S 412-025
(12)
Install the actuator and lockwire in position.
S 412-026
(13)
Install fuel the tank access door (AMM 28-11-02/401).
(14)
Refuel the fuel tanks and do a check for leaks (AMM 12-11-01/301).
S 652-030
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747-400
MAINTENANCE MANUAL
FUEL SYSTEM ELECTRICAL BONDING JUMPER - MAINTENANCE PRACTICES
_____________________________________________________________
TASK 28-00-02-202-001
1. Inspection of the Electrical Bonding Jumpers in the Fuel System
_______________________________________________________________
A. General
(1)
This task contains visual, mechanical and physical inspections of the electrical bonding jumpers in the fuel system.
(2)
The bonding jumper consists of a braided copper wire covered with a tin plating. The tin plating on the bonding jumper usually supplies a smooth finish. When there is deterioration of the tin plating the copper in the wire can react with any sulfur compounds in the tank. The bonding jumper finish becomes rough to the touch and can show signs of fraying.
B.
Reference
(1)
SWPM 20-20-00, Electrical Bonds and Grounds
C.
Access
(1)
Location Zones
133 Wing Center Section (Left)
134 Wing Center Section (Right)
500 Wing (Left)
600 Wing (Right)
D.
Electrical Bonding Jumper Visual Inspection
S 212-002
(1)
Visually inspect the bonding jumper color.
(a)
If the bonding jumper is silver in color and does not show a color change, then the bonding jumper is satisfactory.
(b)
If the wire braid on the bonding jumper has black or brown deposits, do the task: Electrical Bonding Jumpers in the Fuel System Replacement.
(c)
If only the areas near the lugs have black or brown deposits, then do the subsequent procedure.
E.
Electrical Bonding Jumper Mechanical Inspection
S 282-003
(1)
Try to turn the bonding jumper lugs and tube clamps, if applicable, with light finger pressure.
S 352-004
(2)
If the bonding jumper is loose, rework the electical bond path (SWPM 20-20-00).
(3)
If the bonding jumper is secure, then do the subsequent procedure.
S 282-013
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747-400 MAINTENANCE MANUAL
F. Electrical Bonding Jumper Physical Inspection
S 212-005
CAUTION: DO NOT FLEX, BEND OR KINK THE BONDING JUMPERS MORE THAN IS
_______ NECESSARY. IF THE BONDING JUMPERS ARE MOVED TOO MUCH, IT CAN CAUSE THE LOSS OF TIN PLATING ON THE WIRE BRAID OF THE BONDING JUMPER.
(1)
Feel along the length of the bonding jumper and visually inspect the bonding jumper to find deterioration.
(a)
If there are broken strands in the wire braid, then do this task: Electrical Bonding Jumpers in the Fuel System Replacement.
(b)
If the bonding jumper feels rough, then do this task: Electrical Bonding Jumpers in the Fuel System Replacement.
NOTE: This shows there is a loss of tin and possible
____ degradation of the copper in the wire braid.
(c) The bonding jumper is satisfactory when: 1) The bonding jumper does not feel rough 2) The tin plating is smooth and free from flakes 3) The wire braid does not have broken strands.
TASK 28-00-02-962-006
2. Electrical Bonding Jumpers in the Fuel System Replacement
_________________________________________________________
A. Reference
(1)
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747-400 AMM 飞机维护手册 燃油 FUEL 1(15)
