# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT

SUBJECT: ATA 57- INSPECT LH AND RH BOTTOM SKIN FASTENERS AT MAIN LANDING GEAR RIB 5 FOOTPRINT LOCATION FOR MIGRATED OR MISSING FASTENER AIRCRAFT TYPE: A318,A319,A320 OUR REF.: A57N006-14 Rev 00 dated 04/December/2014 04-DEC-2014. 1. AIRCRAFT AFFECTED Applicable to MSN 5817, 5826, 5837, 5848 , 5855 , 5864, 5875, 5886, 5896, 5910 and all A318, A319 and A320 Aircraft delivered from MSN 5918 onwards . 2 . REFERENCED DOCUMENTATION 2.1 APPENDIX AOT A57N006-14 Appendix A: decision tree for weekly inspection. AOT A57N006-14 Appendix B: decision tree for the 4 months inspection . AOT A57N006-14 Appendix C: reporting sheet. 2.2 REFERENCES All limitations provided with concession suffix R related to this topic issued on delivered aircraft since November 2014 are superseded by this AOT. Ref. A: SRM 51-42-11 Paragraph 9 Ref. B: AMM 57-51-37-000-008 Removal of the Access Door Ref. C: AMM 57-51-37-400-008 Installation of the Access Door Ref. D: AMM 51-78-00-615-005 Removal of Corrosion Preventive Compound Ref. E: AMM 51-78-00-916-001 Application of Temporary Protection System (TPS) 3. REASON Inspection of Taperlok fasteners on A320 Family aircraft, located in the joint between the Main Landing Gear Support Rib lower flanges & lower wing skins on LH & RH wings, is required to ensure continued airworthiness. The inspection program is aimed at detecting Taperloks that have failed . 3.1 FACTS During production of A318 , A319 , A320 wings a number of taperlok fasteners have been found failed after installation . Initial investigations highlight an issue with taperlok fasteners . The fasteners in question are located at the bottom skin of the MLG reinforcing plate , wing skin and Gear Support Rib 5 lower flange (refer to fig . 1 and 2) . The taperlok fasteners are installed on A318, A319 & A320 aircraft wings . A321 aircraft are NOT affected as wing assembly is done using parallel fasteners .


### AOT ref: A57N006-14 Rev 00 Page 1 of 15 Date: 04-Dec-2014 CAIRBUS S.A.S. 2014 All RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT

Figure 1- Location of affected fasteners FORWARD

+ 

# L

+ + OUTBOARD



### All fasteners heads identified as

# .A.to be inspected on a weekly basis
Gear SupportRib D572-5Z580 

### Figure 2a- Location of affected fasteners heads, view looking up AOT 

### ref: A57N006-14 Rev 00 Page 

### 2 of 15 Date: 04-Dec-2014 CAIRBUS S.A.S. 2014. All RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT

All fasteners tails/nuts identified on the 

### inboard to be inspected on a weekly basis

Gear support Rib D572-52SI!O FORWARD 

# L

All fasteners tails/nuts identified on the 

### outboard to be inspected on a 

### 4-monthly basis OUTBOARD

Figure 2b- Location of affected fasteners tails/nuts . MLG support rib bottom flange upper surface 3.2 CONSEQUENCES Failure ofthese fasteners may results in a reduction in the design margin ofthe structure . 3.3AIM The aim of this AOT is to ensure that taperlok fasteners, affected by the failure mode, are identified and replaced in order to restore the design margin. Aircraft in the effectivity as per section1 are required to perform a weekly Detail Visual Inspection (DVI) of the external surface of the LH and RH lower wing surface for migrating or missing fasteners and ofthe inboard side of the MLG support rib lower flange for broken fastener tails/nuts (refer to fig . 2a and 2b). In addition, Aircraft in the effectivity are required to perform a repeat DVI every 4 Months of the MLG Support Rib lower flange upper surface on outboard side ofthe MLG support rib lower flange for failed nuts 

### I tails (refer to fig. 2b).
AOT ref: A57N006-14 Rev 00 Page 

### 3 of 15 Date : 04-Dec-2014 Cl AIRBUS S.A.S 2014 All RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT 4. SHORT TERM ACTION For the weekly inspection : Refer to appendix AOT A57N006-14 Appendix A. In the event of no more than 1 finding (fastener migration or missing , tail/nuts missing) per side, the affected fastener needs to be removed (if in place) within 1 week and re-install within 

### 4 months. NOTE :

- In case of more than one finding per side, the operator has to replace affected fasteners before next flight leaving no more than 1 failed fastener until the 4 months inspection.

- Remove/apply Temporary Protection System (TPS) in open hole as per Ref. D and E. -Apply 1 layer of speed tape over the affected location and 1 more layer overlapping it at 

### go•. For the 4 months inspection : Refer to appendix AOT A57N006-14 Appendix B. In the event of finding (fastener migration or missing , tail/nuts missing) during DVI , fastener(s) needs to be replaced before further flight as per Ref. A. For both inspections, after fastener replacement, the inspections described in this AOT still have to be performed at the same intervals until further notice. 4.1 PLANNING AND MANPOWER 4.1 .1 ACCOMPLISHMENT TIMESCALE For the weekly inspection : Do a DVI ofthe external surface ofthe LH an RH lower wing surface for migrating or missing fasteners and a DVI ofthe inboard MLG support rib lower flange for broken nut/tail. THRESHOLD : No later than 1 week from issuance of the AOT. GRACE PERIOD : N/A INTERVAL: No later than 1 week.

AOT ref: A57N006-14 Rev 00 Page 

### 4 of 15 Date: 04-Dec-2014 0 AIRBUS S.A.S. 2014. All RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT

Fig. 3b example offinding (nut/tail missing on inboard area)

Fig. 4 view of lower surface of MLG rib 5 area

AOT ref: A57N006-14 Rev 00 Page 5 of 15 Date: 04-Dec-2014 Cl AIRBUS S.A S. 2014 . All RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT Area to be inspected

Fig. 5 view of inboard (looking outboard) of MLG rib 5. For the 4 months inspection : Do a DVI of the outboard MLG Support Rib lower flange fasteners and nuts THRESHOLD : No later than 4 Months after issuance of the AOT. GRACE PERIOD : N/A INTERVAL: No later than 4 months.

Fig. 6 view of outboard (lool<ing inboard) of MLG rib 5.
AOT ref: A57N006-14 Rev 00 Page 6 of 15 C AIRBUS SA S. 2014 All RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT 

### Area to be inspected

Date: 04-Dec-2014

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT 4.1 .2 MANPOWER The estimated amount of man hours to perform the weekly inspection is 1 hour per aircraft, both sides included . The estimated amount of man hours to perform the 4 months inspection is 2 hours per aircraft, both sides included . 4.2 DESCRIPTION 4.2.1 ACCESS For the weekly inspection: Support Equipment for access : • Access platform 2M (6 FT) adjustable , • Safety harness. Put an ACCESS PLATFORM 2M (6FT) in position . The use of magnifying tools may be required . For the 4 months inspection: Support Equipment for access: • Access platform 2M (6 FT) adjustable, • Safety harness. Work Zone and Access Panel: ·Access Panel 574AB 

### &674AB (Door entrance of false rear spar area), ·Warning & 

### safety precautions: WARNING:MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. WARNING:PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

- THE FLIGHT CONTROLS

- THE FLIGHT CONTROL SURFACES

- THE LANDING GEAR AND THE RELATED DOORS

- COMPONENTS THAT MOVE. MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT. C.t\UTION BE CAREFUL WHEN YOU DO

**11.11\INTENAHC~** TASKS ON TIIF WING TR/I.ILIN(, EDGE. DO 

### NOT CAUSE DAMAGE TO 

### THE. ELE:CTRIGAL CABLE R<'\CEV\Ii\Y"',

- 00 NOT 

### CAUSE 0/I.Mi\GE TC THE fLt:.CTRIGAL CABLE

**INST/Ill.ATION~·** - !\:lAKE SURE THJ.\T THEEl 

### Eel· fCt,· CABLES ARE 

### INSlAl LED <.,.QRRE.C l LY. INCORRECT INSTALLA.llON CAN CAUSE: DAMAGE. 

### Put an ACCESS PLATFORM 2M (6FT) in position . The use of magnifying tools may be required . Perform access as per Ref. Band C. AOT 

### ref: A57N006-14 Rev 00 Page 7 of 15 Date: 04-Dec-2014 CAIRBUS S.AS. 20 14 All RIGHTS RESERVED. CONFIDENTIAL AND PROPRI ETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT 4.2.2 INSPECTION REQUIREMENTS Do a DVI of the external surface of the LH an RH bottom skin lower wing surface for migrated or missing fasteners. Do a DVI ofthe INBOARD/OUTBOARD MLG Support Rib lower flange fasteners and nuts for missing nuts 

### I tails . 4.2.3 FINDINGS Failed fasteners (broken, migrated, missing) Failed tail/nut (broken, missing) In case offinding, refer to Appendix A and B. If a failed fastener is to be removed the following instructions are to be followed : • Mark the orientation of the fastener on the head (i .e. inboard/outboard) . • Mark the location of the fastener on bolting diagram as per AOT A57N006-14 Appendix C. • Remove affected fastener as per Ref. A. • All effort should be made not to damage the fracture surface of the fastener during removal. • The fastener and associated nut/tail is to be returned to Airbus . • Report all findings to Airbus . Iffinding please report to Airbus as per AOT A57N006- 14 Appendix C. 4.3 SPARES AND TOOLING Fasteners part numbers affected : 

### nominal 1st oversize 2nd oversize NSA 5486-9-27N NSA 5487-9-27N NSA 5488-9-27N NSA 5486-9-28N NSA 5487-9-28N NSA 5488-9-28N NSA 5486-9-29N NSA 5487-9-29N NSA 5488-9-29N NSA 5486-9-30N NSA 5487-9-30N NSA 5488-9-30N NSA 5486-9-31 

### N NSA 5487-9-31 N NSA 5488-9-31 N 

## l ·fw : .g; 

# .. 'I& 

## .. NSA 5486-1 0-22N NSA 5487-10-22N NSA 5488-10-22N NSA 5486- 10-28N NSA 5487-10-28N NSA 5488-10-28N NSA 5486-10-29N NSA 5487-10-29N NSA 5488-10-29N NSA 5486-1 0-30N NSA 5487-10-30N NSA 5488-1 0-30N NSA 5486-10-31N NSA 5487-10-31N NSA 5488-10-31 N NSA 5486-1 0-32N NSA 5487-10-32N NSA 5488- 10-32N NSA 5486-10-33N NSA 5487-10-33N NSA 5488-1 0-33N NSA 5486-10-35N NSA 5487-10-35N NSA 5488-10-35N Nuts part numbers affected : 

### AOT ref: A57N006-14 Rev 00 Page 8 of 15 Date: 04-Dec-2014 C AIRBUS S AS. 2014. All RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT NSA5472-9K7 NSA5472-10K7 Tooling list as per Ref. A to be made available.

5. FURTHER INFORMATION 5.1 FOLLOW-UP PLAN This repeat inspection is to be continued until Airbus has defined a terminating action to this AOT. Pending the level of finding this AOT may be revised to refine its instructions. TFU is under preparation for follow-up . 5.2 IMPACTED DOCUMENTATION N/A

AOT ref: A57N006-14 Rev 00 Page 9 

### of 15 Date: 04-Dec-2014 OAIRBUS S.A S 2014 All RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY OOCUMENT

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT 6. AOT APPROVAL The technical content of this document is approved under the authority of DOA nr. EASA.21J .031. It is anticipated that this AOT will be mandated by the issuance ofan EASA Airworthiness Directive. 7. REPORTING Questions about this AOT should be sent to the SEES2 department via the on-line TechRequest tool. Inspection results with findings are to be sent (ref AOT A57N006-14 Appendix C) to Airbus Customer Services engineering as soon as possible, after the AOT application, to the attention of: Julie BLANCHOT Structure Engineer Structure Engineering - SEES2 CUSTOMER SERVICES Phone : +33(0)5 61 93 60 20 Fax: +33 (0)5 61 93 36 14 Mailto: julie.blanchot@airbus .com Ludovic MENARD Outer Wing Product Leader Structure Engineering - SEES2 CUSTOMER SERVICES Phone: +33(0)5 67 19 16 36 Fax: +33 (0)5 61 93 36 14 Mailto: Ludovic.menard@airbus.com Best Regards,

Jean-Luc MOUYSSET VICE PRESIDENT ENGINEERING SUPPORT CUSTOMER SERVICES Gilles DE CEVINS VICE PRESIDENT A320 PROGRAMME CUSTOMER SERVICES



### AOT ref: A57N006-14 Rev 00 Page 10 of 15 Date: 04-Dec-2014 0 AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT AOT A57N006-14 Appendix A: decision trees for weekly inspection.



### NOTE : 

### In case ofmore than one finding per side, the operator has to replace affected fasteners before next flight leaving no more than 1 failed fastener until the 4 months inspection. AOT ref: A57N006-14 Rev 00 Page 11 of 15**~AIRBUS** SAS. 2014 . /\Ll RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 

### Date:04/Dec/2014

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT AOT A57N006-14 Appendix A: decision trees for weekly inspection .



### NOTE: 

### In case ofmore than one finding per side, the operator has to replace affected fasteners before next flight leaving no more than 1failed fastener until the 4 months inspection.

AOT ref: A57N006-14 Rev 00 Page 12 of 15 Cl AIRBUS S AS 2014 All RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT 

### Date:04/Dec/2014

# ~AIRBUS ALERT OPERATORS TRANSMISSION- AOT AOT A57N006-14 Appendix 8: decision trees for the 4-monthly inspection

AOT ref: A57N006-14 Rev 00 Page 13 of 15 Date:04/Dec/2014 0 AIRBUS SAS 2014 ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

# ~AIRBUS ALERT OPERATORS TRANSM ISSION- AOT AOT A57N006-14 Appendix C: reporting sheet AOT 57N006-14 REPORTING SHEET 

### AIC MSN OPERATOR FLIGHT CYCLES FLIGHT HOURS DATE OF INSPECTION 

# I

**G~v** SvpportR ib.OSU.Sl:SSO



### AOT ref: A57N006-14 Rev 00 Page 14 of 15 Date:04/Dec/2014 OAIRBUS S A.S. 2014. ALL RIGHTS RESERVED CONF!DENTll\l AND PROPRIETARY DOCUMENT

# AIRBUS ALERT OPERATORS TRANSMISSION- AOT AOT A57N006-14 Appendix C: reporting sheet Fastener Number

RETURN TO: LH side RH side

Julie BLANCHOT julie .blanchot@airbus.com TEL +33 (0)5 61 93 60 20 FAX +33 (0)5 61 93 36 14 AIRBUS 

### Missing Migrated Fastener Fastener

Ludovic MENARD ludovic.menard@airbus.com TEL +33 (0)5 67 19 16 36 FAX +33 (0)5 61 93 36 14 CUSTOMER SERVICES ENGINEERING-SEES2 WING -PYLON- STABILIZER 1 rond point Maurice Bellante 31707 BLAGNAC CEDEX France 

### Nut I Tail missing

AOT ref: A57N006-14 Rev 00 Page 

### 15 of 

### 15 Date:04/Dec/2014 C AIRBUS S A.S 2014 ALL RIGHTS RESERVED CONFIDENTIAL AND PROPRIETARY DOCUMENT