# Boeing Alert Service Bulletin 747-53A2900: No revision named - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2019-0524, the docket of AD 2019-19-02. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Alert Service Bulletin 747-53A2900](https://openairdocs.org/service-documents/boeing/747-53a2900.md) - Title as filed: 747-53A2900-00-RB - Pages: 29 - PDF: https://openairdocs.org/files/sha256/9c/44/9c4458e0d0498ea26b6bf665b9ace7aff29348ce1c18ca84a8144a931d631aaf - Page: https://openairdocs.org/service-documents/boeing/747-53a2900/file/9c4458e0d049 ## 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 747 Requirements Bulletin ALERT Number: 747-53A2900 RB Original Issue: April 11, 2019 ATA System: 5300 SUBJECT: FUSELAGE - Section 42 - Underwing Longeron and Fuselage Skin Inspection 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: Copyright © 2019 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 Unpublished Work.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 Original Issue: April 11, 2019 747-53A2900 RB 1 of 29 3.0 ### Page 2 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 2 of 29 REQUIREMENTS BULLETIN 747-53A2900 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 B. Work Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 FIGURE 1: LEFT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION . 18 FIGURE 2: LEFT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 FIGURE 3: LEFT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION . . . . . . . . . 22 FIGURE 4: RIGHT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION . 24 FIGURE 5: RIGHT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 FIGURE 6: RIGHT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION . . . . . . . . . 28 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 3 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 4 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 4 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT BLANK PAGE ### Page 5 Commercial Airplanes 747 Requirements Bulletin ALERT Number: 747-53A2900 RB Original Issue: April 11, 2019 ATA System: 5300 SUBJECT: FUSELAGE - Section 42 - Underwing Longeron and Fuselage Skin Inspection 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 747-400, 747-400F Airplane(s), line number(s) 1308, 1313, 1315-1419 in 1 Group(s). B. Spares Affected None. 2. CONCURRENT REQUIREMENTS None. 3. COMPLIANCE The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to the Boeing Requirements Bulletin 747-53A2900 RB. The Airworthiness Directive will make the compliance tasks and times given in the Boeing Requirements Bulletin 747-53A2900 RB mandatory. Accomplish the required action(s), based on the applicable conditions in Table 1 and Table 2, in accordance with the 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. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 5 of 29 ### Page 6 TABLE 1: LEFT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Within 2,600 flight cycles af- ter the original issue date of Requirements Bulletin 747- 53A2900 RB. Before 6,600 to- tal flight cycles. Do a detailed inspection of the underwing longeron and the adja- cent fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. All Airplanes Do an ultrasonic and High Frequency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. Do an ultrasonic inspec- tion of the underwing longeron at STA 1000, S- 38 on the left side of the airplane for any crack. 2,600 flight cycles.-ACTION 1: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the left side of the air- plane for any crack. CONDITION 1: NO CRACK FOUND -ACTION 2: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. -ACTION 3: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the left side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 6 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 7 TABLE 1: LEFT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Before further flight.ACTION 1: Contact The Boeing Company for re- pair instructions and do the repair. CONDITION 2: ANY CRACK FOUND 2,600 flight cycles.-ACTION 2: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the left side of the air- plane for any crack. -ACTION 3: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. -ACTION 4: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the left side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 7 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 8 TABLE 2: RIGHT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Within 2,600 flight cycles from the release of the original is- sue of Require- ments Bulletin 747-53A2900 RB. Before 6,600 to- tal flight cycles. Do a detailed inspection of the underwing longeron and the adja- cent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. All Airplanes Do an ultrasonic and High Frequency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. Do an ultrasonic inspec- tion of the underwing longeron at STA 1000, S- 38 on the right side of the airplane for any crack. 2,600 flight cycles.-ACTION 1: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. CONDITION 3: NO CRACK FOUND -ACTION 2: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. -ACTION 3: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the right side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 8 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 9 TABLE 2: RIGHT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Repeat Interval (Not to Exceed) Compliance Time (Whichever Occurs Later) ActionCondition -Before further flight.ACTION 1: Contact The Boeing Company for re- pair instructions and do the repair. CONDITION 4: ANY CRACK FOUND 2,600 flight cycles.-ACTION 2: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. -ACTION 3: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. -ACTION 4: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the right side of the airplane for any crack. 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 for the 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 approved 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: April 11, 2019 747-53A2900 RB 9 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 10 Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 10 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT BLANK PAGE ### Page 11 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. 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 747 Structural Repair Manual, Chapter 51. — Values for airframe maintenance tasks are included in Chapter 20 of 747 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 747 Aircraft Maintenance Manual (AMM). — Non-standard torque values for maintenance tasks are included in the applicable installation step. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 11 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 12 5. 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. 6. 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. 7. Use the approved fastener, process and material substitutions in accordance with SRM Chapter 51. 8. 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. 9. 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. 10. The instructions in 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. 11. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. Refer to SOPM 20-50-01 for alternate full threaded fasteners (screws) needed for installation in this service bulletin. B. WORK INSTRUCTIONS 1. Requirements Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 12 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 13 TABLE 1: LEFT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Refer to the listed procedures in SB 747-53A2900 Original Issue or later approved re- visions as an ac- cepted proce- dure: Method of ComplianceActionCondition PART 1: LEFT SIDE OPEN AC- CESS. FIGURE 1Do a detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. All Airplanes -FIGURE 2Do an ultrasonic and High Frequency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. PART 2: LEFT SIDE CLOSE AC- CESS. FIGURE 3Do an ultrasonic inspec- tion of the underwing longeron at STA 1000, S- 38 on the left side of the airplane for any crack. PART 1: LEFT SIDE OPEN AC- CESS. FIGURE 1ACTION 1: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. CONDITION 1: NO CRACK FOUND -FIGURE 2ACTION 2: Repeat the ul- trasonic and High Frequen- cy Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. PART 2: LEFT SIDE CLOSE AC- CESS. FIGURE 3ACTION 3: Repeat the ul- trasonic inspection of the underwing longeron at STA 1000, S-38 on the left side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 13 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 14 TABLE 1: LEFT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Refer to the listed procedures in SB 747-53A2900 Original Issue or later approved re- visions as an ac- cepted proce- dure: Method of ComplianceActionCondition --ACTION 1:Contact The Boeing Company for re- pair instructions and do the repair. CONDITION 2: ANY CRACK FOUND PART 1: LEFT SIDE OPEN AC- CESS. FIGURE 1ACTION 2: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack. -FIGURE 2ACTION 3: Repeat the ul- trasonic and High Frequen- cy Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the left side of the airplane for any crack PART 2: LEFT SIDE CLOSE AC- CESS. FIGURE 3ACTION 4: Repeat the ul- trasonic inspection of the underwing longeron at STA 1000, S-38 on the left side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 14 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 15 TABLE 2: RIGHT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Refer to the listed procedures in SB 747-53A2900 Original Issue or later approved re- visions as an ac- cepted proce- dure: Method of ComplianceActionCondition PART 3: RIGHT SIDE OPEN AC- CESS. FIGURE 4Do a detailed inspection of the underwing longeron and the adja- cent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. All Airplanes -FIGURE 5Do an ultrasonic and High Frequency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. PART 4: RIGHT SIDE CLOSE AC- CESS. FIGURE 6Do an ultrasonic inspec- tion of the underwing longeron at STA 1000, S- 38 on the right side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 15 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 16 TABLE 2: RIGHT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Refer to the listed procedures in SB 747-53A2900 Original Issue or later approved re- visions as an ac- cepted proce- dure: Method of ComplianceActionCondition PART 3: RIGHT SIDE OPEN AC- CESS. FIGURE 4ACTION 1: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. CONDITION 3: NO CRACK FOUND -FIGURE 5ACTION 2: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. PART 4: RIGHT SIDE CLOSE AC- CESS. FIGURE 6ACTION 3: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the right side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 16 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 17 TABLE 2: RIGHT SIDE UNDERWING LONGERON AND FUSELAGE SKIN INSPECTIONS Refer to the listed procedures in SB 747-53A2900 Original Issue or later approved re- visions as an ac- cepted proce- dure: Method of ComplianceActionCondition --ACTION 1: Contact The Boeing Company for re- pair instructions and do the repair. CONDITION 4: ANY CRACK FOUND PART 3: RIGHT SIDE OPEN AC- CESS. FIGURE 4ACTION 2: Repeat the detailed inspection of the underwing longeron and the adjacent fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack. -FIGURE 5ACTION 3: Repeat the ultrasonic and High Fre- quency Eddy Current (HFEC) inspection of the fuselage skin at STA 1000, S-38 on the right side of the airplane for any crack PART 4: RIGHT SIDE CLOSE AC- CESS. FIGURE 6ACTION 4: Repeat the ultrasonic inspection of the underwing longeron at STA 1000, S-38 on the right side of the airplane for any crack. Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 17 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 18 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 STA 990 FUSELAGE SKIN S-38L. 10.0 0.0 00000000000 0000000000 000 EWD UNDERWING LONGERON WING LOWER SKIN DETAILED INSPECTION SKIN DETAILED INSPECTION UNDERWING LONGERON 2861611 FIGURE 1: LEFT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 Copyright © Unpublished 747-53A2900 RB Work - See page 1 for details. 18 of 29 ### Page 19 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Fuselage SkinInspect1 (b)--Underwing LongeronInspect2 (a) Do an external detailed inspection of the fuselage skin for any crack. (b) Do a detailed inspection of the underwing longeron for any crack. FIGURE 1: LEFT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 19 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 20 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 STA 990 FUSELAGE SKIN S-38L 00000000000 00000000000 10000 000 0000 UNDERWING WING LOWER SKIN ) SKIN LONGERON 2861815 FIGURE 2: LEFT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 747-53A2900 RB Copyright © Unpublished Work - See page 1 for details. 20 of 29 ### Page 21 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Fuselage SkinInspect1 (a) Do a High Frequency Eddy Current (HFEC) and ultrasonic inspection of the fuselage skin for any crack, in accordance with 747 NDT Manual Part 4, 53-10-01 (Figure 1, Sheet 5). FIGURE 2: LEFT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 21 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 22 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 FRONT SPAR UPPER CHORD STA 1000 • FRONT SPAR LOWER CHORD 9009 1009 00 000 UNDERWING LONGERON 2861823 FIGURE 3: LEFT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 Copyright © Unpublished 747-53A2900 RB Work - See page 1 for details. 22 of 29 ### Page 23 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Underwing LongeronInspect1 (a) Do an ultrasonic inspection of the underwing longeron for any crack in accordance with 747 NDT Manual Part 4, 53-10-21. FIGURE 3: LEFT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 23 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 24 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 STA 990 FUSELAGE SKIN 10.0 ‚- S-38R ooooo00000 10.0 0000000000 000 WING LOWER SKIN LONGERON UNDERWING 2 DETAILED INSPECTION SKIN DETAILED INSPECTION UNDERWING LONGERON 2861829 FIGURE 4: RIGHT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 747-53A2900 RB Copyright © Unpublished Work - See page 1 for details. 24 of 29 ### Page 25 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Fuselage SkinInspect1 (b)--Underwing LongeronInspect2 (a) Do an external detailed inspection of the fuselage skin for any crack. (b) Do a detailed inspection of the underwing longeron for any crack. FIGURE 4: RIGHT SIDE - UNDERWING LONGERON FUSELAGE SKIN - DETAILED INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 25 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 26 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 STA 990 FUSELAGE SKIN → S-38R 50000000000 1000000 0000000 WING LOWER SKIN UNDERWING • SKIN LONGERON 2861848 FIGURE 5: RIGHT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 747-53A2900 RB Copyright © Unpublished Work - See page 1 for details. 26 of 29 ### Page 27 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Fuselage SkinInspect1 (a) Do a High Frequency Eddy Current (HFEC) and ultrasonic inspection of the fuselage skin for any crack, in accordance with 747 NDT Manual Part 4, 53-10-01 (Figure 1, Sheet 5). FIGURE 5: RIGHT SIDE - FUSELAGE SKIN - ULTRASONIC AND HIGH FREQUENCY EDDY CURRENT (HFEC) INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 27 of 29 REQUIREMENTS BULLETIN 747-53A2900 ALERTALERT ### Page 28 (OCR) REQUIREMENTS BULLETIN 747-53A2900 ALERT ALERT STA 1000 FRONT SPAR UPPER CHORD STA 1000 FRONT SPAR LOWER CHORD •00 opo UNDERWING LONGERON 2861851 FIGURE 6: RIGHT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION (SHEET 1 OF 2) Original Issue: April 11, 2019 Export Controlled ECCN: 9E991 Copyright © Unpublished 747-53A2900 RB Work - See page 1 for details. 28 of 29 ### Page 29 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 each figure. More DataQtyIdentificationNameTaskStep (a)--Underwing LongeronInspect1 (a) Do an ultrasonic inspection of the underwing longeron for any crack in accordance with 747 NDT Manual Part 4, 53-10-21. FIGURE 6: RIGHT SIDE - UNDERWING LONGERON - ULTRASONIC INSPECTION (SHEET 2 OF 2) Export Controlled ECCN: 9E991 Copyright © Unpublished Work - See page 1 for details. Original Issue: April 11, 2019 747-53A2900 RB 29 of 29 REQUIREMENTS BULLETIN 747-53A2900 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.