Observe that rising runway display in ADI is retracted from view, and RWY flag is in view. IF -

EFFECTIVITY

 CONFIG 3

SN 301-350
799 Page 102
Apr 25/88
34-33-00

OK

Release TEST button. Set DH index on height indicator to zero feet and depress TEST button again. Slowly move DH index up in altitude. Verify that DH light on ADI illuminates when DH setting is within | 10 feet of displayed test altitude. IF -

System No. 1 or 2 is operative.

EFFECTIVITY

 CONFIG 3
SN 301-350
799 Page 103
Apr 25/88
34-33-00
PROCEDURE 1

EFFECTIVITY

CONFIG 3
SN 301-350
799 Page 104

34-33-00

 Apr 25/88
 LRRA SYSTEM - TROUBLE SHOOTING
______________________________

 1.  General
_______
 A.  The following trouble shooting procedures are based on performance of the system operational test and are presented in tree-type format. The test steps (heavy-line boxes) are connected by shaded arrows to show the OK condition path. When all steps in the OK condition path check out, the system is operable.
 B.  When a test step does not check out, follow the NOT OK line to the box containing the trouble symptom. Turn to the procedure indicated and continue to follow a single line by analyzing the results of each test step until the required corrective action is determined. Perform the specified corrective action, then repeat the step at which the failure was encountered.
 C.  All trouble shooting procedures are based on the assumption that wiring is OK and that electrical power is available. If the corrective action in the procedure does not correct the problem, check wiring using the wiring diagram.
 D.  The trouble shooting procedures of par. 3 are for LRRA systems 1 and
 2. Use the captain's instruments and controls to check system No. 1 and the first officer's instruments and controls to check system No.
 2.

 E.  The trouble shooting procedures of par. 4 are for LRRA system 3. System 3 contains no operating controls or altitude indicating units. A failure annunciator is provided on the pilots' center instrument panel P2. Operating power for the LRRA-3 system (if installed) is provided by circuit breaker ALTM LOW R3 on the P126 panel.
 2.  Prepare for Trouble Shooting
____________________________
 A.  Close ALTM LOW R1 and R2 circuit breakers on overhead circuit breaker panel P7.
 B.  On airplanes with LRRA-3 installed,
 close ALTM LOW R3 circuit breaker on circuit breaker panel P126.

 C.  Provide electrical power (Ref 24-22-00, Maintenance Practices [Apply Power]).
 D.  Operate equipment cooling system (Ref 21-58-00, Adjustment/Test
 [Operational Test]).

 E.  On captain's and F/O's height indicators, set DH index below zero altitude (or carefully to lower mechanical stop). If DH light on ADI and height indicator (if not marked INOP) are illuminated, pull and then close ALTM LOW R1 or ALTM LOW R2 circuit breaker as applicable to reset DH lights to off.
 EFFECTIVITY

 IB 405, LH ALL  CONFIG 4  01 Page 101  Apr 25/8834-33-00
3. _______________________
LRRA Systems No. 1 or 2

Push and hold TEST (or SET/TEST) button, as applicable, on height indicator. Observe that height indicator indicates 100 |10 feet (LH 001-003, IB), 40 |4 feet (LH 004-099) and warning flag appears on height indicator. IF -
____Antenna bonding problems usually cause a system to malfunction only during
NOTE: flight. The usual in-flight indications are intermittent warning flag and erratic (flickering) altitude indication from approximately 400 feet alti-tude to the pointer stow altitude. The system will usually self-test prop-erly during flight. On the ground, warning flag and altitude indication will usually be normal. When antenna bonding is suspected as the cause of
the system malfunction, refer to 34-33-03, LRRA Antennas - Approved Repairs.

Observe that rising runway display in ADI is retracted from view, and RWY flag is in view. IF -

EFFECTIVITY

CONFIG 4

LH ALL;
799 Page 102

IB 405
Apr 25/88
34-33-00

3. LRRA Systems No. 1 or 2 (Cont)

Release test button. Set DH index on height indicator to zero feet and press and hold test button again. Slowly move DH index up in altitude. Verify DH light (if not marked INOP) on height indicator and DH light on ADI illuminate when DH setting is within |5 feet of test altitude. IF -

EFFECTIVITY

 CONFIG 4
LH ALL;
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747飛機維護手冊AMM CHAPTER 34 - NAVIGATION 第34章導航2(75)