# Boeing Service Bulletin A3515: U.S. DOT/FAA - Boeing Service Bulletin A3515, from page 13 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2011-1250; AD 2012-17-13 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Boeing Service Bulletin A3515](https://openairdocs.org/service-documents/boeing/a3515.md) - Title as filed: U.S. DOT/FAA - Boeing Service Bulletin A3515 - Pages: 41 - PDF: https://openairdocs.org/files/sha256/10/24/1024e89f4f72ffdcf6786513a656030160d50edaa87eac5651bfff1e7c5b6aad - Page: https://openairdocs.org/service-documents/boeing/a3515/file/1024e89f4f72 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 13 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 13 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT ROYAL AUSTRALIAN AIR FORCE (RAA) 1 07814–07815 07818 07820 4 09288 ROYAL JORDANIAN (RJA) 1 07078 08173 09003 09006 SKY AIR CARGO (SAC) 1 07201 SKY AVIATION (SYV) 1 05048 SKYMASTER AIRLINES (SKA) 1 07058 07077 07622 07801 08471 SOUTH AFRICAN AIRFORCE (SFF) 1 08004–08005 08008 08242 08244 SPANISH AIR FORCE (SAF) 1 05131 07405 07611 4 09289 TRANS MEDITERRANEAN AIRWAYS (TMA) 1 07041 07206 07453 08121–08122 TRISTAR (TYS) 1 08203 US AIR FORCE (USF) 1 05826 07057 07107 07212–07213 07254 07256 07258 07807–07810 07813 08222 08271 08313 08327 08407–08410 VENEZUELAN AIR FORCE (VEN) 1 08103–08104 WIMBI DIRA (WIM) 1 07262 WORLD AIRWAYS (GMR) 1 07075 IDENTIFICATION BY NUMBER Variable Group 02001–02020 1 02101–02121 1 02201–02207 1 ### Page 14 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 14 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 02301–02303 1 02401–02418 1 04001–04005 1 04020–04022 1 04101–04106 1 04201–04218 1 04271–04272 1 04301–04303 1 05001–05060 1 05101–05138 1 05201–05208 1 05301–05312 1 05401 1 05601–05605 1 05631–05635 1 05701–05703 1 05801–05802 1 05821–05827 1 05831–05833 1 05851–05854 1 05891–05892 1 05921–05923 1 05941–05942 1 05961–05970 1 06001–06002 1 06101 1 06401–06404 1 06451 4 06461 4 07001–07017 1 07041–07059 1 07071–07081 1 07101–07109 1 07181 1 07191 1 07201–07208 1 07210 1 07212–07215 1 07251–07271 1 Variable Group ### Page 15 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 15 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 07401–07407 1 07451–07458 1 07501–07504 1 07601–07626 1 07661–07662 1 07681–07684 1 07701–07702 1 07801–07821 1 07901–07907 1 08001–08008 1 08021 1 08051–08056 1 08071–08077 1 08101–08104 1 08121–08129 1 08141–08144 1 08151–08153 1 08171–08173 1 08191–08192 1 08201–08208 1 08209–08210 3 08221–08224 1 08241–08244 1 08251 1 08261 1 08271 1 08301–08320 1 08324–08330 1 08333 1 08401–08410 1 08451–08452 1 08471–08475 1 08501–08502 1 08551–08553 1 08581–08582 1 09001–09006 1 09101–09102 1 09103–09105 3 09106–09107 4 Variable Group ### Page 16 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 16 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 2. Spares Affected None. B. Concurrent Requirements None. C. Reason Boeing Service Related Problem (SRP) 707-SRP-55-0033 is related to this service bulletin. 1. ISSUE 1 - Stress Corrosion Cracking in Chords made from 7079 Aluminum in the Horizontal Stabilizer Rear Spar Boeing has received numerous reports of stress corrosion cracking in the chord segments made from 7079 aluminum in the 707 horizontal stabilizer rear spar. This is a material that is known to be susceptible to stress corrosion cracking. Early reports led to service bulletins 707-3356 and 707-3381. Incorporation of the modifications in those service bulletins has helped to slow the development of stress corrosion cracks. Service Bulletin 707A3515 continues the inspections of 707-3356 and 707-3381, but at shorter intervals, and in concurrence with the necessary actions that are the subject of Issue 2 below. The actions of this service bulletin addressing Issue 1 are necessary to adequately detect development of stress corrosion cracking. 2. ISSUE 2 - Early Fatigue Cracking in the Inboard Segment of the Upper Chord in the Horizontal Stabilizer Rear Spar 09161–09167 4 09201–09202 1 09203 2 09204 4 09221–09223 3 09227 4 09231 2 09232 3 09251 4 09271 4 09281 4 09286–09290 4 09411 4 09421 4 09438 4 09441 4 Variable Group ### Page 17 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 17 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT Boeing has received three reports of fatigue cracking in the upper chord of the horizontal stabilizer rear spar at a location near the side of the body. In all cases the fatigue prevention and fail safety improvement modifications of bulletin 707A3313 had been incorporated. The fatigue cracking is considered to be early in the life of the modified structure. The fatigue cracks are generated by frequent use of the airplanes for training flights that include multiple Touch and Goes. This frequent use of the airplane for this type of training has been most prevalent with military operators of commercial model 707 and 720 airplanes. The actions of this service bulletin are necessary to adequately detect early fatigue cracking. 3. CONFIGURATION The ability to move the horizontal stabilizer to a different airplane is of significance to Issue 1 and Issue 2. Parts made from 7079 have been discovered on airplanes not originally delivered with those parts. Therefore, to adequately address Issue 1, it is necessary to determine the horizontal stabilizer rear spar chord configuration on the airplane. It is also necessary to carefully maintain a record of that configuration until all 7079 horizontal stabilizer rear spar chord segments have been removed from the fleet. Regarding Issue 2, since horizontal stabilizers can be moved to different airplanes, it is necessary to implement the inspections for early fatigue cracking on all effective airplanes at the time stated in the 1.E Compliance section, regardless of the current usage of the airplane. D. Description Cycle Definition: To adequately account for in-flight training maneuvers, incorporate the cycle counting procedure defined in this service bulletin. Configuration Check: To Maintain configuration identity, determine the material for each horizontal stabilizer rear spar chord segment addressed by this service bulletin. Maintain the configuration identity indefinitely. Inspections: Complete the inspections for stress corrosion cracking and fatigue cracking in accordance with the methods and times stated in this service bulletin. Repair: Contact Boeing for repair instructions or replace the cracked part with a spare part made from 7075 aluminum. E. Compliance The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. ### Page 18 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 18 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT Boeing recommends the following: Table 1: Determine Flight Cycles and Material of Horizontal Stabilizer Structural Components Condition Action Compliance Time Repeat Interval (Not to Exceed) All airplanes Determine flight cycles as given in Accomplishment Instructions paragraph 3.B.1. Part 1. At time of service bulletin release - All airplanes Determine material of the left and right side horizontal stabilizer structural components as given in Accomplishment Instructions Paragraph 3.B.2. Part 2. Within 180 calendar days after the date of this service bulletin or before further flight when the horizontal stabilizer is replaced 180 calender days or 250 total flight cycles, whichever occurs first (a) Airplanes with horizontal stabilizer components made from 7075 as found in the Accomplishment Instructions Paragraph 3.B.2 Part 2 Inspect and repair the horizontal stabilizer structural components as given in Table 2. (b) -- Airplanes with horizontal stabilizer components made from 7079 as found in the Accomplishment Instructions Paragraph 3.B.2 Part 2 Inspect and repair the horizontal stabilizer structural components as given in Table 3. (b) -- (a) See Part 1 - Cycle Counting Procedure for definition of “cycles.” (b) If you have a mixture of 7075 components and 7079 components, use Tables 2 and 3. ### Page 19 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 19 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT Table 2: Inspect and Repair Horizontal Stabilizer Structural Components Made From 7075 Material Condition Action Compliance Time Repeat Interval (Not to Exceed) Airplanes with horizontal stabilizer components made from 7075 Inspect and repair the upper chord on the inboard end of the rear spar in the left and right side horizontal stabilizers from stabilizer station -13.179 to 92.55 as given in Accomplishment Instructions Paragraph 3.B.3. Part 3. Within 180 calendar days or 500 flight cycles after the date of this service bulletin, whichever occurs first (a) (c) or before further flight when the horizontal stabilizer is being replaced (c) 500 total flight cycles (a) The chord is replaced as given in Accomplishment Instructions Paragraph 3.B.6 Part 6 Inspect and repair the upper chord on the inboard end of the rear spar that was replaced from stabilizer station -13.179 to 92.55 as given in Accomplishment Instructions Paragraph 3.B.3. Part 3. (b) Within 4000 total flight cycles after the date of chord replacement (a) 500 total flight cycles (a) (a) See Part 1 - Cycle Counting Procedure for definition of “cycles.” (b) Continued inspections are only necessary for upper chords of the inboard end of the rear spar that are made from 7075. Continued inspections are not necessary for other spar chord components replaced with 7075 parts. (c) When you replace the chord as given in Accomplishment Instructions Paragraph 3.B.6 Part 6, you can defer the chord inspection given in Accomplishment Instructions Paragraph 3.B.3. Part 3 for a maximum of 4,000 total flight cycles. ### Page 20 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 20 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT Table 3: Inspect and Repair Horizontal Stabilizer Structural Components Made From 7079 Material Condition Action Compliance Time Repeat Interval (Not to Exceed) Airplanes with horizontal stabilizers that have rear spar chord compenents made from 7079 Inspect and repair the upper chord of the inboard side of the rear spar in the left and right side horizontal stabilizers from stabilizer station -13.179 to 92.55 as given in Accomplishment Instructions Paragraph 3.B.3. Part 3. Within 180 calendar days or 250 flight cycles after the date of this service bulletin, whichever occurs first (a) or before further flight when the horizontal stabilizer is being replaced 180 calender days or 250 total flight cycles, whichever occurs first (a) Inspect and repair the web flanges of the upper and lower chords of the rear spar in the left and right side horizontal stabilizers from stabilizer station 92.55 to 272.55 as given in Accomplishment Instructions Paragraph 3.B.4. Part 4. (b) Within 180 calendar days or 1000 flight cycles after the date of this service bulletin, whichever occurs first (a) or before further flight when the horizontal stabilizer is being replaced 180 calender days or 1000 total flight cycles, whichever occurs first (a) Inspect and repair the forward skin flanges of the upper and lower chords of the rear spar in the left and right side horizontal stabilizers from stabilizer station -13.179 to 272.55 as given in Accomplishment Instructions Paragraph 3.B.5. Part 5. (b) Airplanes with horizontal stabilizers that have rear spar chord components made from 7079 for which the Service Bulletin 707-3381 Part II - Preventative Modificaiton is not completed Do Boeing service bulletin 707- 3381 Part II - Preventative Modification as given in Accomplishment Instructions Paragraphs 3.B.4 Part 4 and 3.B.5 Part 5 or replace the chord as given in Accomplishment Instructions Paragraph 3.B.6 Part 6. Before further flight - (a) See Part 1 - Cycle Counting Procedure for definition of “cycles.” (b) Only those components made from 7079 material require the inspection and repair given in the Accomplishment Instructions Paragraphs 3.B.4. Part 4 and 3.B.5. Part 5. Components made from 7075 material do not require the inspection and repair given in the Accomplishment Instructions Paragraphs 3.B.4. Part 4 and 3.B.5. Part 5. ### Page 21 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 21 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT F. Approval This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin 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 service bulletin 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 service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. The Part 3 inspections of this service bulletin supersede and replace the 707 Supplemental Structural Inspection Document (SSID) inspections 55-A25-03, 55-A35-03 and 55-A45-03 mandated by Paragraph (A) of AD 85-12-01, Revision 1. The inspections contained in this service bulletin have been reviewed and approved as an alternate method of compliance to the requirements of Paragraph (A) of AD 85-12-01 for SSID item 55-A25-03, 55-A35-03 and 55-A45-03 covered by this service bulletin. All other provisions of AD 85-12-01 that are not specifically referenced above remain fully applicable and must be complied with. G. Manpower The table below shows an estimate of the task-hours necessary to do this service bulletin for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task-hour data if necessary. The estimate does not include lost time. These are some examples of lost time: — Time to adjust to the workplace — Time to schedule the work — Time to examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. Task Number of Persons Task Hours Elapsed Hours Open Access 2 1.0 0.5 Part 1 - (a) (a) Part 2 2 1.0(b) 0.5(b) Part 3 4 26.0 6.5 Part 4 4 32.0 8.0 Part 5 4 24.0 6.0 Part 6 (c) (c) (c) Close Access 2 1.0 0.5 TOTAL FOR EACH AIRPLANE (d) (d) (a) Considered Lost Time. Not able to estimate. ### Page 22 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 22 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT H. Weight and Balance Changes None. I. Electrical Load Data Not applicable. J. References 1. Existing Data: a. Engineering Change Memo PRR 18101-2RS. b. 707 Aircraft Maintenance Manual (AMM) 27-07-31. c. 707 Nondestructive Test (NDT) Manual D6-48023, Part 6, Subject 51-00-00, Figure 20. d. 707 Nondestructive Test (NDT) Manual D6-48023, Part 6, Subject 55-10-07, Figure 1, Figure 3 and Figure 7. e. 707 Supplemental Structural Inspection Document (SSID) D6-44860, Revision P, Item 55- A25-03, 55-A35-03 and 55-A45-03. f. 707, 720 Nondestructive Testing (NDT) Manual, Part 6, 51-00-00, Figure 20, Part 6, 55-10-07 Figure 1, Figure 3 and Figure 7. g. Boeing Service Bulletin 707-3356 - “STABILIZERS - HORIZONTAL STABILIZER REAR SPAR CHORD INSPECTION, MODIFICATION AND REPAIR”. h. Boeing Service Bulletin 707-3381 -”EMPENNAGE - HORIZONTAL STABILIZER REAR SPAR CHORD FORWARD FLANGE INSPECTION”. i. Service Related Problem (SRP) 707-SRP-55-0033. j. Standard Overhaul Practices Manual (SOPM) 20-41-05. 2. Data supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. (b) Covers conductivity test only, does not include maintenance record review. (c) No estimate is available. (d) No total is given because of the variability in time required for Part 1, Part 2 and Part 6 activities. Task Number of Persons Task Hours Elapsed Hours ### Page 23 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 23 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT K. Publications Affected None. L. Interchangeability and Intermixability of Parts Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. ### Page 24 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 24 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT BLANK PAGE ### Page 25 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 25 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 2. MATERIAL INFORMATION A. Material - Price and Availability None. B. Industry Support Information Boeing warranty remedies are not available for the inspection procedures given in this service bulletin. C. Parts Necessary For Each Airplane 1. Kits/Parts: None. 2. Parts and Materials Supplied by the Operator: 3. Parts Modified and Reidentified: None. Part Number / Specification QTY Name Notes 65-95600-887 1 Upper Chord, Inboard, Left Side (a) (c) (d) 65-95600-888 1 Upper Chord, Inboard, Right Side (a) (c) (e) 65-95600-701 1 Lower Chord, Inboard, Left Side (a) (c) (f) 65-95600-702 1 Lower Chord, Inboard, Right Side (a) (c) (g) 65C80665-165 1 Upper Chord, Outboard, Left Side (a) (c) (h) 65C380665-165 1 Lower Chord, Outboard, Right Side (a) (c) (h) 65C380665-166 1 Lower Chord, Outboard, Left Side (a) (c) (I) 65C80665-166 1 Upper Chord, Outboard, Right Side (a) (c) (i) BMS 3-23 Type II 1 Pint Corrosion Inhibiting compound (b) (a) Discard the existing part. (b) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (c) You can use the existing part to replace the new or changed part. If you use the existing part, you cancel the effect of the change given in this service bulletin. The existing part is interchangeable and intermixable with the new part. (d) 65-95600-887 is the same as 65-3321-27 plus two 66-11433-4 bushings. (e) 65-95600-888 is the same as 65-3321-28 plus two 66-11433-4 bushings. (f) 65-95600-701 is the same as 65-3322-15 plus two 69-38158-1 bushings plus two 69-38158-2 bushings. (g) 65-95600-702 is the same as 65-3322-16 plus two 69-38158-1 bushings plus two 69-38158-2 bushings. (h) 65C80665-165 is the same as 65-05201-3. (i) 65C80665-166 is the same as 65-05201-4. ### Page 26 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 26 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 4. Parts Removed and Not Replaced: None. D. Parts Necessary to Change Spares None. E. Special Tooling - Price and Availability The operator can supply the tools shown in Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin. Tool price and supply data are not given. F. Special Tooling Necessary to do this Service Bulletin See 707 NDT Manual D6-48023 Part 1, Section 51-01-00. ### Page 27 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 27 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. A Special Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. The examination is likely to make extensive use of specialized Inspection techniques and/or equipment. Intricate cleaning and substantial access or disassembly procedure may be required. 4. These work instructions refer to procedures included on 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 “as given in” are included in the instruction, the procedure in the Boeing document must be used. 5. Refer to Appendix A for configuration verification, inspection, material data results form. B. WORK INSTRUCTIONS 1. Part 1 - Cycle Counting Procedure a. Determine flight cycles. NOTE: The term “flight cycle” wherever stated in this bulletin is defined as any one of the following: 1. A complete flight cycle (takeoff and full stop landing). 2. Any touch-and-go cycle within a flight cycle for which the airplane makes a runway approach, with or without runway contact. 2. Part 2 - Configuration Records Inspection ### Page 28 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 28 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT a. Determine what material the left and right side horizontal stabilizer, rear spar, upper chords and lower chords on the inboard and outboard ends of the rear spar are made of using one of the following methods: (1) Review the airplane's maintenance records or the previously completed Appendix A data sheet to identify the location of the upper and lower chords on the horizontal stabilizer rear spar that are made from 7079. If the material cannot be conclusively determined, do step (2). (2) Do a conductivity test to determine whether each upper chord and lower chord on the horizontal stabilizer rear spar listed in Appendix A is made from 7079-T6 or 7075-T73511 material. Refer to 707, 720 NDT, Part 6, 51-00-00, Figure 20 dated April 5, 2004 as an accepted procedure. b. Optional. (1) Record the material of each upper chord and lower chord segment on the Appendix A data sheet. Describe any existing repairs in the “Comments” field. (2) Retain the Appendix A data sheet with the airplane records. 3. Part 3 - Chord Inspection - Horizontal Stabilizer - Rear Spar - Inboard - Upper Chord - Stabilizer Station -13.179 to 92.55e Upper Chords, Horizontal Stabilizer Rear Spar, Inboard Side, Made From 7075 and 7079 a. Do a special detailed inspection of the upper chord on the inboard side of the rear spar of the left and right side horizontal stabilizer as follows: (1) Inspect for cracks in the forward flange of the upper chord of the rear spar along the fasteners common to the skin and the upper chord. Inspect from the inboard edge of the inspar skin to 25.5 inches outboard of the inspar skin on the horizontal stabilizer. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 1, as an accepted procedure. (2) Inspect for cracks in the space between the inspar skin and the forward edge of the exposed upper surface of the upper chord of the rear spar. Inspect from the side of the body outboard towards Stabilizer Station 92.55. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 2, as an accepted procedure. (3) Inspect for cracks in the space between the trailing edge skin and the aft edge of the exposed upper surface of the upper chord of the rear spar. Inspect from the side of the body outboard to Stabilizer Station 92.55. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 2 as an accepted procedure. (4) Inspect for cracks in the aft flange of the upper chord of the rear ### Page 29 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 29 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT spar along the fasteners common to the skin and the upper chord. Inspect from the inboard edge of the inspar skin to 25.5 inches outboard of the inspar skin on the horizontal stabilizer. Refer to 707, 720 NDT, Part 6, 55-10-07 Figure 3, as an accepted procedure. (5) Inspect for cracks along the forward and aft edges of the exposed upper surface of the upper chord of the rear spar. Inspect from the side of the body outboard to Stabilizer Station 92.55. Refer to 707, 720 NDT, Part 6, 55-10-07 Figure 7, as an accepted procedure. b. If a crack is found: (1) Contact Boeing for repair instructions or (2) Replace the spar chord as given in Accomplishment Instructions Paragraph 3.B.6. Part 6. c. Apply corrosion inhibiting compound BMS 3-23 or equivalent to the exposed area of the upper chord. Refer to SOPM 20-41-05 as an accepted procedure. d. Put the airplane back to a serviceable condition. 4. Part 4 - Chord Inspection - Horizontal Stabilizer - Rear Spar - Upper and Lower Chord - Web Flange - Stabilizer Station 92.55 to 272.55 Upper and Lower Chords, Horizontal Stabilizer Rear Spar, Made From 7079 a. Remove and keep the elevator balance bay number 2 through number 5 panels. Refer to 707 AMM 27-07-31 as an accepted procedure. b. Remove and keep the cove shells and supporting structures as required to get access to the aft surface of the vertical flanges of the upper and lower chords of the horizontal stabilizer rear spar. c. Do a High Frequency Eddy Current (HFEC) inspection of the web flanges of the upper and lower chords on the inboard and outboard ends of the rear spar of the left and right side horizontal stabilizer between stabilizer station 92.55 and 272.55 for cracks as given in Figure 1. d. If a crack is found: (1) Replace the spar chord as given in Accomplishment Instructions Paragraph 3.B.6. Part 6 or (2) Complete steps (a) and (b) that follow: (a) Determine if the crack meets the limits defined in service bulletin 707-3356 and has been repaired according to service bulletin 707-3356. ### Page 30 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 30 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 1) For each crack that meets the limits of service bulletin 707-3356, Part III - Repair, Notes (a) and (b), contact Boeing for new repair instructions. 2) For each crack that has been repaired according to service bulletin 707-3356, Part III - Repair Paragraph C, determine if the crack still meets the limits of service bulletin 707-3356, Part III - Repair Paragraph C, and determine if the crack meets the following supplemental limits: {a} The crack path must be within the limits as given in Figure 1, View B-B. {b} The crack must terminate in an existing fastener hole. {c} There must be two or more fastener locations in the repair area as given in Figure 1, View B-B that have no cracks indicated in the adjacent spaces. {d} A stiffener bay with a crack in the upper chord must not also have a crack in the upper or lower chord of either of the adjacent stiffener bays. {e} A stiffener bay with a crack in the lower chord must not also have a crack in the upper or lower chord of either of the adjacent stiffener bays. 3) For a crack that meets the limits of service bulletin 707- 3356, Part III - Repair Paragraph C, but is not repaired as given in service bulletin 707-3356, Part III - Repair Paragraph C, accomplish the repair as given in service bulletin 707-3356, Part III - Repair Paragraph C. Obey the supplemental limits that follow: {a} The crack path must be within the limits as given in Figure 1, View B-B. {b} They crack must terminate in an existing fastener hole. {c} There must be two or more fastener locations in the repair area as given in Figure 1, View B-B that have no crack indicated in the adjacent spaces. {d} A stiffener bay with a crack in the upper chord must have no crack in the upper or lower chord of either of the adjacent stiffener bays. {e} A stiffener bay with a crack in the lower chord must have no crack in the upper or lower chord of either of the adjacent stiffener bays. ### Page 31 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 31 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT 4) For a crack that meets the limits of service bulletin 707- 3356, Part III - Repair Paragraph D, accomplish the repair according to service bulletin 707-3356, Part III - Repair Paragraph D, unless already accomplished. 5) For a crack that does not meet the limits defined in paragraph (1)(b) through (1)(d), contact Boeing for new repair instructions. (b) Determine if all 7079 upper and lower chord segments installed on the horizontal stabilizer have had Service Bulletin 707-3356 Part II, Group 1 Preventative Modification done. If not yet accomplished, do the Service Bulletin 707-3356 Part II, Group 1 Preventative Modification on all 7079 chord segments still installed on the horizontal stabilizer. NOTE: Service Bulletin 707-3356 Part II, Group 1 Preventative Modification is applicable to airplanes for which all chord segments (upper and lower inboard, upper and lower outboard) are made from 7079. It is therefore inclusive of all configurations where 7079 chord segments remain. Since 7079 chords may have been replaced with 7075 chords, it is only necessary to do the modification where the 7079 chord segments are identified. e. Apply corrosion inhibiting compound BMS 3-23 or equivalent to the exposed area of the horizontal stabilizer rear spar chords. Refer to SOPM 20-41-05 as an accepted procedure. f. Restore the airplane to a serviceable condition. 5. Part 5 - Chord Inspection - Horizontal Stabilizer - Rear Spar - Upper and Lower Chord - Forward Skin Flange - Stabilizer Station -13.179 to 272.55 Upper and Lower Chords of the Horizontal Stabilizer Rear Spar Made From 7079 a. Remove and keep the elevator balance bay number 0 through number 5 panels. Refer to 707 AMM 27-07-31 as an accepted procedure. b. Do a Low Frequency Eddy Current (LFEC) inspection of the forward skin flange of the upper chord on the outboard end of the rear spar of the left and right side horizontal stabilizer between stabilizer station 182.55 and 272.55 for cracks as given in Figure 2. c. Do a LFEC inspection of the forward skin flange of the upper chord on the inboard end of the rear spar of the left and right side horizontal stabilizer between stabilizer station 92.55 and 182.55 for cracks as given in Figure 3. d. Do a LFEC inspection of the forward skin flange of the lower chord on the outboard end of the rear spar of the left and right side horizontal ### Page 32 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 32 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT stabilizer between stabilizer station 182.55 and 272.55 for cracks as given in Figure 4. e. Do a LFEC inspection of the forward skin flange of the lower chord on the inboard end of the rear spar of the left and right side horizontal stabilizer between stabilizer station 92.55 and 182.55 for cracks as given in Figure 5. f. Do a LFEC inspection of the forward skin flange of the lower chord on the inboard end of the rear spar of the left and right side horizontal stabilizer between stabilizer station -13.179 and 92.55 for cracks as given in Figure 6. g. If a crack is found: (1) Replace the lower chord as given in Accomplishment Instructions Paragraph 3.B.6. Part 6 or (2) Complete steps (a) and (b) that follow: (a) Contact Boeing for repair instructions. (b) Determine if all 7079 upper and lower chord segments installed on the horizontal stabilizer have had Service Bulletin 707-3381 Part II - Preventative Modification accomplished. If not yet accomplished, do the Service Bulletin 707-3381 Part II - Preventative Modification on all 7079 chord segments still installed on the horizontal stabilizer. NOTE: Service Bulletin 707-3381 Part II - Preventative Modification is applicable to airplanes for which all chord segments (upper and lower inboard, upper and lower outboard) are made from 7079. It is therefore inclusive of all configurations where 7079 chord segments remain. Since 7079 chords may have been replaced with 7075 chords, it is only necessary to do the modification where the 7079 chord segments are identified. h. Apply corrosion inhibiting compound BMS 3-23 or equivalent to exposed area of the upper and lower chords of the horizontal stabilizer rear spar. Refer to SOPM 20-41-05 as an accepted procedure. i. Restore the airplane to a serviceable condition. 6. Part 6 - Chord Replacement a. Replace the chord with the part number given in the Material Information section, Paragraph 2.C.2, Parts and Materials Supplied by the Operator. b. Contact Boeing if chord replacement instructions are needed. ### Page 33 December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 33 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT c. Optional. (1) Upon completion of chord replacement, revise the data on the Appendix A data sheet to match the chord configuration currently on the airplane. (2) Retain the updated Appendix A data sheet with the airplane records. ### Page 34 FIGURE 1: HORIZONTAL STABILIZER - REAR SPAR - UPPER AND LOWER - INBOARD AND OUT- BOARD - CHORD WEB FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 272.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 34 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 1: HORIZONTAL STABILIZER - REAR SPAR - UPPER AND LOWER - INBOARD AND OUTBOARD - CHORD WEB FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 272.55 - INSPECTION BAY NO.3 BALANCE BAY NO.2 BALANCE BAY NO.1 BALANCE BAY NO.0 BALANCE BAY NO.5 BALANCE BAY NO.4 BALANCE A A 182.55 STAB STA 137.55 STAB STA STAB STA 92.55 47.55 STAB STA 272.55 STAB STA STAB STA 227.55 CHORD B B LEFT HORIZONTAL STABILIZER SHOWN, RIGHT OPPOSITE A-A ELEVATOR REAR SPAR FRONT SPAR HINGE 1 1 2 2 496234 (SHEET 1 OF 2) ### Page 35 FIGURE 1: HORIZONTAL STABILIZER - REAR SPAR - UPPER AND LOWER - INBOARD AND OUT- BOARD - CHORD WEB FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 272.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 35 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Access Balance Bay Number 2, 3, 4 and 5 - - 2 Inspect Chord Web Flange - 2 See Table 1.(a) (a) Do a High Frequency Eddy Current (HFEC) inspection of the left and right side horizontal stabilizer rear spar upper and lower inboard and outboard chord web flange between stabilizer station 92.55 and 272.55 for any cracking. Use a pencil probe to scan the aft surface of the chord vertical flange between fasteners and along the tangent line of the flange fillet. Refer to 707, 720 NDT, Part 6, 51-00-00, Figure 4 as an accepted procedure. Table 1 7079 Chord Segment Balance Bay to Inspect Upper Inboard 2,3 Lower Inboard 2,3 Upper Outboard 4,5 Lower Outboard 4,5 B-B 2 2 FASTENER TO FARTHEST POINT OF CRACK 0.125 MAXIMUM FROM CENTERLINE OF FASTENER TO NEAREST POINT OF CRACK 0.22 MINIMUM FROM CENTERLINE OF FASTENER REPAIRFASTENEREXISTING UPPER CHORD STIFFENERSTIFFENER CRACK REAR SPAR UPPER CHORD REAR VIEW STIFFENER BAY REPAIR AREA WEB D64427 (SHEET 2 OF 2) ### Page 36 FIGURE 2: HORIZONTAL STABILIZER - REAR SPAR - UPPER OUTBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 182.55 TO STABILIZER STATION 272.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 36 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 2: HORIZONTAL STABILIZER - REAR SPAR - UPPER OUTBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 182.55 TO STABILIZER STATION 272.55 - INSPECTION The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Inspect Forward Skin Flange - 2 (a) (a) Do a Low Frequency Eddy Current (LFEC) inspection of the left and right side horizontal stabilizer rear spar upper outboard chord forward skin flange between stabilizer station 182.55 and 272.55 for any cracking. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 8 as an accepted procedure. A A FWD INBD PANEL NO.4 BALANCE BAY PANEL NO.5 BALANCE BAY UPPER CHORD REAR SPAR RIGHT OPPOSITE LEFT HORIZONTAL STABILIZER UPPER SURFACE SHOWN, A-A 272.55 1 182.55263.55 UPPER INSPAR SKINRIB STAB STA STAB STASTAB STA 496266 (SHEET 1 OF 1) ### Page 37 FIGURE 3: HORIZONTAL STABILIZER - REAR SPAR - UPPER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 182.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 37 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 3: HORIZONTAL STABILIZER - REAR SPAR - UPPER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 182.55 - INSPECTION The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Inspect Forward Skin Flange - 2 (a) (a) Do a Low Frequency Eddy Current (LFEC) inspection of the left and right side horizontal stabilizer rear spar upper inboard chord forward skin flange between stabilizer station 92.55 and 182.55 for any cracking. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 8 as an accepted procedure. A A BALANCE BAY PANEL NO.2FWD INBD UPPER CHORD REAR SPAR PANEL NO.3 BALANCE BAY RIGHT OPPOSITE LEFT HORIZONTAL STABILIZER UPPER SURFACE SHOWN, A-A 173.55 STAB STA 1 INSPAR SKIN 182.55 STAB STA UPPER 92.55 STAB STA 496279 (SHEET 1 OF 1) ### Page 38 FIGURE 4: HORIZONTAL STABILIZER - REAR SPAR - LOWER OUTBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 182.55 TO STABILIZER STATION 272.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 38 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 4: HORIZONTAL STABILIZER - REAR SPAR - LOWER OUTBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 182.55 TO STABILIZER STATION 272.55 - INSPECTION The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Inspect Forward Skin Flange - 2 (a) (a) Do a Low Frequency Eddy Current (LFEC) inspection of the left and right side horizontal stabilizer rear spar lower outboard chord forward skin flange between stabilizer station 182.55 and 272.55 for any cracking. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 8 as an accepted procedure. A A FWD INBD LOWER CHORD REAR SPAR LEFT HORIZONTAL STABILIZER LOWER SURFACE SHOWN, RIGHT OPPOSITE A-A 1 LOWER INSPAR SKIN 182.55 STAB STA 263.55 STAB STA272.55STAB STA 496285 (SHEET 1 OF 1) ### Page 39 FIGURE 5: HORIZONTAL STABILIZER - REAR SPAR - LOWER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 182.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 39 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 5: HORIZONTAL STABILIZER - REAR SPAR - LOWER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION 92.55 TO STABILIZER STATION 182.55 - INSPECTION The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Inspect Forward Skin Flange - 2 (a) (b) (a) Do a Low Frequency Eddy Current (LFEC) inspection of the left and right side horizontal stabilizer rear spar lower inboard chord forward skin flange between stabilizer station 92.55 and 182.55 for any cracking. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 8 as an accepted procedure. (b) Exclude inspection of areas not accessible due to interference with any vortex generators mounted on the lower surface. However, if any cracks are found at any of the first six (6) inspectable fasteners on either side of the vortex generator, remove the vortex generator and inspect all fastener locations. A A LOWER CHORD REAR SPAR INBD FWD 1 LOWER INSPAR SKIN 92.55 STAB STA 173.55 STAB STA 182.55 STAB STA LEFT HORIZONTAL STABILIZER LOWER SURFACE SHOWN, A-A RIGHT OPPOSITE 496290 (SHEET 1 OF 1) ### Page 40 FIGURE 6: HORIZONTAL STABILIZER - REAR SPAR - LOWER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION -13.179 TO STABILIZER STATION 92.55 - INSPECTION December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 40 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT FIGURE 6: HORIZONTAL STABILIZER - REAR SPAR - LOWER INBOARD CHORD - FORWARD SKIN FLANGE - STABILIZER STATION -13.179 TO STABILIZER STATION 92.55 - INSPECTION The step numbers shown below agree with the numbers shown in the circle symbols in the figure. STEP TASK NAME IDENTIFICATION QTY MORE DATA 1 Inspect Forward Skin Flange - 2 (a) (b) (a) Do a Low Frequency Eddy Current (LFEC) inspection of the left and right side horizontal stabilizer rear spar lower inboard chord forward skin flange between stabilizer station -13.179 and 92.55 for any cracking. Refer to 707, 720 NDT, Part 6, 55-10-07, Figure 8 as an accepted procedure. (b) Exclude inspection of areas not accessible due to interference with any vortex generators mounted on the lower surface. However, if any cracks are found at any of the first six (6) inspectable fasteners on either side of the vortex generator, remove the vortex generator and inspect all fastener locations. A A LOWER CHORD REAR SPAR INBD FWD STAB STA -13.1791 STAB STA 92.55 LOWER INSPAR SKIN STAB STA 83.55 LEFT HORIZONTAL STABILIZER LOWER SURFACE SHOWN, A-A RIGHT OPPOSITE 496349 (SHEET 1 OF 1) ### Page 41 APPENDIX A: CONFIGURATION VERIFICATION - INSPECTION RESULTS FORM - MATERIAL DATA December 19, 2007 A3515 BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. 41 of 41 BOEING SERVICE BULLETIN A3515 ALERT ALERT APPENDIX A: CONFIGURATION VERIFICATION - INSPECTION RESULTS FORM - MATERIAL DATA AIRPLANE REGISTRY: FLIGHT HOURS: FLIGHT CYCLES: LEFT SIDE Horizontal Stabilizer Stabilizer Part Number (a): Stabilizer Serial Number (a): Spar Chord Segment Location Spar Chord Material (b): (from Part 2 - Configuration Check) Upper Inboard Side of Body to SSTA 182.55 Lower Inboard Side of Body to SSTA 182.55 Upper Outboard SSTA 182.55 to Stabilizer Tip Lower Outboard SSTA 182.55 to Stabilizer Tip RIGHT SIDE Horizontal Stabilizer Stabilizer Part Number (a): Stabilizer Serial Number (a): Spar Chord Segment Location Spar Chord Material (b) (from Part 2 - Configuration Check) Upper Inboard Side of Body to SSTA 182.55 Lower Inboard Side of Body to SSTA 182.55 Upper Outboard SSTA 182.55 to Stabilizer Tip Lower Outboard SSTA 182.55 to Stabilizer Tip (a) Record the horizontal stabilizer part number and serial number as recorded on the data plate. (b) Record spar chord material, 7079-T6 or 7075-T73511, as determined from maintenance record review, or electrical conductivity test. For the electrical conductivity test refer to 707 Non-Destructive Testing (NDT) Manual D6-48023 Part 6, 51-00-00, Figure 20, dated April 5, 2004, and Boeing Process Specification BAC5946, Table I, Page 12, Revision (AA) dated July 9, 2001. Comments: --- 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.