DOC AIRBUS | AMM A320FBACKSHELL LOCKWIRE PROCEDURE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
This section describes the standard practices for securing a connector its backshell and associated parts by the use of lockwire.
The lockwire is installed to prevent a part from becoming loose.
The wire is installed to apply an opposing force so that a part will not disengage.
** ON A/C NOT FOR ALL This section describes the standard practices for securing a connector its backshell and associated parts by the use of lockwire.
The lockwire is installed to prevent a part from becoming loose.
The wire is installed to apply an opposing force so that a part will not disengage.
2. Tools and Equipment
** ON A/C NOT FOR ALL | -------------------------------------------------------------------- |
| ! REFERENCE ! DESIGNATION ! |
| !------------------------------------------------------------------! |
| ! No specific ! Wire cutters ! |
| ! No specific ! Pliers ! |
| ! No specific ! Wire twisting pliers ! |
| -------------------------------------------------------------------- |
3. Consumable Material
** ON A/C NOT FOR ALL | ---------------------------------------------------------------------------- |
| ! REFERENCE ! DESIGNATION ! |
| !--------------------------------------------------------------------------! |
| ! MS20995N20 ! Lockwire ! |
| ! MS35265-( ) ! Screw, drilled head (see 70-71-11) ! |
| ---------------------------------------------------------------------------- |
4. Reference Information
** ON A/C NOT FOR ALL | ---------------------------------------------------------------------------- |
| ! REFERENCE ! DESIGNATION ! |
| !--------------------------------------------------------------------------! |
| ! 70-71-11 ! Connector backshell replacement parts ! |
| ---------------------------------------------------------------------------- |
5. Standard Practices for Lockwire
A. Procedure
(1) Any connectors with non-selflocking coupling nuts which are used in high vibration areas must be safety wired. The coupling nut must be safety wired to a fixed point.
(2) If a backshell is used that provides a saddle clamp for strain relief, the saddle clamp mounting screws must be safety wired.
(3) If a backshell is installed that has safety wiring provisions in the coupling nut it must be safety wired.
(4) On strain relief saddle clamps where a drilled head screw is not provided, replace the existing screw with a drilled fillister head screw of the same strength rating.
(5) All safety wiring is to be of the double twist wire method.
(6) Safety wire should be installed so that if the item being safety wired becomes to loose, it will apply a tightening pull on the attach point.
(7) Safety wiring twists should be uniform. There should be 6 to 10 twists per inch.
(8) Excess wire should be cut square and bent back.
6. Safety Wiring Procedure
| CAUTION : LOCKWIRE IS NOT REUSABLE. ALWAYS USE NEW LOCKWIRE. |
A. Procedure
Safety wire the connector, adapter or backshell, as follows:
Safety wire the connector, adapter or backshell, as follows:
Backshell Lockwiring(1) Pull half the wire through the safety wire hole in the part being safety wired.
(2) Twist the wires in a clockwise direction. Twist the wires tight enough to prevent loops.
(3) Continue to twist the wires until they reach the attaching point. The twisted portion should be within 0.125 inch (3.18 mm) of attach point.
(4) Separate the wires and put one wire through the hole in the attach point.
(5) Join the wires again and twist the wires clockwise 0.25 to 0.50 inch (6.35 to 12.7 mm) beyond the attach point.
(6) Cut off the excess wire and bend the end back toward the attach point so that it will not cause damage.