### Commercial **Airplanes** 

# 777 Service Bulletin **SPECIAL ATTENTION Number: 777-27-0115**  Original Issue: May 22, 2013 ATA System: 2731 **SUBJECT:** FLIGHT CONTROLS - Elevator Control System - Pitch Rate Sensor (PRS) 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 Unpublished Work.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Original Issue: May 22, 2013 777-27-0115 1 of 24 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 2 of 24 **BOEING SERVICE BULLETIN 777-27-0115**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 20 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 FIGURE 1: FORWARD CARGO COMPARTMENT - PITCH RATE SENSOR (PRS) INSPECTION . . 23

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 3 of 24 **BOEING SERVICE BULLETIN 777-27-0115**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 4 of 24 **BOEING SERVICE BULLETIN 777-27-0115**

BLANK PAGE

### Commercial **Airplanes** 

# 777 Service Bulletin **SPECIAL ATTENTION Summary**  **Number: 777-27-0115** Original Issue: May 22, 2013 ATA System: 2731 **SUBJECT:** FLIGHT CONTROLS - Elevator Control System - Pitch Rate Sensor (PRS) Inspection And Replacement BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to inspect maintenance records, and replace the existing flight control system Pitch Rate Sensors (PRS) if the inspection finds it necessary. One of two possible part numbers of PRS can produce erroneous output. If two PRS on one side of the airplane produce erroneous output, this could cause an automatic disengagement of the autopilot and autoland at low altitude. Boeing has received two reports of automatic autopilot disengagement. An investigation found that this was caused by erroneous output by two existing PRS on one side of the airplane. The four (4) PRS each measure the pitch rate of the airplane. If one PRS starts producing an erroneous output, the Primary Flight Control System (PFCS) flags it as faulty and removes it from any control laws. If two PRS on the same side of an aircraft are each flagged as faulty, this causes the PFCS to change from normal mode to secondary mode. The latest PRS design was introduced in production in March 2012. Boeing has determined that the latest PRS design may be less reliable than its preceding design. Accomplishment of this service bulletin will make sure that the PRS version that was used in production before March 2012 is installed in each of the four PRS locations on the airplane. Four (4) PRS are located behind the endwall in the aft end of the forward cargo compartment, with two (2) each on the left and right hand sides. The replacement PRS was produced by a different supplier, has a better service record, and is expected to decrease the chance of automatic autopilot disengagement. Boeing Service Related Problem (SRP) 777-SRP-27-0226 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 777 FTD 27-12001 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected Yes Spares Affected

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 5 of 24**Reference Affected**  **Planning Data** Paragraph 1.E., Compliance and 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 Yes 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 Group 1:**  Check maintenance records to find if PRS part number 402875-03-01 is installed in all four (4) PRS locations. If the maintenance records check does not find that PRS part number 402875-03-01 is installed in all four (4) PRS locations: Open access to each of the four (4) PRS and inspect for the part number of each PRS in accordance with PART 1. Replace each existing PRS part number 402875-05-01 with part number 402875-03-01 in accordance with PART 2. If records show no PRS part number 402875-05-01 have been installed, then no further action is required. **Group 2:** Open access to each of the four (4) PRS and inspect for the part number of each PRS in accordance with PART 1. Replace each existing PRS part number 402875-05-01 with part number 402875-03-01 in accordance with PART 2. **EFFECTIVITY** 777-200LR/F/300/300ER Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **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. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 6 of 24 **BOEING SERVICE BULLETIN 777-27-0115 MANPOWER**  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: May 22, 2013 777-27-0115 7 of 24 **BOEING SERVICE BULLETIN 777-27-0115**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 8 of 24 **BOEING SERVICE BULLETIN 777-27-0115**

### Commercial **Airplanes** 

# 777 Service Bulletin **SPECIAL ATTENTION Number: 777-27-0115**  Original Issue: May 22, 2013 ATA System: 2731 **SUBJECT:** FLIGHT CONTROLS - Elevator Control System - Pitch Rate Sensor (PRS) Inspection And Replacement BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 777-200LR/F/300/300ER Airplanes L/N 94-998 and 1050-1110, that had Pitch Rate Sensors 402875-03-01 installed in production, but may have replaced one or more units with a 402875-05-01 in-service - 1

777-200LR/F/300ER Airplanes L/N 999-1049, that had Pitch Rate Sensors 402875-05-01 installed in production - 2

Airplane Models: 777-200LR, 777-300, 777-300ER, 777F **Group Variable Number**  1 WB501 - WB512 1 WB531 - WB537 1 WB551 - WB554 1 WB591 - WB597 1 WB601 - WB606

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 9 of 24**Group Variable Number**  1 WB611 - WB622 1 WB631 - WB638 1 WB646 - WB649 1 WD001 - WD002 1 WD011 - WD018 1 WD031 - WD036 1 WD046 - WD055 1 WD066 - WD075 1 WD081 - WD089 1 WD091 1 WD096 1 WD101 - WD105 1 WD111 1 WD116 2 WD117 1 WD501 - WD513 1 WD521 - WD541 1 WD546 - WD554 1 WD561 - WD573 1 WD581 - WD599 1 WD606 - WD609 1 WD621 - WD632 1 WD651 - WD665 1 WD671 - WD677 1 WD691 - WD709 1 WD741 - WD752 1 WD761 - WD771 1 WD786 - WD788 1 WD796 - WD819 1 WD826 - WD837 1 WD846 - WD867 1 WD871 - WD887 2 WD888

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 10 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Group**  **Variable Number** 1 WD889 - WD892 1 WD911 - WD915 2 WD916 - WD917 1 WD918 1 WD921 - WD922 2 WD923 1 WD924 - WD929 1 WD936 - WD939 2 WD940 - WD941 1 WD942 - WD943 1 WD946 - WD954 2 WD955 1 WD956 - WD957 1 WD966 - WD970 1 WD981 - WD982 1 WD986 - WD987 2 WD991 1 WD992 - WD993 1 WD996 1 WE001 - WE004 1 WE011 - WE012 1 WE021 - WE026 1 WE031 - WE034 1 WE051 - WE055 1 WE071 - WE072 1 WE081 - WE084 1 WE091 - WE093 1 WE126 - WE137 1 WE141 1 WE151 - WE155 2 WE156 - WE159 1 WE160 - WE163 1 WE176 - WE177

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 11 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Group**  **Variable Number** 1 WE186 - WE192 2 WE193 - WE204 1 WE205 - WE207 1 WE216 - WE217 1 WE226 - WE228 2 WE229 - WE230 1 WE231 1 WE236 2 WE237 - WE240 1 WE241 - WE243 2 WE251 - WE253 2 WE261 1 WE262 - WE265 2 WE271 - WE272 1 WE273 - WE275 1 WE301 - WE307 1 WE331 - WE334 1 WE351 1 WE416 1 WF001 - WF004 1 WF016 - WF021 1 WF031 - WF034 2 WF035 1 WF036 - WF038 1 WF046 - WF059 2 WF060 - WF063 1 WF064 1 WF075 - WF077 1 WF081 - WF088 1 WF096 - WF101 1 WF106 - WF107 2 WF108 - WF109 1 WF111 - WF113

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 12 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Group**  **Variable Number** 2 WF114 1 WF115 1 WF121 - WF124 1 WF131 - WF133 1 WF136 2 WF137 1 WF138 2 WF146 1 WF147 2 WF151 1 WF152 2. Spares Affected Examine your spares supply for the parts or components identified below. If any parts or components are found, refer to Paragraph 2.C., Parts Necessary for Each Airplane, for the recommended action.
**Part Number** 402875-05-01 **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to inspect maintenance records, and replace the existing flight control system Pitch Rate Sensors (PRS) if the inspection finds it necessary. One of two possible part numbers of PRS can produce erroneous output. If two PRS on one side of the airplane produce erroneous output, this could cause an automatic disengagement of the autopilot and autoland at low altitude. Boeing has received two reports of automatic autopilot disengagement. An investigation found that this was caused by erroneous output by two existing PRS on one side of the airplane. The four (4) PRS each measure the pitch rate of the airplane. If one PRS starts producing an erroneous output, the Primary Flight Control System (PFCS) flags it as faulty and removes it from any control laws. If two PRS on the same side of an aircraft are each flagged as faulty, this causes the PFCS to change from normal mode to secondary mode. The latest PRS design was introduced in production in March 2012. Boeing has determined that the latest PRS design may be less reliable than its preceding design.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 13 of 24 **BOEING SERVICE BULLETIN 777-27-0115**Accomplishment of this service bulletin will make sure that the PRS version that was used in production before March 2012 is installed in each of the four PRS locations on the airplane. Four (4) PRS are located behind the endwall in the aft end of the forward cargo compartment, with two (2) each on the left and right hand sides. The replacement PRS was produced by a different supplier, has a better service record, and is expected to decrease the chance of automatic autopilot disengagement. Boeing Service Related Problem (SRP) 777-SRP-27-0226 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 777 FTD 27-12001 is related to this service bulletin. **D. Description Group 1:**  Check maintenance records to find if PRS part number 402875-03-01 is installed in all four (4) PRS locations. If the maintenance records check does not find that PRS part number 402875-03-01 is installed in all four (4) PRS locations: Open access to each of the four (4) PRS and inspect for the part number of each PRS in accordance with PART 1. Replace each existing PRS part number 402875-05-01 with part number 402875-03-01 in accordance with PART 2. If records show no PRS part number 402875-05-01 have been installed, then no further action is required. **Group 2:** Open access to each of the four (4) PRS and inspect for the part number of each PRS in accordance with PART 1. Replace each existing PRS part number 402875-05-01 with part number 402875-03-01 in accordance with PART 2. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 125, 126 777-200LR, 777-300, 777- 300ER, 777F **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 125, 126 777-200LR, 777-300ER, 777F **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. Do the required actions in accordance with Paragraph 3. Accomplishment Instructions.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 14 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Group 1:**  **Table 1: Pitch Rate Sensor (PRS) - Inspection and Replacement Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Within 60 monthsafter the original issue date of this service bulletin.Do a check of maintenance records to find if PRS part number 402875-03-01 is installedin all four (4) PRS locations. All Airplanes

- Within 60 monthsafter the original issue date of this service bulletin. Do PART 1: PRS PART NUMBER INSPECTION. CONDITION 1: THE MAINTENANCE RECORDS CHECK DOES NOT FIND THAT PRS PART NUMBER 402875- 03-01 IS INSTALLED INALL FOUR (4) PRS LOCATIONS

- - No further action is re- quired. CONDITION 2: PRS PART NUMBER402875-03-01 IS INSTALLED IN ALL FOUR (4) PRS LOCATIONS

- Before further flight Do PART 2: REPLACE- MENT OF PRS PART NUMBER 402875-05-01 WITH 402875-03-01. CONDITION 3: ONE OR MORE OF THE FOUR (4) PRS WITH PART NUMBER 402875- 05-01 IS FOUND

- - No further action is re- quired. CONDITION 4: PRS PART NUMBER 402875-03-01 IS FOUNDIN ALL FOUR (4) PRS LOCATIONS Do the required actions in accordance with Paragraph 3. Accomplishment Instructions. **Group 2: Table 1: Pitch Rate Sensor (PRS) - Inspection and Replacement**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 60 monthsafter the original issue date of this service bulletin. Do PART 1: PRS PART NUMBER INSPECTION. All Airplanes

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 15 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Group 2:**  **Table 1: Pitch Rate Sensor (PRS) - Inspection and Replacement Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Before further flight Do PART 2: REPLACE- MENT OF PRS PART NUMBER 402875-05-01 WITH 402875-03-01. CONDITION 3: ONE OR MORE OF THE FOUR (4) PRS WITH PART NUMBER 402875- 05-01 IS FOUND

- - No further action is re- quired CONDITION 4: PRS PART NUMBER 402875-03-01 IS FOUNDIN ALL FOUR (4) PRS LOCATIONS **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. **G. Manpower** The table below shows an estimate of the task hours necessary to do this change 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 inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Elapsed Hours Task Hours**  **Number of Persons Task**  0.75 0.75 1 Open Access 0.20 0.20 1 Figure 1 0.65 0.65 1 Replace (a) 0.35 0.35 1 Test (a)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 16 of 24 **BOEING SERVICE BULLETIN 777-27-0115 Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.75 0.75 1 Close Access 1.70 1.70 TOTAL FOR EACH AIRPLANE (a) Estimates given for these tasks are for each PRS that requires replacement and are not included in total shown. Multiply the number of PRS units requiring replacement by the estimates shown and add to the totals given to calculate the revised total. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Related Problem (SRP) 777-SRP-27-0226 b. Service Bulletin Index D624W001 c. Standard Wiring Practices Manual (SWPM) 20-10-11, 20-10-12, 20-10-19 d. 777 Aircraft Maintenance Manual (AMM) 25-52-17, 27-31-11 e. 777 Fleet Team Digest (FTD) 27-12001 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected** 1. Publications: **Chapter-Section**

**Publication** Equipment list 777 Wiring Diagram Manual 27-31 777 Illustrated Parts Catalog 2. Damage Tolerance Based Structural Inspections:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 17 of 24 **BOEING SERVICE BULLETIN 777-27-0115**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** Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability information. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 18 of 24 **BOEING SERVICE BULLETIN 777-27-0115 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. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are not available for the configuration changes given in this service bulletin. **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.
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (a) (b) 402875-05-01 PITCH RATE SENSOR 4 402875-03-01 (a) This part is used in production. (b) You cannot use the existing part to replace the new or changed part.
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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 19 of 24 **BOEING SERVICE BULLETIN 777-27-0115 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: May 22, 2013 777-27-0115 20 of 24 **BOEING SERVICE BULLETIN 777-27-0115 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 limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures, and SWPM 20-10-19 for the wire separation requirements, as accepted procedures. 6. 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. 7. 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. 8. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 9. Shaded areas in Figures are to separate the non-critical and non-authoritative information from the critical and authoritative information. 10. The compliance times for the actions in Paragraph 3.B., WORK INSTRUCTIONS are in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 21 of 24 **BOEING SERVICE BULLETIN 777-27-0115 B. WORK INSTRUCTIONS** 
1. **Group 1:** Do a check of maintenance records to find if PRS part number 402875-03-01 is installed in all four (4) PRS locations. **CONDITION 1: THE MAINTENANCE RECORDS CHECK DOES NOT FIND THAT PRS PART NUMBER 402875-03-01 IS INSTALLED IN ALL FOUR (4) PRS LOCATIONS**  a. Do PART 1: PRS PART NUMBER INSPECTION. **CONDITION 2: PRS PART NUMBER 402875-03-01 IS INSTALLED IN ALL FOUR (4) PRS LOCATIONS**  a. No further action is required. 2. **Group 2:** Do PART 1: PRS PART NUMBER INSPECTION. **PART 1: PRS PART NUMBER INSPECTION** 1. Remove the aft end wall of forward cargo compartment. Refer to 777 AMM 25-52-17 as an accepted procedure. 2. Inspect for the part number of each PRS, in accordance with FIGURE 1. **CONDITION 3: ONE OR MORE OF THE FOUR (4) PRS WITH PART NUMBER 402875-05-01 IS FOUND**  a. Do PART 2: REPLACEMENT OF PRS PART NUMBER 402875-05-01 WITH 402875-03-01. **CONDITION 4: PRS PART NUMBER 402875-03-01 IS FOUND IN ALL FOUR (4) PRS LOCATIONS**  a. Close the aft end wall of forward cargo compartment. Refer to 777 AMM 25-52-17 as an accepted procedure. b. Put the airplane back to a serviceable condition. **PART 2: REPLACEMENT OF PRS PART NUMBER 402875-05-01 WITH 402875-03-01** 1. Replace each existing PRS part number 402875-05-01 with part number 402875-03-01. Refer to 777 AMM 27-31-11 as an accepted procedure. 2. Do the PRS system test. Refer to 777 AMM 27-31-11 as an accepted procedure. 3. Close the aft end wall of forward cargo compartment. Refer to 777 AMM 25-52-17 as an accepted procedure. 4. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 22 of 24 **BOEING SERVICE BULLETIN 777-27-0115 FIGURE 1: FORWARD CARGO COMPARTMENT - PITCH RATE SENSOR (PRS) INSPECTION**  **(SHEET 1 OF 2)** Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 23 of 24 **BOEING SERVICE BULLETIN 777-27-0115**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  (a) 4

- PITCH RATE SENSOR Inspect 1 (a) Record the part number of each PRS.

**FIGURE 1: FORWARD CARGO COMPARTMENT - PITCH RATE SENSOR (PRS) INSPECTION (SHEET 2 OF 2)**  Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: May 22, 2013 777-27-0115 24 of 24 **BOEING SERVICE BULLETIN 777-27-0115**