# Boeing Alert Requirements Bulletin 727-53A0235 RB: No revision named - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2018-0452; AD 2018-20-05 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Requirements Bulletin 727-53A0235 RB](https://openairdocs.org/service-documents/boeing/727-53a0235-rb.md) - Title as filed: RB 727-53A0235-00-- - Pages: 18 - PDF: https://openairdocs.org/files/sha256/2c/2d/2c2d685c02b1ad5c0dcbae66895b21e97edc9205f98ba7397bd6efd7d9f411d3 - Page: https://openairdocs.org/service-documents/boeing/727-53a0235-rb/file/2c2d685c02b1 ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Commercial Airplanes 727 Requirements Bulletin ALERT Number: 727-53A0235 RB Original Issue: October 12, 2017 ATA System: 5311 SUBJECT: FUSELAGE - Body Station 259.5 - Frame Inspection From The First Stiffener Above Stringer S-10 to S-13, Left and Right Side. Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991ECCN: BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2017 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, Poseidon and Boeing liveries are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing. Original Issue: October 12, 2017 727-53A0235 RB 1 of 18 2.0 ### Page 2 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 2 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT BLANK PAGE ### Page 3 Table of Contents 1. EFFECTIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 A. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 B. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. CONCURRENT REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. COMPLIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. APPROVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 A. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 B. Work Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 FIGURE 1: LEFT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 . . . . . . . . . . . . . . . . . . . . . . . . . . 13 FIGURE 2: RIGHT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 3 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 4 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 4 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT BLANK PAGE ### Page 5 Commercial Airplanes 727 Requirements Bulletin ALERT Number: 727-53A0235 RB Original Issue: October 12, 2017 ATA System: 5311 SUBJECT: FUSELAGE - Body Station 259.5 - Frame Inspection From The First Stiffener Above Stringer S-10 to S-13, Left and Right Side. THIS DOCUMENT IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS DOCUMENT TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS DOCUMENT TO THE NEW OWNER. 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. 1. EFFECTIVITY A. Airplanes This bulletin is applicable to all 727-100/100C/200/200F, 727C Airplanes, line numbers 1 through 1832. B. Spares Affected None. 2. CONCURRENT REQUIREMENTS None. 3. COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to Requirements Bulletin 727-53A0235 RB. The Airworthiness Directive will make the compliance tasks and times given in Requirements Bulletin 727-53A0235 RB mandatory. Do the required actions in accordance with the Accomplishment Instructions. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 5 of 18 ### Page 6 Table 1: High Frequency Eddy Current (HFEC) and Low Frequency Eddy Current (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S-13 left and right side for any crack. Repeat Interval (Not to Exceed) Compliance TimeActionCondition -Within 1,000 flight cycles after the original issue date of Requirements Bulletin 727- 53A0235 RB. Do High Frequency Eddy Current (HFEC) Eddy Current (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S-13 left and right side for any crack. (a) All Airplanes. -Before further flight. (ACTION 1): Contact the Boeing Company for repair instructions and do the repair. CONDITION 1: ANY CRACK FOUND. 8,600 flight cycles.-(ACTION 2): Repeat High Frequency Eddy Current (HFEC) and Low Fre- quency Eddy Current (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S- 13 left and right side for any crack. (a) 8,600 flight cycles.-Repeat High Frequency Eddy Current (HFEC) and Low Fre- quency Eddy Current (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S- 13 left and right side for any crack. (a) CONDITION 2: NO CRACK FOUND. (a) It is not required to do the inspections in accordance with Requirements Bulletin 727-53A0235 RB in areas where an existing repair covers the inspection area and meets the following criteria: 1. The repair was installed after the Original Issue date of Requirements Bulletin 727-53A0235 RB. AND 2. The repair was approved by the Boeing Organization Designation Authorization (ODA) via an FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 6 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 7 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 Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service 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 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 7 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 8 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 8 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT BLANK PAGE ### Page 9 5. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION NOTE: 1. 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 727 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 727 Aircraft Maintenance Manual (AMM). 2. Use the approved fastener, process and material substitutions in accordance with SRM Chapter 51. 3. 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. 4. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 5. 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. 6. 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. 7. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 8. Use of colors in Figures is based on guidance from the ATA e-Business Program (ATA) iSpec 2200. 9. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 9 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 10 10. 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. 11. 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. 12. Boeing Service Letter 727-SL-51-041, 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. 13. 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 number or an OPTION number, do all of the ACTION numbers for that CONDITION number or OPTION number. B. WORK INSTRUCTIONS Actions Required for Compliance: 1. Requirements Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 10 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 11 Table 1: High Frequency Eddy Current (HFEC) and Low Frequency Eddy Current (LFEC) inspection of STA 259.5 bulkhead frame web from the first stiffener above S-10 to S-13 left and right side for any crack. Refer to the listed proce- dures in SB 727-53A0235 Original Issue or later approved revisions as an accepted procedure Method of ComplianceActionCondition ACCESS: PART 1: OPEN ACCESS TO THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 LEFT AND RIGHT SIDE. -Do High Frequency Eddy Current (HFEC) and Low Frequency Eddy Current (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S-13 left and right side for any crack. (a) All Airplanes. -FIGURE 1 and FIGURE 2. RESTORATION: PART 2: CLOSE ACCESS TO THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 LEFT AND RIGHT SIDE. -(ACTION 1): Contact the Boeing Compa- ny for repair instructions and do the repair. CONDITION 1: ANY CRACK FOUND. ACCESS: PART 1: OPEN ACCESS TO THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 LEFT AND RIGHT SIDE. -(ACTION 2): Repeat High Frequency Eddy Current (HFEC) and Low Frequency Eddy Cur- rent (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S- 13 left and right side for any crack. (a) -FIGURE 1 and FIGURE 2. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 11 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 12 Table 1: High Frequency Eddy Current (HFEC) and Low Frequency Eddy Current (LFEC) inspection of STA 259.5 bulkhead frame web from the first stiffener above S-10 to S-13 left and right side for any crack. Refer to the listed proce- dures in SB 727-53A0235 Original Issue or later approved revisions as an accepted procedure Method of ComplianceActionCondition RESTORATION: PART 2: CLOSE ACCESS TO THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 LEFT AND RIGHT SIDE. --CONDITION 2: NO CRACK FOUND. ACCESS: PART 1: OPEN ACCESS TO THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 LEFT AND RIGHT SIDE. -Repeat High Frequency Eddy Current (HFEC) and Low Frequency Eddy Cur- rent (LFEC) inspections of the STA 259.5 bulkhead frame web from the first stiffener above S-10 to S- 13 left and right side for any crack. (a) -FIGURE 1 and FIGURE 2. (a) It is not required to do the inspections in accordance with Requirements Bulletin 727-53A0235 RB in areas where an existing repair covers the inspection area and meets the following criteria: 1. The repair was installed after the Original Issue date of Requirements Bulletin 727-53A0235 RB. AND 2. The repair was approved by the Boeing Organization Designation Authorization (ODA) via an FAA Form 8100-9. Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 12 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 13 (OCR) REQUIREMENTS BULLETIN 727-53A0235 ALERT ALERT STA 259.5 S-10L - OUTER CHORD S-11L TYPICAL CRACK STIFFENER WEB A~ S-12L INNER CHORD + O STIFFENER S-13L - + + + INBD HFEC INSPECTION AREA A-A 2583519 FIGURE 1: LEFT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 1 OF 3) Original Issue: October 12, 2017 Export Controlled ECCN: 9E991 - BOEING 727-53A0235 RB PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 18 ### Page 14 (OCR) REQUIREMENTS BULLETIN 727-53A0235 ALERT ALERT OUTBOARD EDGE OF WEB WEB ® THIRD • FASTENER LOCATION • STIFFENER OUTER CHORD HFEC INSPECTION AREA LFEC INSPECTION AREA 2583515 FIGURE 1: LEFT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 2 OF 3) Original Issue: October 12, 2017 Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished 727-53A0235 RB Work - See page 1 for details. 14 of 18 ### Page 15 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 DataQtyIdentificationNameTaskStep (a)(d)165-16310-3Bulkhead Frame WebInspect1 (b)(d)165-16310-3Bulkhead Frame WebInspect2 (c)(d)165-16310-3Bulkhead Frame WebInspect3 (a) Do an HFEC inspection of the bulkhead frame web around the fasteners for any crack in accordance with 727 NDT Manual Part 6, 51-00-00 Procedure 4 or Procedure 23. Do the inspection from the aft side of the bulkhead frame. (b) Do an LFEC inspection of the bulkhead frame web around the fasteners through the stiffener for any crack in accordance with 727 NDT Manual Part 6, 51-00-26. Do the inspection from the aft side of the bulkhead frame. (c) Do an HFEC inspection of the bulkhead frame web along the edge of the bulkhead frame web stiffener from the outboard end to the location on the web that is adjacent to the third fastener on the stiffener when counted from the outboard edge for any crack in accordance with 727 NDT Manual Part 6, 51-00- 00 Procedure 4 or Procedure 23. Do the inspection from the aft side of the bulkhead frame. (d) It is not required to do the inspections in accordance with Requirements Bulletin 727-53A0235 RB in areas where an existing repair covers the inspection area provided: 1. The repair was installed after the Original Issue date of Requirements Bulletin 727-53A0235 RB. AND 2.The repair was approved by the Boeing Organization Designation Authorization (ODA) via an FAA Form 8100-9. FIGURE 1: LEFT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 3 OF 3) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 15 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT ### Page 16 (OCR) REQUIREMENTS BULLETIN 727-53A0235 ALERT ALERT STA 259.5 ~S-10R OUTER CHORD STIFFENER • S-11R WEB TYPICAL CRACK INNER CHORD - S-12R STIFFENER + + + - S-13R + HFEC INSPECTION AREA INBD A-A 2583520 FIGURE 2: RIGHT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 1 OF 3) Original Issue: October 12, 2017 Export Controlled ECCN: 9E991 - BOEING 727-53A0235 RB PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 16 of 18 ### Page 17 (OCR) REQUIREMENTS BULLETIN 727-53A0235 ALERT ALERT OUTBOARD WEB EDGE OF WEB THIRD FASTENER LOCATION STIFFENER INBD OUTER CHORD HFEC INSPECTION AREA LFEC INSPECTION AREA 2583518 FIGURE 2: RIGHT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 2 OF 3) Original Issue: October 12, 2017 PROPRIETARY - Copyright © Unpublished Export Controlled ECCN: 9E991 - BOEING 727-53A0235 RB Work - See page 1 for details. 17 of 18 ### Page 18 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 DataQtyIdentificationNameTaskStep (a)(d)165-16310-4Bulkhead Frame WebInspect1 (b)(d)165-16310-4Bulkhead Frame WebInspect2 (c)(d)165-16310-4Bulkhead Frame WebInspect3 (a) Do an HFEC inspection of the bulkhead frame web around the fasteners for any crack in accordance with 727 NDT Manual Part 6, 51-00-00 Procedure 4 or Procedure 23. Do the inspection from the aft side of the bulkhead frame. (b) Do an LFEC inspection of the bulkhead frame web around the fasteners through the stiffener for any crack in accordance with 727 NDT Manual Part 6, 51-00-26. Do the inspection from the aft side of the bulkhead frame. (c) Do an HFEC inspection of the bulkhead frame web along the edge of the bulkhead frame web stiffener from the outboard end to the location on the web that is adjacent to the third fastener on the stiffener when counted from the outboard edge for any crack in accordance with 727 NDT Manual Part 6, 51-00- 00 Procedure 4 or Procedure 23. Do the inspection from the aft side of the bulkhead frame. (d) It is not required to do the inspections in accordance with Requirements Bulletin 727-53A0235 RB in areas where an existing repair covers the inspection area provided: 1. The repair was installed after the Original Issue date of Requirements Bulletin 727-53A0235 RB. AND 2. The repair was approved by the Boeing Organization Designation Authorization (ODA) via an FAA Form 8100-9. FIGURE 2: RIGHT SIDE - HIGH FREQUENCY EDDY CURRENT (HFEC) AND LOW FREQUENCY EDDY CURRENT (LFEC) INSPECTIONS OF THE STA 259.5 BULKHEAD FRAME WEB FROM THE FIRST STIFFENER ABOVE S-10 TO S-13 (SHEET 3 OF 3) Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 12, 2017 727-53A0235 RB 18 of 18 REQUIREMENTS BULLETIN 727-53A0235 ALERTALERT --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.