On this page
Text · 10
From the PDF’s text layer: layout, tables and figures are lost. The PDF is the document. © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2019-0979, the docket of AD 2020-05-18. Not covered by OpenAirDocs’ CC0 dedication.
Query with SQL
duckdb -csv -c "SELECT p.page, p.text_source, p.text, f.rights_holder, f.license FROM 'https://openairdocs.org/data/latest/service_document_file_page.parquet' p JOIN 'https://openairdocs.org/data/latest/service_document_file.parquet' f USING (file_sha256) WHERE p.file_sha256 = '9c45eedaaa8e9d4de46d60fa8ad32aa5d8b3f19bb8b2f94fa6d0e0dc43d44b0c' ORDER BY p.page"
Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.
SELECT p.page, p.text_source, p.text, f.rights_holder, f.license FROM 'https://openairdocs.org/data/latest/service_document_file_page.parquet' p JOIN 'https://openairdocs.org/data/latest/service_document_file.parquet' f USING (file_sha256) WHERE p.file_sha256 = '9c45eedaaa8e9d4de46d60fa8ad32aa5d8b3f19bb8b2f94fa6d0e0dc43d44b0c' ORDER BY p.page
Run it at the DuckDB prompt, or in any tool that reads Parquet over HTTPS. More ways to query the release are on Use the data.
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 1 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT SUBJECT: ATA 57 – Inspection of Forward Pintle Bearing Lock Washer AIRCRAFT TYPE: A350 OUR REF.: A57P013-19 Rev 00 dated 04 April 2019
1. AIRCRAFT AFFECTED A350-900 MSN 5-276 (except MSN 214, 224, 234, 237, 246, 249, 251, 257, 260, 265, 270, 272) A350-1000 MSN 88-262 (except MSN 215, 229, 241)
MODEL OPR MSN A350-900 AAR 94 117 144 176 198 218 CAL 49 57 66 73 92 105 121 138 151 162 179 191 208 239 CCA 167 178 217 231 240 247 268 CES 248 261 269 CHH 98 112 226 245 CPA 29 32 34 38 39 46 53 58 61 70 72 75 85 93 101 109 119 128 137 148 154 155 CRK 124 153 168 187 235 256 CSC 52 55 60 DAL 115 135 149 160 164 175 182 190 199 204 210 267 DLH 74 80 87 127 136 146 174 184 202 209 212 255 ETH 40 43 89 103 120 147 180 196 205 259 FBU 5 193 FIN 18 19 20 22 23 28 51 97 104 113 134 264 FWI 82 91 HVN 14 15 16 17 56 67 86 129 150 173 192 197 IBE 219 227 271 MAS 159 165 183 195 203 213 MAU 145 157 PAL 221 228 236 243 QTR 6 7 8 9 10 11 12 13 21 25 33 36 42 47 63 64 69 76 78 79 83 90 100 106 114 126 132 143 163 172 207 211 SIA 26 30 31 37 41 54 62 68 77 81 84 96 99 107 116 122 133 140 158 170 186 216 220 223 230 232 238 244 254 263 276 TAM 24 27 35 45 48 200 250 THA 44 50 95 111 123 130 142 177 181 185 189 201 A350-1000 CPA 118 169 188 206 225 233 252 258 262 QTR 88 102 110 125 141 161
2. REFERENCED DOCUMENTATION
2.1 APPENDIX Appendix 1: Flow Chart Appendix 2: Inspection Reporting Sheet
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 2 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
2.2 REFERENCES [1] A350 Maintenance IPD 57-26-63-02000-94AA-A – ATTACHMENT INSTL MLG [2] MP Task A350-A-32-12-XX-00ZZZ-397Z-A – Open the MLG Doors for Maintenance [3] NDT A350-A-51-99-XX-01001-040A-A – Visual [4] MP TASK A350-A-57-51-71-02001-520A-A - Removal of the Lower Access Panels - Inboard Trailing Edge [5] PMS 01-05-03 – Locking using tab washers
3. REASON
3.1 FACTS A deviation to the installation of the lock washer tab at the MLG (Main Landing Gear) Forward Pintle Bearing, affecting the bearing nut locking, has been identified on a limited number of A350-900/A350- 1000 aircraft in production.
The Forward Pintle Bearing is installed in the Trunnion Block and provides the connection between the MLG and the outer wing rear spar. The bearing nut is locked by bending one of the lock washer tabs into a slot around the nut circumference.
A350-900 shown, A350-1000 similar Figure 1 – Location of Inspection B C
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 3 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT FWD Bearing Tab washer Nut C Figure 2 – Trunnion Block Assembly
3.2 CONSEQUENCES The absence of an engaged lock washer tab at the bearing nut could lead to an un-expected rotation of the nut and loss of torque. This could progressively allow an axial movement of the bearing housing. If no corrective action is performed, this could potentially lead to a MLG collapse.
3.3 AIM The aim of this AOT is to provide instructions for the inspection of the MLG forward pintle bearing nut lock washer to check that a tab is correctly engaged and the nut is locked.
4. SHORT TERM ACTION
4.1 PLANNING AND MANPOWER
4.1.1 ACCOMPLISHMENT TIMESCALE The inspection detailed in this AOT is expected to be mandated by an Airworthiness Directive (AD) published by the Airworthiness Authorities.
The inspection as described in paragraph 4.2 has to be completed at the first opportunity but no later than 5 months or 500FC whichever occurs first from the effective date of the associated AD.
4.1.2 MANPOWER The estimated time to perform the inspection defined in paragraph 4.2 is 2 Man Hours per A/C. The inspection can be performed by one person.
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 4 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
4.2 DESCRIPTION
4.2.1 ACCESS A standard platform or cherry picker is necessary to get access to the inspection area close to the wing MLG forward pintle pin trunnion assembly. Open the MLG Doors for access, refer to Ref [2].
4.2.2 INSPECTION REQUIREMENTS NOTE: For clarification of inspection sequence, please refer to flowchart in Appendix 1.
Through this AOT, it is required to perform a Detailed Inspection (DET) as follows on the Left Hand and the Right Hand wing:
a. Perform a Visual Inspection (refer to ref [3]) of the bearing nut and lock washer at the forward face of the Trunnion block (area identified in Figure 3) to confirm that one tab of the lock washer is correctly bent:
The bent tab can be at any position around the nut circumference.
The lock washer is located between the trunnion block and rear spar and is therefore not directly visible. Any suitable tools may be used to complete this inspection i.e. Light, inspection mirror, borescope.
i. If the bearing nut is correctly locked by the tab washer (see example Figure 4a) no further action is required.
ii. If no lock washer tab is bent (see example Figure 4b) proceed to step (b)
b. Perform DET of the Bearing Assembly to Trunnion interface on the forward and aft face for discrepancies (sign of axial migration of the bearing assembly or rotation of the nut) as follows:
At any accessible position, use feeler gage to confirm there is no gap between the bearing nut / lock washer and lock washer / trunnion block (refer to Figure 6).
Be aware that the bearing nut has a chamfer of 6.0mm Visually inspect for gap or damage to the sealant bead at the bearing assembly to trunnion block aft face (area identified in Figure 5).
i. If there is no discrepancy observed then either; before next flight perform the applicable corrective action defined in §4.2.3, or, to defer the corrective action, proceed to step (c).
ii. In case of discrepancy finding contact Airbus before next flight.
c. Apply witness mark to monitor bearing nut for evidence of rotation:
Apply witness mark using CML code 04SAB2 (Varnish Polyurethane- Marking Structure) or equivalent Apply the witness mark as a continuous line, approximate width of 3.5 mm (0.14 in.), across the bearing housing and nut at approximately the 6 o’clock position (refer to Figure 3 for example).
Prior to application of witness mark clean the surface with a clean 14SBA1 (Textile_Lint free Cotton) and 08BAA9 (Non Aqueous Cleaner_General) or equivalent.
d. Perform Repeat DET (refer to ref [3]) at interval of 5 months or 500FC whichever occurs first, without exceeding 6 YRS from ToT, for evidence of nut rotation or bearing migration.
Inspect the witness mark applied in step (c) for signs of nut rotation Visually inspect for gap or damage to the sealant bead at the bearing assembly to trunnion block aft face (area identified in Figure 5).
i. In case of nut rotation or bearing migration finding during repeat inspection contact Airbus before next flight.
e. In all cases, including NIL FINDINGS, send the result of initial inspection to Airbus as detailed in §7.
See Appendix 2 – Inspection Reporting Sheet.
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 5 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Trunnion block view from below
View on lock washer and nut looking aft from rear spar Figure 3 – Area of Inspection
(a) Example Lock Washer Correctly Engaged (b) Example Lock washer tab not engaged Figure 4 – Example Inspection Photos X Witness Mark
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 6 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Figure 5 – Trunnion Block, view looking forward Figure 6 – Trunnion Block and Bearing Cross Section (Extracted from Drawing V575-59333, V575-57019 & V575-56734 similar) Inspect Trunnion Block to Bearing interface
LOCK WASHER
BEARING NUT
BEARING HOUSING NO GAP CHAMFER 6.0MM
TRUNNION BLOCK
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 7 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT
4.2.3 CORRECTIVE ACTION In case a lock washer tab is not engaged in the bearing nut, and no sign of damage, - No later than 6 years from first ToT (Transfer of Title) perform the applicable corrective actions to lock the nut:
i. If one tab of the lock washer is found aligned with a slot in the bearing nut, perform action A.
ii. If no lock washer tab is aligned with a slot in the nut, perform action B1 or B2.
A. Bend the washer tab to lock the bearing nut, refer to PMS 01-05-03. Note:
Any suitable means can be used to bend the tab of the lock washer. However, due to very limited access, Airbus is currently developing specific tools to enable the tab to be bent at any circumferential position. Contact Airbus for further recommendations on a case-by-case basis.
Do not use steel or other hard metal tools which could damage the lock washer or surrounding structure.
Removal of panel 571CB (671CB) may be required to improve access when performing corrective action. Refer to Ref [4].
B1. Perform Corrective Action with MLG removal in accordance with Ref R57V-40094.
B2. Corrective Action instructions without MLG removal will be provided in a revision of this AOT, expected in Q3/2019.
Specific tools and instructions to enable the bearing nut to be re-torqued and the lock washer tab to be bent without MLG removal are currently under development by Airbus.
4.3 SPARES AND TOOLING No specific tooling is required to perform this inspection.
5. FURTHER INFORMATION
5.1 FOLLOW-UP PLAN This AOT is expected to be mandated by an Airworthiness Directive (AD) published by the Airworthiness Authorities.
A revision of the AOT is considered for Q3/2019 to provide alternative corrective action instructions in case of finding the bearing nut not locked and not aligned with the tab washer.
5.2 IMPACTED DOCUMENTATION No specific documentation is impacted.
6. AOT APPROVAL The technical content of this document is approved under the authority of DOA nr. EASA.21J.031.
7. REPORTING
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 8 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Questions about this AOT are to be addressed to Airbus Customer Services through TechRequest on Airbus World, selecting Engineering Domain (Engineering Support) and ATA 57-26.
As per latest reporting policy (Ref to OIT 999.0018/16), inspection results (with or without findings) are to be addressed to Airbus Customer Services through the generic e-mail address: inspection.results@airbus.com.
Best Regards, Christian FREMONT
VICE PRESIDENT ENGINEERING SUPPORT
CUSTOMER SERVICES Stephane GOSSELIN VICE PRESIDENT A350 PROGRAMME
CUSTOMER SERVICES
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 9 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT APPENDIX 1 – Inspection Flow Chart Within 500FC or 5Months whichever occurs first from AD issue date Perform DET of MLG Bearing Lock Washer LH AND RH Wing Is the Bearing Nut correctly locked by tab washer?
No Further Action Required Discrepancy observed?
YES YES NO NO A – Aligned Tab Washer Lock tab washer refer to PMS 01-05-03 Contact AIRBUS before next flight Perform Repeat DET Interval: 500FC / 5 Months Limit: 6YRS from ToT OR Apply Witness Mark Rotation or migration?
YES NO Contact AIRBUS before next flight OR B2 – Misaligned Tab Washer Await AOT Revision for RI without MLG removal B1 – Misaligned Tab Washer Perform Corrective Action with MLG removal per R57V-40094 Perform applicable Corrective Action No Further Action Required
ALERT OPERATORS TRANSMISSION - AOT AOT ref: A57P013-19 Rev 00 Page 10 of 10 Date: 04-APR-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT APPENDIX 2 – Inspection Report Form A/C INFORMATION:
OPERATOR:
A/C MSN:
A/C REGISTRATION:
FLIGHT CYCLES FLIGHT HOURS:
DATE OF INSPECTION:
INSPECTION RESULT:
LH WING RH WING
LOCK WASHERTAB BENT AND CORRECTLY LOCKED? (Y/N) CORRECTIVE ACTIONS:
In case of finding, report the actions performed at time of inspection:
LH WING RH WING
IS LOCK WASHER TAB ALIGNED WITH NUT SLOT? (Y/N)
WITNESS MARK APPLED, CORRECTIVE
ACTION DEFERRED (Y/N) COMMENTS: