B. Two jumper cables - one 20 feet long and one 1 foot long, fabricated from RG-141/U, or equivalent (Ref Test Cable Diagram, Fig. 102).
C. Sealant (Ref 51-31-01)
D. Nose Landing Gear Door Lock - 7MIT65B04012
3. Prepare for Trouble Shooting
____________________________
EFFECTIVITY
ALL 08 Page 103 Sep 25/9434-31-12
300 ‘V
Figure 101
EFFECTIVITY ALL
799 Page 104
34-31-12
Sep 25/94Prepare system for troubleshooting as described in par. 2. Check track antenna rf distribution runs by disconnecting capture antenna coaxial cable connectors DB554A and DB555A at hybrid couplers on station 400 bulkhead (Fig. 103).
____NOTE: AF 115-120,123-151;
The hybrid coupler coaxial connectors DB554A and DB555A need not be discon-
nected. This is because the glide slope capture antennas are disconnected
from the station 400 hybrid couplers by the glide slope capture antenna
coaxial relays which are de-energized when the landing gear are down
(Details A and B, Fig. 103).
Adjust signal generator power output and check at what MICROVOLT dial settings glide slope flags in captain's and first officer's HSIs retract from view. The lower microvolts setting should be greater than 70% of the higher microvolts setting (equivalent to a 3 db differential in sensitivity) that retract the flags. IF -
____ The system with the higher microvolts setting is the system to be checkedNOTE: in the following procedure if the compared sensitivity values are out-of-
tolerance.
EFFECTIVITY
LH 001-010; AF 101-120,123-151;SN 301-350; IB 405
799 Page 105
34-31-12
Sep 25/94
T34239
AF 101-114; LH 001-010; SN 301-350 and IB 405; Check glide slope capture antenna rf distribution runs by reconnecting capture antenna cable connectors DB554A and DB555A and disconnecting track antenna cable connectors DB554B and DB555B at hybrid couplers B554 and B555 on station 400 bulkhead.
AF 115-120,123-151; Disconnect track antenna cable connectors DB554B and DB555B at hybrid couplers B554 and B555; open glide slope system circuit breakers on P7 and the primary and alternate landing gear display and control circuit breakers on P12; dis-connect connectors DM93 and DM809 at landing gear logic units M93 and M809 at station 400 bulkhead; ground pin 35 of connector DM93 and pin 36 of DM809; and close slope system circuit breakers on P7.
Position signal generator with test antenna orientated as shown in Fig. 101 for testing capture antennas. Adjust signal generator power output and check at what signal level the glide slope flags in captain's and first officer's HSI's retract. The lower microvolts setting should be greater than 70% of the higher microvolts setting that retracts the flags. IF -
____ The system with the higher microvolts setting is the system to be checked
NOTE: in the following procedure if the compared sensitivity values are out-of-tolerance.
NOT OK COMPARED SENSITIVITY VALUES REMAIN OUT-OF-TOLERANCE -PERFORM PROCEDURE 2.
AF 115-120,123-151;
NOT OK
GS FLAGS DO NOT DISAPPEAR IN EITHER THE CAPTAIN'S OR THE FIRST OFFICER'S HSI - Replace coaxial relay B404 if faulty display is in captain's HSI or coaxial relay B405 if faulty display is in first officer's HSI. Repeat test.
OK
System is operable.
T34259
EFFECTIVITY
LH 001-010; AF 101-120,123-151;SN 301-350; IB 405
799 Page 106
34-31-12
Sep 25/94
PROCEDURE 1
T34278
..... ...XA
CAUTION: WHEN INSTALLING DOOR CAVITY ACCESS PANELS, TAKE CARE TO PROVIDE CLEAN FAYING SURFACE WITH AN UNDAMAGED ALODINE COATING AND TIGHTEN BOLTS FOR PROPER SURFACE TO SURFACE CONTACT TO PREVENT DETUNING THE DOOR CAVITY.
1
________ Check antenna tuning per AMM 34-31-00, page 514. IF NOT OK:
OPTIONAL: Replace track antenna without removing door assembly per OHM 32-22-55 and tune new antenna per AMM 34-31-00, page 514.
EFFECTIVITY LH 001-010; AF 101-120,123-151, AND AF 157,161,183,184 WITHOUT SB 34-2264; SN 301-350; IB 405
799 Page 107
34-31-12
Sep 25/94
PROCEDURE 2
CAUTION: WHEN INSTALLING DOOR CAVITY ACCESS PANELS, TAKE CARE TO PROVIDE CLEAN FAYING SURFACE WITH AN UNDAMAGED ALODINE COATING AND TIGHTEN BOLTS FOR PROPER SURFACE TO SURFACE CONTACT TO PREVENT DETUNING THE DOOR CAVITY.
T34295
EFFECTIVITY LH 001-010; AF 101-120,123-151,AND AF 157,161,183,184 WITHOUT SB 34-2264; SN 301-350; IB 405
799 Page 108
34-31-12
Sep 25/94 Prepare system for troubleshooting as described in par. 2. Check track antenna rf distribution runs. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747飞机维护手册AMM CHAPTER 34 - NAVIGATION 第34章导航2(47)
