DOC AIRBUS | AMM A320FAssembly - PWA 316 - Safety Wire (Lockwire) Installation [PW11]
TASK 70-24-00-910-811-A
Assembly - PWA 316 - Safety Wire (Lockwire) Installation
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Job Set-up
Subtask 70-24-00-860-051-A ** ON A/C NOT FOR ALL
Subtask 70-24-00-910-051-A ** ON A/C NOT FOR ALL
(2) Obey the maximum safety wire length limits that follow:
(a) The maximum length (span) of safety wire between two tension points is 6 in. (152.4 mm), unless specified differently by the specific maintenance manual maintenance task.
(b) The maximum length of safety wire used to safety multiple fasteners together in a series (3 or 4) is 24 in. (0.6 m), unless specified differently by the specific maintenance manual maintenance task.
(3) Obey the maximum number of fasteners in a series limits that follow:
(a) Do not safety more than four fasteners in a series with one continuous length of wire, unless specified differently by the specific maintenance manual maintenance task.
(b) If there are more than four fasteners in a series and the text or illustration specifies "Safety Wire Together", do the steps that follow:
1 Divide this group into smaller groups of two, three or four fasteners.
2 Safety each of the smaller groups separately with safety wire.
3 Safety the smaller groups in series with each other with safety wire.
(4) Procedure
(a) Torque the parts before you install the safety wire as follows:
1 All fasteners must be correctly torqued before you install the safety wire.
2 For two or more fasteners safetied together, you must also put the wire holes in a correct position in relation to each other.
3 To get the correct hole alignment, torque the fasteners to the limits for fasteners with wire holes. Refer to the specific maintenance manual maintenance task or the Standard Torques.
4 Do not increase the torque more than the specified limit to correctly align the wire holes.
5 If necessary, use another fastener or part to correctly align the wire holes within the specified torque limits.
(b) Select the number of strands of the safety wire as follows:
1 Use two strands of safety wire twisted together (double-twisted), unless specified differently by the specific maintenance manual maintenance task.
2 Use a single strand safety wire only where specified by the specific maintenance manual maintenance task.
(c) Examine the safety wire holes as follows:
2 Remove the burrs or sharp edges from the safety wire holes.
3 If necessary, replace the parts with burrs or sharp safety wire holes.
(d) Examine the PLIERS-SAFETY WIRE as follows:
1 Examine the jaws of the PLIERS-SAFETY WIRE for sharp edges or corners.
2 If necessary, round off the sharp plier jaws and make them smooth.
2 Install safety wire for a group of two bolts or nuts with the wire wrapped over the top of a bolt or nut as shown in examples 7 and 8.
a Use this method if there is little or no clearance around the bolt or nut.
3 Install safety wire for a square plug to a lug with a safety wire hole as shown in example 9.
4 Install safety wire for a single screw to a lug with a safety wire hole as shown in example 10.
5 Install safety wire for two bolts that are on a different plane as shown in example 11.
6 Install safety wire for hollow head plugs as shown in examples 12 through 14.
7 Install a single strand of safety wire for multiple screws as shown in example 15.
8 Install safety wire wrapped around an adjacent bracket for a bolt as shown in example 16.
a Use this method to safety any part if there is no lug with a safety wire hole.
9 Install safety wire for the tube and hose nuts or electrical connectors as shown in examples 17 and 18.
10 Install safety wire for the tube and hose nuts or electrical connectors with a lug with a safety wire hole as shown in examples 19 and 20.
11 Install safety wire for the tube and hose nuts or electrical connectors without a lug with a safety wire hole as shown in examples 21 and 22.
12 Install safety wire for the small tube nuts or nuts made of soft material as shown in example 23.
a Use this method for all nuts with a thin wall thickness at the safety wire holes.
b Wrap the wire around the nut as shown to prevent a break through the thin wall section.
13 Install safety wire for two adjacent tube and hose nuts or electrical connectors as shown in example 24.
14 Install safety wire for the tube and hose nuts or electrical connectors to a lug with a safety wire hole as shown in example 25.
15 Install safety wire for the tube nuts on a tee as shown in example 26.
16 Install safety wire for a straight bulkhead tube nut to a bolt as shown in example 27.
17 Install safety wire for the tube nuts and jam nuts as shown in examples 28 through 30.
18 Install a lead seal to the end of the safety wire as shown in examples 31 and 32.
a Attach the seal at the end of the safety wire after the last item is safetied.
b Wrap the loose end of the wire to the safety wire in front of the seal or to an empty safety wire hole.
(f) Install the safety wire as follows:
1 Install the safety wire so that it always applies tension to tighten the parts.
2 Make sure that there is no additional tension on the wire other than the original tension.
3 If the torque on the threaded part becomes reduced, do the steps that follow:
a Remove the safety wire.
b Tighten the fastener again to the specified torque limits.
c Install the safety wire again.
4 Obey all the assembly instructions if any slack is necessary between tension points.
5 Pull the safety wire tight as you twist it and make the recommended number of twists.
(g) Trim off the unwanted safety wire as follows:
a Do not twist off the end of the safety wire with the wire twist pliers.
b You must use wire cutting pliers to cut off the end of the wire.
2 Make sure that the safety wire does not have loose or non-twisted ends.
3 Make sure that the safety wire does not have sharp ends.
4 Bend the end of the wire in towards the part so that it does not point out.
1 Examine the safety wire for flex limits as follows:
a Push on the safety wire at mid-span with light finger pressure, approximately 2 lb (0.91 kg).
b The total flex for the safety wire must not be more than the limits as shown below:
2 Examine the safety wire for damage as follows:
b Examine the wire for nicks, kinks or damage. Nicks, kinks or damage are not permitted.
c Remove and replace the safety wire if you find any cracks, broken strands, nicks, kinks or damage.
d Examine the safety wire for abrasions. Light abrasions from the PLIERS-SAFETY WIRE are permitted.
3 Examine the safety wire for clearance as follows:
a Examine the safety wire for clearance between all adjacent parts.
b The wire must not touch, chafe or rub on adjacent parts during engine operation.
c The wire must not stretch or get too much tension during engine operation.
d The above limits apply for all parts that move during engine operation, (examples are variable stator rings, bleed valves, actuators, control cables and linkage).
[Rev.10 from 2021]
2026.04.01 02:20:17 UTC
Assembly - PWA 316 - Safety Wire (Lockwire) Installation
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
NOTE: Always obey the specific procedures and limits in the specific maintenance manual maintenance tasks.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | PLIERS-SAFETY WIRE |
| REFERENCE | DESIGNATION |
|---|---|
Safety Wire InstallationSubtask 70-24-00-860-051-A ** ON A/C NOT FOR ALL
A. Not Applicable
4. ProcedureSubtask 70-24-00-910-051-A ** ON A/C NOT FOR ALL
WARNING:
USE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.
A. Installation of the Safety Wire (Lockwire) NOTE: The nomenclatures lockwire and safety wire are interchangeable. Safety wire is also referred to as lockwire.
(1) Use the correct safety wire as specified in the specific maintenance manual maintenance task. (2) Obey the maximum safety wire length limits that follow:
(a) The maximum length (span) of safety wire between two tension points is 6 in. (152.4 mm), unless specified differently by the specific maintenance manual maintenance task.
(b) The maximum length of safety wire used to safety multiple fasteners together in a series (3 or 4) is 24 in. (0.6 m), unless specified differently by the specific maintenance manual maintenance task.
(3) Obey the maximum number of fasteners in a series limits that follow:
(a) Do not safety more than four fasteners in a series with one continuous length of wire, unless specified differently by the specific maintenance manual maintenance task.
(b) If there are more than four fasteners in a series and the text or illustration specifies "Safety Wire Together", do the steps that follow:
1 Divide this group into smaller groups of two, three or four fasteners.
2 Safety each of the smaller groups separately with safety wire.
3 Safety the smaller groups in series with each other with safety wire.
(4) Procedure
(a) Torque the parts before you install the safety wire as follows:
1 All fasteners must be correctly torqued before you install the safety wire.
2 For two or more fasteners safetied together, you must also put the wire holes in a correct position in relation to each other.
3 To get the correct hole alignment, torque the fasteners to the limits for fasteners with wire holes. Refer to the specific maintenance manual maintenance task or the Standard Torques.
4 Do not increase the torque more than the specified limit to correctly align the wire holes.
5 If necessary, use another fastener or part to correctly align the wire holes within the specified torque limits.
(b) Select the number of strands of the safety wire as follows:
1 Use two strands of safety wire twisted together (double-twisted), unless specified differently by the specific maintenance manual maintenance task.
2 Use a single strand safety wire only where specified by the specific maintenance manual maintenance task.
(c) Examine the safety wire holes as follows:
CAUTION:
DO NOT INSTALL THE SAFETY CABLE IN HOLES WITH BURRS OR SHARP EDGES. IF YOU DO, THE SAFETY CABLE CAN BREAK DURING ENGINE OPERATION.
1 Examine the safety wire holes for burrs or sharp edges. 2 Remove the burrs or sharp edges from the safety wire holes.
3 If necessary, replace the parts with burrs or sharp safety wire holes.
(d) Examine the PLIERS-SAFETY WIRE as follows:
1 Examine the jaws of the PLIERS-SAFETY WIRE for sharp edges or corners.
2 If necessary, round off the sharp plier jaws and make them smooth.
NOTE: This will prevent nicks and damage to the safety wire.
(e) Determine the direction and pattern of the safety wire for the parts that must be safetied. NOTE: Safety Wire Examples do not show every possible combination of parts that can be safety wired. Use these figures as a guide for other applications.
1 Install safety wire for a group of three bolts or screws as shown in examples 3 through 6. 2 Install safety wire for a group of two bolts or nuts with the wire wrapped over the top of a bolt or nut as shown in examples 7 and 8.
a Use this method if there is little or no clearance around the bolt or nut.
3 Install safety wire for a square plug to a lug with a safety wire hole as shown in example 9.
4 Install safety wire for a single screw to a lug with a safety wire hole as shown in example 10.
5 Install safety wire for two bolts that are on a different plane as shown in example 11.
6 Install safety wire for hollow head plugs as shown in examples 12 through 14.
7 Install a single strand of safety wire for multiple screws as shown in example 15.
8 Install safety wire wrapped around an adjacent bracket for a bolt as shown in example 16.
a Use this method to safety any part if there is no lug with a safety wire hole.
9 Install safety wire for the tube and hose nuts or electrical connectors as shown in examples 17 and 18.
10 Install safety wire for the tube and hose nuts or electrical connectors with a lug with a safety wire hole as shown in examples 19 and 20.
11 Install safety wire for the tube and hose nuts or electrical connectors without a lug with a safety wire hole as shown in examples 21 and 22.
12 Install safety wire for the small tube nuts or nuts made of soft material as shown in example 23.
a Use this method for all nuts with a thin wall thickness at the safety wire holes.
b Wrap the wire around the nut as shown to prevent a break through the thin wall section.
13 Install safety wire for two adjacent tube and hose nuts or electrical connectors as shown in example 24.
14 Install safety wire for the tube and hose nuts or electrical connectors to a lug with a safety wire hole as shown in example 25.
15 Install safety wire for the tube nuts on a tee as shown in example 26.
16 Install safety wire for a straight bulkhead tube nut to a bolt as shown in example 27.
17 Install safety wire for the tube nuts and jam nuts as shown in examples 28 through 30.
18 Install a lead seal to the end of the safety wire as shown in examples 31 and 32.
a Attach the seal at the end of the safety wire after the last item is safetied.
b Wrap the loose end of the wire to the safety wire in front of the seal or to an empty safety wire hole.
(f) Install the safety wire as follows:
1 Install the safety wire so that it always applies tension to tighten the parts.
2 Make sure that there is no additional tension on the wire other than the original tension.
3 If the torque on the threaded part becomes reduced, do the steps that follow:
a Remove the safety wire.
b Tighten the fastener again to the specified torque limits.
c Install the safety wire again.
4 Obey all the assembly instructions if any slack is necessary between tension points.
5 Pull the safety wire tight as you twist it and make the recommended number of twists.
| Wire Diameter Inch (mm) | Twists/Inch (25.4mm) |
|---|---|
| 0.015 in. (0.381 mm) - 0.017 in. (0.432 mm) | 11 - 14 |
| 0.019 in. (0.483 mm) - 0.021 in. (0.533 mm) | 9 - 13 |
| 0.024 in. (0.610 mm) - 0.026 in. (0.660 mm) | 9 - 12 |
| 0.030 in. (0.762 mm) - 0.034 in. (0.864 mm) | 7 - 10 |
| 0.038 in. (0.965 mm) - 0.042 in. (1.067 mm) | 7 - 10 |
| 0.049 in. (1.245 mm) - 0.053 in. (1.346 mm) | 5 - 8 |
| 0.061 in. (1.549 mm) - 0.065 in. (1.651 mm) | 5 - 8 |
NOTE: One twist is a twist of the wires through an arc of 180 degrees, equal to half of a complete turn.
6 Twist the wire to 0.125 in. (3.175 mm) distance from the safety wire hole. (g) Trim off the unwanted safety wire as follows:
CAUTION:
BE SURE THAT THE CUT WIRE ENDS DO NOT FALL INTO THE ENGINE. IF THEY DO, THE SAFETY WIRE CAN CAUSE DAMAGE DURING ENGINE OPERATION.
1 Cut off the unwanted wire at the end of the last fastener and keep at least three full twists. a Do not twist off the end of the safety wire with the wire twist pliers.
b You must use wire cutting pliers to cut off the end of the wire.
2 Make sure that the safety wire does not have loose or non-twisted ends.
3 Make sure that the safety wire does not have sharp ends.
4 Bend the end of the wire in towards the part so that it does not point out.
NOTE: If the ends point out they could be a safety hazard to persons who work on the engine. They could also vibrate in the airstream during engine operation and break off.
(h) Examine the safety wire after installation as follows: 1 Examine the safety wire for flex limits as follows:
a Push on the safety wire at mid-span with light finger pressure, approximately 2 lb (0.91 kg).
b The total flex for the safety wire must not be more than the limits as shown below:
| Index A Safety Wire Length (Span) Inch (mm) | Index B Full Flex Limit Inch (mm) | Index C Half Flex Limit Inch (mm) |
|---|---|---|
| 0.5 in. (12.700 mm) | 0.125 in. (3.175 mm) | 0.063 in. (1.600 mm) |
| 1.0 in. (25.400 mm) | 0.250 in. (6.350 mm) | 0.125 in. (3.175 mm) |
| 2.0 in. (50.800 mm) | 0.375 in. (9.525 mm) | 0.188 in. (4.775 mm) |
| 3.0 in. (76.200 mm) | 0.500 in. (12.700 mm) | 0.250 in. (6.350 mm) |
| 4.0 in. (101.600 mm) | 0.500 in. (12.700 mm) | 0.250 in. (6.350 mm) |
| 5.0 in. (127.000 mm) | 0.625 in. (15.875 mm) | 0.313 in. (7.950 mm) |
| 6.0 in. (152.400 mm) | 0.625 in. (15.875 mm) | 0.313 in. (7.950 mm) |
CAUTION:
BE SURE THAT THERE ARE NO CRACKS IN THE WIRE. IF THERE ARE, THE SAFETY WIRE CAN BREAK AND CAUSE DAMAGE DURING ENGINE OPERATION.
a Examine the wire for cracks or broken strands. Cracks or broken strands are not permitted. b Examine the wire for nicks, kinks or damage. Nicks, kinks or damage are not permitted.
c Remove and replace the safety wire if you find any cracks, broken strands, nicks, kinks or damage.
d Examine the safety wire for abrasions. Light abrasions from the PLIERS-SAFETY WIRE are permitted.
3 Examine the safety wire for clearance as follows:
a Examine the safety wire for clearance between all adjacent parts.
b The wire must not touch, chafe or rub on adjacent parts during engine operation.
c The wire must not stretch or get too much tension during engine operation.
d The above limits apply for all parts that move during engine operation, (examples are variable stator rings, bleed valves, actuators, control cables and linkage).