Hydraulic Power − Hydraulic System No. 3 − Inspection of the System Accumulator Screw−Caps

These pages transmit: Revision B of Alert Service Bulletin A670BA−29−012, pages 1 thru 20, dated Dec 22/2010. and Revision A of Appendix A pages A1 thru A9, dated Jul 27/2010.
The changes in this revision have no effect on aircraft that have incorporated a previous issue of this service bulletin.

Reason:

Revised Planning Information, paragraph 1., to: Remove aircraft serial numbers 10302 thru 10999, 15233, 15234, 15239, and 15259 thru 15990 from the effectivity of the service bulletin. Add a note in Compliance paragraph 1.D. Add Bombardier Regional Jet Series All Operator Message (AOM), No. 614, Parker Service Information Letter 900097−29−226, and to change Parker Service Bulletin 900097−1−29−392 Revision 1 for Revision 2 in References paragraph 1.K.
Revised Accomplishment Instructions, paragraph 2., to: Change task AMM 29−12−11−720−801 for AMM 29−12−11−720−802. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 1 of 2 Dec 22/2010 

# SERVICE BULLETIN REVISION TRANSMITTAL SHEET

CL−600−2C10, CL−600−2D15, CL−600−2D24 and CL−600−2E25 CANADAIR REGIONAL JET (CRJ) AIRCRAFT

SUBJECT:This revision also includes small editorial changes that do not have an effect on the technical content.

Document Instructions: Discard the copy of Alert Service Bulletin A670BA−29−012, Revision A, dated Jul 27/2010. Replace with the copy attached. Service Bulletin History: Initial issue, dated Mar 13/2008. Revision A, dated Jul 27/2010. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 2 of 2 Dec 22/2010 

### REVISION TRANSMITTAL SHEETHydraulic Power − Hydraulic System No. 3 − Inspection of the System Accumulator Screw−Caps

1. PLANNING INFORMATION A. Effectivity (1) Aircraft Affected: Service Bulletin: CL−600−2C10 Canadair Regional Jet (CRJ) Aircraft Serial Numbers 10003 thru 10301.
Production: There is no production effectivity.
Service Bulletin: CL−600−2D15 Canadair Regional Jet (CRJ) and CL−600−2D24 Canadair Regional Jet (CRJ) Aircraft Serial Numbers 15001 thru 15232, 15235 thru 15238, and 15240 thru 15258.
Production: There is no production effectivity.

NOTE : The instructions in this service bulletin are only applicable to the systems and parts installed at the time of delivery of the aircraft or as changed by Bombardier Aerospace Service Bulletin. Before you do this bulletin, examine all STC, STA or equivalent action changes to make sure this bulletin can be completed. ATA SYSTEM: 29−11 NUMBER: A670BA−29−012

S.B. A670BA−29−012 Page 1 of 20 Mar 13/2008 Revision B, Dec 22/2010 

# ALERT SERVICE BULLETIN

Technical Publications

THIS SERVICE BULLETIN IS SENT TO EACH OPERATOR. IF THE OPERATOR HAS LEASED AIRCRAFT, THIS SERVICE BULLETIN MUST BE SENT TO THE LESSEE. IF THE OPERATOR HAS SOLD AIRCRAFT OR TRANSFERRED SPARES IN THE LAST SIX MONTHS, THIS SERVICE BULLETIN MUST BE SENT TO THE NEW OWNER, UNLESS CONFIRMATION WAS RECEIVED THAT BOMBARDIER COMMERCIAL AIRCRAFT DIVISION HAS INCLUDED THE NEW OPERATOR ON THE DISTRIBUTION LIST.

SUBJECT:B. Reason (1) Condition It is possible for the screw−caps of the system No. 3 accumulator to have cracks in the inner shoulder. This can cause the screw−cap to rupture and cause damage to the aircraft structure and systems. (2) Evidence A screw−cap ruptured and disconnected from the hydraulic side of hydraulic system No. 1 on a CRJ 200 aircraft. (3) Objective/Benefit This service bulletin gives the procedure to do a detailed inspection and an ultrasonic inspection on the screw−caps of the accumulator of hydraulic system No. 3. This will prevent damage to the accumulators, aircraft structure and systems. C. Description This service bulletin is divided in two parts: PART A and PART B. PART A − Detailed Inspection of the System Accumulator Screw−Caps The access panel for the hydraulic system No. 3 components is opened. The hydraulic pressure is released from system No. 3. The electrical power is removed. The circuit breakers are opened. The nitrogen pressure is bled from the system No. 3 accumulator. A visual inspection is done on both ends of the system accumulator screw−caps. The circuit breakers are closed. The servicing of the system accumulator is done. The access panel for the hydraulic system No. 3 components is closed. PART B − Ultrasonic Inspection of the System Accumulator Screw−Caps The access panel for the hydraulic system No. 3 components is opened. The hydraulic pressure is released from system No. 3. The electrical power is removed. The circuit breakers are opened. The nitrogen pressure is bled from the system No. 3 accumulator. The system accumulator is removed. An ultrasonic inspection is done on the system accumulator screw−caps. The system accumulator is installed. The circuit breakers are closed. If necessary, hydraulic system No.3 is filled. The servicing of the system accumulator is done. The nitrogen leak test is done. The hydraulic system is bled. The access panel for the hydraulic system No. 3 components is closed. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 2 of 20 Mar 13/2008 Revision B, Dec 22/2010D. Compliance Alert Service Bulletin. NOTE : It is not necessary to do this service bulletin when Service Bulletin 670BA−29−015, Hydraulic Power − Hydraulic System No. 3 − Replacement of Accumulator P/N 900097

– 1 by P/N 900122

– 1, is done. Bombardier Aerospace recommends that this service bulletin be done as shown in the table below, unless otherwise directed by the airworthiness authority of the operator: NOTE : The letter ‘M’ added at the end of the serial number of accumulators P/N 900097−1 identifies that the new screw−caps were installed as shown in Parker Service Bulletin 900097−1−29−392. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 3 of 20 Mar 13/2008 Revision B, Dec 22/2010APPLICABLE COMPLIANCE INSPECTION RESULTS ACTION

For hydraulic system No. 3: Accumulators P/N 900097−1 with serial numbers without letter ‘M’ at the end (For the list of serial numbers see TABLE 1 and the note below). For accumulators that have 4500 flight cycles or less, it is necessary to do PART A of this service bulletin before accumulators have 5000 flight cycles. If a crack is found during the detailed inspection (PART A), it is necessary to replace the accumulator before next flight.
The crack must be identified by an ultrasonic inspection described in PART B. It is necessary to repeat the detailed inspection (PART A) every 500 flight cycles from the initial inspection. Or
It is not necessary to do or repeat PART A if PART B is done. For accumulators that have more than 4500 flight cycles, it is necessary to do PART A of this service bulletin no more than 500 flight cycles from the issue date on this service bulletin.

For accumulators that have 3000 flight cycles or less, it is necessary to do PART B of this service bulletin before accumulators have 5000 flight cycles. If a crack is found during the ultrasonic inspection (PART B), it is necessary to replace the accumulator before next flight. It is necessary to do PART B of this service bulletin every 1500 flight cycles from the initial PART B inspection. For accumulators that have more than 3000 flight cycles, it is necessary to do PART B of this service bulletin before 2000 flight cycles from the issue date of this service bulletin. For hydraulic system No. 3: Accumulators P/N 900097−1 with serial numbers with letter ‘M’ at the end. It is not necessary to do this service bulletin. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 4 of 20 Mar 13/2008 Revision B, Dec 22/2010TABLE 1

60207−0001 thru 60207−0008 60207−0010
60207−0013 thru 60207−0020 60207−0022 thru 60207−0026 60207−0029 thru 60207−0039 60207−0041 thru 60207−0045 60207−0047 thru 60207−0052 60207−0054 thru 60207−0056, 60207−0059 thru 60207−0067, 60207−0069 thru 60207−0070, 60207−0073 thru 60207−0080 60207−0082
60207−0084 thru 60207−0088 60207−0090 thru 60207−0097 60207−0101 thru 60207−0105 60207−0107 thru 60207−0114 60207−0116 thru 60207−0118 60207−0120 thru 60207−0122 60207−0124 thru 60207−0126 60207−0128 thru 60207−0134 60207−0138 thru 60207−0147 60207−0149 thru 60207−0163 60207−0165 thru 60207−0180 60207−0182 thru 60207−0204 60207−0206 thru 60207−0224 60207−0226 thru 60207−0233 60207−0235
60207−0237 thru 60207−0243 60207−0245
60207−0247 thru 60207−0249 60207−0251 thru 60207−0257 60207−0259 thru 60207−0261 60207−0263
60207−0265 thru 60207−0266 60207−0269 thru 60207−0273 60207−0275 thru 60207−0297 60207−0299 thru 60207−0309 60207−0311 thru 60207−0315 60207−0317 thru 60207−0319 60207−0321 thru 60207−0326 60207−0328 thru 60207−1002 60207−1005 thru 60207−1011 60207−1016 thru 60207−1019

NOTE : For serial numbers listed in TABLE 2 below, the new screw−caps were installed by Parker but it is necessary to incorporate Parker Service Bulletin 900097−1−29−392 to add the letter ‘M’ at the end of the serial numbers. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 5 of 20 Mar 13/2008 Revision B, Dec 22/2010TABLE 2

60207−0009 60207−0011 60207−0012 60207−0021 60207−0027 60207−0028 60207−0040 60207−0046 60207−0053 60207−0057 60207−0058 60207−0068 60207−0071 60207−0072 60207−0081 60207−0083A 60207−0089 60207−0098 60207−0099 60207−0100 60207−0106 60207−0115 60207−0119 60207−0123 60207−0127 60207−0135 60207−0136 60207−0137 60207−0148 60207−0164A 60207−0181 60207−0205 60207−0225 60207−0234A 60207−0236 60207−0244 60207−0246 60207−0250 60207−0258 60207−0262 60207−0264 60207−0267 60207−0268 60207−0274 60207−0298 60207−0310 60207−0316 60207−0320 60207−0327 60207−1003 60207−1004 60207−1012 60207−1013 60207−1014 60207−1015 60207

– 1020 thru 60207

– 1321

This service bulletin does not affect Airworthiness Limitations (AWLs) or Damage Tolerance Inspections (DTIs). E. Approval The technical content of this service bulletin has been approved under the authority of the TCCA Design Approval Organization No: DAO #93−Q−02. F. Manpower The man−hours given below are an estimate for direct labor done by an experienced crew on an aircraft prepared for maintenance. These estimates do not include the time necessary for: − Administrative functions such as planning, liaison, familiarization, and report writing. − Non productive elapsed time such as rest time, having meals, and crew shift changes. − Elapsed time such as for paint to dry, sealant to cure, and fuel tank venting. − Preparation for modification (unless specified in the accomplishment instructions) such as cleaning and getting parts, tools, consumables, and ground equipment. − Quality assurance inspections, troubleshooting and/or correction of discrepancies found when a task is done. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 6 of 20 Mar 13/2008 Revision B, Dec 22/2010− All other activities that are not considered by Bombardier Aerospace as directly related to the accomplishment of this procedure. NOTE : For on−site labor assistance, please speak with a Fleet Services representative for a quote. The Fleet Services team can be contacted via the CRC at 514−855−8500 or email at thd.crj@aero.bombardier.com. PART A − Detailed Inspection of the System Accumulator Screw−Caps It will take an estimated 3.0 man−hours to complete PART A of this service bulletin. The man−hours are divided as shown in the table that follows:

TASK MAN−HOURS (1) Job Set−Up 1.0 (2) Procedure 0.5 (3) Test 1.0 (4) Job Close−Out 0.5

NOTE : The man−hours for the procedure do not include the hours to replace damaged parts. If replacement is necessary, add 2.0 hours for the accumulator. PART B − Ultrasonic Inspection of the System Accumulator Screw−Caps It will take an estimated 5.5 man−hours to complete PART B of this service bulletin. The man−hours are divided as shown in the table that follows:

TASK MAN−HOURS (1) Job Set−Up 1.0 (2) Procedure 3.0 (3) Test 1.0 (4) Job Close−Out 0.5
G. Material − Price and Availability (1) There are no kits for this service bulletin. (2) Refer to paragraph 3.C. for a list of consumables for this service bulletin. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 7 of 20 Mar 13/2008 Revision B, Dec 22/2010H. Tooling − Price and Availability (1) The tool kit in the table that follows is available from Bombardier commercial aircraft. NOTE : For a list of the kit contents, refer to paragraph 3.A.

KIT NUMBER NAME

670BA29012K90 NDT Calibration Tool

NOTE : 601R29−030K90 NDT calibration tool can be used as an alternative tool. (2) Please send a purchase order to the address below to schedule the kit:
Bombardier Service Bulletin Kit Support Team 123 Garratt Blvd, N42−24 Toronto, Ontario Canada M3K 1Y5 Fax: 416−375−3060 Phone: 416−375−3920 email: sbkits@aero.bombardier.com Please contact your Service Bulletin Kit Support Team at the address above for terms and conditions. I. Weight and Balance Not changed.
J. Electrical Load Data Not changed.
K. References − Restriction and/or Special Instruction (RSI), C−29−1052−00, Revision B. − Parker Service Bulletin 900097−1−29−392, Revision 2, dated Sep 30/2010. − Bombardier Regional Jet Series All Operator Message (AOM), No. 614. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 8 of 20 Mar 13/2008 Revision B, Dec 22/2010− Parker Service Information Letter 900097−29−226. − Aircraft Maintenance Manual (AMM), CSP B−001. − Nondestructive Testing Manual (NDT), CSP B−010. − For Bombardier Aerospace reference only: PCA 72957.
L. Other Publications Affected None. M. Relationship Chart Not applicable. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 9 of 20 Mar 13/2008 Revision B, Dec 22/20102. ACCOMPLISHMENT INSTRUCTIONS PART A − Detailed Inspection of the System Accumulator Screw−Caps A. Job Set−Up (1) Reference Information

REFERENCE DESIGNATION AMM 12−00−00−867−801 Standard Aircraft Configuration for Maintenance
AMM 12−00−06−862−804 Release Hydraulic Pressure of System No. 3
AMM 12−12−29−614−801 Servicing of the Hydraulic System Accumulators
AMM 24−00−00−861−802 Remove Electrical Power from the Aircraft
AMM 24−00−00−910−801 Electrical/Electronic Safety Precautions
AMM 29−00−00−910−801 Hydraulic Safety Precautions
AMM 53−52−32−010−801 Opening of the Hydraulic Lower Access Panel (195AB)
AMM 53−52−32−410−801 Closing of the Hydraulic Lower Access Panel (195AB) (2) Standard Practices Information

REFERENCE DESIGNATION AMM 51−26−00−110−801 Solvent Cleaning
NDT 51−20−009−210 Visual − Inspection Procedures (3) Make sure that the aircraft is in standard configuration for maintenance (AMM 12−00−00−867−801). 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 10 of 20 Mar 13/2008 Revision B, Dec 22/2010Refer to Figure 1. (4) Open the system accumulator pressure fill point access door (196CR). (5) Open the hydraulic lower access panel (195AB) (AMM 53−52−32−010−801). WARNING : OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU DO MAINTENANCE ON OR NEAR ELECTRICAL/ELECTRONIC EQUIPMENT. YOU CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT. (6) Obey all the electrical/electronic safety precautions (AMM 24−00−00−910−801). (7) Remove the electrical power from the aircraft (AMM 24−00−00−861−802). WARNING : OBEY ALL HYDRAULIC SAFETY PRECAUTIONS WHEN YOU DO WORK ON THE HYDRAULIC SYSTEM AND HYDRAULIC SYSTEM COMPONENTS. YOU CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE EQUIPMENT. (8) Obey all the hydraulic safety precautions (AMM 29−00−00−910−801). (9) Release the hydraulic pressure from hydraulic system No. 3 (AMM 12−00−06−862−804). (10) Install safety placard “ No ground hydraulic power connection of No. 3 hydraulic system ” on the pilot control column. Refer to Figure 2. WARNING : USE PROTECTIVE GLOVES TO CAREFULLY LOOSEN THE VALVE NUT ON THE NITROGEN CHARGING VALVE. KEEP YOUR HANDS AWAY FROM THE NITROGEN LEAKAGE. THE NITROGEN LINE IS PRESSURIZED AND CAN CAUSE INJURY. (11) Release the nitrogen pressure as follows: (a) Remove the dust cap (4) from the nitrogen charge valve (3). (b) Carefully loosen the thin nut on the nitrogen charge valve (3). (c) Let the nitrogen pressure go to zero. (d) Install the dust cap (4) from the nitrogen charge valve (3).
B. Procedure Refer to Figures 1 and 2. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 11 of 20 Mar 13/2008 Revision B, Dec 22/2010WARNING : OBEY ALL CLEANING SAFETY PRECAUTIONS. YOU CAN CAUSE INJURIES TO PERSONS AND DAMAGE TO THE EQUIPMENT. (1) Clean the inspection area section of the system accumulator screw caps (2) with isopropyl alcohol and a dry, clean cloth. (2) Do a visual inspection of the two screw−caps (2) of the system accumulator (1) for an indication of a crack (NDT 51−20−009−210). (3) If there is an indication of a crack on the system accumulator (1), do PART B. C. Job Close−Out (1) Remove all tools, equipment, and unwanted materials from the work area. (2) Remove safety placard for “ No ground hydraulic power connection of No.3 hydraulic system ” on the pilot control column. (3) Do the servicing of the hydraulic system No.3 accumulator (AMM 12−12−29−614−801). (4) Close the system accumulator pressure fill point access door (196CR). (5) Close the hydraulic lower access panel (195AB) (AMM 53−52−32−410−801). (6) When PART A of this service bulletin is completed, make this entry in the applicable logbook as follows: "Alert Service Bulletin A670BA−29−012, Revision B, Hydraulic Power − Hydraulic System No. 3 − Inspection of the System Accumulator Screw−Caps, PART A incorporated." PART B − Ultrasonic Inspection of the System Accumulator Screw−Caps A. Job Set−Up (1) Reference Information

REFERENCE DESIGNATION AMM 12−00−00−867−801 Standard Aircraft Configuration for Maintenance
AMM 12−00−06−862−804 Release Hydraulic Pressure of System No. 3
AMM 12−12−29−611−802 Servicing of the Hydraulic System No.3 Reservoirs 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 12 of 20 Mar 13/2008 Revision B, Dec 22/2010REFERENCE DESIGNATION AMM 12−12−29−614−801 Servicing of the Hydraulic System Accumulators
AMM 24−00−00−861−802 Remove Electrical Power from the Aircraft
AMM 24−00−00−910−801 Electrical/Electronic Safety Precautions
AMM 29−00−00−910−801 Hydraulic Safety Precautions
AMM 29−10−00−870−802 Bleed Hydraulic system No.3
AMM 29−12−11−720−802 Functional Test of the System No.3 Accumulator Pressure Decay Rate
AMM 29−12−11−000−801 Removal of the System No.3 Accumulator
AMM 29−12−11−400−801 Installation of the System No.3 Accumulator
AMM 53−52−32−010−801 Opening of the Hydraulic Lower Access Panel (195AB)
AMM 53−52−32−410−801 Closing of the Hydraulic Lower Access Panel (195AB) (2) Make sure that the aircraft is in standard configuration for maintenance (AMM 12−00−00−867−801). WARNING : OBEY ALL HYDRAULIC SAFETY PRECAUTIONS WHEN YOU DO WORK ON THE HYDRAULIC SYSTEM AND HYDRAULIC SYSTEM COMPONENTS. YOU CAN CAUSE INJURY TO PERSONS AND DAMAGE TO THE EQUIPMENT. (3) Obey all the hydraulic safety precautions (AMM 29−00−00−910−801). (4) Release the hydraulic pressure from hydraulic system No. 3 (AMM 12−00−06−862−804). (5) Install safety placard “ No ground hydraulic power connection of No. 3 hydraulic system ” on the pilot control column. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 13 of 20 Mar 13/2008 Revision B, Dec 22/2010Refer to Figure 1. (6) Open the system accumulator pressure fill point access door (196CR). (7) Open the hydraulic lower access panel (195AB) (AMM 53−52−32−010−801). WARNING : OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU DO MAINTENANCE ON OR NEAR ELECTRICAL/ELECTRONIC EQUIPMENT. YOU CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT. (8) Obey all the electrical/electronic safety precautions (AMM 24−00−00−910−801). (9) Remove the electrical power from the aircraft (AMM 24−00−00−861−802). (10) Open, safety, and tag the circuit breakers that follow:

CB−PANEL CB NO. NAME CBP−1 F11 HYD SYST AC PUMP CONT 3B CBP−2 F14 HYD SYST AC PUMP CONT 3A Refer to Figure 2. WARNING : USE PROTECTIVE GLOVES TO CAREFULLY LOOSEN THE VALVE NUT ON THE NITROGEN CHARGING VALVE. KEEP YOUR HANDS AWAY FROM THE NITROGEN LEAKAGE. THE NITROGEN LINE IS PRESSURIZED AND CAN CAUSE INJURY. (11) Release the nitrogen pressure as follows: (a) Remove the dust cap (4) from the nitrogen charge valve (3). (b) Carefully loosen the thin nut on the nitrogen charge valve (3). (c) Let the nitrogen pressure go to zero. (d) Install the dust cap (4) from the nitrogen charge valve (3). 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 14 of 20 Mar 13/2008 Revision B, Dec 22/2010(12) Remove the hydraulic system No. 3 accumulator (1) (AMM 29−12−11−000−801).
B. Procedure (1) Do an ultrasonic inspection on the screw caps (2) of the system accumulator (1) (Refer to Appendix A). (2) If there is a crack, do as follows: (a) Send the system accumulator (1) with the results to: Bombardier Aerospace CRJ In Service Engineering 13100 Boulevard Henri Fabre, Mirabel Quebec, Canada J7N 3C6 C/O ISE group Dept# 662 (b) Install a new system accumulator (1) (AMM 29−12−11−400−801). (3) If there is no crack, install the system accumulator (1) (AMM 29−12−11−400−801). 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 15 of 20 Mar 13/2008 Revision B, Dec 22/20105

4 ACCUMULATOR 3 196CRba5009a01.cgm B A B A

LEGEND 3. Nut. 4. Dust cap. 5. Pressure gauge. 

### ALERT SERVICE BULLETIN A670BA−29−012

Accumulator Location Figure 1

S.B. A670BA−29−012 Page 16 of 20 Mar 13/2008 Revision B, Dec 22/2010C D C

E 1 1

1

2 1 2

E

E

D LEGEND 1. System accumulator P/N 900097−1. 2. Screw cap.ba5009a02.cgm NOTE Inspection area. 1 

### ALERT SERVICE BULLETIN A670BA−29−012

Accumulator Inspection Location Figure 2

S.B. A670BA−29−012 Page 17 of 20 Mar 13/2008 Revision B, Dec 22/2010C. Job Close−Out (1) Remove all tools, equipment, and unwanted materials from the work area. (2) Remove safety placard for “ No ground hydraulic power connection of No.3 hydraulic system ” on the pilot control column. (3) Remove the tags and close the circuit breakers that follow:

CB−PANEL CB NO. NAME CBP−1 F11 HYD SYST AC PUMP CONT 3B CBP−2 F14 HYD SYST AC PUMP CONT 3A (4) Replenish the hydraulic system No. 3 reservoir (AMM 12−12−29−611−802). (5) Do the servicing of the hydraulic system No. 3 accumulator (1) (AMM 12−12−29−614−801). (6) Bleed hydraulic system No. 3 (AMM 29−10−00−870−802). (7) Do the functional test for the hydraulic system No. 3 accumulator pressure decay rate (AMM 29−12−11−720−802)

. (8) Close the system accumulator pressure fill point access door (196CR). (9) Close the hydraulic lower access panel (195AB) (AMM 53−52−32−410−801). (10) When PART B of this service bulletin is completed, make this entry in the applicable logbook as follows: "Alert Service Bulletin A670BA−29−012, Revision B, Hydraulic Power − Hydraulic System No. 3 − Inspection of the System Accumulator Screw−Caps, PART B incorporated." 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 18 of 20 Mar 13/2008 Revision B, Dec 22/20103. MATERIAL INFORMATION A. Kit Information Kit Content:

KIT 670BA29012K90

PART NUMBER QUANTITY NAME ALTERNATE PART(S) NOTES

T11651 1 NDT Calibration Tool [1] Refer to paragraph 1.H. for special terms and conditions.

B. Consumable Information The material that follows is necessary to do this service bulletin and can be ordered from Bombardier Aerospace Regional Aircraft or purchased directly from industry sources. If the material is ordered from Bombardier Aerospace Regional Aircraft, there can be some lead time because of shelf life of the material.

CONSUMABLES

SPECIFICATION QUANTITY NAME REFERENCE

As necessary Cloths, cleaning, low lint 05−001 [1]

TT−I−735 As necessary Alcohol, isopropyl 11−004 [1]

[1] Refer to AMM 51−31−00−992−801.

NOTE : To complete this list of consumables, refer to the different tasks and Appendix A given as references in this service bulletin. C. Special Tools and Equipment For a list of special tools and equipment, refer to the different tasks and Appendix A given as references in this service bulletin. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 19 of 20 Mar 13/2008 Revision B, Dec 22/2010D. Disposition of Parts Not applicable. 

### ALERT SERVICE BULLETIN A670BA−29−012

S.B. A670BA−29−012 Page 20 of 20 Mar 13/2008 Revision B, Dec 22/2010Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A1 of A9 

## PROCEDURE

The procedure contained in this appendix is given as references in the ACCOMPLISHEMENT INSTRUCTION of Service Bulletin A670BA-29-012

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A2 of A9 Ultrasonic Inspection of the Screw Caps installed on the System Accumulator assemblies P/N 900097-1 (Hydraulic System No. 3).
1. General
A. Function Refer to Figure A1.
This inspection procedure is used to detect the subsurfa ce cracks at the internal shoulder of the screw caps (gas and fl uid sides) installed on the System Accumulator assembly P/N 900097-1 (1).
B. Reference Information For additional data that is necessary to do this inspection, refer to the following manuals:

- Nondestructive Testing Manual ( NDTM CSP A-010) Part 1, 51-20-004-270 A01, General Information;

- Structural Repair Manual (SRM);

- Aircraft Maintenance Manual (AMM).
C. Location The inspection area is found in Z one 160 (Refer to AMM 06-20-00-992-801 A01). The System Accumulator assembly P/N 900097-1 (1) is installed in the Aft RHS of the MLG bay. The piston-type accu mulator assembly is cylindrical and closed with screw caps at each end.
D. Access WARNING: OBEY ALL SAFETY PR ECAUTIONS WHEN YOU DO MAINTENANCE ON OR NEAR ELECTRICAL/ELECTRONIC EQUIPMENT AND/OR PRESSURIZED HYDRAULIC SYSTEMS. IF YOU DO NOT OBEY THE SAFETY PRECAUTIONS, INJURIES TO PERSONS AND/OR DAMAGE TO EQUIPMENT CAN OCCUR. (1) Remove the System Accumulator a ssembly P/N 900097-1 (1). Refer to the applicable AMM Tasks for System Accu mulator assembly P/N 900097-1 (1) Removal/Installation.
WARNING: OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU USE CHLORINATED OR OTHER SOLVENTS TO CLEAN THE WORK SURFACES. MAKE SURE THAT THERE IS A SUFFI CIENT SUPPLY OF FRESH AIR. USE PROTECTIVE CLOTHING AND SAFETY GL ASSES. IF THIS IS NOT DONE, INJURIES TO PERSONS CAN OCCUR.

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A3 of A9 (2) Using solvent and a dry clean cloth, clean the entire (360 degrees around) tapered section of the screw caps wher e the transducer is to make contact during the inspection (see Figure A1 and Figure A4). Refer to AMM Task 51-26- 00-110-801 for the Solvent Cleaning procedure. E. Parts examined in this procedure:
DESCRIPTION ACCUMULATOR PART NUMBER VENDOR PART NUMBER MATERIAL
Parts examined in this procedure: Hydraulic System #3 Accumulator assembly - Screw Cap 900097-1 Accumulator : 900097- 1 Screw cap material :7075- T73 Al Alloy

2. Tools and Equipment A. Use the items that follow, or their equivalent (Refer to the NDTM Part 1, 51- 20-004-270-A01). B. NOTE: Equivalent ul trasonic equipment can be used providing that it satisfies the requirements of this proc edure and is capable of resolving the reference notch(es) in the calibrati on reference standard (CRS) at the required level of sensitivity.

- Ultrasonic flaw detector with A-scan pr esentation, Sonatest Model: UFDS

- Potted angle beam contact transducer , 45 deg refractive angle in aluminum,

5.0 MHz frequency, contact surface 0.33- inch (8.38 mm) by 0.70-inch (17.78 mm), 0.57-inch (14.48 mm) high. Harisonic Model: PAB-0504, 45o AL.

- Microdot to BNC type coaxial cable.

- Ultrasound Calibration Re ference Standard Tool, similar in geometry as the

part to be inspected containing severa l electrical discharge machined (EDM) notches (Figure A2). Tactair Part Number: T11651

- Inspectech LTD: Gorptech Industrial Ultrasonic Couplant Gel. 3. Inspection for Subsurface Cracks on the Screw Cap Inner Shoulder of the Syst em Accumulator A. Equipment Calibration Refer to Figure A2 and Figure A3.

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A4 of A9 NOTE: Make sure that you follow th e manufacturer’s instructions when operating the test equipment. NOTE: Do not allow the ultrasonic couplan t to dry on the inspection surface. If necessary, add more couplant, to replenish the surface.
(1) Attach the 45 deg angle beam transducer to coaxial cable and connect the cable to the ultrasonic instrument. (2) Turn on the power and set the ultrasoni c instrument to pulse-echo test mode and 5 MHz test frequency. (3) Apply a generous and even layer of couplant to the tapered section of the calibration reference standard (CRS) T11651. (4) Place the transducer firmly on the tapered section on the CRS such that sound beam is directed towards the in ternal shoulder of the screw cap. (5) Manipulate the transducer by slight ly swiveling and moving it towards and away from the internal shoulder to obtain a maximized am plitude signal from the 0.050-inch radius notch A (NA). (6) Adjust the instrument GA IN (sensitivity) control to set the amplitude signal at 80% full screen height (FSH). (7) Adjust and position the leading edge of the notch signal at 50% of the horizontal baseline and the signal from the external shoulder should appear at approximately 90% of the horizontal baseline.

B. Inspection Procedure Refer to Figure A1 and Figure A3.
(1) After carrying out the Equipment Calib ration procedure as outlined in the previous subsection, apply an even layer of couplant to the tapered section of the screw caps to be inspected (both the gas and fluid sides). (2) Place the transducer firmly on the taper ed section of the screw cap such that the sound beam is in the directio n of the internal shoulder. (3) Manipulate the transducer towards and away from the shoulder with a slight swiveling motion. (4) Inspect for cracks 360 degrees (full ci rcumference) around the screw cap. (5) Repeat step 3.B.(1) through (4 ) for the other screw cap.

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A5 of A9 C. Evaluation of Indications (1) Any indication with an amplitude si gnal of 60% FSH or greater at approximately 50% of the hor izontal baseline limit is considered a suspect indication and represents a c ause for further evaluation. (2) Verify and ensure that the indication is not from the ex ternal shoulder, i.e. the transducer moved too forward to the edge of the external shoulder or the baseline was shifted accidentally. (3) If the indication corresponds to a crack, determine the approximate crack length by scanning in both di rections from the peak sig nal until the signal has dropped to 30% FSH and mark the center point of the transducer. The circumferential crack length is t he distance between the two points.
D. Acceptance / Rejection Criteria (1) All distinct indications with an am plitude signal of 60% FSH or greater appearing at approximately 50% of the horizontal baseline are classified as a crack indications and represent causes for rejection. (2) Record and report all results.

4. Close-out Procedure
A. Refer to close-out section of Aler t Service Bulletin A670BA-29-012 PART B.

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A6 of A9ba5010a01.cgm A B A

1

1

2 1 2

C

C

B LEGEND 1. System accumulator P/N 900097-1. 2. Screw cap.

NOTE Inspection area. 1

C 1



## System Accumulator Screw Cap Locations Figure A1

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A7 of A9 0.050 in. (1.27 mm) DP
NOTCH B 0.080 in. (2.03 mm) BOTH SIDES

NOTCH A NOTCH C 0.050 in. (1.27 mm) BOTH SIDES

0.050 in. (1.27 mm) DP 0.050 in. (1.27 mm) DP

0.121 in. (3.07 mm) BOTH SIDES 45 DEGREE

45 DEGREE C D

E

C D E A A B

B A A

B Bba5011a01.cgm



## Tactair CRS Number T11651 Figure A2

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A8 of A9 IP

EES 100%

50%

0 50 100 ENA

IP

EES IP = INITIAL PULSE ENA = ECHO FROM NOTCH A EES = ECHO FROM EXTERNAL SHOULDER

100%

50%

0 50 100 360° AROUND TAPERED SURFACE TRANSDUCER MOVEMENT

EDM NOTCH A TRANSDUCER SOUND EXIT POINT

CRS T11651 TRANSDUCER PLACEMENT

EXTERNAL SHOULDER

INTERNAL SHOULDER 0.25 in. (6.35 mm)
END OF TAPEREDba5012a01.cgm



## Transducer location and CRT Display Figure A3

### Appendix A

Mar 13/2008 APPENDIX A Revision A, Jul 27/2010 Page A9 of A9 EXTERNAL SHOULDER

POTENTIAL CRACK AT INTERNAL SHOULDERba5013a01.cgm



## Potential Crack Location Figure A4THANK YOU FOR ANSWERING THIS EVALUATION FORM UPON COMPLETION OF THIS EVALUATION FORM/COMPLIANCE SHEET, FAX TO 450-476-7300 

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