Requirements Bulletin - 757-57A0075 RB

1 NE301 - NE302 1 NE311 - NE325 1 NJ001 - NJ004 1 NJ031 - NJ032 1 NJ551 - NJ555 1 NL001 - NL002 1 NL006 - NL017 1 NL101 - NL109 1 NL141 1 NL601 - NL616 1 NN001 - NN002 1 NN051 - NN052 1 NP901 - NP904 1 NS601 - NS616 Group Variable Number 1 NT001 - NT009 1 NT201 - NT202 1 NT231 - NT234 1 NT237 - NT240 1 NT242 1 NT245 - NT248 1 NT281 - NT289 1 NT341 - NT347 1 NT351 - NT360 1 NT371 - NT373 1 NT375 - NT379 1 NT381 - NT386 1 NT401 - NT409 1 NT411 - NT412 1 NT426 - NT427 1 NT431 - NT432 1 NT436 - NT438 1 NT441 - NT442 1 NT446 1 NT701 - NT769 1 NT791 - NT796 1 NT861 - NT862 1 NT881 - NT885 1 NT901 - NT916 1 NT971 - NT985 1 NU031 - NU038 1 NU701 - NU705 1 NU721 - NU728 1 NU731 - NU732 B. Spares Affected None. 2. CONCURRENT REQUIREMENTS None. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 6 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT 3. COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to Requirements Bulletin 757-57A0075 RB. The Airworthiness Directive will make the compliance tasks and times given in Requirements Bulletin 757-57A0075 RB mandatory. Accomplish the required actions, based on the applicable conditions in Table 1, Table 2 and Table 3 in accordance with Accomplishment Instructions. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for that CONDITION or OPTION. Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Within 4,000 flight cycles af- ter the original issue date of Requirements Bulletin 757- 57A0075 RB. Before 25,000 total flight cy- cles. OPTION 1: Do an exter- nal High Frequency Eddy Current (HFEC) inspec- tion of the center wing box lower skin and rear spar lower chord for any crack. All Airplanes. OPTION 2: Do an internal detailed inspection of the center wing box lower skin and rear spar lower chord for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 7 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Before further flight. CONDITION 1 (ACTION 1): Contact The Boeing Company for repair in- structions and do the re- pair. CONDITION 1: ANY CRACK FOUND DURING OPTION 1 INSPECTION. 4,000 flight cycles. - CONDITION 1 ACTION 2 (OPTION 1): Repeat external High Frequency Eddy Current (HFEC) in- spection of the center wing box lower skin and rear spar lower chord for any crack at the unre- paired areas.(a)(b) - Within 4,000 flight cycles after the most recent OPTION 1 inspection was done. CONDITION 1 ACTION 2 (OPTION 2): Do an in- ternal detailed inspection of the center wing box lower skin and rear spar lower chord for any crack at the unrepaired ar- eas.(a)(b) 4,000 flight cycles. - CONDITION 2 (OPTION 1): Repeat external High Frequency Eddy Current (HFEC) inspection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) CONDITION 2: NO CRACK FOUND DURING OPTION 1 INSPECTION. - Within 4,000 flight cycles after the most recent OPTION 1 inspection was done. CONDITION 2 (OPTION 2): Do an internal detailed inspection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 8 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Before further flight. CONDITION 3 (ACTION 1): Contact The Boeing Company for repair in- structions and do the re- pair. CONDITION 3: ANY CRACK FOUND DURING OPTION 2 INSPECTION. - Within 6,000 flight cycles after the most recent OPTION 2 inspection was done. CONDITION 3 ACTION 2 (OPTION 1): Do an ex- ternal High Frequency Eddy Current (HFEC) in- spection of the center wing box lower skin and rear spar lower chord for any crack at the unre- paired areas.(a)(b) 6,000 flight cycles. - CONDITION 3 ACTION 2 (OPTION 2): Repeat internal detailed inspec- tion of the center wing box lower skin and rear spar lower chord for any crack at the unrepaired areas.(a)(b) - Within 6,000 flight cycles after the most recent OPTION 2 inspection was done. CONDITION 4 (OPTION 1): Do an external High Frequency Eddy Current (HFEC) inspection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) CONDITION 4: NO CRACK FOUND DURING OPTION 2 INSPECTION. 6,000 flight cycles. - CONDITION 4 (OPTION 2): Repeat internal de- tailed inspection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) (a) After the accomplishment of this OPTION, it is acceptable to change the repeat action from this OPTION to any other OPTION under this CONDITION. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 9 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition (b) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757-57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. Table 2: Internal Ultrasonic Inspection of the Center Wing Box Lower Chord and Detailed Inspection of the Lower Skin at the Rear Spar Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Within 4,000 flight cycles after the original issue date of Requirements Bulletin 757- 57A0075 RB. The compliance times given in 1., 2., and 3., whichever occurs first: 1. Before 120,000 total flight hours. 2. Before 50,000 total flight cycles. 3. Before the result of 80000-(0.5 X TFH) - TFC is less than or equal to zero. TFC = Total Flight Cy- cles Do an internal ultra- sonic inspection of the center wing box lower chord and detailed in- spection of the lower skin at the rear spar for any crack. All Airplanes. TFH = Total Flight Hours Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 10 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 2: Internal Ultrasonic Inspection of the Center Wing Box Lower Chord and Detailed Inspection of the Lower Skin at the Rear Spar Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Before further flight. CONDITION 5 (AC- TION 1): Contact The Boeing Company for repair instructions and do the repair. CONDITION 5: ANY CRACK FOUND. 12,000 flight cy- cles. - CONDITION 5 (AC- TION 2): Repeat inter- nal ultrasonic inspec- tion of the center wing box lower chord and detailed inspection of the lower skin at the rear spar for any crack at the unre- paired areas.(a) 12,000 flight cy- cles. - CONDITION 2: Re- peat internal ultrason- ic inspection of the center wing box lower chord and detailed in- spection of the lower skin at the rear spar for any crack.(a) CONDITION 6: NO CRACK FOUND. (a) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757-57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. Table 3: Internal Detailed Inspection of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Within 4,000 flight cycles af- ter the original issue date of Requirements Bulletin 757- 57A0075 RB. Before 50,000 total flight cy- cles. Do an internal detailed inspection of the center wing box lower skin and rear spar lower chord for any crack. All Airplanes. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 11 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 3: Internal Detailed Inspection of the Center Wing Box Lower Skin and Rear Spar Lower Chord Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) Action Condition - Before further flight. CONDITION 7 (ACTION 1): Contact The Boeing Company for repair in- structions and do the re- pair. CONDITION 7: ANY CRACK FOUND. 12,000 flight cy- cles. - CONDITION 7 (ACTION 2): Repeat internal de- tailed inspection of the center wing box lower skin and rear spar lower chord for any crack at the unrepaired areas.(a) 12,000 flight cy- cles. - CONDITION 2: Repeat internal detailed inspec- tion of the center wing box lower skin and rear spar lower chord for any crack.(a) CONDITION 8: NO CRACK FOUND. (a) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757-57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. 4. APPROVAL This Requirements Bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this document comply with the applicable regulations and are FAA approved, as well as European Union Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in this Requirements Bulletin effectivity. This document and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this Requirements Bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this Requirements Bulletin. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 12 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT 5. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION NOTE: 1. This is an Enhanced Required for Compliance document. There will be a separate Service Bulletin (SB) and a separate Requirements Bulletin (RB). If an RB is mandated by an Airworthiness Directive (AD), then all applicable requirements specified in the RB must be done. For the related SB, some locations are marked RC Start and RC End to identify the requirements that are restated from the RB. For the related SB, the areas between RC Start and RC End, including sub-steps and any figures identified between RC Start and RC End, must be done to comply with the AD. Therefore, an Alternative Method of Compliance (AMOC) is required for any deviations to steps between RC Start and RC End, including substeps and identified figures. For the related SB, the steps not between RC Start and RC End may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC; this is provided that the steps between RC Start and RC End, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. Figures not required for compliance are omitted from the RB. 2. This is an Enhanced Required for Compliance document. The Boeing processes used to create the Service Bulletin (SB) and the Requirements Bulletin (RB) ensure that the information between "RC Start" and "RC End" in the SB are identical to the information in the same sections (Compliance, Work Instructions...) of the RB which the SB refers to as the related document. 3. The compliance times for the actions in WORK INSTRUCTIONS are in Compliance. 4. Boeing Service Letter 757-SL-51-022, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 5. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque Values: — Values for structural fasteners are given in 757 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 757 Aircraft Maintenance Manual (AMM). — Values for electrical maintenance tasks are included in Chapter 20 of Standard Wiring Practices Manual (SWPM). — Values for engine maintenance tasks are included in Chapter 70 of 757 Aircraft Maintenance Manual (AMM). Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 13 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT — Non-standard torque values for maintenance tasks are included in the applicable installation step. 6. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 7. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 8. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 9. Use the approved fastener, process and material substitutions in accordance with SRM Chapter 51. 10. A Detailed Inspection is defined as: An intensive examination of a specific item, installation or assembly to detect damage, failure or irregularity. This could include tactile assessment in which a component or assembly can be checked for tightness/security. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors and magnifying lenses may be necessary. Surface cleaning and elaborate access procedures may be required. 11. When more than one OPTION is given for a CONDITION, do only one of the OPTION numbers. When more than one ACTION is given for a CONDITION or an OPTION, do all of the ACTION numbers for that CONDITION or OPTION. B. WORK INSTRUCTIONS 1. Requirements. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 14 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition Do PART 1: GET ACCESS FOR EXTERNAL INSPEC- TION. - OPTION 1: Do an external High Frequen- cy Eddy Current (HFEC) in- spection of the center wing box lower skin and rear spar lower chord for any crack. All airplanes. - FIGURE 1 Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - OPTION 2: Do an internal detailed inspec- tion of the center wing box lower skin and rear spar low- er chord for any crack. - FIGURE 2 Do PART 3: CLOSE AC- CESS FOR EXTERNAL IN- SPECTION. - CONDITION 1 (ACTION 1): Contact The Boeing Compa- ny for repair instructions and do the repair. CONDITION 1: ANY CRACK FOUND DUR- ING OPTION 1 IN- SPECTION. Do PART 1: GET ACCESS FOR EXTERNAL INSPEC- TION. - CONDITION 1 (ACTION 2) (OPTION 1): Repeat external High Fre- quency Eddy Current (HFEC) inspection of the center wing box lower skin and rear spar lower chord for any crack at unrepaired areas.(a)(b) - FIGURE 1 Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - CONDITION 1 (ACTION 2) (OPTION 2): Do an internal detailed inspec- tion of the center wing box lower skin and rear spar low- er chord for any crack at the unrepaired areas.(a)(b) - FIGURE 2 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 15 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition Do PART 3: CLOSE AC- CESS FOR EXTERNAL IN- SPECTION. - CONDITION 2 (OPTION 1): Repeat external High Fre- quency Eddy Current (HFEC) inspection of the center wing box lower skin and rear spar lower chord for any crack. (a)(b) CONDITION 2: NO CRACK FOUND DUR- ING OPTION 1 IN- SPECTION. Do PART 1: GET ACCESS FOR EXTERNAL INSPEC- TION. - - FIGURE 1 Do PART 3: CLOSE AC- CESS FOR EXTERNAL IN- SPECTION. - CONDITION 2 (OPTION 2): Do an internal detailed inspec- tion of the center wing box lower skin and rear spar low- er chord for any crack.(a)(b) Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - - FIGURE 2 Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - CONDITION 3 (ACTION 1): Contact The Boeing Compa- ny for repair instructions and do the repair. CONDITION 3: ANY CRACK FOUND DUR- ING OPTION 2 IN- SPECTION. Do PART 1: GET ACCESS FOR EXTERNAL INSPEC- TION. - CONDITION 3 (ACTION 2) (OPTION 1): Do an external High Frequen- cy Eddy Current (HFEC) in- spection of the center wing box lower skin and rear spar lower chord for any crack at unrepaired areas.(a)(b) - FIGURE 1 Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - CONDITION 3 (ACTION 2) (OPTION 2): Repeat internal detailed in- spection of the center wing box lower skin and rear spar lower chord for any crack at the unrepaired areas.(a)(b) - FIGURE 2 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 16 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 1: External or Internal Inspections of the Center Wing Box Lower Skin and Rear Spar Lower Chord Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - CONDITION 4 (OPTION 1): Do an external High Frequen- cy Eddy Current (HFEC) in- spection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) CONDITION 4: NO CRACK FOUND DUR- ING OPTION 2 IN- SPECTION. Do PART 1: GET ACCESS FOR EXTERNAL INSPEC- TION. - - FIGURE 1 Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - CONDITION 4 (OPTION 2): Repeat internal detailed in- spection of the center wing box lower skin and rear spar lower chord for any crack.(a)(b) Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - - FIGURE 2 (a) After the accomplishment of this OPTION, it is acceptable to change the repeat action from this OPTION to any other OPTION under this CONDITION. (b) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757- 57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. Table 2: Internal Ultrasonic Inspections of the Center Wing Box Lower Chord and Detailed Inspection of the Lower Skin at the Rear Spar Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - Do an internal ultrasonic in- spection of the center wing box lower chord and detailed inspection of the lower skin at the rear spar for any crack. All airplanes. - FIGURE 3 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 17 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 2: Internal Ultrasonic Inspections of the Center Wing Box Lower Chord and Detailed Inspection of the Lower Skin at the Rear Spar Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition - - CONDITION 5 (ACTION 1): CONDITION 5: ANY CRACK FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - CONDITION 5 (ACTION 2): Repeat internal ultrasonic in- spection of the center wing box lower chord and detailed inspection of the lower skin at the rear spar for any crack at the unrepaired areas.(a) - FIGURE 3 Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION - Repeat internal ultrasonic in- spection of the center wing box lower chord and detailed inspection of the lower skin at the rear spar for any crack. (a) CONDITION 6: NO CRACK FOUND. Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - - FIGURE 3 (a) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757- 57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. Table 3: Internal Detailed Inspection of the Center Wing Box Lower Skin and Rear Spar Lower Chord Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - Do an internal detailed inspec- tion of the center wing box lower skin and rear spar low- er chord for any crack. All airplanes. - FIGURE 4 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 18 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT Table 3: Internal Detailed Inspection of the Center Wing Box Lower Skin and Rear Spar Lower Chord Refer to the listed proce- dures in SB 757-57A0075 Original Issue or later ap- proved revisions as an ac- cepted procedure Method of Compliance Action Condition - - CONDITION 7 (ACTION 1): CONDITION 7: ANY CRACK FOUND. Contact The Boeing Compa- ny for repair instructions and do the repair. Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - CONDITION 7 (ACTION 2): Repeat internal detailed in- spection of the center wing box lower skin and rear spar lower chord for any crack at unrepaired areas.(a) - FIGURE 4 Do PART 4: CLOSE AC- CESS FOR INTERNAL IN- SPECTION. - Repeat internal detailed in- spection of the center wing box lower skin and rear spar lower chord for any crack. (a) CONDITION 8: NO CRACK FOUND. Do PART 2: GET ACCESS FOR INTERNAL INSPEC- TION. - - FIGURE 4 (a) It is not required to do the inspection in areas where a repair covers the affected inspection area if the repair meets the conditions that follow: 1. The repair is the corrective action to the crack condition identified in Requirements Bulletin 757- 57A0075 RB and installed after the original issue date of Requirements Bulletin 757-57A0075 RB. 2. The installed repair was approved by the Boeing Organization Designation Authorization (ODA) via a FAA Form 8100-9. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 19 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 1: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 1 SURFACE HFEC INSPECTION (SHEET 1 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 20 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 1: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 1 SURFACE HFEC INSPECTION (SHEET 2 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 21 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. More Data Qty Identification Name Task Step (a) 1 - LOWER SKIN Inspect 1 (b) 1 - LOWER CHORD Inspect 2 (a) Do an external surface HFEC inspection on the edge of lower skin at the rear spar for any crack in accor- dance with 757 NDT Manual Part 6, 51-00-01 or 757 NDT Manual Part 6, 51-00-19. (b) Do an external surface HFEC inspection on the edge of the rear spar lower chord for any crack in accor- dance with 757 NDT Manual Part 6, 51-00-01 or 757 NDT Manual Part 6, 51-00-19 as an accepted pro- cedure. FIGURE 1: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 1 SURFACE HFEC INSPECTION (SHEET 3 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 22 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 2: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 2 DETAILED INSPECTION (SHEET 1 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 23 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 2: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 2 DETAILED INSPECTION (SHEET 2 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 24 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. More Data Qty Identification Name Task Step (a) - - SEALANT Remove 1 (b) 1 - LOWER SKIN Inspect 2 (c) 1 - LOWER CHORD Inspect (d) - BMS 5-45 FUEL TANK SEALANT Apply 3 (d) - BMS 5-168 FAST CURE FUEL TANK SEALANT Apply (a) Remove any sealant from the lower skin or lower chord inspection area. Refer to 757-200 SRM 51-80- 01, 757-200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01 as an accepted procedure. (b) Do an internal detailed inspection of lower skin at the rear spar for any crack. (c) Do an internal detailed inspection of the rear spar lower chord for any crack. (d) In areas where the sealant was removed, apply sealant in accordance with 757-200 SRM 51-80-01, 757- 200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01. FIGURE 2: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - OPTION 2 DETAILED INSPECTION (SHEET 3 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 25 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 3: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL ULTRASONIC AND DETAIL INSPECTION (SHEET 1 OF 4) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 26 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 3: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL ULTRASONIC AND DETAIL INSPECTION (SHEET 2 OF 4) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 27 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. More Data Qty Identification Name Task Step (a) - - SEALANT Remove 1 (b) 1 - LOWER SKIN Inspect 2 (c) 1 - LOWER CHORD Inspect 3 (d) - BMS 5-45 FUEL TANK SEALANT Apply 4 (d) - BMS 5-168 FAST CURE FUEL TANK SEALANT Apply (a) Remove any sealant from the lower skin or lower chord inspection area. Refer to 757-200 SRM 51-80- 01, 757-200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01 as an accepted procedure. (b) Do an internal detailed inspection of the lower skin at the rear spar for any crack. FIGURE 3: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL ULTRASONIC AND DETAIL INSPECTION (SHEET 3 OF 4) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 28 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT More Data Qty Identification Name Task Step (c) Do an internal ultrasonic inspection of the center wing box rear spar lower chord for any crack in accordance with 757 NDT Manual Part 4 57-10-01. (d) In areas where the sealant was removed, apply sealant in accordance with 757-200 SRM 51-80-01, 757- 200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01. FIGURE 3: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL ULTRASONIC AND DETAIL INSPECTION (SHEET 4 OF 4) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 29 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 4: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL DETAILED INSPECTION (SHEET 1 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 30 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT FIGURE 4: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL DETAILED INSPECTION (SHEET 2 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 31 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure. More Data Qty Identification Name Task Step (a) - - SEALANT Remove 1 (b) 1 - LOWER SKIN Inspect 2 (c) 1 - LOWER CHORD Inspect (d) - BMS 5-45 FUEL TANK SEALANT Apply 3 (d) - BMS 5-168 FAST CURE FUEL TANK SEALANT Apply (a) Remove any sealant from the lower skin or lower chord inspection area. Refer to 757-200 SRM 51-80- 01, 757-200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01 as an accepted procedure. (b) Do an internal detailed inspection of lower skin at the rear spar for any crack. (c) Do an internal detailed inspection of the rear spar lower chord for any crack. (d) In areas where the sealant was removed, apply sealant in accordance with 757-200 SRM 51-80-01, 757- 200PF SRM 51-80-01, 757-200CB SRM 51-80-01 or 757-300 SRM 51-80-01. FIGURE 4: CENTER WING BOX - REAR SPAR, LOWER SKIN AND LOWER CHORD - INTERNAL DETAILED INSPECTION (SHEET 3 OF 3) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: August 25, 2021 757-57A0075 RB 32 of 32 REQUIREMENTS BULLETIN 757-57A0075 ALERT ALERT