© 2005 Hamilton Sundstrand Corporation PROPRIETARY 

THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN ARE THE PROPERTY OF HAMILTON SUNDSTRAND CORPORATION (HSC). RECIPIENT AGREES TO HOLD ALL SUCH INFORMATION IN CONFIDENCE AND AGREES IT SHALL BE USED ONLY FOR RECIPIENT'S INTERNAL PURPOSES tO MAINTAIN RECIPIENT'S 

EQUIPMENT OR AS MAY OTHERWISE BE PERMITIED IN AN APPLICABLE AGREEMENT BET'NEEN RECIPIENT AND HSC. THIS DOCUMENT AND THE INFORMATION 

CONTAINED HEREIN SHALL NOT BE USED FOR ANY OTHER PURPOSE. INCLUDING THE CREATION. MANUFACTURE, DEVELOPMENT, OR DERIVATION OF ANY REPAIRS, MODIFICATIONS, SPARE PARTS, DESIGN. OR CONFIGURATION CHANGES. OR TO OBTAIN FAA OR ANY OTHER GOVERNMENT OR REGULATORY APPROVAL 

FOR SAME. RECIPIENT AGREES NOT TO DISCLOSE SUCH INFORMATION TO ANY THIRD PARTY, EXCEPT AS MAY OTHERWISE BE PROVIDED FOR IN AN APPLICABLE 

AGREEMENT BET'NEEN RECIPIENT AND HSC. COPYING OR DISCLOSURE OF THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN BY ANYONE WITHOUT 

HSC'S PRIOR WRITIEN PERMISSION IS NOT AUTHORIZED AND MAY RESULT IN CRIMINAL AND/OR CIVIL LIABILITY. 

I THE DATA IN THIS DOCUMENT WERE DEVELOPED ONLY TO MAINTAIN SYSTEMS AND/OR PARTS MANUFACTURED BY OR FOR HAMILTON SUNDSTRAND OR 

APPROVED BY HAMILTON SUNDSTRAND. THE DATA MAY NOT BE APPLICABLE TO ANY OTHER SYSTEMS AND/OR PARTS, REGARDLESS OF THEIR APPARENT SIMILARITY TO SYSTEMS AND/OR PARTS MANUFACTURED BY OR FOR HAMILTON SUNDSTRAND OR APPROVED BY HAMILTON SUNOSTRAND. DO NOT RELY IN ANY 

WAY ON DATA IN THIS DOCUMENT TO MAINTAIN OR OTHERWISE SUPPORT SYSTEMS AND/OR PARTS THAT WERE NOT MANUFACTURED BY OR FOFI HAMILTON 

SUNDSTRAND OR APPROVED BY HAMILTON SUNDSTRAND WITHOUT EVIDENCE THAT THE FEDERAL AVIATION ADMINISTRATION OR OTHER REGULATORY AGENCY 

HAS DETERMINED THAT THE DATA IN THIS DOCUMENT IS VALID FOR SUCH USE. 

Information Subject to Export Control Laws 

Export Permitted Under NLA 

Hydraulic Power- Ram Air Turbine - Replace Counterweight and Flyweight Assemblies 

1. Planning Information 

A. Effectivity 

Sundstrand Ram Air Turbine/Hydraulic Pump (RAT), part number 729548 series (Boeing part number S258T71 0 series), which contains turbine assembly, part number 734350 series, serial numbers 

0666, 0673 through 0684, 0686, 0687, and 0689, used on Boeing 767 aircraft. 

NOTE: Turbine assemblies (with the serial numbers listed above) were manufactured between 

1989 and 1990 and were installed on aircraft delivered during 1990 and 1991 . However, this 

lot of turbine assemblies may now be installed on different Boeing model 767 aircraft or may 

be stocked as spares by an operator. 

B. Reason 

During a sub-assembly spin test at Hamilton Sundstrand, a material defect in a tungsten counterweight was found on a RAT turbine assembly that had been returned for service. The material defect 

occurred within the normal RAT governing range. In-flight failure of a counterweight during RAT operation will cause turbine overspeed and probable loss of RAT function. In-service turbine assemblies 

which contain counterweight assemblies from the same lot are subject to replacement. 

C. Description 

This bulletin gives the instructions necessary to return the turbine assembly to Hamilton Sundstrand 

for modification. It also gives the instructions necessary for Hamilton Sundstrand to modify the turbine assembly. 

D. Compliance 

Incorporation of this service bulletin is to be accomplished at the earliest opportunity. 

E. Approval 

This service bulletin has been reviewed by Boeing and the Federal Aviation Administration (FAA). 

The repairs and modifications herein comply with Title 14 of the Code of Federal Regulations 

(14CFR) Part 25; and are on record as FAA approved for installation on Boeing Model 767 aircraft. 

Nov 30/05 729548-29-15 

Page 1 of 6 
HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

F. Manpower 

A maximum of 13.0 man-hours will be required to disassemble the turbine assembly, modify the turbine assembly, and test the turbine assembly at a Hamilton Sundstrand repair facility. 

G. Material -Cost and Availability 

Hamilton Sundstrand will incorporate this modification into returned units at no charge until 

November 29, 2007. A limited number of turbine assemblies will be placed in a rotable pool for operator use. These will be available to operators for exchange, based upon availability. Operators 

should contact Hamilton Sundstrand at the following address for scheduling information. Send repair 

units with a copy of your purchase order to: 

Hamilton Sundstrand Corporation 

Rockford Repair Station Plant 6 

4747 Harrison Ave. 

Rockford, IL 61108 

Attention: Repair Administration 

Telephone: 815-226-6849 

Fax: 815-226-6826 

If the unit was a scheduled removal, and it is returned to a Hamilton Sundstrand repair facility, the 

operator may be subject to charges for work done beyond the scope of this service bulletin. 

H. Tooling - Price and Availability 

No tooling other than that required for shop maintenance of the RAT is required to do this modification. 

I. Weight and Balance 

None. 

J. Electrical Load Data 

Not affected. 

K. References 

Applicable Boeing Aircraft Maintenance Manual (AMM), Hamilton Sundstrand Component Maintenance Manual (CMM) 29-21-01 , Hamilton Sundstrand Standard Practices Manual (SPM) 20-00-00, 

and Hamilton Sundstrand Engineering Changes 58250E and 58980E. 

L. Other Publications Affected 

Hamilton Sundstrand CMM 29-21-01 will be revised to incorporate this service bulletin. 

Nov 30/05 729548-29-15 

Page 2 

Use or disclosure of this data is subject to restrictions on the front page of this document. 
HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

2. Accomplishment Instructions 

A. General 

(1 ) The user should obtain the material safety data sheets [Occupational Safety and Health Act 

(OSHA) Form 20 or equivalent] from the manufacturers or suppliers of materials to be used. 

The user must become completely familiar with the manufacturer/supplier information and 

adhere to the procedures, recommendations, warnings, and cautions of the manufacturer/supplier for the safe use, handling, storage, and disposal of these materials. The user should also 

read the long version of the warnings contained in this service bulletin. The long version warnings are contained in Hamilton Sundstrand Warnings Registry 341-006 available free of charge 

to all organizations that are on distribution for this service bulletin. The Warnings Registry 

341-006 is also available at www.hsvas.com. 

B. Return for Modification 

NOTE: The turbine assembly part number and serial number are located on the identification plate 

(refer to Figure 1 of this bulletin). 

NOTE: RAT turbine assemblies are line-replaceable units (LRU) on the aircraft. Therefore, the suspect turbine assemblies may be removed while the RAT is installed on the aircraft (refer to 

the applicable Boeing AMM). 

(1) Use the seed unit shipping container to return the turbine assembly (640, -640A, -640B, or 

-640C, IPL Figure 1, CMM 29-21-01) to Hamilton Sundstrand (refer to paragraph 1.G. of this 

bulletin). 

NOTE: A limited number of turbine assemblies will be placed in a rotable pool for operator use. 

Operators are to contact Hamilton Sundstrand for a replacement unit. 

C. Modification (at Hamilton Sundstrand) 

(1 ) If necessary, disassemble the RAT (refer to CMM 29-21-01, DISASSEMBLY) as necessary to 

remove the turbine assembly (640, -640A, -640B, or -640C, IPL Figure 1). 

(2) Disassemble the turbine assembly as necessary to remove flyweight assemblies (-240, IPL Figure 3) and counterweight assemblies (-650). 

(3) Use new counterweight assemblies, part number 729759B, and new flyweight assemblies, part 

number 734277 A, to assemble the turbine assembly (refer to CMM 29-21 -01 , ASSEMBLY). 

(4) Balance the turbine assembly (refer to CMM 29-21-01 , ASSEMBLY). 

(5) Identify the turbine assembly as follows (refer to SPM 20-00-00, ASSEMBLY): 

Nov 30/05 

(a) If the turbine assembly is part number 734350D, mark new part number 734350E and the 

symbol 29-15 on a new identification plate, part number 753432. 

(b) If the turbine assembly is part number 734350/A/B/C, mark the existing part number and 

the symbol 29-15 on a new identification plate, part number 753432. 

(c) Transfer all other information from the existing identification plate (40) or part number 

753432 to the new identification plate, part number 753432. 

729548-29-15 

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Use or disclosure of this data is subject to restrictions on the front page of this document. 
HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

(d) Remove and discard the existing identification plate (40) or part number 753432 (refer to 

CMM 29-21-01 , DISASSEMBLY). 

(e) Install the new identification plate, part number 753432, as follows (refer to CMM 29-21-01 , 

ASSEMBLY): 

WARNING: USE ISOPROPYL ALCOHOL, ASTM D770, CORRECTLY. ISOPROPYL 

ALCOHOL IS FLAMMABLE, EXPLOSIVE, AND A MILD POISON. IT CAN 

HAVE A BAD EFFECT ON YOUR HEALTH OR SAFETY. BEFORE YOU 

USE THE ALCOHOL, GET THE MATERIAL SAFETY DATA SHEET FROM 

THE MANUFACTURER OR SUPPLIER OF THE MATERIAL AND READ IT 

CAREFULLY. READ THE DETAILED WARNING, W0046SE, IN THE 

WARNING REGISTRY 341-006. BEFORE YOU USE THE ALCOHOL, PUT 

ON CHEMICAL-SPLASH GOGGLES. MAKE SURE THAT YOU HAVE SUFFICIENT AIRFLOW TO KEEP THE ALCOHOL FUMES BELOW THE MATERIAL SAFETY DATA SHEET LIMIT. 

1 Use clean isopropyl alcohol (ASTM D770) to clean the surface of the turbine assembly where the identification plate is to be installed. 

2 Let the isopropyl alcohol evaporate for five minutes minimum. 

3 Remove the paper backing from the identification plate. 

4 Secure the identification plate on the turbine assembly by pressing firmly to remove 

air pockets. 

(f) Do a test of the turbine assembly (refer to CMM 29-21-01 , TESTING AND TROUBLESHOOTING). 

D. Assembly 

(1) If the turbine assembly is to be installed in a RAT off the aircraft, do the following: 

E. Test 

(a) Use the modified turbine assembly, part number 734350E, or part number 734350/AJB/C 

(identified with the symbol29-15), to assemble the RAT (refer to CMM 29-21 -01 , ASSEMBLY). 

(1) Do one of the following: 

(a) If the turbine assembly is installed in a RAT off the aircraft, do a test of the RAT (refer to 

CMM 29-21-01 , TESTING AND TROUBLESHOOTING). 

(b) If the turbine assembly is installed in a RAT on the aircraft, do a ground check of the RAT 

(refer to the applicable Boeing AMM). 

F. Identification 

(1) No identification of the RAT is necessary. 

Nov 30/05 729548-29-15 

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Use or disclosure of this data is subject to restrictions on the front page of this document. 
Nov 30/05 

HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

TURBINE 

ASSEMBLY 

IDENTIFICATION 

PLATE 

SB-7295482915-30403 

Location of Turbine Assembly Identification Plate 

Figure 1 

729548-29-15 

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Use or disclosure of this data is subject to restrictions on the front page of this document. 
HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

3. Materiallnformation 

NOTE: Refer to Hamilton Sundstrand CMM 29-21-01 for expendable parts information. 

Qty 

Per Unit Disposition/ 

New P/N Unit List Price Key Word Old P/N Instructions 

Same RF Not Applicable Ram Air Turbine/ 729548 Series Modify 

Hydraulic Pump (Note 1) 

734350E 1 Not Applicable Turbine Assembly 7343500 Modify and reidentify 

Same 734350/A/B/C or identify with 

symbol 29-15 

7297598 2 (Note 2) Counterweight 729759A Remove old and 

Assembly install new 

734277A 2 (Note 2) Flyweight Assembly 734277 Remove old and 

install new 

753432 1 (Note 2) Identification Plate 753432 Remove and discard 

734516 old, install new 

Note 1: End item interchangeability is not affected. 

Note 2: Hamilton Sundstrand will install the noted parts at no charge (refer to paragraph 1.G. of this bulletin). 

Nov 30/05 729548-29-15 

Page 6 

Use or disclosure of this data is subject to restrictions on the front page of this document. 
© 2010 Hamilton Sundstrand Corporation PROPRIETARY 

THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN ARE THE PROPERTY OF HAMILTON SUNDSTRAND CORPORATION (HSC). RECIPIENT AGREES TO 

HOLD ALL SUCH INFORMATION IN CONFIDENCE AND AGREES IT SHALL BE USED ONLY FOR RECIPIENTS INTERNAL PURPOSES TO MAINTAIN RECIPIENTS 

EQUIPMENT OR AS MAY OTHERWISE BE PERMITTED IN AN APPLICABLE AGREEMENT BETWEEN RECIPIENT AND HSC. THIS DOCUMENT AND THE INFORMATION 

CONTAINED HEREIN SHALL NOT BE USED FOR ANY OTHER PURPOSE, INCLUDING THE CREATION, MANUFACTURE, DEVELOPMENT, OR DERIVATION OF ANY REPAIRS, MODIFICATIONS, SPARE PARTS, DESIGN, OR CONFIGURATION CHANGES, OR TO OBTAIN FAA OR ANY OTHER GOVERNMENT OR REGULATORY APPROVAL 

FOR SAME. RECIPIENT AGREES NOT TO DISCLOSE SUCH INFORMATION TO ANY THIRD PARTY, EXCEPT AS MAY OTHERWISE BE PROVIDED FOR IN AN APPLICABLE 

AGREEMENT BETWEEN RECIPIENT AND HSC. COPYING OR DISCLOSURE OF THIS DOCUMENT AND THE INFORMATION CONTAINED HEREIN BY ANYONE WITHOUT HSC'S PRIOR WRITTEN PERMISSION IS NOT AUTHORIZED AND MAY RESULT IN CRIMINAL ANOIOR CIVIL LIABILITY. 

I THE DATA IN THIS DOCUMENT WERE DEVELOPED ONLY TO MAINTAIN SYSTEMS AND/OR PARTS MANUFACTURED BY OR FOR HAMILTON SUNDSTRAND OR 

APPROVED BY HAMILTON SUNDSTRAND. THE DATA MAY NOT BE APPLICABLE TO ANY OTHER SYSTEMS AND/OR PARTS, REGARDLESS OF THEIR APPARENT 

SIMILARITY TO SYSTEMS AND/OR PARTS MANUFACTURED BY OR FOR HAMILTON SUNDSTRAND OR APPROVED BY HAMILTON SUNDSTRAND. DO NOT RELY IN ANY 

WAY ON DATA IN THIS DOCUMENT TO MAINTAIN OR OTHERWISE SUPPORT SYSTEMS AND/OR PARTS THAT WERE NOT MANUFACTURED BY OR FOR HAMILTON 

SUNDSTRAND OR APPROVED BY HAMILTON SUNDSTRAND WITHOUT EVIDENCE THAT THE FEDERAL AVIATION ADMINISTRATION OR OTHER REGULATORY AGENCY 

HAS DETERMINED THAT THE DATA IN THIS DOCUMENT IS VALID FOR SUCH USE. 

lnfoi'1NIIIon Subject to Export Control Laws 

THE TECHNICAL DATA IN THIS DOCUMENT (OR FILE) IS CONTROLLED FOR EXPORT UNDER THE EXPORT ADMINISTRATION REGULATIONS (EAR), 15 CFR PARTS 730-

774, ECCN· 9E991 VIOLATIONS OF THESE LAWS MAY BE SUBJECT TO FINES AND PENALTIES UNDER THE EXPORT ADMINISTRATION ACT. 

Emergency Hydraulic Power - Ram Air Turbine - Replace Balance Washer Retention Screws 

1. Planning Information 

A. Effectivity 

The Hamilton Sundstrand Turbine Assemblies, part number 734350 series, that are listed below and 

used on Boeing 767 aircraft: 

NOTE: 

NOTE: 

Part Number 

Series 

734350 

Feb 10/10 

The turbine assemblies may be stocked as spares, rotables, or repair parts, or installed on 

Hamilton Sundstrand Ram Air Turbine/Hydraulic Pumps (RAT), part number 729548 series 

(Boeing part number S258T71 0 series). 

Nonconforming screws from the affected manufacturing lots were distributed to other 

sources supplying the aircraft industry. Turbine assemblies or RATs repaired or overhauled 

by facilities other than Hamilton Sundstrand could therefore be suspect and not included in 

the serial number list that follows. Nonconforming screws known to be affected are those 

manufactured by Northeast Fasteners, Inc., manufacturing lot 24057. 

Serial Numbers 

0042, 0074, 0170, 0183, 0207, 0311,0312, 0324, 0336, 0337, 0347,0367, 0372, 0379, 

0381 , 0391 , 0427, 0431 , 0469, 0495, 0500,0530, 0531, 0533, 0538,0539, 0550,0551, 

0575, 0584, 0619, 0626, 0666, 0670, 0676, 0690,0700, 701,0734, 0750, 0800, 0801 , 

0813, 0835, 0836, 0908, 0923, 0958, 0968, 0980, 1009, 1012, 1019, 1046, 1052, 1054, 

1102, 1127, 1167, 1264, 1285, 1300, 1317, 1322, 1362, 1372, 1394, 1398, 1436, 1594, 

1633, 1634, 1635, 1636, 1637, 1638, 1639, 1640, 1641' 1642, 1643, 1644, 1645, 1646, 

1647, 1648, 1649, 1650, 1651 , 1652,X2063 

729548-29-18 

Page 1 of 15 
HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

Records indicate the following Hamilton Sundstrand RATs, part number 729548 series (Boeing part 

number S258T710 series), were delivered with affected turbine assemblies from the list above. This 

list is provided for reference only. Incorporation of this service bulletin shall be tracked by turbine 

assembly serial number. 

Part Number 

Series Serial Numbers 

729548 01 31, 0215, 0349, 0358, 0382, 0396, 0670, 0680, 0839, 0863, 0894, 1026, 1036, 1037, 

1038, 1039, 1040, 1041 , 1042, 1043, 1045 

B. Concurrent Requirements 

None. 

C. Reason 

Hamilton Sundstrand has discovered that RATs were manufactured with nonconforming screws. To 

date, there have been six instances of a fractured balance washer screw (PN MS24667-14) on multiple RAT part number configurations. Four of the units were production returns. Two fractures were 

in a single unit discovered prior to production shipment. Another three screws have fractured on inservice aircraft during removal for screw replacement. Fracture of a balance washer screw can result 

in the loss of the associated balance washer and create an unacceptable turbine imbalance. Inspection of other screws in Hamilton Sundstrand stock revealed metallographic nonconformities consistent with those of the fractured screws. The suspect screws have been isolated to a lot from a 

specific supplier. Analysis indicates the nonconformance could be a result of the supplier's heat treat 

process, which increases susceptibility to brittle fracture. Replacement of the suspect screws with 

confirmed conforming screws will eliminate potential loss of a balance washer. Incorporation of this 

bulletin will ensure that the RAT balance washer screws conform to specification. 

D. Description 

This bulletin gives instructions to replace the balance washer screws and identify the turbine assembly. Refer to Figure 1 of this bulletin for the location of the balance washers and screws. 

For a turbine assembly or RAT with a missing balance washer, or with a balance washer screw that 

cannot be removed in its entirety, instructions are also given to disassemble the unit as necessary to 

remove the fractured screw and balance washer, balance the turbine assembly, assemble the unit, 

and test the unit. 

E. Compliance 

Incorporation of this service bulletin is to be accomplished at the earliest opportunity. 

F. Approval 

The repairs and modifications herein are minor per 14 Code of Federal Regulations (CFR) 21 .93/CS 

21 .93 and comply with the applicable regulations and are on record with the supplier as Federal Aviation Administration (FAA) approved, as well as EASA/JAA approved by process 

via 14 CFR 21 .95/CS 21 .95. 

Feb 10/10 729548-29-18 

Page 2 

Use or disclosure of this data is subject to restrictions on the front page of this document. 

. 

• 
HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

G. Manpower 

A maximum of 0.5 man-hour will be required to replace the balance washer screws and identify the 

turbine assembly. 

For a turbine assembly or RAT with a missing balance washer, or with a balance washer screw that 

cannot be removed in its entirety, a maximum of 9.0 man-hours will be required to disassemble the 

unit as necessary to remove the fractured screw and balance washer, balance the turbine assembly, 

assemble the unit, and test the unit. 

H. Material -Cost and Availability 

(1 ) Hamilton Sundstrand will supply replacement parts on a no charge basis until 

February 1, 2012. Replacement parts are currently available in limited quantities. Operators 

approved by Hamilton Sundstrand to perform modification of units at their facility should place a 

single "no charge" order to Hamilton Sundstrand. Operators can forward these orders to their 

assigned Hamilton Sundstrand Commercial Spares Administrator (or fax to + 1-815-226-2624, if 

the responsible Administrator is not known). In addition, operators can also use the Hamilton 

Sundstrand website at www.hamiltonsundstrand.com to contact the Commercial Spares group. 

Upon entering the website, select "Customer Service" followed by "Commercial Spares" for 

other contact and order processing options that are available. Orders must clearly reference 

fleet requirements, noting the service bulletin number, serial numbers of affected units, total 

quantity of parts, and anticipated incorporation schedule (refer to paragraph 3. for the parts 

breakdown). Hamilton Sundstrand will acknowledge the operator order with an established 

delivery rate. 

(2) Hamilton Sundstrand will also give the following : 

Feb 10/10 

(a) A maximum labor allowance of 0.5 man-hour multiplied by the operator's current approved 

hourly rate for accomplishment of this service bulletin in the shop. The labor allowance will 

expire February 1, 2012. 

(b) A maximum labor allowance of 0.5 man-hour multiplied by the operator's current approved 

hourly rate for replacement of the balance washer screws on the aircraft. The labor allowance will expire February 1, 2012. 

(c) If removal from the aircraft is required, a maximum labor allowance of 4.0 man-hours multiplied by the operator's current approved hourly rate for replacement of the turbine assembly or RAT on the aircraft and test on wing. The labor allowance will expire 

February 1, 2012. 

(d) Operators should forward a claim for labor reimbursement to their assigned Hamilton 

Sundstrand Rockford Warranty Administrator. If the responsible Administrator is not 

known, the claim should be mailed to Warranty Administration, 4747 Harrison Ave, Rockford, IL 61126, USA, MS 106-6. The claim should reference the service bulletin number, 

serial numbers modified, date modified, total hours, and approved labor rate. 

729548-29-18 

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Use or disclosure of this data is subject to restrictions on the front page of this document. 
HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

(3) For units with a missing balance washer, or with a balance washer screw that cannot be 

removed in its entirety, Hamilton Sundstrand will incorporate this modification into returned units 

at no charge until February 1, 2012. Contact Hamilton Sundstrand at the address that follows 

for scheduling information: 

Hamilton Sundstrand 

4747 Harrison Avenue 

P.O. Box 7002 

Rockford, IL 61125-7002 

Attention: Repair Administration 

Mail Stop 151-6 

Telephone: +1-815-226-6849 

Fax: 815-394-2414 

I. Tooling - Price and Availability 

No tooling other than that required for shop maintenance of the turbine assembly or RAT is required 

to do this modification. 

J. Weight and Balance 

None. 

K. Electrical Load Data 

Not changed. 

L. References 

Hamilton Sundstrand Component Maintenance Manuals (CMM) 29-21-01 , Hamilton Sundstrand 

Standard Practices Manual (SPM) 20-00-00, and applicable Boeing Aircraft Maintenance Manuals 

(AMM). 

M. Other Publications Affected 

Hamilton Sundstrand CMMs 29-21-01 will be revised to incorporate this service bulletin. 

Feb 10/10 729548-29-18 

Page 4 

Use or disclosure of this data is subject to restrictions on the front page of this document. 
Feb 10/10 

HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

LOCATION OF 

BALANCE WASHERS 

AND SCREWS 

(QUANTITY 12) 

SB-7295482918-93830 

Location of Balance Washers and Screws 

Figure 1 

729548-29-18 

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HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

2. Accomplishment Instructions 

A. General 

CAUTION: THE TURBINE ASSEMBLY OR RAT CONTAINS DESIGN CRITICAL CHARACTERISTICS, PROCESSES, AND PROCEDURES. THE DESIGN CRITICAL CHARACTERISTICS ARE IDENTIFIED WITH THE SYMBOL »DCC«. REFER TO THE 

INTRODUCTION SECTION OF CMM 29-21-01 FOR A COMPLETE EXPLANATION 

OF DESIGN CRITICAL CHARACTERISTICS. 

(1) The user should obtain the material safety data sheets [Occupational Safety and Health Act 

(OSHA) Form 20 or equivalent] from the manufacturers or suppliers of materials to be used. 

The user must become completely familiar with the manufacturer/supplier information and 

adhere to the procedures, recommendations, warnings, and cautions of the manufacturer/supplier for the safe use, handling, storage, and disposal of these materials. The user should also 

read the long version of the warnings contained in this service bulletin. The long version warnings are contained in Hamilton Sundstrand Warnings Registry 341-006 available free of charge 

to all organizations that are on distribution for this Service Bulletin. The Warnings Registry 

341 -006 is also available at www.hsvas.com. 

(2) This service bulletin can be accomplished on a stand-alone RAT or turbine assembly, or on a 

RAT installed on aircraft, unless removal of the RAT or turbine assembly is specified herein. 

B. Modification 

(1) If the unit is installed on the aircraft, make sure the RAT is deployed (refer to the applicable 

AMM). 

CAUTION: THE RAT TURBINE BLADES SHOULD BE PROTECTIVELY COVERED DURING 

BALANCE WASHER SCREW REMOVAL AND INSTALLATION. THE BLADES CAN 

BE EASILY DAMAGED. 

(2) Install a protective covering on the RAT turbine blades to prevent damage to the blades from 

contact with the tooling or screws. 

(3) Manually rotate the turbine assembly and do a check for missing balance washers 

(10 through -101 , IPL Figure 3, CMM 29-21-01). 

NOTE: The 12 threaded holes around the turbine cover circumference (in the front balance 

plane) each have a balance washer installed and use a countersunk socket head cap 

screw MS24667-14 to secure the washers [refer to screw (20, IPL Figure 3, CMM 29-

21-01)]. 

NOTE: The rear balance plane is not affected by this bulletin. 

NOTE: Missing balance washers are evidenced by the remaining screw shank and the lack of 

a visible hexagonal screw socket on the turbine assembly. 

(4) If any balance washers are missing (because of a fractured screw), do the steps that follow: 

Feb 10/1 0 

(a) If the unit is installed on the aircraft, remove either the turbine assembly or the entire RAT 

from the aircraft (refer to the applicable AMM) for removal of the fractured screw and to balance the turbine assembly. The unit must be returned to Hamilton Sundstrand or to a repair 

facility that has the capability to disassemble, repair, balance, and test the RAT. 

729548-29-18 

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Feb 10/10 

HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

(b) Report any occurrences of a fractured screw to Hamilton Sundstrand as follows: 

Gary D. Siegrist 

Hamilton Sundstrand Service Engineering 

Phone: +1-815-226-6644 

Fax: + 1-860-660-5414 

E-Mail: gary.siegrist@hs.utc.com 

(c) Disassemble the turbine assembly or RAT (refer to CMM 29-21-01 , DISASSEMBLY) as 

necessary to remove the following parts and to get access to the fractured screw. 

- Balance washers (10 through -101, IPL Figure 3, CMM 29-21-01) 

- Screws (20, IPL Figure 3, CMM 29-21-01) 

NOTE: Some screws, depending on how near they are to a turbine blade, can not be 

extracted unless the turbine blades are disassembled from the turbine assembly. 

In those cases, either the turbine assembly or the entire RAT must be removed 

from the aircraft and disassembled as necessary to remove the screw. 

(d) If the remaining portion of the fractured screw is protruding above the turbine cover surface, do the steps that follow: 

1 Apply protective tape on the turbine (in the area of the screw) to prevent surface damage during the removal attempt. 

2 Use pliers, a vice grip, or an equivalent gripping tool to remove the screw. 

3 Remove the protective tape from the turbine. 

4 If the screw is removed in its entirety, proceed to step 2.B.(4)(f) of this bulletin. 

(e) If the remaining portion of the screw is flush or below the turbine cover surface, or if the 

screw cannot be removed in its entirety, use a screw extractor (or equivalent) to remove 

the remaining portion of the fractured screw. Make sure no filings or fragments enter the 

turbine assembly. Do not use heat or fluid to remove the screw. 

(f) Do a visual check of the self-locking screw thread insert to make sure there is no mechanical damage. Do the following if the visual examination reveals no obvious mechanical 

damage: 

1 Temporarily thread a balance weight screw (PN MS24667-14) into the insert to verify 

smooth engagement. Required torque should be less than the normal assembled 

torque of 18 to 22 pound inches (2.1 to 2.4 Newton meters). 

2 

3 

NOTE: For reference, the torque value through the self-locking segment of a new 

insert is approximately 5 pound inches (0.6 Newton meters). 

Remove the temporarily installed screw. 

If the engagement is not smooth, requires excessive torque, or if the self-locking feature appears to be ineffective, replace the insert [refer to SPM 20-00-00, Repair, 

SP R1 , paragraph 3. Procedure Tang Drive Inserts (MS21209 Series)]. 

729548-29-18 

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HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

(g) Assemble the turbine assembly as necessary (refer to CMM 29-21-01 , ASSEMBLY). 

(h) Remove the protective covering from the RAT turbine blades. 

(i) Balance the turbine assembly using new screws (PN MS24667-14) (refer to CMM 29-21-

01 , ASSEMBLY). 

0) Assemble the RAT as necessary (refer to CMM 29-21-01 , ASSEMBLY). 

NOTE: If only the turbine assembly was removed from the aircraft, the turbine assembly 

must be installed into a slave RAT strut for testing. 

(k) Do a test of the RAT (refer to CMM 29-21-01 , TESTING AND TROUBLESHOOTING). 

(I) If necessary, remove the turbine assembly from the slave RAT strut that was used for testing. 

(m) Proceed to paragraph 2.B.(6) of this bulletin. 

CAUTION: REPLACE THE BALANCE WASHER SCREWS ONE AT A TIME. DO NOT REMOVE 

ALL OF THE SCREWS AT THE SAME TIME. IF MORE THAN ONE SCREW IS 

REMOVED AT A TIME, THE TURBINE ASSEMBLY MUST BE RE-BALANCED. 

(5) If no balance washers are missing, do the steps that follow to replace the balance washer 

screws (one at a time): 

Feb 10/10 

(a) Use a suitable temporary marking method (tape, indelible ink, or equivalent) to mark the 

radial orientation of the installed balance washer. The original installed radial orientation of 

the washer must be maintained. 

(b) Do one of the steps that follow: 

2 

If the unit is installed on the aircraft, rotate the turbine assembly until the balance 

washer is positioned in a manner to minimize the potential for the balance washer to 

fall out (when the associated screw is removed). 

If the turbine assembly or RAT is off the aircraft, position the unit to access the balance washer facing up. 

729548-29-18 

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Feb 10/10 

HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

CAUTION: DO NOT USE A WORN HEX TOOL WITH ROUNDED CORNERS TO REMOVE 

THE SCREW. IF A WORN TOOL IS USED, THE POTENTIAL EXISTS FOR 

STRIPPING THE SOCKET HEAD OF THE SCREW. 

CAUTION: USE CARE NOT TO DAMAGE EITHER THE BALANCE WASHER OR TURBINE 

ASSEMBLY IF IT IS NECESSARY TO STRIKE THE HEAD OF THE SCREW 

BECAUSE THE BREAK-AWAY TORQUE IS EXCESSIVE. 

(c) While holding the balance washer in place, use a 3/32-inch hex tool to remove one screw 

from one balance washer. 

NOTE: The use of a hex insert bit is preferred. 

NOTE: If the screw break-away torque is excessive, it is permissible to lightly strike the 

head of the screw using a small hammer and a 5/16-inch (8-millimeter) pin punch. 

It should not be necessary to strike more than two times. 

(d) If the screw is fractured (with the balance washer installed) or if a screw fractures during 

removal, do the steps that follow to remove the remaining portion of the screw: 

1 Report any occurrences of a fractured screw to Hamilton Sundstrand as follows: 

Gary D. Siegrist 

Hamilton Sundstrand Service Engineering 

Phone: + 1-815-226-6644 

Fax: +1-860-660-5414 

E-Mail: gary.siegrist@hs.utc.com 

2 If the remaining portion of the fractured screw is protruding above the turbine cover 

surface, do the steps that follow: 

b 

d 

Apply protective tape on the turbine (in the area of the screw) to prevent surface 

damage during the removal attempt. 

Use pliers, a vice grip, or an equivalent gripping tool to remove the screw. 

Remove the protective tape from the turbine. 

If the screw is removed in its entirety, proceed to step 2.B.(5)(e) of this bulletin. 

729548-29-18 

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Feb 10/10 

HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

3 If the remaining portion of the screw is flush or below the turbine cover surface, or if 

the screw can not be removed in its entirety, do the steps that follow: 

NOTE: If the unit is installed on the aircraft, Hamilton Sundstrand recommends 

either the turbine assembly or the entire RAT be removed from the aircraft 

(refer to the applicable AMM) for removal of the fractured screw. The unit 

should either be returned to Hamilton Sundstrand or to a repair facility that 

has the capability to disassemble, repair, balance, and test the RAT. 

However, as an option, and at the operator's discretion, an attempt to 

mechanically extract a screw while the unit is installed on the aircraft is 

allowed. 

The procedure to mechanically extract a fractured screw, or one with a 

stripped socket head, must not use any heat or fluid . Care must be taken to 

make sure no filings or fragments enter the turbine assembly. 

The turbine hub and turbine blades should be protectively covered to prevent 

mechanically induced damage during the extraction procedure. 

£ For turbine assemblies or RATs removed from the aircraft, disassemble the unit 

(refer to CMM 29-21-01, DISASSEMBLY) as necessary to get access to the fractured screw. 

NOTE: Some screws, depending on how near they are to a turbine blade, can 

not be extracted unless the turbine blades are disassembled from the 

turbine assembly. In those cases, either the turbine assembly or the 

entire RAT must be removed from the aircraft and disassembled as necessary to remove the screw. 

b Use a screw extractor (or equivalent) to remove the remaining portion of the fractured screw. Make sure no filings or fragments enter the turbine assembly. Do not 

use heat or fluid to remove the screw. 

c Do a visual check of the self-locking screw thread insert to make sure there is no 

mechanical damage. Do the following if the visual examination reveals no obvious mechanical damage: 

-Temporarily thread a balance weight screw (PN MS24667-14) into the 

insert to verify smooth engagement. Required torque should be less than 

the normal assembled torque of 18 to 22 pound inches (2.1 to 2.4 Newton 

meters). 

Note: For reference, the torque value through the self-locking segment 

of a new insert is approximately 5 pound inches (0.6 Newton 

meters). 

- Remove the temporarily installed screw. 

- If the engagement is not smooth, requires excessive torque, or if the selflocking feature appears to be ineffective, replace the insert [refer to 

SPM 20-00-00, Repair, SP R1 , paragraph 3. Procedure Tang Drive Inserts 

(MS21209 Series)]. 

729548-29-18 

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Feb10/10 

HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

4 If disassembly of the turbine assembly was not required to remove the fractured 

screw, proceed to step 2.B.(5)(e) of this bulletin. 

5 For units removed from the aircraft, if disassembly of the turbine assembly was 

required to remove the fractured screw, do the following : 

~ Remove the remaining screws (20, IPL Figure 3, CMM 29-21-01) and the following balance washers: 

-Balance washers (10 through -101) 

b Do a visual check of the self-locking screw thread insert to make sure there is no 

mechanical damage. Do the following if the visual examination reveals no obvious mechanical damage: 

-Temporarily thread a balance weight screw (PN MS24667-14) into the 

insert to verify smooth engagement. Required torque should be less than 

the normal assembled torque of 18 to 22 pound inches (2.1 to 2.4 Newton 

meters). 

Note: For reference, the torque value through the self-locking segment 

of a new insert is approximately 5 pound inches (0.6 Newton 

meters). 

- Remove the temporarily installed screw. 

- If the engagement is not smooth, requires excessive torque, or if the selflocking feature appears to be ineffective, replace the insert [refer to 

SPM 20-00-00, Repair, SP R1 , paragraph 3. Procedure Tang Drive Inserts 

(MS21209 Series)). 

2 Assemble the turbine assembly as necessary (refer to CMM 29-21-01, ASSEMBLY). 

d Remove the protective covering from the RAT turbine blades. 

e Balance the turbine assembly using new screws (PN MS24667-14) (refer to 

CMM 29-21-01 , ASSEMBLY). 

f Assemble the RAT as necessary (refer to CMM 29-21 -01 , ASSEMBLY). 

NOTE: If only the turbine assembly was removed from the aircraft, the turbine 

assembly must be installed into a slave RAT strut for testing. 

9. Do a test of the RAT (refer to CMM 29-21-01 , TESTING AND TROUBLESHOOTING). 

h If necessary, remove the turbine assembly from the slave RAT strut that was 

used for testing. 

Proceed to paragraph 2.B.(6) of this bulletin. 

729548-29-18 

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HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

CAUTION: IF A BALANCE WASHER IS MISPLACED AFTER SCREW REMOVAL AND ITS 

ORIGINALLY INSTALLED ORIENTATION CANNOT BE DETERMINED, THE 

TURBINE ASSEMBLY OR ENTIRE RAT MUST BE RETURNED TO HAMILTON 

SUNDSTRAND OR TO A REPAIR FACILITY THAT HAS THE CAPABILITY TO 

BALANCE THE RAT. 

(e) If the balance washer inadvertently falls off after the screw is removed, install the balance 

washer in its original installed orientation, as determined from the marking method used in 

step 2.B.(5)(a) of this bulletin. 

(f) While holding the balance washer in place, install a new screw MS24667-14. Torque the 

screw 18 to 22 pound inches (2.1 to 2.4 Newton meters). 

(g) Use a suitable temporary marking method (tape, indelible ink, or equivalent) to mark the 

location where the balance washer screw has been replaced. 

(h) Repeat steps 2.B.(5)(a) through (g) of this bulletin for each balance washer screw. 

(i) Remove any tape {that was used to mark the orientation of the installed balance washers 

or the locations where the screws had been replaced). 

0) Remove the protective covering from the RAT turbine blades. 

(6) After all of the balance washer screws have been replaced, identify the turbine assembly as follows (refer to SPM 20-00-00, ASSEMBLY): 

(a) Add the symbol 29-18 to a blank area of the turbine assembly identification plate 

(40 or -40A, IPL Figure 3, CMM 29-21-01). 

(7) If the unit is installed on the aircraft, make sure the RAT is re-stowed (refer to the applicable 

AMM). 

C. Identification 

NOTE: After all of the balance washer screws have been replaced, the turbine assembly is identified by adding the symbol 29-18 to a blank area of the turbine assembly identification plate. 

D. Test 

(1) For units in the shop (if no balance washers were found missing, disassembly of the turbine was 

not required, and the balance washer screws were replaced one screw at a time), a test of the 

RAT is not required (refer to CMM 29-21-01 , TESTING AND TROUBLESHOOTING). 

(2) For RATs on the aircraft, if no balance washers were missing and the screws have been 

replaced as directed by this service bulletin, then a test of the RAT is not required. 

Feb 10/10 729548-29-18 

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HAMIL TON SUNDSTRAND 

SERVICE BULLETIN 

E. Return Balance Washer Screws to Hamilton Sundstrand 

(1 ) If the unit had a missing balance washer or a fractured screw, return all of the removed screws 

(including the remnants of the fractured screw) to Hamilton Sundstrand for further investigation 

as follows: 

(a) Put the screws in a mailing package. 

(b) Tag the screws (or include a note) to identify the part number and serial number of the turbine assembly (and if applicable, the part number and serial number of the RAT) the 

screws were removed from and to identify the applicable aircraft MSN. 

(c) Return the screws with the applicable part numbers, serial numbers, and aircraft MSN to 

the address that follows: 

Hamilton Sundstrand Service Engineering 

4747 Harrison Avenue 

P.O. Box 7002 

Rockford, IL 61125-7002 

Attention: Gary D. Siegrist 

Phone: + 1-815-226-6644 

Fax: + 1-860-660-5414 

E-Mail: gary.siegrist@hs.utc.com 

F. Notification of Completion Form 

(1) Do the following upon completion of this service bulletin: 

Feb 10/10 

(a) Make a copy of the "Notification of Completed SB 729548-29-18" form (refer to Figure 2 of 

this bulletin), complete the form, and fax the completed form to Hamilton Sundstrand as follows: 

Hamilton Sundstrand Corporation 

Retrofit Management Group 

Fax: +1-860-998-3695 

729548-29-18 

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HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

SENT FROM: 

Sender Name: 

NOTIFICATION OF COMPLETED 58 729548-29-18 

" Replace Balance Washer Screws" 

Sender Company: 

Aircraft Operator: 

Sender Fax#: 

Send Date: 

**PLEASE SUBMIT THIS NOTIFICATION SHEET WITHIN 10 DAYS AFTER MODIFICATION** 

SEND TO: 

Hamilton Sundstrand Corporation 

Retrofit Management Group 

Fax: + 1-860-998-3695 

Turbine 

Assembly 

Serial Number 

Feb10/10 

Aircraft MSN 

or Tail Number 

Bulletin 

Completion Date 

Notification of Completion Form 

Figure 2 

Comments 

729548-29-18 

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HAMIL TON SUN OSTRAND 

SERVICE BULLETIN 

3. Material Information 

NOTE: Refer to Hamilton Sundstrand CMM 29-21-01 for expendable parts information. 

Qty 

Per Unit Disposition/ 

New P/N Unit List Price Key Word Old P/N Instructions 

Same RF Not Applicable Ram Air Turbine/ 729548 Series Change 

(Note 1) Hydraulic Pump (Note 2) 

Same 1 Not Applicable Turbine Assembly 734350 Series Change and identify 

with the symbol 

29-18 

Same 12 (Note 3) Screw MS24667-14 Remove suspect old 

screws, install new 

conforming screws 

Note 1: Turbine assemblies or RATs modified according to this service bulletin are identified by marking the 

symbol 29-18 on the turbine assembly identification plate. 

Note 2: End item interchangeability is not affected. 

Note 3: Hamilton Sundstrand will supply the noted part at no charge (refer to paragraph 1.H. of this bulletin for 

details). 

Feb 10/10 729548-29-18 

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