### Commercial **Airplanes** 

# 747

Service Bulletin **Number: 747-71A2329**  Original Issue: September 27, 2013 Revision 1: May 28, 2015 ATA System: 7121 **SUBJECT:** POWER PLANT - Engine Mounts - Forward Engine Mount Barrel Nut Inspection and

Replacement 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. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET Copyright © 2013 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 Unpublished Work.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: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 1of42 6.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 2of42 **BOEING SERVICE BULLETIN 747-71A2329**

BLANK PAGE**Table of Contents**

Revision Transmittal Sheet

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Summary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1. PLANNING INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 B. Concurrent Requirements

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 C. Reason

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 D. Description

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 E. Compliance

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 F. Approval

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 G. Manpower

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 H. Weight and Balance Changes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 I. Electrical Load Data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 J. References

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Existing Data:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Data Supplied with this Service Bulletin:

. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3. Installation Drawings Used in the Preparation of this Service Bulletin:

. . . . . . . . . . . 17 K. Publications Affected

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 L. Interchangeability and Intermixability of Parts

. . . . . . . . . . . . . . . . . . . . . . . . . . . 18 M. Software Accomplishment Summary

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. MATERIAL INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. Material - Price and Availability

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. Industry Support Information

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 C. Parts Necessary for Each Airplane

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1. Kits/Parts

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2. Parts and Materials Supplied by the Operator

. . . . . . . . . . . . . . . . . . . . . . . . 19 3. Parts Modified and Reidentified

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4. Parts Removed and Not Replaced

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 D. Parts Necessary to Change Spares

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 E. Special Tooling - Price and Availability

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 F. Special Tooling Necessary to do this Service Bulletin

. . . . . . . . . . . . . . . . . . . . . . . 20 3. ACCOMPLISHMENT INSTRUCTIONS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. GENERAL INFORMATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. WORK INSTRUCTIONS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 FIGURE 1: FORWARD ENGINE MOUNT BARREL NUT ULTRASONIC (UT) INSPECTION

. . . . . 25 FIGURE 2: FORWARD ENGINE MOUNT BOLT AND BARREL NUT REPLACEMENT

. . . . . . . . 28 APPENDIX A: INSPECTION RESULTS REPORT

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE

. . . . . . . . . . . . . . . . . . . . . . 36

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 3of42 **BOEING SERVICE BULLETIN 747-71A2329**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 4of42 **BOEING SERVICE BULLETIN 747-71A2329**

BLANK PAGE

### Commercial **Airplanes** 

# 747

Service Bulletin **Revision Transmittal Sheet Number:**  **747-71A2329** Original Issue: September 27, 2013 Revision 1: May 28, 2015 ATA System: 7121 **SUBJECT:** POWER PLANT - Engine Mounts - Forward Engine Mount Barrel Nut Inspection and

Replacement This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-24-12 is related to this service bulletin. Effects of this Issue on airplanes on which original release was previously done: See Paragraph 1.D., Descriptionfor more information. Airplanes RC009, RC021, RC035-RC040, RC066, RC510-RC513, RC526-RC528, RC550, RC564, RC573, RC641-RC642, and RC671-RC672, were removed from this service bulletin effectivity because these airplanes received the intent of the change provided in Service Bulletin 747-71-2332 prior to delivery. **REASON FOR REVISION** This revision is sent to advise affected operators that airplanes RC009, RC021, RC035-RC040, RC066, RC510-RC513, RC526-RC528, RC550, RC564, RC573, RC641-RC642, and RC671-RC672, were removed from this service bulletin effectivity because these airplanes received the intent of the change provided in Service Bulletin 747-71-2332 prior to delivery. New redesigned SL4750NA forward engine mount barrel nuts were incorporated in production with Line Number 1489 and Line Number 1500 and on. Also, compliance times were changed in Table 1: Inspection of the Barrel Nuts on the Forward Engine Mount. These sections were changed: 1. In Section 1.A., Effectivity, table was changed to show updated effectivity. 2. In Section 1.E., Compliance, table was changed to show updated compliance times. 3. In Section 1.J., References, Boeing Service Bulletin 747-71-2332 and AD 2013-24-12 were added. 4. In Figure 1 and Figure 2 illustrations were changed. 5. In Section 1.F.,. Approval, AD AMOC paragraph was added. 6. In Section 1.E., Compliance, existing paragraph was replaced with AD paragraph. 7. On Summary Page in Compliance, existing paragraph was replaced with AD paragraph.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 5of428. In Appendix A, Steps 4 and 10 were changed.

The data given in Information Notice 747-71A2329 IN 01 is included in this revision. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity and format changes, to show the location of all content changes. Pages with no vertical lines have no changes. **REVISION HISTORY** September 27, 2013 Original Issue: May 28, 2015 Revision 1:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 6of42 **BOEING SERVICE BULLETIN 747-71A2329**

### Commercial **Airplanes** 

# 747

Service Bulletin

**Summary Number:**  **747-71A2329** Original Issue: September 27, 2013 Revision 1: May 28, 2015 ATA System: 7121 **SUBJECT:** POWER PLANT - Engine Mounts - Forward Engine Mount Barrel Nut Inspection and

Replacement **CONCURRENT REQUIREMENTS** None. **BACKGROUND** Accomplishment of this service bulletin will make sure the barrel nuts on the forward engine mount do not have a crack. A crack on both sides of the barrel nut will cause complete failure of the barrel nut. Complete failure of two or more barrel nuts on the same engine reduces the load capacity of the forward engine mount and could result in separation of an engine from the airplane. Separation of an inboard engine under power could result in loss of control of the airplane. An operator reported that while replacing the No.2 engine, the Non Destructive Test (NDT) inspection of the barrel nuts on the forward engine mount revealed cracks on 2 out of 4 barrel nuts. The operator also discovered 1 cracked barrel nut on the No. 1 engine. This is the first reported occurrence on the 747-8. Also, The Boeing Company did a NDT inspection of barrel nuts on a flight test airplane. There were 2 barrel nuts where a crack had initiated on the No. 2 engine. These barrel nuts are located at the forward end of the strut box and are used to fasten the forward engine mount to the strut. A barrel nut with a crack on one side will still be able to carry ultimate load. A crack on both sides of the barrel nut will cause complete failure of the barrel nut. Boeing has not received any reports of a barrel nut with a crack on both sides. This service bulletin gives instructions to inspect the barrel nuts on the forward engine mount and replace barrel nuts that have a crack. This will prevent the complete failure of barrel nuts that could result in the separation of an engine from the airplane. This service bulletin also has operators report the results of barrel nut inspections to Boeing, as well as sending any cracked parts to Boeing. The inspection reports will be used in the root cause investigation of this issue. Boeing will issue a service bulletin for terminating action of this issue after completion of the root cause investigation. Boeing Fleet Team Digest (FTD)747 FTD 71-13001is related to this service bulletin. Boeing Service Related Problem (SRP)747-8-SRP-71-0060is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 7of42**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Complianceand Paragraph 1.F., Approval Yes AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected No Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator Yes Operator Supplied Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required
**ACTION** 1. Do ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 1: No Crack Found During UT Inspection
a. Send inspection results report and any cracked bolts and barrel nuts to Boeing. b. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 2: Any Crack Found On Any Barrel Nut During UT Inspection
a. Do removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. b. Send inspection results report and any cracked bolts and barrel nuts to Boeing.
c. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 3: Barrel nuts replaced in accordance with removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount.
a. Send inspection results report and any cracked bolts and barrel nuts to Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 8of42 **BOEING SERVICE BULLETIN 747-71A2329**b. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. **EFFECTIVITY** Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s). **COMPLIANCE** Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-24-12 is related to this service bulletin. The effective date of AD 2013-24-12 is December 17, 2013. Refer to Paragraph 1.E., Compliance

. **INDUSTRY SUPPORT INFORMATION** Warranty remedies have not been determined. However, for all affected aircraft Boeing will reimburse inspection task hours and if the condition is found during inspection, the additional task hours and materials required. Send a warranty claim to BCA Fleet Support Contracts. Termination of Offer: Customers are encouraged to promptly incorporate Service Bulletin 747-71-2332. This offer will terminate once Customers have had reasonable time to incorporate 747-71-2332. **MANPOWER Elapsed Hours**  **Total Task Hours Engines**  6.00 6.00 PART 1: ULTRASONIC (UT) INSPECTION OF BARREL NUTS ON FORWARD ENGINE MOUNT 6.80 16.40 PART 2: REMOVAL AND DYE PENETRANT INSPECTIONOF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT (a) (a) PART 3: SEND APPENDIX A INSPECTION RESULTS RE- PORT AND ANY CRACKED BOLTS AND BARREL NUTS (a) No manpower estimate was calculated for this task. Refer to Paragraph 1.G., Manpower

. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability

.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 9of42 **BOEING SERVICE BULLETIN 747-71A2329**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 10of42 **BOEING SERVICE BULLETIN 747-71A2329**

### Commercial **Airplanes** 

# 747

Service Bulletin **Number: 747-71A2329**  Original Issue: September 27, 2013 Revision 1: May 28, 2015 ATA System: 7121 **SUBJECT:** POWER PLANT - Engine Mounts - Forward Engine Mount Barrel Nut Inspection and

Replacement **1. PLANNING INFORMATION A.**  **Effectivity** 1. Airplanes Refer toService Bulletin Index D6-30300Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplane(s) shown below. **DESCRIPTION CONFIGURATION**  **GROUP** 747-8/-8F airplanes Line Number 1420-1434, 1436, 1438-1484, 1486, 1488, 1492, 1494 and 1497-1498. - 1

Airplane Models: 747-8, 747-8F **Group Variable Number**  1 RC001 - RC008 1 RC022 - RC034 1 RC501 - RC509 1 RC521 - RC525 1 RC541 1 RC546 - RC549 1 RC551 - RC563 1 RC571 - RC572 1 RC574 - RC582 1 RC601 - RC605

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 11of422. Spares Affected None. **B. Concurrent Requirements**  None. **C. Reason**  Accomplishment of this service bulletin will make sure the barrel nuts on the forward engine mount do not have a crack. A crack on both sides of the barrel nut will cause complete failure of the barrel nut. Complete failure of two or more barrel nuts on the same engine reduces the load capacity of the forward engine mount and could result in separation of an engine from the airplane. Separation of an inboard engine under power could result in loss of control of the airplane. An operator reported that while replacing the No.2 engine, the Non Destructive Test (NDT) inspection of the barrel nuts on the forward engine mount revealed cracks on 2 out of 4 barrel nuts. The operator also discovered 1 cracked barrel nut on the No. 1 engine. This is the first reported occurrence on the 747-8. Also, The Boeing Company did a NDT inspection of barrel nuts on a flight test airplane. There were 2 barrel nuts where a crack had initiated on the No. 2 engine. These barrel nuts are located at the forward end of the strut box and are used to fasten the forward engine mount to the strut. A barrel nut with a crack on one side will still be able to carry ultimate load. A crack on both sides of the barrel nut will cause complete failure of the barrel nut. Boeing has not received any reports of a barrel nut with a crack on both sides. This service bulletin gives instructions to inspect the barrel nuts on the forward engine mount and replace barrel nuts that have a crack. This will prevent the complete failure of barrel nuts that could result in the separation of an engine from the airplane. This service bulletin also has operators report the results of barrel nut inspections to Boeing, as well as sending any cracked parts to Boeing. The inspection reports will be used in the root cause investigation of this issue. Boeing will issue a service bulletin for terminating action of this issue after completion of the root cause investigation. Revision 1 is sent to advise affected operators that airplanes RC009, RC021, RC035-RC040, RC066, RC510-RC513, RC526-RC528, RC550, RC564, RC573, RC641-RC642, and RC671-RC672, were removed from this service bulletin effectivity because these airplanes received the intent of the change provided in Service Bulletin 747-71-2332 prior to delivery. New redesigned SL4750NA forward engine mount barrel nuts were incorporated in production with Line Number 1489 and Line Number 1500 and on. Also, compliance times were changed in Table 1: Inspection of the Barrel Nuts on the Forward Engine Mount. These sections were changed: 1. In Section 1.A., Effectivity, table was changed to show updated effectivity. 2. In Section 1.E., Compliance, table was changed to show updated compliance times. 3. In Section 1.J., References, Boeing Service Bulletin 747-71-2332 was added.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 12of42 **BOEING SERVICE BULLETIN 747-71A2329**4. In Figure 1 and Figure 2 illustrations were changed. 5. In Section 1.F.,. Approval, AD AMOC paragraph was added. 6. In Section 1.E., Compliance, existing paragraph was replaced with AD paragraph. 7. On Summary Page in Compliance, existing paragraph was replaced with AD paragraph. 8. In Appendix A, Steps 4 and 10 were changed. The data given in Information Notice 747-71A2329 IN 01 is included in this revision. Boeing Fleet Team Digest (FTD)747 FTD 71-13001is related to this service bulletin. Boeing Service Related Problem (SRP)747-8-SRP-71-0060is related to this service bulletin. **D. Description**  1. Do ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 1: No Crack Found During UT Inspection
a. Send inspection results report and any cracked bolts and barrel nuts to Boeing. b. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 2: Any Crack Found On Any Barrel Nut During UT Inspection
a. Do removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. b. Send inspection results report and any cracked bolts and barrel nuts to Boeing.
c. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Condition 3: Barrel nuts replaced in accordance with removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount.
a. Send inspection results report and any cracked bolts and barrel nuts to Boeing. b. Repeat ultrasonic (UT) inspection of the barrel nuts on the forward engine mount for cracked barrel nuts or removal and dye penetrant inspection of existing bolt and barrel nuts and installation of new or serviceable bolt and barrel nuts on the forward engine mount. Revision 1 - Effects of this Issue on airplanes on which original release was previously done:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 13of42 **BOEING SERVICE BULLETIN 747-71A2329**See Paragraph 1.D., Descriptionfor more information.

The work in this service bulletin is done in the maintenance zone(s) given below. **Affected Maintenance Zones Zone**  **Model** 412, 422, 432, 442 747-8, 747-8F **E. Compliance**  Federal Aviation Administration (FAA) Airworthiness Directive AD 2013-24-12 is related to this service bulletin. The effective date of AD 2013-24-12 is December 17, 2013. 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. The Conditions, Actions and Compliance times shown apply to each engine independently. Do the required actions in accordance with Paragraph 3. Accomplishment Instructions. The following abbreviations are used in the compliance tables: 1. PART 1: UT INSPECTION refers to PART 1: ULTRASONIC (UT) INSPECTION OF BARREL NUTS ON FORWARD ENGINE MOUNT. 2. PART 2: DYE PENETRANT INSPECTION refers to PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT. 3. PART 3: SEND REPORT AND ANY CRACKED PARTS refers to PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS AND BARREL NUTS. **Table 1: Inspection of the Barrel Nuts on the Forward Engine Mount Repeat In**  **terval (Not to Ex**  **ceed) Compliance Time (Whichever occurs**  **later) Action**  **Condition**

200 flight cycles Within 30 days after the original issue dateof this service bulletin. Within 200 flight cycles from the date of issuance of theoriginal certificate of airworthiness or the original export certificate of airworthiness. Do PART 1: UT INSPECTION orPART 2: DYE PENETRANT INSPECTION.(b) All Airplanes (a) (c)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 14of42 **BOEING SERVICE BULLETIN 747-71A2329 Table 1: Inspection of the Barrel Nuts on the Forward Engine Mount**  **Repeat In terval (Not** **to Ex ceed)**  **Compliance Time (Whichever occurs later)**  **Action Condition** 

- - Within 10 days after accom- plishment of PART 1: UT INSPECTION. ACTION 1: Do PART 3: SEND REPORT AND ANY CRACKED PARTS. CONDITION 1: NO CRACK FOUNDDURING UT INSPECTION

- - Before further flight. ACTION 1: CONDITION 2: ANY CRACK FOUND ON ANY BARREL NUTDURING UT INSPECTION Do PART 2: DYE PENETRANT INSPECTION.(b)

- - Within 10 days after accom- plishment of installation ofbolts and barrel nuts in accordance with PART 2:DYE PENETRANT INSPECTION. ACTION 2: Do PART 3: SEND REPORT AND ANY CRACKED PARTS.

- - Within 10 days after accom- plishment of installation ofbolts and barrel nuts in accordance with PART 2:DYE PENETRANT INSPECTION. ACTION 1: Do PART 3: SEND REPORT AND ANY CRACKED PARTS. CONDITION 3: BARREL NUTSAND BOLTS REPLACED IN ACCORDANCE WITH PART 2: DYEPENETRANT INSPECTION (a) Incorporating new redesigned SL4750NA forward engine mount barrel nut per Service Bulletin 747-71- 2332 is a terminating action for Service Bulletin 747-71A2329. (b) Whenever PART 2: DYE PENETRANT INSPECTION is done, all bolts and barrel nuts on that engine mount must be removed and replaced with new or serviceable parts. (c) or 500 flight cycles or 12 months, whichever comes first, provided that there have been four (4) consecutive inspections results with no crack findings from nut installation. This inspection must be performed while the nut is installed on the airplane. If the nut is removed and needs to be reinstalled, then an additional four (4) consecutive inspections results with no crack findings from nut reinstallation are required before returning to the 500 flight cycles or 12 months inspection **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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 15of42 **BOEING SERVICE BULLETIN 747-71A2329**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. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the accomplishment of the inspection and corresponding corrective actions defined in this service bulletin as an alternative method of compliance to the accomplishment of the inspections and corresponding corrective actions defined in SB 747-71A2329, dated September 27, 2013, required by paragraph (g) of AD 2013-24-12. All provisions of AD 2013-24-12 that are not specifically referenced in the above statement remain fully applicable and must be complied with accordingly. **G. Manpower**  The table below shows an estimate of the task hours necessary to do this inspection and installation for each engine. 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 inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **PART 1: ULTRASONIC (UT) INSPECTION OF BARREL NUTS ON FORWARD ENGINE MOUNT Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.00 1.00 1 Open Access 4.00 4.00 1 FIGURE 1 1.00 1.00 1 Close Access 6.00 6.00 TOTAL FOR EACH ENGINE **PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON**  **FORWARD ENGINE MOUNT Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.40 4.20 3 Open Access 4.00 8.00 2 FIGURE 2 1.40 4.20 3 Close Access 6.80 16.40 TOTAL FOR EACH ENGINE

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 16of42 **BOEING SERVICE BULLETIN 747-71A2329 PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS**  **AND BARREL NUTS Elapsed Hours**  **Task Hours Number of Persons**  **Task**

- - - Send Report and Parts (a) (a) TOTAL FOR EACH ENGINE (a) No manpower estimate was calculated for this task. **H. Weight and Balance Changes**  None. **I. Electrical Load Data**  Not changed. **J. References**  1. Existing Data:
a. Boeing Service Related Problem (SRP)747-8-SRP-71-0060 b. Service Bulletin Index D6-30300
c. Standard Overhaul Practices Manual (SOPM)20-50-01 d. Standard Wiring Practices Manual (SWPM)20-10-11,20-10-12,20-10-19
e. 747 Fleet Team Digest (FTD)71-13001 f. 747-8 Aircraft Maintenance Manual (AMM)54-62-04,71-00-00,71-11-04,71-21-03 g. Boeing Service Bulletin 747-71-2332 h. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2013-24-12 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: **Title Drawing Number**  ENGINE MOUNT TO STRUT MODULE - GENX-2B 310U8010 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 17of42 **BOEING SERVICE BULLETIN 747-71A2329 K.**  **Publications Affected**

1. Publications: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary. **L. Interchangeability and Intermixability of Parts**  Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary**  Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 18of42 **BOEING SERVICE BULLETIN 747-71A2329 2. MATERIAL INFORMATION**  **A. Material - Price and Availability**  The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. The Boeing price data shown below is given for planning purposes. Supply data can be given if requested. The parts are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 **REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION**  **Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **QTY Date**  **Name Part Number** 

$383.00 76 144 10/11/2013 BARREL NUT SL4081C14SP1 856 12/23/2013 $98.00 146 16 10/11/13 BOLT BACB30US14-31M 184 03/14/2014 **B. Industry Support Information**  Warranty remedies have not been determined. However, for all affected aircraft Boeing will reimburse inspection task hours and if the condition is found during inspection, the additional task hours and materials required. Send a warranty claim to BCA Fleet Support Contracts. Termination of Offer: Customers are encouraged to promptly incorporate Service Bulletin 747-71-2332. This offer will terminate once Customers have had reasonable time to incorporate 747-71-2332. **C. Parts Necessary for Each Airplane**  1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator The following parts or materials are necessary to do the change in this service bulletin. Parts and materials in the manuals given in Paragraph 1.J., References, can also be necessary. Examine operator part and material supply to make sure all necessary parts and materials are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 19of42 **BOEING SERVICE BULLETIN 747-71A2329 Notes**  **Name QTY**  **Part Number / Specification**  (b) BARREL NUT 4(a) SL4081C14SP1 (c) BOLT 4(a) BACB30US14-31M (d) MARKING LACQUER 2 ounces - (a) Quantity of 4 required for each engine. Quantity may vary based on inspection results. (b) Shur-Lock Company (97393), 2541 White Road Irvine, California 92614 (c) LISI Aerospace North America (727622), 2600 Skypark Drive Torrance, CA 90505 (d) F-925, Skydrol Resistant Torque Seal, Organic Products Company, PO Box 560625, Dallas, TX 75356-0625 (MSDS41617) 3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares**  None. **E. Special Tooling - Price and Availability**  None. **F. Special Tooling Necessary to do this Service Bulletin**  No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 20of42 **BOEING SERVICE BULLETIN 747-71A2329 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. 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 Airplane 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 Airplane Maintenance Manual (AMM).

— Non-standard torque values for maintenance tasks are included in the applicable installation step.
4. Use the approved fastener, process and material substitutions in accordance with

SRM Chapter 51. 5. Refer to theSWPM 20-10-11andSWPM 20-10-12for the wire installation procedures,

andSWPM 20-10-19for the wire separation requirements, as accepted procedures. 6. The necessary conditions for selection of clamp type and size are included inSWPM 20-10-12. If any wire bundle support clamp specified in this service bulletin does not make a correct fit on the wire bundle, refer toSWPM 20-10-12as an accepted procedure to select a clamp that fits correctly.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 21of42 **BOEING SERVICE BULLETIN 747-71A2329**7. 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 toSOPM 20-50-01for alternate full threaded fasteners (screws) needed for installation in this service bulletin. 8. A Detailed Inspection (DET) is defined as: An intensive examination of a specific

item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 9. 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. 10. Refer toAPPENDIX Afor Inspection Results Report instructions. 11. Refer toAPPENDIX Bfor Ultrasonic (UT) Inspection procedure. 12. 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. 13. 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. 14. 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. 15. If shading is used, shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 16. 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. 17. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance

. 18. The CONDITIONS, ACTIONS and OPTIONS shown apply to each engine independently.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 22of42 **BOEING SERVICE BULLETIN 747-71A2329**19. Some steps in the Work Instructions are labeled as Required for Compliance (RC). If this service bulletin is mandated by an Airworthiness Directive (AD), then the steps labeled as RC, including sub-steps under an RC step and any figures identified in an RC step, must be done to comply with the AD. An Alternative Method of Compliance (AMOC) is required for any deviations to RC steps, including sub-steps and identified figures. Steps not labeled as RC 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 RC steps, including sub-steps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. **B. WORK INSTRUCTIONS**  1. Do PART 1: ULTRASONIC (UT) INSPECTION OF BARREL NUTS ON FORWARD ENGINE MOUNT for cracked barrel nuts or PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT. **CONDITION 1: NO CRACK FOUND DURING UT INSPECTION**
a. ACTION 1: Do PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS AND BARREL NUTS. **CONDITION 2: ANY CRACK FOUND ON ANY BARREL NUT DURING UT INSPECTION**
a. ACTION 1: Do PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT. b. ACTION 2: Do PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS AND BARREL NUTS. **CONDITION 3: BARREL NUTS REPLACED IN ACCORDANCE WITH PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION**  **OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT**
a. ACTION 1: Do PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS AND BARREL NUTS. 2. Put the airplane back to a serviceable condition. **PART 1: ULTRASONIC (UT) INSPECTION OF BARREL NUTS ON FORWARD ENGINE MOUNT** 1. Open fan cowl. Refer to747-8 AMM 71-11-04as an accepted procedure. 2. PrepareAPPENDIX AInspection Results Report. 3. RC - Do UT inspection of forward engine mount barrel nuts in accordance with FIGURE 1

. 4. Close fan cowl. Refer to747-8 AMM 71-11-04as an accepted procedure.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 23of42 **BOEING SERVICE BULLETIN 747-71A2329 PART 2: REMOVAL AND DYE PENETRANT INSPECTION OF EXISTING BOLT AND BARREL** 

**NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT**  1. Remove fan cowl. Refer to747-8 AMM 71-11-04as an accepted procedure. 2. Remove the No. 2 Forward Fairing. Refer to747-8 AMM 54-62-04as an accepted procedure. 3. Install the forward bootstrap tool assembly. Refer to747-8 AMM 71-00-00as an accepted procedure. 4. RC - Apply the load to the forward engine mount. Refer to747-8 AMM 71-00-00as an accepted procedure. **NOTE:** Apply the load to the forward engine mount to remove the tension load from the forward engine mount bolts. 5. PrepareAPPENDIX AInspection Results Report. 6. RC - Replace barrel nuts and do dye penetrant inspection in accordance with FIGURE 2

. 7. Remove the load to the forward engine mount. Refer to747-8 AMM 71-00-00as an accepted procedure. 8. Remove the forward bootstrap tool assembly. Refer to747-8 AMM 71-00-00as an accepted procedure. 9. Install the No. 2 Forward Fairing. Refer to747-8 AMM 54-62-04as an accepted procedure. 10. Install fan cowl. Refer to747-8 AMM 71-11-04as an accepted procedure. **PART 3: SEND APPENDIX A INSPECTION RESULTS REPORT AND ANY CRACKED BOLTS AND BARREL NUTS**  1. RC - Send Appendix A Inspection Results Report and any cracked bolts and barrel nuts to The Boeing Company. Refer toAPPENDIX Afor instructions.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1: May 28, 2015 24of42 **BOEING SERVICE BULLETIN 747-71A2329 FIGURE 1:**  **FORWARD ENGINE MOUNT BARREL NUT ULTRASONIC (UT) INSPECTION (SHEET 1 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 25of42 **BOEING SERVICE BULLETIN 747-71A2329 FIGURE 1:**  **FORWARD ENGINE MOUNT BARREL NUT ULTRASONIC (UT) INSPECTION (SHEET 2 OF 3)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 26of42 **BOEING SERVICE BULLETIN 747-71A2329**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 engine. **More Data Qty**  **Identification Name**  **Task Step**  Identify location of the barrel nut so that the location can by recorded inAPPENDIX A

. 4 SL4081C14SP1 BARREL NUT Identify 1 Do UT Inspection of barrel nuts for any crack in accordance withAPPENDIX B

. 4 SL4081C14SP1 BARREL NUT Inspect 2 Record the location and UT inspection results inAPPENDIX A

. 4 SL4081C14SP1 BARREL NUT Record 3

**FIGURE 1: FORWARD ENGINE MOUNT BARREL NUT ULTRASONIC (UT) INSPECTION**  **(SHEET 3 OF 3)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 27of42 **BOEING SERVICE BULLETIN 747-71A2329 FIGURE 2:**  **FORWARD ENGINE MOUNT BOLT AND BARREL NUT REPLACEMENT (SHEET 1 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 28of42 **BOEING SERVICE BULLETIN 747-71A2329**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 engine.

**FIGURE 2: FORWARD ENGINE MOUNT BOLT AND BARREL NUT REPLACEMENT**  **(SHEET 2 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 29of42 **BOEING SERVICE BULLETIN 747-71A2329 More Data**  **Qty Identification**  **Name Task**  **Step** Identify and mark the location and orientation of the barrel nut so that the location and orientation can by recorded in APPENDIX A

. 4 SL4081C14SP1 BARREL NUT Identify 1

If torque stripe is present, do a DET of the torque stripe for evidence of fastener rotation so that the results can be recorded inAPPENDIX A. Evidence of fastener rotation is if the edges of the torque stripe are not aligned across the fastener and the structure. 4 BACB30US14-31M BOLT Inspect 2

Refer to747-8 AMM 71-00-00as an accepted procedure. 4 BACB30US14-31M BOLT Remove Refer to747-8 AMM 71-00-00as an accepted procedure. 4 BACW10BP14ACU WASHER Remove / Keep Refer to747-8 AMM 71-00-00as an accepted procedure. 4 SL4081C14SP1 BARREL NUT Remove Refer to747-8 AMM 71-00-00as an accepted procedure. 4 SLR4124C14 RETAINER Remove / Keep (a)Do a dye penetrant inspection for any crack in accordance with747-8 AMM 71-21-03
. 4 BACB30US14-31M BOLT Inspect 3 (a) (b)Do a dye penetrant inspection for any crack in accordance with747-8 AMM 71-21-03

. 4 SL4081C14SP1 BARREL NUT Inspect (a)Record the location, orientation, iftorque stripe is aligned and dye penetrant or UT inspection results inAPPENDIX A

. 4 SL4081C14SP1 BARREL NUT Record 4

**FIGURE 2: FORWARD ENGINE MOUNT BOLT AND BARREL NUT REPLACEMENT**  **(SHEET 3 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 30of42 **BOEING SERVICE BULLETIN 747-71A2329 More Data**  **Qty Identification**  **Name Task**  **Step** (c)Refer to747-8 AMM 71-00-00as an accepted procedure. 4 BACB30US14-31M BOLT Install (New) 5 Refer to747-8 AMM 71-00-00as an accepted procedure. 4 BACW10BP14ACU WASHER Install (Kept) (c)Refer to747-8 AMM 71-00-00as an accepted procedure. 4 SL4081C14SP1 BARREL NUT Install (New) Refer to747-8 AMM 71-00-00as an accepted procedure. 4 SLR4124C14 RETAINER Install (Kept) Apply a torque stripe to bolt head andforward engine mount. Refer to Paragraph 2.C.2., Parts and Materials Supplied by the Operator for acceptable material. 4 - MARKING LAC- QUER Apply

(a) The dye penetrant inspection of the removed bolts and barrel nuts may be performed at a later time if new bolts and barrel nuts are installed. Dye penetrant inspection must be performed in time to comply with CONDITION 2, ACTION 2, or CONDITION 3, ACTION 1 of Paragraph 1.E., Compliance

. (b) No dye penetrant inspection is required for any barrel nut that was shown to be cracked during UT inspection. All other barrel nuts must be dye penetrant inspected. (c) A serviceable part may be installed in place of a new part if the part has been dye penetrant inspected since it was last removed from service and no crack was found.

**FIGURE 2: FORWARD ENGINE MOUNT BOLT AND BARREL NUT REPLACEMENT**  **(SHEET 4 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 31of42 **BOEING SERVICE BULLETIN 747-71A2329 APPENDIX A:** **INSPECTION RESULTS REPORT (SHEET 1 OF 4)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 32of42 **BOEING SERVICE BULLETIN 747-71A2329 Service Bulletin 747-71A2329** 

**Airplane Registry, Variable or Line Number: Date of Inspection:**  **Flight Cycles: Flight Hours:**  **Barrel Nut Being In**  **stalled (New /** **Service able)**  **Location of Crack**  **on Bolt or Barrel Nut**  **(LEFT SIDE /**  **RIGHT SIDE /**  **BOTH SIDES) (If** **applica ble)**  **Barrel Nut Lot Num**  **ber Location**  **of Lot Number**  **on Barrel Nut (For**  **ward Face / Aft Face)**  **Torque Stripe**  **Aligned (Yes / No)**  **Crack Found (Y /**  **N) on (BOLT /**  **BARREL NUT /**  **BOTH) Inspection**  **Method Used (UT /** **DYE PENE TRANT)**  **Bolt and Barrel Nut**  **Location Engine**  **Number**

A 1 B

C D A 2 B

C D A 3 B

C D A 4 B

C D **REPORTING INSTRUCTIONS:** 1. Record the airplane registry, variable or line number. 2. Refer to illustration above for bolt and barrel nut location and orientation.

**APPENDIX A: INSPECTION RESULTS REPORT** 

**(SHEET 2 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 33of42 **BOEING SERVICE BULLETIN 747-71A2329**3. Record which inspection method was used.

4. Record if any crack was found or if no crack was found for every barrel nut. Record if any crack was found on any bolts that were dye penetrant inspected.
a. If no crack was found, mark "No". b. If any crack was found, mark "Yes" and mark if the cracked part was the "Bolt", the "Barrel Nut" or "Both". **NOTE:** Step 5 through Step 9 are only required if PART 2: REMOVAL AND DYE PENETRANT

INSPECTION OF EXISTING BOLT AND BARREL NUTS AND INSTALLATION OF NEW OR SERVICEABLE BOLT AND BARREL NUTS ON FORWARD ENGINE MOUNT was done. 5. Record inspection results of the torque stripe. If the torque stripe is aligned, mark "Yes". If the torque stripe is not aligned, mark "No". If no torque stripe is present, mark "N/A". 6. Record which face of the barrel nut the lot number is on, the forward face or the aft face. Mark "Forward Face" or "Aft Face" 7. Record the lot number of the barrel nut. The barrel nut has the lot number marked on either the forward face or the aft face. The part number is marked on the opposite face from the lot number. If UT Inspection was done, record if lot number was visible. (Lot Number Example: XX-XXX) 8. Report the location of any crack found for all cracked bolts and barrel nuts. Report which side of the bolt or barrel nut was cracked. Report "Left Side, Right Side, or Both Sides". 9. Record if the barrel nut being installed inFIGURE 2is a new barrel nut or a previously used barrel nut. **NOTE:** This information may be used for the terminating action. 10. If any cracks are detected on any barrel nuts, send the inspection results report to Boeing through Boeing Communication System (BCS). Inspection reports resulting with no cracks do not have to be reported to Boeing. 11. Please provide any detailed explanation or comments about the cracked bolts or barrel nuts in the BCS message to Boeing. 12. Send any cracked bolts or barrel nuts to: Spares Distribution Center Warranty and Overhaul Area, SSA 111 THE BOEING COMPANY Attention: Chris Morrow/Constantine Kostakis (425) 237-1425

**APPENDIX A: INSPECTION RESULTS REPORT**  **(SHEET 3 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 34of42 **BOEING SERVICE BULLETIN 747-71A2329**Mail Code 04-AR 2201 S. 142nd St PO BOX 3707 98124-2207 (This line is only required if shipped via U.S. Postal Service) SEATAC WA 98168-3713 USA

**APPENDIX A: INSPECTION RESULTS REPORT**  **(SHEET 4 OF 4)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 35of42 **BOEING SERVICE BULLETIN 747-71A2329 BARREL NUT ULTRASONIC (UT) INSPECTION** 

1. PURPOSE
a. Use this ultrasonic procedure to detect cracks in the four barrel nuts of the forward engine mount. This procedure will detect a crack that completely severs one side of the barrel nut. 2. EQUIPMENT
a. Instrument (1) Use an ultrasonic flaw detector. (2) A GE USM Go was used to develop this procedure, alternate instruments can be used. b. Transducer (1) Use a transducer that: (a) Operates at 10 MHz. (b) Is cylindrical in shape. (c) Has a case diameter of 0.31 inch (7.9 mm), or less. (d) Has a top mount micro-dot connector. (e) Has a minimum length of 0.50 inch (12.7 mm) and a maximum length of 1.0 inch (25 mm), not including the connector. (f) Does not have a delay line. (2) The transducer that follows was used to help prepare this procedure but, alternate transducers can be used: (a) Gamma, 10.0 MHz/.187" P/N 389-084-180; GE Inspection Technologies.
c. Transducer Extension Handle (1) Two transducer extension handles are recommended to help get access to the inspection area. It is difficult to reach the inspection areas without the extensions. (a) A 2 inch long (51 mm) extension handle is recommended to help examine the right and left barrel nuts on the forward side and the right barrel nut on the aft side of the forward engine mount. The transducer extension handle that follows was used to help prepare this procedure but, alternate handles can be used: 1) SPC-604FX-2; EC-NDT

**APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE**  **(SHEET 1 OF 7)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 36of42 **BOEING SERVICE BULLETIN 747-71A2329**(b) An 8 inch long (203 mm), flexible shaft, extension handle is recommended to help examine the left barrel nut on the aft side of the forward engine mount. This extension handle is used because the position of the de-icing duct on the left side of the engine restricts the access to the barrel nut. The transducer extension handle that follows was used to help prepare this procedure but, alternate handles can be used: 1) SPC-604FX-8; EC-NDT d. Reference Standard (1) Use an un-installed new or serviceable forward engine mount barrel nut for a reference standard to calibrate the equipment. (2) The barrel nuts are made from Inconel 718. (3) The barrel nuts are 1.5 inches (38.1 mm) long. 3. PREPARATION FOR INSPECTION
a. Identify and get access to the inspection area on the airplane. Refer to the service bulletin. b. Remove all dirt and grease from the inspection area that the transducer will touch.
c. Select the reference standard that will be used to calibrate the equipment. See para. 2.d. to select the reference standard. 4. INSTRUMENT CALIBRATION
a. Connect the transducer to the instrument. b. Set the instrument frequency to 10 MHz, or a broadband setting that includes 10 MHz.
c. Set the initial pulse to 0% full screen width. See Appendix B Figure B1. d. If the material velocity can be adjusted on the instrument, set the velocity to 0.224 inches/microsecond (5.69 mm/microsecond).
e. Set the display to show a 2 inch (51 mm) screen range. f. Identify the inspection area. g. Select the optional transducer extension recommended for the applicable location of the barrel nut to be examined. See Para. 2.c. (Transducer Extension Handle). h. Put couplant on the flat surface of an un-installed new or serviceable barrel nut. i. Put the transducer on the center of the barrel nut. (see Appendix B Figure B1, detail I and Appendix B Figure B2)

**APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE**  **(SHEET 2 OF 7)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 37of42 **BOEING SERVICE BULLETIN 747-71A2329 NOTE:**  Make sure that the transducer fully touches the barrel nut and is not at the location of the retainer. j. If the velocity and screen range have been adjusted as specified above, the signal from the threaded bore in the barrel nut will occur at approximately 18% Full Screen Width (FSW) (0.39 inch (10 mm)). Adjust the gain so the threaded bore signal on the display to 90% Full Screen Height (FSH). See Appendix B Figure B1, Detail II. k. If necessary, adjust the range and delay to cause the threaded bore signal to occur at approximately 18% FSW (0.39 inch (10 mm) on a 2 inch (51 mm) screen range). See Appendix B Figure B1, Detail II. l. Move the transducer until it is aligned with the edge of the barrel nut. See Appendix B Figure B1, detail III and Appendix B Figure B2. **NOTE:** Do not permit the transducer to overhang the edge of the barrel nut since the transducer will be restricted by the barrel nut bore of the engine mount hanger fitting during the inspection on the airplane.
m. The signal from the back surface of the barrel nut will occur at approximately 75% FSW (1.5 inches (38.1 mm) on a 2 inch (51 mm) screen range with the correct velocity). See Appendix B Figure B1, Detail IV.
n. Adjust the gain to get the back surface signal height to 100% FSH.
o. Add 6dB of gain. p. Crack indications will occur between 25% and 50% FSW. 5. INSPECTION PROCEDURE
a. Identify and get access to the inspection area. b. A total of 4 barrel nuts will be examined. (Two on the forward side of the forward engine mount and two on the aft side). (1) Examine the two forward barrel nuts as follows: (a) Put the transducer on the forward side of a barrel nut in the center of the nut to get a signal to occur from the threaded hole. Keep the transducer against the retainer to help guide the transducer. See Appendix B Figure B2. **NOTE:** The 2 inch long (51 mm) transducer extension handle is recommended to help examine the barrel nuts on the forward side of the engine mount. (b) Move the transducer away from the center to the outer edge of the barrel nut until it stops at the edge of the bore in the hanger fitting. Examine on both sides of the threaded hole. See Appendix B Figure B2. (c) Identify all barrel nuts as cracked if:
**APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE**  **(SHEET 3 OF 7)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 38of42 **BOEING SERVICE BULLETIN 747-71A2329**1) A signal occurs between 25% and 50% FSW. **NOTE:** The back surface signal of the barrel nut will not occur when the transducer is positioned in the area of the threaded hole because the hole will block the sound from reaching the back surface. Multiple reflections from the threaded hole can occur. Appendix B Figure B1, Detail II shows the first threaded hole reflection at approximately 18% FSW and the second multiple at approximately 36% FSW. The amplitude of the threaded hole signals will rise and fall together. (2) Examine the two aft barrel nuts as follows: **NOTE:** The two inch long (51 mm) transducer extension handle is recommended to examine the right, aft barrel nut and the eight inch long (203 mm) handle is recommended to examine the left, aft barrel nut. (a) Put the transducer on the aft side of the of a barrel nut in the center of the nut to get a signal to occur from the threaded hole. Keep the transducer against the retainer to help guide the transducer. See Appendix B Figure B2. (b) Move the transducer away from the center to the outer edge of the barrel nut until it stops at the edge of the bore in the hanger fitting. Examine on both sides of the threaded hole. See Appendix B Figure B2. (c) Identify all barrel nuts as cracked if: 1) A signal occurs between 25% and 50% FSW. 2) The back surface signal is not displayed on the screen at approximately 75% FSW when the transducer on the barrel nut is adjacent to either side of the barrel nut bore and the retainer as shown in Appendix B Figure B2. **NOTE:** The back surface signal of the barrel nut will not occur when the transducer is positioned in the area of the threaded hole because the hole will block the sound from reaching the back surface. Multiple reflections from the threaded hole can occur. Appendix B Figure B1, Detail II shows the first threaded hole reflection at approximately 18% FSW and the second multiple at approximately 36% FSW. The amplitude of the threaded hole signals will rise and fall together. 6. INSPECTION RESULTS
a. If a signal occurs between 25% and 50% FSW, the barrel nut must be considered cracked even if the back surface signal is shown on the instrument display. b. If no back surface signal occurs and no signal occurs between 25% and 50% FSW then: (1) Make sure that there is sufficient couplant on the barrel nut. (2) Make sure that the transducer is in good contact with the surface of the barrel nut.
**APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE**  **(SHEET 4 OF 7)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 39of42 **BOEING SERVICE BULLETIN 747-71A2329**(3) Make sure that the transducer is not on the retainer. (4) Off angle cracks can prevent the back surface signal from occurring. Reject the barrel nut if a back surface signal does not occur on the instrument display.

**APPENDIX B: ULTRASONIC (UT) INSPECTION PROCEDURE**  **(SHEET 5 OF 7)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 40of42 **BOEING SERVICE BULLETIN 747-71A2329 APPENDIX B:** **ULTRASONIC (UT) INSPECTION PROCEDURE (SHEET 6 OF 7)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 41of42 **BOEING SERVICE BULLETIN 747-71A2329 APPENDIX B:** **ULTRASONIC (UT) INSPECTION PROCEDURE (SHEET 7 OF 7)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 27, 2013 747-71A2329 Revision 1 May 28, 2015 42of42 **BOEING SERVICE BULLETIN 747-71A2329**