(3)
On airplanes with supplementary fuel tanks, system controls include the circuit breaker, the mach airspeed warning test switch, the mach airspeed-gear down airspeed selector switch, the fuel tank relay and the fuel level float switches.
EFFECTIVITY
ALL 02 Page 6 Apr 25/7934-14-00
MACH AIRSPEED WARNING - TROUBLE SHOOTING
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1. General
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A. The following trouble shooting procedures are based on performance of the system operational test and are presented in tree-type format to aid in rapid fault isolation. 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 and complete the test to check out the system.
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.
2. Reference Procedures
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A. 24-22-00, Maintenance Practices (Apply Power)
B. 31-26-02, Removal/Installation
C. 34-11-00, Maintenance Practices (Pressurization)
D. 34-14-00, Maintenance Practices
3. Prepare for Trouble Shooting
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A. Verify that mach airspeed warning system circuit breakers on P12 panel are closed.
B. Verify that auxiliary pitot-static system No. 2 is at ambient pressure.
C. Verify that the MACH AIRSPEED - GEAR DOWN AIRSPEED select switch is in normal (lever down) position.
D. On airplanes with supplementary fuel tanks,
verify that at least one tank is not empty (Ref 12-11-01).
E. Apply electrical power (Ref 24-22-00).
EFFECTIVITY
ALL 15 Page 101 Jan 25/8034-14-00
PROCEDURE 1WARNING OCCURS -heard in flight deck. Prepare for trouble shooting as described in par. 2. Observe no warning can be NOT OK OK
(34-11-00). trouble shoot auxiliary pitot static system No. 2 TEST RESULTS ARE NOT CORRECTED BY SWITCH REPLACEMENT, perform specified test. faulty airspeed warning switch (34-14-00) and TEST RESULTS ARE NOT WITHIN TOLERANCE - Replace system test (34-14-00). Check that test results are within tolerance. IF -. Check airspeed pressure switch operation by performing mach airspeed warning OK NOT OK NOT OK
System is operable.
T33532
EFFECTIVITY ALL
706 Page 102
34-14-00
Apr 25/79
PROCEDURE 1
EFFECTIVITY ALL
701 Page 103
34-14-00
Oct 10/73
NO WARNING CLACKER IS HEARD - Open MACH
WARNING CLACKER IS HEARD - Open MACH
WARN circuit breaker on P12 panel.
WARN circuit breaker on panel P12.
Check continuity between contacts 1 and
Reconnect connector on front of mach
2; 4 and 5; 7 and 8 of mach airspeed -
airspeed warning switch. Drop the main
gear down airspeed selector switch
airspeed warning test switch module out
on E2-1 equipment rack. IF -
of panel P5.
On airplanes without supplementary
fuel tanks, short together the two wires connected to the back of the test switch. On airplanes with supplementary fuel tanks, short pins 6 and 7 at the back of test switch. Close MACH WARN circuit breaker on panel P12. IF -
CONTINUITY OK - Replace aural
NO CONTINUITY - Replace mach warning module and perform
airspeed - gear down airspeed specified test (31-26-02).
selector switch and perform specified test (34-14-00).
WARNING CLACKER IS HEARD - Open MACH WARN circuit breaker on panel P12. Replace mach airspeed warning test switch and perform specified test (34-14-00).
NO WARNING CLACKER IS HEARD - Open MACH WARN circuit breaker on panel P12. Return test switch module to original configuration. Replace mach airspeed warning switch and perform specified test (34-14-00).
T33543
EFFECTIVITY ALL
725 Page 104
34-14-00
Apr 25/79
PROCEDURE 3
EFFECTIVITYALL
725 Page 105
34-14-00
Apr 15/75
PROCEDURE 4
WARNING CLACKER IS HEARD - Open MACH WARN circuit breaker on panel P12. Reconnect connector on front of mach airspeed warning switch. Drop the mach airspeed warning test switch module out of panel P5. Short together pins 7 and 11 at the back of test switch. Close MACH WARN circuit breaker on panel P12. IF - 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1(88)
