### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-34A0191**  Original Issue: September 20, 2011 Revision 1: March 23, 2012 ATA System: 3433 **SUBJECT:** NAVIGATION - Radio Altimeter System - Radio Altimeter Transceiver Replacement Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2011 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. 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, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 1 of 21 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 2 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 14 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 17 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 18 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 FIGURE 1: RADIO ALTIMETER TRANSCEIVER REPLACEMENT . . . . . . . . . . . . . . . . . . . 20

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 3 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 4 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 777-34A0191** Original Issue: September 20, 2011 Revision 1: March 23, 2012 ATA System: 3433 **SUBJECT:** NAVIGATION - Radio Altimeter System - Radio Altimeter Transceiver Replacement This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** No more work is necessary on the airplanes changed in accordance with the original issue of this service bulletin.

**REASON FOR REVISION** This revision is sent to add one airplane to the effectivity list of the original issue of this service bulletin. These sections were changed: 1. In PLANNING INFORMATION, Paragraph 1.A.1., airplane WE091 was added to the effectivities. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. **REVISION HISTORY** September 20, 2011 Original Issue: March 23, 2012 Revision 1:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 5 of 21BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 6 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Summary**  **Number: 777-34A0191** Original Issue: September 20, 2011 Revision 1: March 23, 2012 ATA System: 3433 **SUBJECT:** NAVIGATION - Radio Altimeter System - Radio Altimeter Transceiver Replacement THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to replace the existing Radio Altimeter (RA) Transceivers with the upgraded units. The upgraded Radio Altimeter Transceivers have improved antenna monitoring capabilities for detecting antenna deterioration caused by the environmental conditions or damage to the antenna during antenna alteration which can result in breaks in the coaxial cables or damage to the coax connector. If the changes in this service bulletin are not done, incorrect Radio Altimeter output may be observed on the Primary Flight Displays (PFD). Some operators have reported inconsistent Radio Altimeter Transceiver outputs during the flight and on the ground. The antenna alteration at the antenna level can create micro cracks on the electrical grounding connection, damage the coax cables or the coax connector center pin contact. Any one of these damages to the antenna assembly can affect the Radio Altimeter system functionality. Boeing Service Related Problem 777-SRP-34-0120 is related to this service bulletin. Boeing Fleet Team Digest 777 FTD 34-10013 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 Paragraph 1.E., Compliance No 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

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 7 of 21**Reference Affected**  **Planning Data** 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 Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required
**ACTION (PRR 62777-85S)** 1. Gain access to the E5 rack in the forward cargo compartment. 2. Replace the Radio Altimeter (RA) Transceivers. 3. Do Installation Test. **EFFECTIVITY** 777-200, 777-200LR, 777-300, 777-300ER, and 777F Airplane(s). Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s). **COMPLIANCE** Boeing recommends that the changes given in this service bulletin be done within 24 months after the original issue date of this service bulletin. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the configuration changes given in this service bulletin.

**MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  1.65 1.65 All
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 8 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 9 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 10 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 777 Service Bulletin **ALERT Number: 777-34A0191**  Original Issue: September 20, 2011 Revision 1: March 23, 2012 ATA System: 3433 **SUBJECT:** NAVIGATION - Radio Altimeter System - Radio Altimeter Transceiver Replacement THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes This service bulletin is for the airplane(s) shown below. Refer to PRR 62777-85S for data about this change. Refer to Service Bulletin Index D624W001 Part 3 for Airplane Variable Number, Line Number, and Serial Number data.

**DESCRIPTION CONFIGURATION**  **GROUP** Replace existing Radio Altimeter Transceivers with 9599-607-19996 part number - 1

Airplane Models: 777-200, 777-200LR, 777-300, 777-300ER, 777F **Group Variable Number**  1 WA196 - WA198 1 WB101 - WB106 1 WB161 - WB177 1 WB306 - WB307 1 WB631 - WB638

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 11 of 21**Group Variable Number**  1 WB646 - WB649 1 WC111 - WC120 1 WC581 1 WD046 - WD055 1 WD581 - WD599 1 WD606 - WD609 1 WD621 - WD632 1 WD671 - WD677 1 WD846 - WD862 1 WD921 - WD922 1 WE091 1 WF031 - WF032 1 WF131 2. Spares Affected Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for the recommended use.
**B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to replace the existing Radio Altimeter (RA) Transceivers with the upgraded units. The upgraded Radio Altimeter Transceivers have improved antenna monitoring capabilities for detecting antenna deterioration caused by the environmental conditions or damage to the antenna during antenna alteration which can result in breaks in the coaxial cables or damage to the coax connector. If the changes in this service bulletin are not done, incorrect Radio Altimeter output may be observed on the Primary Flight Displays (PFD). Some operators have reported inconsistent Radio Altimeter Transceiver outputs during the flight and on the ground. The antenna alteration at the antenna level can create micro cracks on the electrical grounding connection, damage the coax cables or the coax connector center pin contact. Any one of these damages to the antenna assembly can affect the Radio Altimeter system functionality. Boeing Service Related Problem 777-SRP-34-0120 is related to this service bulletin. Boeing Fleet Team Digest 777 FTD 34-10013 is relate to this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 12 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**Revision 1 is sent to add WE091 to the effectivity list of the airplanes in the original issue of this service bulletin. **D. Description** 1. Gain access to the E5 rack in the forward cargo compartment. 2. Replace the Radio Altimeter (RA) Transceivers. 3. Do Installation Test. Revision 1 - No more work is necessary on airplanes changed in accordance with the original issue of this service bulletin.
The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 122, 211, 212 777-200, 777-200LR, 777-300, 777-300ER, 777F **E. Compliance** Boeing recommends that the changes given in this service bulletin be done within 24 months after the original issue date of this service bulletin.
**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

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 13 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**• 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**  0.25 0.25 1 Open Access 0.90 0.90 1 Figure 1 0.25 0.25 1 RA Installation tests 0.25 0.25 1 Close Access 1.65 1.65 TOTAL FOR EACH AIRPLANE **H. Weight and Balance Changes** None.

**I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Engineering Change Memo PRR 62777-85S b. Service Related Problem (SRP) 777-SRP-34-0120 c. Fleet Team Digest (FTD) 777 FTD 34-10013 d. 777 Maintenance Manual (AMM) Subject 777 AMM 34-33-01 e. THALES SB ERT-550-34-04
2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin
**Title Drawing Number**  EQUIPMENT INSTL - E5 RACK 284W1205

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 14 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**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. **K. Publications Affected** 1. Publications: **Chapter-Section**

**Publication** 34-33 777 Aircraft Maintenance Manual EQUIPMENT LIST 777 Wiring Diagram Manual 34-33, 25-17 777 Illustrated Parts Catalog 34-32 Component Maintenance Manual 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 15 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 16 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**

BLANK PAGE**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 . Refer to THALES SB ERT-550-34-04 for price and upgrade kit availability.
**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
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  (a) (b) (c) 9599-607-19991 or 9599- 607-19992 or 9599-607- 19993 Radio Altimeter Transceiver 3 9599-607-19996

(a) The existing/installed Radio Altimeter Transceivers have one of the part numbers mentioned in the "Existing Part Number" column. (b) You can use the existing Radio Altimeter Transceivers to upgrade to 9599-607-19996 part number. Refer to THALES SB ERT-550-34-04 for the information on how to upgrade the existing Radio Altimeter Transceivers to 9599-607-19996 part number. (c) 9599-607-19991 and 9599-607-19992 units must first be converted to 9599-607-19993 part number before they can be upgraded to 9599-607-19996 part number. Refer to the "Concurrent Requirements" section of THALES SB ERT-550-34-04 for this information.

3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None **D. Parts Necessary to Change Spares**
To get the parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 17 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT QTY**  **Name Part Number** 

- Radio Altimeter Transceiver 9599-607-19996 (a) (a) Refer to THALES SB ERT-550-34-04 for the information on how to upgrade the existing RAs to 9599-607-19996 part number. **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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 18 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION CAUTION:**  KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. 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. **B. WORK INSTRUCTIONS** 1. Get access to Electronic Equipment Rack E5 in the Forward Cargo Compartment. 2. Replace the Radio Altimeter (RA) Transceivers in accordance with FIGURE 1. 3. Do installation test. Refer to 777 AMM 34-33-01 as an accepted procedure. 4. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1: March 23, 2012 19 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT FIGURE 1: RADIO ALTIMETER TRANSCEIVER REPLACEMENT**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1 March 23, 2012 20 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**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) 3 9599-607-19991 OR 9599-607-19992 OR 9599-607-19993 RADIO ALTIMETER TRANSCEIVER Remove 1

(b) 3 9599-607-19996 RADIO ALTIMETER TRANSCEIVER Install (Changed) 2 (a) Refer to 777 AMM 34-33-01 as an accepted procedure. The existing/installed Radio Altimeter Transceivers have one of the following 9599-607-19991, 9599-607-19992 or 9599-607-19993 part numbers. (b) Refer to 777 AMM 34-33-01 as an accepted procedure.

**FIGURE 1: RADIO ALTIMETER TRANSCEIVER REPLACEMENT (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 20, 2011 777-34A0191 Revision 1 March 23, 2012 21 of 21 **BOEING SERVICE BULLETIN 777-34A0191 ALERT**  **ALERT**