control on the radar indicator. (3) Controller/indicator, Bendix type IN-1152A. Refer to Figure 1. The unit is mounted on panel 2P, and provides all controls necessary for operation of the system. Weather/ground targets scanned by the system are shown on the display screen between the controls. Page 1
SD3-60 AIRCRAFT MAINTENANCE MANUAL A colour display is provided where certain colours are used to differentiate the levels of target intensity in both the weather and mapping modes; four colours are employed:- Green - in weather and mapping modes indicates the lowest level of intensity. Yellow - in weather and mapping modes indicates the second level of intensity. Red - in mapping mode indicates the highest level of intensity. Magenta - in weather mode indicates the highest level of intensity. NOTE: When operating in the weather alert mode (WXA) high intensity levels are indicated by the contour areas alternating between magenta and no colour on the display. Internally generated range marks appear as evenly spaced concentric arcs on the display to assist in determing range. A yellow track cursor may be moved left or right, to assist in determining aimuth bearings of targets. The display also provides an alphanumeric on-screen readout of the range and range mark intervals. A NAV butt and a FLT LOG button are provided on the indicator and are operated only when an optional remote computer unit (IU-2023A) is connected. If the interface is not connected the words NO NAV and NO LOG will be displayed in the lower left hand corner. Page 2
2. Operation CAUTION: RADAR MUST NOT BE OPERATED WITH AN OPEN WAVEGUIDE WITHOUT A 'DUMMY LOAD' CONNECTED TO THE PORTION WHICH IS CONNECTED TO THE TRANSMITTER. WARNING: 1. DO NOT OPERATE RADAR INSIDE A HANGAR OR OTHER ENCLOSURE. CARRY OUT FUNCTION CHECKS ON AN APRON POINTING AWAY FROM NEARBY BUILDING. 2. DO NOT PERMIT PERSONNEL AT THE OPEN END OF A WAVEGUIDE UNLESS THE RADAR IS OFF AND WILL REMAIN OFF. 3. DO NOT OPERATE RADAR DURING FUELLING OPERATIONS OR IN THE VICINITY OF TRUCKS OR CONTAINERS ACCOMMODATING FLAMMABLES OR EXPLOSIVES. 4. DO NOT PERMIT PERSONNEL WITHIN 50 FT OF AN AREA BEING SCANNED BY THE ANTENNA WITH THE SYSTEM TRANSMITTING. 5. FLASH BULBS MAY BE EXPLODED BY RADAR ENERGY. 6. TAKE NOTE OF ANY LOCAL RESTRICTIONS GOVERNING THE USE OF A RADAR SYSTEM. The antenna is supplied with 115V AC 400 H from the left AC busbar via C/B No.322 on distribution panel 1D.28V DC for the rest of the system is supplied from the left avionics busbar via C/B No.412 on distribution panel 5D. Refer to Figure 1. With the appropriate control selections made on the indicator and power supplied, the system will provide weather or mapping information along the flight path to a maximum of 320 nautical miles. This information is displayed in various colours to represent differing intensities. Using the system the pilot can detect and assess the severity of weather and adjust the flight path accordingly to minimie the turbulence normally associated with a thunderstorm. In addition to weather avoidance data, the system is capable of ground mapping to the extent of displaying prominent terrain features such as rivers and lakes. By tilting the antenna downward, the pilot can use the display as a navigation aid by correlating the features displayed either with a map or his own familiarity with the area. Page 3
SD3-60 AIRCRAFT MAINTENANCE MANUAL Alphanumerics are used to display:- Operating modes TEST WX WXA MAP STAB OFF HOLD (self-test) (weather mode) (weather alert mode) (ground mapping mode) (antenna stabiliation) (display froen) Page 4
Weather Radar Indicator & Test Display Figure 1 Page 5
SD3-60 AIRCRAFT MAINTENANCE MANUAL Table 1 is a list of controls with a brief description of each. Control Function selector Mode pushbuttons Wx WxA MAP NAV ) ) FLT LOG) RANGE increase pushbutton RANGE decrease pushbutton TRACK pushbutton Function and system operational characterestic (1) OFF position removes primary power from the system. (2) STBY position places the system in the standby condition during warm-up period and when the system is not in use. (3) TEST position selects test function to determine operability of the system. Refer to Figure 1 for test pattern. (4) ON position selects the condition for normal operation. Selects the weather mode when pressed. Pushbutton switch returns to normal position when released. Selects the weather alert mode when pressed; contour areas alternate between magenta and no colour. Pushbutton switch returns to previous mode (Wx or MAP) upon push-off. Selects the ground mapping mode when pressed. Mechanical operation same as W x. Functions available only when optional IU-2023 remote computer unit is fitted. Further information is available in the Manufacturers Manual. With the button engaged the display is cleared and it advances the indicator to the next higher range each time the button is pressed (e.g. 20 to 40, 40 to 80, etc.), until 320 mile range is reached. The range selected is displayed in the upper right hand corner on the last range mark. Clears the display and places the indicator in the next lower range each time the button is pressed (e.g. 40 to 20), until minimum range is reached. When pressed, a yellow track cursor line appears and moves to the left in one degree steps while the pushbutton is held depressed. The track cursor stops when the pushbutton is released, and remains for about 10 to 20 seconds, then disappears unless the pushbutton is pressed again. The differential heading will be indicated in yellow numerals in the upper left hand corner of the display. Indicator Controls and Functions Table 1 Page 6
Control TRACK pushbutton HOLD pushbutton TILT/STAB switch GAIN control BRT control Function and system operational characterestic When pressed, the yellow track cursor appears and moves to the right while held depressed. Operation is as outlined above. Retains the display (weather or map) when pushbutton is pressed. When the HOLD pushbutton is pressed a second time the distance and direction of the target movement, during the duration of the HOLD period is displayed on the indicator. The word HOLD flashes on and off in the upper left hand corner of the display to provide a direct indication of the mode operation. Disables the antenna stabiliation. The words STAB OFF flash on and off in the upper left hand corner of the display during operation. Adjusts the antenna angle ± 15 either side of the horiontal. Varies the radar receiver gain when in the MAP mode. Adjusts display brightness Indicator Controls and Functions Table 1 Page 7
AMM 42.0.0.0WEATHER RADAR SYSTEM (BENDIX RDR 1150 COLOUR) - MAINTENANCE PRACTICES 1. Adjustment/Test WARNING: ALL PERSONNEL OPERATING WEATHER RADAR SYSTEMS SHOULD BE ACQUINTED WITH THE CONTENTS OF FAA ADVISORY CIRCULAR 20-68B ON THE RECOMMENDED RADIATION SAFETY PRECAUTIONS FOR AIRBORNE WEATHER RADAR. A. Bench tests The Weather Radar system should be tested in accordance with the procedure in the relevant Manufacturers Maintenance Manual. B. Pre-installation tests Check that the units are free from signs of mechanical damage, corrosion or other defects. C. Post-installation tests (1) Mechanical alignment (a) Check the mechanical alignment of the scanner to the following limits. 1 Horiontally aligned to fore and aft centre line ± 0.5. 2 Vertically 2 nose down ± 0.5 at ero tilt position. Use a minimum of packing washers to achieve this alignment accuracy and once aligned, operate the scanner at all tilt positions and check that no foul occurs with the radome. (b) Check the waveguide, cabling, and "black box" installation for secureness both mechanically and electrically. (2) Hangar functioning (a) Preparation 1 Set the function switch on the radar indicator to the OFF position. 2 Close C/B Nos. 322 and 412 on distribution panels 1D and 5D respectively. 3 Identify No.1 vertical gyro, idented 1FD5, and situated on the roof between Stns. 146.2 and 158.9. 4 Maintaining the electrical connection, mount the vertical gyro on a tilt table or some other means of tilting the gyro through known angles. 5 Set the function switch to the TEST position. Page 201
SD3-60 AIRCRAFT MAINTENANCE MANUAL 6 Ensure that a test pattern appears on the indicator display after approximately 7-8 seconds. 7 Select the appropriate RANGE INCREASE or RANGE DECREASE control to provide a 80-mile range on the indicator display. 8 Refre to Figure 201. Check that the test pattern is as shown. 9 Set the TILT/STAB control on the indicator to 0 and disable the antenna stabiliation by pulling the TILT/STAB control to its off position. 10 Check that the words "STAB OFF" appear in the upper left hand corner of the indicator display. 11 Check that the antenna drive assembly scans within its 120 aimuth range, and that "update" on the indicator moves in synchronism and in the same direction as antenna scan. "Update" is observed as a small "ripple" moving along the outer green band. 12 Depress the HOLD pushbutton on the indicator, checking that the antenna continues to scan, and that the word "HOLD" flashes in the upper left hand corner of the indicator display. 13 Push-off the HOLD pushbutton to deactivate the hold condition. NOTE: NOTE: When the antenna stabiliation is disabled and the HOLD pushbutton on, the words "STAB OFF" flashes alternately with the word "HOLD" in the upper left hand corner of the indicator display. 14 Rotate the function switch to the STBY position. 15 Adjust the TILT/STAB control to +5, +10 and then +15, checking that the antenna tilts upward smoothly without interference. 16 Adjust the TILT/STAB control to -5, -10 and then -15, checking that the antenna tilts downward smoothly without interference. 17 Return the control to the 0 position. (b) TEST mode check. 1 Rotate the function switch on the indicator to the TEST position. 2 Adjust the BRT control to obtain a comfortable level of brightness and observe the test pattern on the indicator display. 3 Check that the magenta area in the test pattern is steady in the Wx mode, and that the magenta band flashes on and off in the WxA mode. Page 202
4 Check that the word "TEST" appears in the upper right hand corner of the display. (c) Antenna stabiliation check NOTE: The following tests require accurate positioning of the vertical gyro in both pitch and roll axes. If a tilt table is not available, the gyro may be positioned by reference to the flight director or artifical horion or some other method of accurately tilting the gyro in the aircraft. This calibration procedure should be performed after any period of gyro or antenna maintenance. 1 Rotate the function switch on the radar indicator to STBY. 2 Place the aircraft vertical gyro to ero degrees pitch and ero degrees roll. 3 Set the TILT/STAB control on the indicator to position the antenna to its ero degree position, ensuring that the control setting is between -1 and + 1. 4 Set the TILT/STAB control to position the antenna to the 10 "up" reference mark, ensuring that the control setting is between + 8.5 and + 13. 5 Set the TILT/STAB control to position the antenna at the 10 "down" reference mark, ensuring that the control setting is between - 8.5 and -13. (d) Pitch calibration check. 1 Manually position the antenna to ero degrees aimuth and insert the boresight pin into the 0 slot to lock the antenna in aimuth. CAUTION: ENSURE THAT THE FUNCTION SWITCH ON THE RADAR INDICATOR IS NOT MOVED FROM STBY OR OFF WITH PIN INSTALLED. 2 Adjust the TILT/STAB control on the radar indicator to position the antenna precisely at ero degrees in elevation. 3 Position the aircraft vertical gyro for 10 nose up and ero degrees bank. 4 Check that the position of the antenna elevation is 10 "down". NOTE: If the position of the antenna elevation is incorrect adjust the pitch gain potentiometer on the antenna drive assembly for the correct deflection. 5 Position the vertical gyro for 10 nose down and ero degrees bank, ensuring that the position of the antenna elevation is between + 8.5 and + 11.5 "up". 6 Pull-off the TILT/STAB control to disable the antenna stabiliation and check that the antenna returns to the ero degree position. Page 203
SD3-60 AIRCRAFT MAINTENANCE MANUAL 7 Remove the boresight pin to unlock the antenna aimuth drive and return the pin to its holder. (e) Roll calibration check 1 Set the roll trim potentiometer on the radar indicator to midrange. 2 Manually position the antenna to 60 clockwise and lock the aimuth drive by inserting the boresight pin into the 60 CW slot. 3 Position the aircraft vertical gyro to ero degrees pitch and 30 right roll. 4 Check that the position of the antenna elevation is 26 "up". NOTE: If the position of the antenna elevation is incorrect adjust the roll gain potentiometer on the antenna drive assembly for the correct deflection. 5 Position the vertical gyro to ero degrees pitch and 30 left roll, ensuring that the position of the antenna elevation is between +24.5 and + 27.5 down. 6 Pull off the TILT/STAB control on the radar indicator to disable the antenna stabiliation and check that the antenna returns to the ero degree position. 7 Remove the boresight pin to unlock the antenna aimuth drive and return the pin to its holder. (3) Apron functioning (a) Observing any traffic restrictions, tow the aircraft to a clear ahead area where metal buildings, aircraft, etc. are not in the line of sight. (b) Set the function switch on the radar indicator to TEST. (c) Ensure that the antenna scan is 120 and select the Wx operational mode. (d) Push-on the TILT/STAB control on the indicator and select a position for the tilt control. (e) Select the appropriate RANGE INCREASE or RANGE DECREASE control to provide a 80-mile range on the indicator display. (f) Refer to Figure 201. Check that the test pattern appears on the display and adjust the BRT control as required. (g) Check that the antenna drive assembly is scanning within its 120 aimuth range, and that "update" on the indicator moves in synchronism and in the same direction as antenna scan. "Update" is observed as a small "ripple" moving along the outer green band. (h) Release the Wx mode pushbutton. Page 204
(i) (j) (k) (l) Press the WxA mode shbutton and check that the magenta coloured band on the indicator display alternates from magenta to black approximately once per second. Release the WxA pushbutton. Push-on the HOLD control on the indicator, ensuring that the update "ripple" disappears and that the word "HOLD" flashes in the upper left hand corner of the indicator display. Push-off the HOLD control and check that the update "ripple" resumes. (m) Rotate the function switch to the ON position. (n) Select the RANGE DECREASE pushbutton to provide a 40-mile range on the indicator display. (o) Starting from 0 adjust the antenna tilt control up (+ degrees) in small increments until a clear picture develops of any local weather. Close-in ground targets may also appear on the display. By + 15, no ground targets should appear on the display. (p) Rotate the function switch to the OFF position and return the aircraft to the unpowered state. Page 205