## 1. DESCRIPTION This sheet transmits Revision 01 to Service Bulletin 170-24-0048. This is a complete reissue of the Bulletin. 2. ADDITIONAL ACTION Aircraft that have complied with the previous issue of this bulletin do not need any additional action. 3. RECORD OF REVISION Basic issue: 31/Mar/2010. Revisio n 01 : 1 2 /May/2010. 4. HIGHLIGHTS The topics, affected pages, and a brief description of the content-related changes introduced by this revision are presented below. Revision bars are put in the left margin of each page to show the location of the significant changes. Text displacement and text format changes are not indicated.

TOPIC/PAGE DESCRIPTION OF REVISION 1. PLANNING INFORMATION 1.C. REASON / 03 Added reason of Revision 01. 1.G. ESTIMATED MANPOWER / 06 Updated manpower of test. 3. ACCOMPLISHMENT INSTRUCTIONS/ 10 Removed step 3.D.3) and corrected editorial error. 

# TRANSMITTAL LETTER

SB No.: 170-24-0048 PAGE: 1 of 1 Embraer Copyright © 2010. All rights reserved.

## ELECTRICAL POWER - RAT (RAM AIR TURBINE) - REPLACEMENT OF BALANCE WASHER SCREWS
1. PLANNING INFORMATION
A. SB EFFECTIVITY
Aircraft affected:
MODEL SN Embraer 170( ) and 175( ) 17000002, 17000004 thru 17000013, and 17000015 thru 17000307.
Affected component: The Hamilton Sundstrand Ram Air Turbines (RAT), Model ERPS37T, PN 1703781 Series, serial numbers: 0101, 0104, 0105, 0106, 0108, 0112, 0115, 0116, 0117, 0118, 0119, 0122, 0125, 0131, 0132, 0134, 0139, 0140, 0142, 0143, 0145, 0146, 0148, 0152, 0155, 0158, 0159, 0161, 0164, 0165, 0166, 0167, 0169, 0170, 0171, 0172, 0173, 0175, 0176, 0177, 0178, 0179, 0181, 0186, 0187, 0188, 0190, 0196, 0198, 0199, 0200, 0201, 0202, 0203, 0204, 0205, 0208, 0209, 0210, 0212, 0213, 0214, 0217, 0218, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0228, 0229, 0230, 0233, 0234, 0236, 0238, 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0249, 0250, 0251, 0253, 0255, 0256, 0257, 0264, 0265, 0266, 0268, 0272, 0273, 0277, 0279, 0281, 0283, 0285, 0286, 0287, 0288, 0290, 0291, 0293, 0294, 0295, 0299, 0300, 0301, 0302, 0303, 0307, 0308, 0309, 0311, 0313, 0314, 0315, 0316, 0317, 0318, 0319, 0320, 0321, 0322, 0323, 0324, 0326, 0329, 0331, 0333, 0334, 0335, 0336, 0337, 0339, 0340, 0341, 0346, 0347, 0348, 0349, 0350, 0352, 0353, 0364, 0370, 0371, 0374, 0375, 0385, 0386, 0389, 0394, 0412, 0416, 0417, 0424, 0430, 0454, 0467, 0469, 0473, 0474, 0479, 0480, 0481, 0482, 0483, 0484, 0485, 0486, 0487, 0488, 0489, 0490, 0491, 0492, 0493, 0494, 0495, 0496, 0497, 0498, 0499, 0500, 0501, 0502, 0503, 0504, 0505, 0506, 0507, 0508, 0509, 0510, 0511, 0512, 0513, 0514, 0515, 0516, 0517, 0518, 0519, 0520, 0521, 0522, 0523, 0524, 0525, 0526, 0527, 0528, 0529, 0530, 0531, 0532, 0533, 0534, 0535, 0536, 0537, 0538, 0539, 0540, 0541, 0542, 0543, 0544, 0545, 0546, 0547, 0548, 0549, 0550, 0551, 0552, 0553, 0554, 0555, 0556, 0557, 0558, 0559, 0560, 0562, 0563, 0564, 0565, 0566, 0567, 0568, 0569, 0570, 0571, 0572, 0573, 0574, 0575, 0576, 0577, 0578, 0579, 0580, 0581, 0582, 0583, 0584, 0585, 0586, 0587, 0588, 0589, 0590, 0591, 0592, 0593, 0594, 0595, 0596, 0597, 0598, 0599, 0600, 0602, 0603, 0604, 0605, 0606, 0607, 0608, 0609, 0610, 0611, 0613, 0614, 0615, 0616, 0617, 0619, 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 1 of 27 Embraer Copyright © 2010. All rights reserved.

## 0620, 0621, 0622, 0623, 0624, 0625, 0626, 0628, 0629, 0630, 0631, 0633, 0634, 0636, 0637, 0638, 0639, 0640, 0641, 0642, 0643, 0644, 0645, 0647, 0648, 0649, 0650, 0651, 0652, 0653, 0654, 0655, 0656, 0657, 0658, 0659, 0660, 0661, 0662, 0663, 0664, 0666, 0667, 0668, 0669, 0670, 0671, 0672, 0673, 0674, 0675, 0676, 0677, 0678, 0679, 0681, 0682, 0683, 0684, 0686, 0687, 0688, 0689, 0690, 0691, 0692, 0693, 0695, 0696, 0697, 0698, 0699, 0700, 0701, 0702, 0703, 0704, 0705, 0706, 0707, 0708, 0709, 0710, 0712, 0713, 0714, 0715, 0716, 0717, 0719, and 0720. NOTE: This effectivity list includes the aircraft originally equipped with the affected component. Since this component is a “Line Replaceable Unit” (LRU), it may be necessary to refer to the fleet maintenance control record and verify whether the unit has been replaced with another one during routine maintenance. In-production effectivity: Embraer 170( ) and 175( ) model aircraft SN 17000308 and on, have an equivalent modification factory-incorporated.
B. CONCURRENT REQUIREMENTS
None.
C. REASON (1) HISTORY Hamilton Sundstrand has discovered that some Ram Air Turbine (RAT)s were manufactured with nonconforming screws. Analysis indicated that this nonconformance could be a result of the supplier’s heat treat process, which increases susceptibility to brittle fracture. (2) OBJECTIVE To inspect the RAT model, part number and Serial number and, if applicable, to replace the existing balance screw installed in the unit. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 2 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

## (3) EXPECTED BENEFITS To return the RAT to its original design configuration. (4) REVISION HISTORY
REVISION 01: This revision has been issued to update item 1.G. ESTIMATED MANPOWER , to remove step 3.D.3) and to correct editorial error in item 3. ACCOMPLISHMENT INSTRUCTIONS

. D. DESCRIPTION The accomplishment of this bulletin consists in inspecting the Ram Air Turbine (RAT) model, PN and Serial Number and, if applicable, replacing the balance screw of the equipment and to reidentify it. This service bulletin also presents Hamilton Sundstrand SB ERPS37T-24-5, dated March 22/2010, attached to Section 4. APPENDIX 1 , which provides instructions for the replacement of the balance screw and the re-identification of the RAT. This Bulletin is divided into 2 PARTS, as follows:
PART I INSPECTION OF RAT MODEL, PART NUMBER AND SERIAL NUMBER Applicable to: SB EFFECTIVITY 

## PART I of this bulletin consists in inspecting the Model, PN and serial number of the RAT. – If the RAT is identified as Model ERPS37T, PN 1703781 Series, serial numbers: 0101, 0104, 0105, 0106, 0108, 0112, 0115, 0116, 0117, 0118, 0119, 0122, 0125, 0131, 0132, 0134, 0139, 0140, 0142, 0143, 0145, 0146, 0148, 0152, 0155, 0158, 0159, 0161, 0164, 0165, 0166, 0167, 0169, 0170, 0171, 0172, 0173, 0175, 0176, 0177, 0178, 0179, 0181, 0186, 0187, 0188, 0190, 0196, 0198, 0199, 0200, 0201, 0202, 0203, 0204, 0205, 0208, 0209, 0210, 0212, 0213, 0214, 0217, 0218, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0228, 0229, 0230, 0233, 0234, 0236, 0238, 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0249, 0250, 0251, 0253, 0255, 0256, 0257, 0264, 0265, 0266, 0268, 0272, 0273, 0277, 0279, 0281, 0283, 0285, 0286, 0287, 0288, 0290, 0291, 0293, 0294, 0295, 0299, 0300, 0301, 0302, 0303, 0307, 0308, 0309, 0311, 0313, 0314, 0315, 0316, 0317, 0318, 0319, 0320, 0321, 0322, 0323, 0324, 0326, 0329, 0331, 0333, 0334, 0335, 0336, 0337, 0339, 0340, 0341, 0346, 0347, 0348, 0349, 0350, 0352, 0353, 0364, 0370, 0371, 0374, 0375, 0385, 0386, 0389, 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 3 Embraer Copyright © 2010. All rights reserved.

## 0394, 0412, 0416, 0417, 0424, 0430, 0454, 0467, 0469, 0473, 0474, 0479, 0480, 0481, 0482, 0483, 0484, 0485, 0486, 0487, 0488, 0489, 0490, 0491, 0492, 0493, 0494, 0495, 0496, 0497, 0498, 0499, 0500, 0501, 0502, 0503, 0504, 0505, 0506, 0507, 0508, 0509, 0510, 0511, 0512, 0513, 0514, 0515, 0516, 0517, 0518, 0519, 0520, 0521, 0522, 0523, 0524, 0525, 0526, 0527, 0528, 0529, 0530, 0531, 0532, 0533, 0534, 0535, 0536, 0537, 0538, 0539, 0540, 0541, 0542, 0543, 0544, 0545, 0546, 0547, 0548, 0549, 0550, 0551, 0552, 0553, 0554, 0555, 0556, 0557, 0558, 0559, 0560, 0562, 0563, 0564, 0565, 0566, 0567, 0568, 0569, 0570, 0571, 0572, 0573, 0574, 0575, 0576, 0577, 0578, 0579, 0580, 0581, 0582, 0583, 0584, 0585, 0586, 0587, 0588, 0589, 0590, 0591, 0592, 0593, 0594, 0595, 0596, 0597, 0598, 0599, 0600, 0602, 0603, 0604, 0605, 0606, 0607, 0608, 0609, 0610, 0611, 0613, 0614, 0615, 0616, 0617, 0619, 0620, 0621, 0622, 0623, 0624, 0625, 0626, 0628, 0629, 0630, 0631, 0633, 0634, 0636, 0637, 0638, 0639, 0640, 0641, 0642, 0643, 0644, 0645, 0647, 0648, 0649, 0650, 0651, 0652, 0653, 0654, 0655, 0656, 0657, 0658, 0659, 0660, 0661, 0662, 0663, 0664, 0666, 0667, 0668, 0669, 0670, 0671, 0672, 0673, 0674, 0675, 0676, 0677, 0678, 0679, 0681, 0682, 0683, 0684, 0686, 0687, 0688, 0689, 0690, 0691, 0692, 0693, 0695, 0696, 0697, 0698, 0699, 0700, 0701, 0702, 0703, 0704, 0705, 0706, 0707, 0708, 0709, 0710, 0712, 0713, 0714, 0715, 0716, 0717, 0719, or 0720, the balance screw should be replaced according to PART II. – If the RAT is not identified as described above, no action is required. To gain access to the work area, it is necessary to deploy the RAT located in the RH forward fuselage bottom, zone 124.
PART II REPLACEMENT OF THE BALANCE SCREW Applicable to: SB EFFECTIVITY 

## The modification applicable to PART II of this bulletin consists in replacing the balance screw of the RAT. To gain access to the work area, it is necessary to deploy the RAT located in the RH forward fuselage bottom, zone 124. NOTE: 1) The modification presented in PART I of this bulletin does not affect the Fatigue Critical Structure (FCS) 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 4 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

## 2) The modification presented in PART II of this bulletin affects the Fatigue Critical Structure (FCS); however, no change to the related Damage Tolerance Inspection (DTI) instructions is required.
E. COMPLIANCE Refer to paragraph 1.E. Compliance of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
F. APPROVAL The technical aspects of this service bulletin are approved by: Agência Nacional de Aviação Civil (ANAC).
G. ESTIMATED MANPOWER This estimate is for direct labor only, performed by experienced personnel, and does not include the time to plan, prepare, or inspect the work. It is assumed that all the tools, parts, and other means are readily available when necessary. This estimate does not include the sealant, paint, or adhesive curing time. (1) PART I - RAT INSPECTION – Access opening: 0.1 man-hours. – Inspection: 0.1 man-hours. – Modification: Not applicable. – Access closure: Not applicable. – Test: Not applicable. (2) PART II - BALANCE SCREW REPLACEMENT AND REIDENTIFICATION OF RAT – Access opening: Not applicable. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 5 Embraer Copyright © 2010. All rights reserved.

## – Inspection: Not applicable. – Modification: Refer to paragraph 1.G.Manpower of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
– Access closure: 0.2 man-hours. – Test: Refer to paragraph 1.G.Manpower of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
H. WEIGHT AND BALANCE
None.
I. SOFTWARE ACCOMPLISHMENT SUMMARY
None.
J. REFERENCES AMM 170/( ) Aircraft Maintenance Manual PART II - 20-00-00 - STANDARD PRACTICES-AIRFRAME. AMM 170/( ) Aircraft Maintenance Manual PART II - 24-23-00 - ELECTRICAL POWER.
HS SB ERPS37T-24-5 EMERGENCY ELECTRICAL POWER - RAM AIR TURBINE - REPLACE BALANCE WASHER SCREWS. K. OTHER PUBLICATIONS AFFECTED
None. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 6 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

## 2. MATERIAL INFORMATION
A. MATERIAL - PRICE AND AVAILABILITY (1) MATERIAL AVAILABLE FROM EMBRAER None. (2) MATERIAL AVAILABLE FROM OTHER VENDORS Refer to paragraph 2. A. MATERIAL - PRICE AND AVAILABILITY of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
B. INDUSTRY SUPPORT INFORMATION Refer to paragraph 2. B. INDUSTRY SUPPORT INFORMATION of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
C. MATERIAL NECESSARY FOR EACH AIRCRAFT Refer to paragraph 2. C. MATERIAL NECESSARY FOR EACH UNIT of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
D. MATERIAL NECESSARY FOR EACH SPARE Refer to paragraph 2. D. MATERIAL NECESSARY FOR EACH SPARE of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
E. REIDENTIFIED PARTS Refer to paragraph 2. E. REIDENTIFIED PARTS of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
F. TOOLING - PRICE AND AVAILABILITY Whenever required, necessary the tooling presented in the AMM Tasks referred to in this bulletin should be procured from the operator’s inventories or ordered as spares. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 7 Embraer Copyright © 2010. All rights reserved.

## 3. ACCOMPLISHMENT INSTRUCTIONS NOTE: 1) For the purpose of this Service Bulletin, a General Visual Inspection (GVI) is “A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance, unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.” 2) Obey all of the WARNINGS and CAUTIONS included in the referenced manuals and procedures. 3) The manuals and other documents are referred to by acronyms or using a simplified form. Refer to section 1.J. REFERENCES for a more complete definition. 4) This Service Bulletin effectivity is divided into 2 PARTS. The SB PARTS are featured to allow their independent accomplishment. The steps below outline the general accomplishment instructions. The detailed sequence is given in SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin.
A. Make sure that the aircraft is safe for maintenance. Refer to AMM TASK 20-00-00-910-801-A/200 - Aircraft Maintenance Safety Procedures - Standard Procedures. B. Deploy the RAT. Refer to AMM TASK 24-23-00-710-801-A/500 - Ram-Air-Turbine (RAT) Manual Deployment - Operational Test.
C. PART I - RAT INSPECTION (1) Check the RAT Model, PN and Serial number, as shown in Figure 1

. (a) If the RAT is identified as Model ERPS37T, PN 1703781 Series, serial numbers: 0101, 0104, 0105, 0106, 0108, 0112, 0115, 0116, 0117, 0118, 0119, 0122, 0125, 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 8 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

## 0131, 0132, 0134, 0139, 0140, 0142, 0143, 0145, 0146, 0148, 0152, 0155, 0158, 0159, 0161, 0164, 0165, 0166, 0167, 0169, 0170, 0171, 0172, 0173, 0175, 0176, 0177, 0178, 0179, 0181, 0186, 0187, 0188, 0190, 0196, 0198, 0199, 0200, 0201, 0202, 0203, 0204, 0205, 0208, 0209, 0210, 0212, 0213, 0214, 0217, 0218, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0228, 0229, 0230, 0233, 0234, 0236, 0238, 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0249, 0250, 0251, 0253, 0255, 0256, 0257, 0264, 0265, 0266, 0268, 0272, 0273, 0277, 0279, 0281, 0283, 0285, 0286, 0287, 0288, 0290, 0291, 0293, 0294, 0295, 0299, 0300, 0301, 0302, 0303, 0307, 0308, 0309, 0311, 0313, 0314, 0315, 0316, 0317, 0318, 0319, 0320, 0321, 0322, 0323, 0324, 0326, 0329, 0331, 0333, 0334, 0335, 0336, 0337, 0339, 0340, 0341, 0346, 0347, 0348, 0349, 0350, 0352, 0353, 0364, 0370, 0371, 0374, 0375, 0385, 0386, 0389, 0394, 0412, 0416, 0417, 0424, 0430, 0454, 0467, 0469, 0473, 0474, 0479, 0480, 0481, 0482, 0483, 0484, 0485, 0486, 0487, 0488, 0489, 0490, 0491, 0492, 0493, 0494, 0495, 0496, 0497, 0498, 0499, 0500, 0501, 0502, 0503, 0504, 0505, 0506, 0507, 0508, 0509, 0510, 0511, 0512, 0513, 0514, 0515, 0516, 0517, 0518, 0519, 0520, 0521, 0522, 0523, 0524, 0525, 0526, 0527, 0528, 0529, 0530, 0531, 0532, 0533, 0534, 0535, 0536, 0537, 0538, 0539, 0540, 0541, 0542, 0543, 0544, 0545, 0546, 0547, 0548, 0549, 0550, 0551, 0552, 0553, 0554, 0555, 0556, 0557, 0558, 0559, 0560, 0562, 0563, 0564, 0565, 0566, 0567, 0568, 0569, 0570, 0571, 0572, 0573, 0574, 0575, 0576, 0577, 0578, 0579, 0580, 0581, 0582, 0583, 0584, 0585, 0586, 0587, 0588, 0589, 0590, 0591, 0592, 0593, 0594, 0595, 0596, 0597, 0598, 0599, 0600, 0602, 0603, 0604, 0605, 0606, 0607, 0608, 0609, 0610, 0611, 0613, 0614, 0615, 0616, 0617, 0619, 0620, 0621, 0622, 0623, 0624, 0625, 0626, 0628, 0629, 0630, 0631, 0633, 0634, 0636, 0637, 0638, 0639, 0640, 0641, 0642, 0643, 0644, 0645, 0647, 0648, 0649, 0650, 0651, 0652, 0653, 0654, 0655, 0656, 0657, 0658, 0659, 0660, 0661, 0662, 0663, 0664, 0666, 0667, 0668, 0669, 0670, 0671, 0672, 0673, 0674, 0675, 0676, 0677, 0678, 0679, 0681, 0682, 0683, 0684, 0686, 0687, 0688, 0689, 0690, 0691, 0692, 0693, 0695, 0696, 0697, 0698, 0699, 0700, 0701, 0702, 0703, 0704, 0705, 0706, 0707, 0708, 0709, 0710, 0712, 0713, 0714, 0715, 0716, 0717, 0719, or 0720, the balance screw should be replaced according to PART II. (b) If the Model is not identified as described above, no action is required, and go to Step 3.E.
D. PART II - BALANCE SCREW REPLACEMENT AND REIDENTIFICATION OF RAT 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 9 Embraer Copyright © 2010. All rights reserved.

## 1) Replace the balance screw of the RAT as per the instructions presented in item 3. ACCOMPLISHMENT INSTRUCTIONS of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin. 2) Identify the RAT according to item 3.C. Identification of HS SB ERPS37T-24-5 attached to Section 4. APPENDIX 1 of this bulletin. Refer to Figure 1 of this bulletin.
E. Stow the retraction of the RAT. Refer to AMM TASK 24-23-00-840-801-A/200 - Ram-Air-Turbine (RAT) - Retraction.
F. Restore the aircraft to normal. G. Enter the accomplishment of this bulletin in the applicable documents. NOTE: 1) Please inform us by e-mail fleet.reliability@embraer.com.br of the aircraft manufacturer serial number and the SB incorporation date, specifying the SB Part(s) incorporated or whether the whole SB has been incorporated. This will enable Embraer to consider your aircraft configuration when providing future modifications. 2) To formally inform that the SB has been incorporated fleet-wide or that the SB will not be incorporated, so that Embraer can update the affected technical publications, use the “Service Bulletin Full-Fleet Incorporation Report” form, which is available on the Flyembraer portal (http://www.flyembraer.com). 3) Use the attached “Service Bulletin Evaluation” form to send us your comments regarding this SB. Your feedback will be much appreciated as an aid to help us improve the quality of the SBs. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 10 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.ZONE 124 

## A



# A B



# C RAT IDENTIFICATION PLATE (REF.) 

## C



# B
SYMBOL "24−5" (ENGRAVE) RAT (REF.)



### PART NO

FAA/PMA SERIAL NO DATE OF MFG AMENDMENT 

# RAM AIR TURBINE FAA/PMA

24−5EM170SB240404A.DGN 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 11 FIGUR E 1 - IDENTIFICATION OF THE RAM AIR TURBINE (RAT) (SHEET 01 OF 01)

Embraer Copyright © 2010. All rights reserved.

## 4. APPENDIX 1 HS SB ERPS37T-24-5 - EMERGENCY ELECTRICAL POWER - RAM AIR TURBINE - REPLACE BALANCE WASHER SCREWS 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 12 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 1 of 15 EMERGENCY ELECTRICAL POWER - RAM AIR TURBINE - REPLACE BALANCE WASHER SCREWS
© 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 RECIPIENT’S INTERNAL PURPOSES TO MAINTAIN RECIPIENT’S 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 AND/OR CIVIL LIABILITY. Information 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 Administrati on Act.
The data in this document were developed only to maintain systems and/or parts manufactured by or for Hamilton Sundstrand or ap proved by Hamilton Sundstrand. The data may not be applicable to any other systems and/or parts, regardless of their apparent similari ty to systems and/or parts manufactured by or for Hamilton Sundstrand or approved by Hamilton Sundstrand. Do not rely in any way on d ata 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. 1. Planning Information A. Effectivity The Hamilton Sundstrand Ram Air Turbines (RAT), Model ERPS37T, that are listed below and used on Embraer 170 and 190 aircraft.

Part Number Series Serial Numbers 1703781 0101, 0104, 0105, 0106, 0108, 0112, 0115, 0116, 0117, 0118, 0119, 0122, 0125, 0131, 0132, 0134, 0139, 0140, 0142, 0143, 0145, 0146, 0148, 0152, 0155, 0158, 0159, 0161, 0164, 0165, 0166, 0167, 0169, 0170, 0171, 0172, 0173, 0175, 0176, 0177, 0178, 0179, 0181, 0186, 0187, 0188, 0190, 0196, 0198, 0199, 0200, 0201, 0202, 0203, 0204, 0205, 0208, 0209, 0210, 0212, 0213, 0214, 0217, 0218, 0221, 0222, 0223, 0224, 0225, 0226, 0227, 0228, 0229, 0230, 0233, 0234, 0236, 0238, 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0249, 0250, 0251, 0253, 0255, 0256, 0257, 0264, 0265, 0266, 0268, 0272, 0273, 0277, 0279, 0281, 0283, 0285, 0286, 0287, 0288, 0290, 0291, 0293, 0294, 0295, 0299, 0300, 0301, 0302, 0303, 0307, 0308, 0309, 0311, 0313, 0314, 0315, 0316, 0317, 0318, 0319, 0320, 0321, 0322, 0323, 0324, 0326, 0329, 0331, 0333, 0334, 0335, 0336, 0337, 0339, 0340, 0341, (continued on the next page) 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 13 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 2 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. B. Concurrent Requirements None. C. Reason Hamilton Sundstrand has discovered that RATs were manufactured with nonconforming screws. To date, there have been five instances of a fractured balance washer screw on multiple RAT part number configurations. 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. Part Number Series Serial Numbers 1703781 (continued from the previous page) 0346, 0347, 0348, 0349, 0350, 0352, 0353, 0364, 0370, 0371, 0374, 0375, 0385, 0386, 0389, 0394, 0412, 0416, 0417, 0424, 0430, 0454, 0467, 0469, 0473, 0474, 0479, 0480, 0481, 0482, 0483, 0484, 0485, 0486, 0487, 0488, 0489, 0490, 0491, 0492, 0493, 0494, 0495, 0496, 0497, 0498, 0499, 0500, 0501, 0502, 0503, 0504, 0505, 0506, 0507, 0508, 0509, 0510, 0511, 0512, 0513, 0514, 0515, 0516, 0517, 0518, 0519, 0520, 0521, 0522, 0523, 0524, 0525, 0526, 0527, 0528, 0529, 0530, 0531, 0532, 0533, 0534, 0535, 0536, 0537, 0538, 0539, 0540, 0541, 0542, 0543, 0544, 0545, 0546, 0547, 0548, 0549, 0550, 0551, 0552, 0553, 0554, 0555, 0556, 0557, 0558, 0559, 0560, 0562, 0563, 0564, 0565, 0566, 0567, 0568, 0569, 0570, 0571, 0572, 0573, 0574, 0575, 0576, 0577, 0578, 0579, 0580, 0581, 0582, 0583, 0584, 0585, 0586, 0587, 0588, 0589, 0590, 0591, 0592, 0593, 0594, 0595, 0596, 0597, 0598, 0599, 0600, 0602, 0603, 0604, 0605, 0606, 0607, 0608, 0609, 0610, 0611, 0613, 0614, 0615, 0616, 0617, 0619, 0620, 0621, 0622, 0623, 0624, 0625, 0626, 0628, 0629, 0630, 0631, 0633, 0634, 0636, 0637, 0638, 0639, 0640, 0641, 0642, 0643, 0644, 0645, 0647, 0648, 0649, 0650, 0651, 0652, 0653, 0654, 0655, 0656, 0657, 0658, 0659, 0660, 0661, 0662, 0663, 0664, 0666, 0667, 0668, 0669, 0670, 0671, 0672, 0673, 0674, 0675, 0676, 0677, 0678, 0679, 0681, 0682, 0683, 0684, 0686, 0687, 0688, 0689, 0690, 0691, 0692, 0693, 0695, 0696, 0697, 0698, 0699, 0700, 0701, 0702, 0703, 0704, 0705, 0706, 0707, 0708, 0709, 0710, 0712, 0713, 0714, 0715, 0716, 0717, 0719, 0720 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 14 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 3 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. D. Description This bulletin gives instructions to replace the balance washer screws and identify the RAT.
For a 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 RAT as necessary to remove the fractured screw and balance washer, balance the turbine assembly, assemble the RAT, and test the RAT. E. Compliance Incorporation of this service bulletin is to be accomplished at the earliest opportunity. F. Approval Government or other regulatory agency approval of the bulletin is the responsibility of Embraer. Embraer has reviewed and approved this document. G. Manpower A maximum of 0.5 man-hour will be required to replace the balance washer screws and identify the RAT.
For a RAT with a missing balance washer, or with a balance washer screw that cannot be removed in its entirety, a maximum of 8.0 man-hours will be required to disassemble the RAT as necessary to remove the fractured screw and balance washer, balance the turbine assembly, assemble the RAT, and test the RAT. H. Weight and Balance None. I. Electrical Load Data Not applicable. J. Software Accomplishment Summary Not applicable. K. References Applicable Aircraft Maintenance Manual (AMM), Hamilton Sundstrand Component Maintenance Manual (CMM) 24-23-60, Hamilton Sundstrand Standard Practices Manual (SPM) 20-00-00, and Embraer Service Bulletins 170-24-0048 and 190-24-0019. L. Other Publications Affected Hamilton Sundstrand CMM 24-23-60 will be revised to incorporate this service bulletin. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 15 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 4 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. M. Interchangeability or Intermixability of Parts Not affected. 2. Material Information A. Material - Price and Availability (1) Hamilton Sundstrand will supply the replacement parts required for accomplishment of this bulletin on a no-charge basis until March 21, 2012 . The replacement parts are currently available in limited quantities (refer to Table 1 of this bulletin for the parts breakdown). Operators approved by Hamilton Sundstrand to perform the 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 bulletin number, serial numbers of affected units, total quantity of parts, and anticipated incorporation schedule. Hamilton Sundstrand will acknowledge the operator order with an established delivery rate. B. Industry Support Information (1) Hamilton Sundstrand will also give the following: (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 March 21, 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 (refer to Embraer Service Bulletin 170-24-0048 or 190-24-0019). The labor allowance will expire March 21, 2012

. (c) If removal from the aircraft is required, a maximum labor allowance of 6.0 manhours multiplied by the operator's current approved hourly rate for replacement of the RAT on the aircraft and test on wing (refer to Embraer Service Bulletin 170-24-0048 or 190-24-0019). The labor allowance will expire March 21, 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. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 16 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 5 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. (2) 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 March 21, 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 C. Material Necessary For Each Unit (1) Material to be Purchased Table 1 New Parts Necessary

Table 1 Note 1: Operators should order a quantity of 10 screws for each unit for incorporation of this bulletin. Table 1 Note 2: Hamilton Sundstrand will supply the noted part at no charge (refer to paragraph 2.A. of this bulletin). (2) Material Supplied by the Operator (a) None. D. Material Necessary For Each Spare (1) The same as the material necessary for each unit. E. Reidentified Parts (1) Refer to paragraph 3.C. of this bulletin. F. Tooling - Price and Availability (1) No tooling other than that required for shop maintenance of the RAT is required to do this modification. New Part Number Nomenclature Old Part Number Qty Unit Price Disposition Instructions Same Screw MS24667-14 AR (Note 1) (Note 2) Remove suspect old screws, install new conforming screws 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 17 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 6 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. 3. Accomplishment Instructions A. General CAUTION: THE 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 24-23-60 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. B. Modification (1) If the RAT 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. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 18 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 7 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. (3) Rotate the turbine assembly and do a check for missing balance washers (refer to the items that follow): - Balance washers (360, -360A, -360B, or -360C, IPL Figure 2, CMM 24-23-60),

(370 or -370A), and (-375). NOTE: The number of balance washers installed will vary according to the magnitude of the imbalance that existed before the turbine assembly was balanced. - The threaded holes around the turbine circumference that are not used for

balance washers have a set screw installed. The set screw is secured using a 5/64-inch internal hex tool. The set screws should not be removed or replaced. - The threaded holes around the turbine circumference with balance

washers installed, use a countersunk socket head cap screw MS24667-14 to secure the washers [refer to screw (380)]. NOTE: Missing balance washers are evidenced by the remaining screw and primer residue (in a rectangular or circular shaped pattern) on the turbine assembly (refer to Figure 1 of this bulletin). (4) If any balance washers are missing (because of a fractured screw), do the steps that follow: NOTE: If the RAT is installed on the aircraft, it must be removed from the aircraft (refer to the applicable AMM) for removal of the fractured screw and to balance the turbine assembly. The RAT must either be returned to Hamilton Sundstrand or to a repair facility that has the capability to disassemble, repair, balance, and test the RAT. (a) Report any occurrences of a fractured screw to Hamilton Sundstrand as follows: Greg Kuczek Hamilton Sundstrand Service Engineering Phone: +1- 815-226-6581 Fax: +1-860-660-4995 E-Mail: gregory.kuczek@hs.utc.com (b) Disassemble the RAT (refer to CMM 24-23-60, DISASSEMBLY) as necessary to remove the following parts and to get access to the fractured screw. - Balance washers (360, -360A, -360B, or -360C, IPL Figure 2, CMM 24-23-60),

(370 or -370A), and (-375) - Screws (380) 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, the RAT must be disassembled as necessary to remove the screw. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 19 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 8 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. (c) 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. (d) Do a visual check of the self-locking screw thread insert to make sure there is no mechanical damage. (e) Assemble the turbine assembly as necessary (refer to CMM 24-23-60, ASSEMBLY). (f) Remove the protective covering from the turbine blades. (g) Balance the turbine assembly (refer to CMM 24-23-60, ASSEMBLY). (h) Assemble the RAT as necessary (refer to CMM 24-23-60, ASSEMBLY). (i) Do a test of the RAT (refer to 24-23-60, TESTING AND FAULT ISOLATION). (j) After all of the balance washer screws have been replaced, identify the RAT as follows (refer to SPM 20-00-00, ASSEMBLY):

1 Put the symbol 24-5 in the AMENDMENT block of the identification plate (380, IPL Figure 1, CMM 24-23-60). (k) Proceed to paragraph 3.E. 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 ONESCREW IS REMOVED AT A TIME, THE TURBINE ASSEMBLY MUST BE REBALANCED. (5) If no balance washers are missing, do the steps that follow to replace the balance washer screws (one at a time): (a) For each balance washer that is unsymmetrical in shape, 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. NOTE: If a balance washer is circular in shape, it is not necessary to mark its radial orientation. (b) Do one of the steps that follow: 1 If the RAT 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). 2 If the RAT is off the aircraft, position the unit to access the balance washer facing up. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 20 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 9 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. CAUTION: DO NOT USE A WORN INTERNAL 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 internal 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: Greg Kuczek Hamilton Sundstrand Service Engineering Phone: +1- 815-226-6581 Fax: +1-860-660-4995 E-Mail: gregory.kuczek@hs.utc.com 2 If the remaining portion of the fractured screw is protruding above the turbine surface, do the steps that follow:

a Apply protective tape on the turbine (in the area of the screw) to prevent surface damage during the removal attempt. b Use pliers, a vice grip, or an equivalent gripping tool to remove the screw.
c Remove the protective tape from the turbine. d If the screw is removed in its entirety, proceed to step 3.B.(5)(e) of this bulletin. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 21 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 10 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. 3 If the remaining portion of the screw is flush or below the turbine surface, or if the screw can not be removed in its entirety, do the steps that follow: NOTE: If the RAT is installed on the aircraft, Hamilton Sundstrand recommends the RAT be removed from the aircraft (refer to the applicable AMM) for removal of the fractured screw. The RAT 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 RAT 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. The self-locking screw thread insert should be visually inspected (after the screw is extracted) to make sure there is no mechanical damage.
a For RATs removed from the aircraft, disassemble the RAT (refer to CMM 24-23-60, 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, the RAT must be 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. NOTE: If the RAT is installed on the aircraft, and the screw can not be extracted, the RAT must be removed from the aircraft (refer to the applicable AMM) and disassembled as necessary to remove the fractured screw. The RAT should either be returned to Hamilton Sundstrand or to a repair facility that has the capability to disassemble, repair, balance, and test the RAT. 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 22 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 11 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. c Do a visual check of the self-locking screw thread insert to make sure there is no mechanical damage. 4 If disassembly of the turbine assembly was not required to remove the fractured screw, proceed to step 3.B.(5)(e) of this bulletin. 5 For RATs removed from the aircraft, if disassembly of the turbine assembly was required to remove the fractured screw, do the following:

a Remove the remaining screws (380, IPL Figure 2, CMM 24-23-60) and the following balance washers: - Balance washers (360, -360A, -360B, or -360C), (370 or -370A), and

(-375) b Assemble the turbine assembly as necessary (refer to CMM 24-23-60, ASSEMBLY).
c Remove the protective covering from the RAT turbine blades. d Balance the turbine assembly (refer to CMM 24-23-60, ASSEMBLY).
e Assemble the RAT as necessary (refer to CMM 24-23-60, ASSEMBLY). f Do a test of the RAT (refer to CMM 24-23-60, TESTING AND FAULT

ISOLATION). g After all of the balance washer screws have been replaced, identify the RAT as follows (refer to SPM 20-00-00, ASSEMBLY):

1) Put the symbol 24-5 in the AMENDMENT block of the identification plate (380, IPL Figure 1, CMM 24-23-60). h Proceed to paragraph 3.E. of this bulletin. (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 3.B.(5)(a) of this bulletin. (f) While holding the balance washer in place, install a new screw MS24667-14. Torque the screw 16 to 20 pound inches (1.9 to 2.2 Newton meters). NOTE: It is not necessary to remove the existing primer residue or apply new primer if the balance washer inadvertently fell off after the screw was removed. (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 3.B.(5)(b) through (g) of this bulletin for each balance washer screw. (i) Record the total number of replaced screws. 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 23 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 12 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. (j) Remove any tape (that was used to mark the orientation of the installed balance washers or the locations where the screws had been replaced). (k) Remove the protective covering from the RAT turbine blades. (6) After all of the balance washer screws have been replaced, identify the RAT as follows (refer to SPM 20-00-00, ASSEMBLY): (a) Put the symbol 24-5 in the AMENDMENT block of the identification plate (380, IPL Figure 1, CMM 24-23-60). (7) If the RAT 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 RAT is identified by adding the symbol 24-5 in the AMENDMENT block of the 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 optional based on operator experience, normal shop practices, and reason for removal (refer to CMM 24-23-60, TESTING AND FAULT ISOLATION). 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 RAT the screws were removed from and to identify the applicable aircraft MSN. (c) Return the screws with the applicable RAT part number, RAT serial number, and aircraft MSN to the address that follows: Hamilton Sundstrand Service Engineering 4747 Harrison Avenue P.O. Box 7002 Rockford, IL 61125-7002 Attention: Greg Kuczek Phone: +1- 815-226-6581 Fax: +1-860-660-4995 E-Mail: gregory.kuczek@hs.utc.com 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 24 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 13 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. F. Notification of Completion Form (1) Do the following upon completion of this service bulletin: (a) Make a copy of the “Notification of Completed SB ERPS37T-24-5” form (refer to Table 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 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 25 Embraer Copyright © 2010. All rights reserved.Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 14 

# SERVICE BULLETIN

Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. Figure 1 Missing Balance Washer

SB-ERPS37T245-104620 

# SERVICE BULLETIN

SB No.: 170-24-0048 PAGE: 26 DATE: 31/Mar/2010 REVISION No.: 01 - 12/May/2010 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN

Original Issue Date: Mar 22/10 ERPS37T-24-5 Page 15 Hamilton Sundstrand Proprietary - Use or disclosure of this data is subject to restrictions on the title page of this document. Table 2 Notification of Completion Form NOTIFICATION OF COMPLETED SB ERPS37T-24-5 “Replace Balance Washer Screws”
SENT FROM: Sender Name: 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

RAT Serial Number Aircraft MSN or Tail Number Bulletin Completion Date Number of Replaced

Screws Comments 

# SERVICE BULLETIN

DATE: 31/Mar/2010 REVISION No.:01 - 12/May/2010 

## SB No.: 170-24-0048 PAGE: 27 Embraer Copyright © 2010. All rights reserved.

# SERVICE BULLETIN EVALUATION

THE PURPOSE OF THIS FORM IS TO COLLECT DATA THAT WILL BE USED TO IMPROVE THE QUALITY OF OUR SERVICE BULLETINS AND UPDATE THE TECHNICAL PUBLICATIONS. PLEASE FILL IN FORM AND RETURN IT TO: EMBRAER - EMPRESA BRASILEIRA DE AERONÁUTICA S.A. EFTC - SERVICE BULLETIN ENGINEERING AV. BRIGADEIRO FARIA LIMA, 2170 SÃO JOSÉ DOS CAMPOS - SP - 12227-901 BRASIL Fax: + 55 12 3927-6600 (ext. 1624) e-mail: fleet.reliability@embraer.com.br 

### S.B. Title: S.B.: (Number / Rev.) Operator:
SB Implementation Report Aircraft Serial Number or Registration Number: Incorporation Date: Aircraft Flight Hours: Aircraft Landings:

POST-ACCOMPLISHMENT EVALUATION: (Check applicable squares below) 

### ESTIMATED MANPOWER: [ ] OK [ ] NOT OK (Explain Below) MATERIAL & KITS: [ ] OK [ ] NOT OK (Explain Below) ACCOMPLISHMENT INSTRUCTIONS: [ ] OK [ ] NOT OK (Explain Below) FIGURES: [ ] OK [ ] NOT OK (Explain Below) SB GENERAL EVALUATION: [ ] OK [ ] NOT OK (Explain Below) COMMENTS: (Bulletin quality/ Difficulties found at the time of incorporation/ Suggested improvements/ Other)

Organization: Fax: Phone:
E-mail: Address: Prepared by:(Name/Title) Date:



### Embraer Copyright © 2010. All rights reserved.