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A

747-400
MAINTENANCE MANUAL

DOUBLE TWIST PROCEDURE

DOUBLE TWIST PROCEDURE

Lockwire Installation
Figure 401

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747-400 MAINTENANCE MANUAL
 B. Procedure - Install the Lockwire
 S 804-007
 (1)  Use these types of wires for lockwire:
 (a)  
Use monel, inconel, or corrosion-resistant lockwire in high temperature areas.

 (b)  
Use 0.020-inch diameter copper wire on emergency equipment only. Use it where a seal is necessary on emergency equipment to show no person has used the equipment. Emergency equipment includes portable fire extinguishers, first aid kits, emergency valve, and oxygen regulators.

 (c)  
Use Clad 5056 aluminum alloy wire for lockwire that touches magnesium to prevent galvanic corrosion.

 (d) This table shows BAC standard wire sizes. ~............................................................................. | MATERIAL | SIZE (INCH) | ...............................................................................
 | Monel or Inconel  |  .020  .032  .040  .051  .091  |
 | Corrosion Resistant Steel  |  .020  .032  .040  .051  .091  |
 | Aluminum Alloy  |  .020  .032  .040  .051  .091  |

 2......................................…......................................1
 S 424-003
 (2)  Use these steps to install lockwire to bolts and screws (Fig. 401):
 (a)  
On all fittings where you install lockwire, attach the fitting to the mating part or an adjacent part.

 (b)  
Install the lockwire for right threads as shown in the figures for this procedure. Install the lockwire for left threads opposite to that shown.

 (c)  
Make sure the loop of double wire goes around the head of the bolt or screw.

 NOTE: The wire must not go above the head.
____
 CAUTION: DO NOT LOOSEN OR TIGHTEN A NUT OR BOLT OUT OF ITS
_______ SPECIFIED TORQUE RANGE. DAMAGE CAN OCCUR.
 (d)  When you install lockwires on nuts and bolts, tighten to the low values of the torque range. If it is necessary, continue to tighten until a slot aligns with the safety hole.
 S 424-004
 (3)  To install lockwire on electrical connectors, see Fig. 402.
 (a)  Use the instructions for the installation of lockwires to bolt and screws when you install lockwires on electrical connectors.
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747-400
MAINTENANCE MANUAL

LOCKWIRE
LOCKWIRE
LOCKWIRE
SELF-LOCKING NUT
PUT CLAMP TO GRIP COUPLING NUT
SELF-LOCKING NUT
LOCKWIRE
CLAMPS
ATTACH TO 
STRUCTURE OR  ATTACH TO 
LOCKWIRE  ADJACENT PART  STRUCTURE OR 
ON UNIT  ADJACENT PART 
ON UNIT 
SELF-LOCKING NUT 
CLAMP 

PUT CLAMP TO GRIP COUPLING NUT
PUT CLAMP TO GRIP ATTACH TO COUPLING NUT STRUCTURE OR
ADJACENT PART LOCKWIRE
ON UNIT
CLAMP (2 LOCATIONS)
SELF-LOCKING NUT AND SCREW OR BOLT
Connector Lockwire - InstallationFigure 402
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