Landing Gear − Brake System − Detailed Inspection of the Accumulator Screw−Caps Threads

These pages transmit: Revision B of Service Bulletin 670BA−32−026, pages 1 thru 17, dated Dec 22/2010. and Initial Issue of Appendix A pages A1 thru A9, dated Jan 29/2010.
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: Add a note in Compliance paragraph 1.D. Add Bombardier Regional Jet Series All Operator Message (AOM), No. 614, in References paragraph 1.K.

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

Document Instructions: Discard the copy of Service Bulletin 670BA−32−026, Revision A, dated Jul 27/2010. Replace with the copy attached. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 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:KEEP TACTAIR SERVICE BULLETIN SB0860204001−32−02.
Service Bulletin History: Initial issue, dated Jan 29/2010. Revision A, dated Jul 27/2010. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 2 of 2 Dec 22/2010Landing Gear − Brake System − Detailed Inspection of the Accumulator Screw−Caps Threads

1. PLANNING INFORMATION A. Effectivity (1) Aircraft Affected:
Service Bulletin: CL−600−2C10 Canadair Regional Jet (CRJ) Aircraft with the component part numbers/serial numbers that follow installed:

PART NUMBER: 0860204001

Serial Number: Serial numbers without letter ‘T’ at the end: For the list of the serial numbers refer to Compliance paragraph 1.D., TABLE 1. NOTE: For the serial numbers listed in Compliance paragraph 1.D., TABLE 2, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02.
Installed at the time of delivery on aircraft serial numbers: 10003 thru 10253 

# SERVICE BULLETIN

ATA SYSTEM: 32−43 NUMBER: 670BA−32−026

S.B. 670BA−32−026 Page 1 of 17 Jan 29/2010 Revision B, Dec 22/2010 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:PART NUMBER: 0860204001

Spares: Examine all spare parts. If a part, with a serial number listed above, is found, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02.
CL−600−2C10 If parts, with the serial numbers listed above, are installed on aircraft that were not identified at the time of delivery, on the same or on a different aircraft model, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02.

Production: There is no production effectivity.

Service Bulletin: CL−600−2D15 Canadair Regional Jet (CRJ) and CL−600−2D24 Canadair Regional Jet (CRJ) Aircraft with the component part numbers/serial numbers that follow installed:

PART NUMBER: 0860204001

Serial Number: Serial numbers without letter ‘T’ at the end: For the list of the serial numbers refer to Compliance paragraph 1.D., TABLE 1. NOTE: For the serial numbers listed in Compliance paragraph 1.D., TABLE 2, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02.
Installed at the time of delivery on aircraft serial numbers: 15001 thru 15104, 15110, 15111, 15113, 15114, and 15128

Spares: Examine all spare parts. If a part, with a serial number listed above, is found, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 2 of 17 Jan 29/2010 Revision B, Dec 22/2010PART NUMBER: 0860204001

CL−600−2D15 and CL−600−2D24 If parts, with the serial numbers listed above, are installed on aircraft that were not identified at the time of delivery, on the same or on a different aircraft model, it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02.

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 Service Bulletin(s). Before you do this bulletin, examine all STC, STA or equivalent action changes to make sure this bulletin can be completed.
B. Reason (1) Condition It is possible to have a thread interference in the thread engagement between the screw−cap and the end−cap of accumulator 0860204001. (2) Evidence
A CL−600

– 2B19 in−service aircraft had one screw−cap disconnect from the body of the outboard brake accumulator. Analysis shows that defective end−caps were also installed on the brake accumulators of CL600−2C10, CL−600−2D15 and CL−600−2D24 aircraft. (3) Objective/Benefit This service bulletin gives the procedure to do an ultrasonic inspection on the screw−caps of the inboard and outboard brake accumulators. The inspection will make sure that no end−caps with cracks are installed on the accumulator. This will prevent the separation of the end−caps from the accumulator assembly. C. Description The hydraulic access door is removed and the electrical bay door is opened. Electrical power is removed from the aircraft. Hydraulic pressure of applicable hydraulic system No. 2 and/or No. 3 is released. The brake pedals of the pilot or co−pilot are operated to release the hydraulic pressure from the brake accumulators. Circuit breakers are opened. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 3 of 17 Jan 29/2010 Revision B, Dec 22/2010The applicable inboard and/or outboard brake accumulator(s) is removed. An ultrasonic inspection is done on the screw−caps of the applicable inboard and/or outboard brake accumulator(s). If a crack is found, the applicable accumulator(s) is replaced. If no crack is found, the applicable accumulator(s) is installed. The circuit breakers are closed. The servicing of the removed inboard and/or outboard brake accumulator(s) is done. The servicing of the applicable hydraulic system No. 2 and/or No. 3 reservoir(s) is done. The applicable system No. 2 and/or No. 3 is bled. The removed inboard and/or outboard brake accumulator(s) is bled. An operational check of the removed inboard and/or outboard brake accumulator(s) is done. The hydraulic access door is installed and the electrical bay door is closed. D. Compliance Recommended Service Bulletin.
NOTE : It is not necessary to do this service bulletin when Service Bulletin 670BA−32−028, Landing Gear − Brake System − Replacement of Accumulator P/N 0860204001 by P/N 90006691, is done
NOTE : The letter ‘T’ identifies that new screw−caps were installed on the accumulator: − The accumulator was made and delivered with letter ‘T’ at the end of the serial number. OR − The accumulator was changed by Tactair Service Bulletin SB0860204001−32−02. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 4 of 17 Jan 29/2010 Revision B, Dec 22/2010Applicable Compliance Results Action

For inboard and outboard brakes:
Accumulators P/N 0860204001 with serial numbers without letter ‘T’ at the end (For the list of serial numbers see TABLE 1 and the note below). For accumulators that have 4000 flight cycles or less, it is necessary to do this service bulletin before the accumulators have 5000 flight cycles. If there is an indication of a crack during the ultrasonic inspection, it is necessary to replace the accumulator before next flight.

or If no indication of a crack is found, no action is necessary before next flight. It is necessary to repeat this service bulletin every 500 flight cycles from the initial inspection. For accumulators that have more than 4000 flight cycles, it is necessary to do this service bulletin no more than 1000 flight cycles from the issue date on this service bulletin.
For accumulators P/N 0860204001 with serial numbers with letter ‘T’ at the end. It is not necessary to do this service bulletin. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 5 of 17 Jan 29/2010 Revision B, Dec 22/2010TABLE 1

60204−0001 thru 60204−0006 60204−0008 thru 60204−0047 60204−0049 thru 60204−0077 60204−0080 thru 60204−0088 60204−0090 thru 60204−0102 60204−0104 thru 60204−0111 60204−0113 thru 60204−0118 60204−0120 thru 60204−0122 60204−0124 thru 60204−0132 60204−0134 thru 60204−0140 60204−0142
60204−0144 thru 60204−0151 60204−0154 thru 60204−0163 60204−0165 thru 60204−0166 60204−0169 thru 60204−0177 60204−0179 thru 60204−0192 60204−0194 thru 60204−0197 60204−0200 thru 60204−0204 60204−0207 thru 60204−0219 60204−0221 thru 60204−0223 60204−0225 thru 60204−0226 60204−0228
60204−0230 thru 60204−0237 60204−0239 thru 60204−0256 60204−0258 thru 60204−0259 60204−0262 thru 60204−0263 60204−0265 thru 60204−0266 60204−0270 thru 60204−0275 60204−0277 thru 60204−0279 60204−0283 thru 60204−0286 60204−0288 thru 60204−0295 60204−0299 thru 60204−0314 60204−0316 60204−0319 thru 60204−0335 60204−0337 thru 60204−0338 60204−0340 thru 60204−0342 60204−0344 thru 60204−0350 60204−0352 thru 60204−0353 60204−0355 thru 60204−0394 60204−0396 thru 60204−0415 60204−0417 thru 60204−0454 60204−0457 thru 60204−0463 60204−0465
60204−0467 thru 60204−0477 60204−0479 thru 60204−0488 60204−0490 thru 60204−0507 60204−0509
60204−0511 thru 60204−0550 60204−0552 thru 60204−0555 60204−0557 thru 60204−0573 60204−0575 thru 60204−0577 60204−0579 thru 60204−0582 60204−0584 thru 60204−0621 60204−0623 thru 60204−0643 60204−0645 thru 60204−0647 60204−0649 thru 60204−0661 60204−0663 thru 60204−0682 60204−0684 thru 60204−0686 60204−0688
60204−0690 thru 60204−0699 60204−0701 thru 60204−1999

NOTE : For serial numbers listed in TABLE 2 below, the new screw−caps were installed by Tactair but it is necessary to incorporate Tactair Service Bulletin SB0860204001−32−02 to add the letter ‘T’ at the end of the serial numbers. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 6 of 17 Jan 29/2010 Revision B, Dec 22/2010TABLE 2

60204−0007 60204−0048 60204−0078 60204−0079 60204−0089 60204−0103 60204−0112 60204−0119 60204−0123 60204−0133 60204−0141 60204−0143 60204−0152 60204−0153 60204−0164 60204−0167 60204−0168 60204−0178 60204−0193 60204−0198 60204−0199 60204−0205 60204−0206A 60204−0220 60204−0224 60204−0227 60204−0229 60204−0238 60204−0257 60204−0260 60204−0261 60204−0264 60204−0267 60204−0268 60204−0269 60204−0276 60204−0280 60204−0281 60204−0282 60204−0287A 60204−0296 60204−0297 60204−0298 60204−0315A 60204−0317 60204−0318 60204−0336 60204−0339 60204−0343 60204−0351 60204−0354 60204−0395 60204−0416 60204−0455 60204−0456 60204−0464 60204−0466 60204−0478 60204−0489 60204−0508 60204−0510 60204−0551 60204−0556 60204−0574 60204−0578 60204−0583 60204−0622 60204−0644 60204−0648 60204−0662 60204−0683 60204−0687 60204−0689 60204−0700 60204−2000 thru 60204−2598

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. This estimate does 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. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 7 of 17 Jan 29/2010 Revision B, Dec 22/2010− Quality assurance inspections, troubleshooting and/or correction of discrepancies found when a task is done. − All other activities that are not considered by Bombardier 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. It will take an estimated 5.5 man−hours to complete 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 There are no kits for this service bulletin. (1) Refer to paragraph 3.B. for a list of consumables for this service bulletin. H. Tooling − Price and Availability (1) The tool kit in the table that follows is available from Bombardier.
NOTE : For a list of the kit contents, refer to paragraph 3.A.

KIT NUMBER NAME

670BA32026K90 NDT Calibration Tool Kit

NOTE : 670BA29013K90, 601R29−033K90, or 601R32−106K90, NDT calibration tool kit, can be used as an alternative kit. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 8 of 17 Jan 29/2010 Revision B, Dec 22/2010(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. (3) Refer to paragraph 3.C. for a list of special tools and equipment for this service bulletin. I. Weight and Balance Not changed.
J. Electrical Load Data Not changed.
K. References − Restriction and/or Special Instruction (RSI), C−32−1187−00. − Tactair Service Bulletin SB0860204001−32−02, dated Jan 27, 2010. − Bombardier Regional Jet Series All Operator Message (AOM), No. 614. − Aircraft Maintenance Manual (AMM), CSP B−001. − Nondestructive Testing Manual (NDT), CSP B−010. − For Bombardier reference only: PCA 73521.
L. Other Publications Affected
None. M. Relationship Chart Not applicable. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 9 of 17 Jan 29/2010 Revision B, Dec 22/20102. ACCOMPLISHMENT INSTRUCTIONS A. Job Set−Up (1) Reference Information

REFERENCE DESIGNATION
AMM 12−00−00−867−801 Standard Aircraft Configuration for Maintenance
AMM 12−00−06−862−802 Release Hydraulic Pressure of System No. 1 and No. 2
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 12−12−29−611−801 Servicing of the Hydraulic System No. 1 and No. 2 Reservoirs
AMM 12−12−29−611−802 Servicing of the Hydraulic System No. 3 Reservoir
AMM 24−00−00−910−801 Electrical/Electronic Safety Precautions
AMM 29−00−00−910−801 Hydraulic Safety Precautions
AMM 29−10−00−870−801 Bleed Hydraulic System No. 1 and No. 2
AMM 29−10−00−870−802 Bleed Hydraulic System No. 3
AMM 32−43−00−870−801 Bleeding of the Brakes
AMM 32−43−16−000−801 Removal of the Brake Accumulator
AMM 32−43−16−400−801 Installation of the Brake Accumulator
AMM 32−43−16−710−801 Operational Test of the Brake Accumulator
AMM 52−45−56−000−801 Removal of the Hydraulic Access Door (121AL) 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 10 of 17 Jan 29/2010 Revision B, Dec 22/2010REFERENCE DESIGNATION
AMM 52−45−56−400−801 Installation of the Hydraulic Access Door (121AL)
(2) Make sure that the aircraft is in standard configuration for maintenance (AMM 12−00−00−867−801). (3) Open hydraulic access door 121AL. (4) Open electrical bay door 211AL.
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. (5) Obey all the electrical/electronic safety precautions (AMM 24−00−00−910−801). (6) Remove the electrical power from the aircraft (AMM 24−00−00−861−802). (7) Open main avionic−compartment door 811.
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 EQUIPMENT. (8) Release the hydraulic pressure from hydraulic system No. 2 (AMM 12−00−06−862−802). (9) Release the hydraulic pressure from hydraulic system No. 3 (AMM 12−00−06−862−804). (10) Operate the brake pedals of the pilot or co−pilot to release the hydraulic pressure from the brake accumulators (approximately six times). (11) Open, safety, and tag the circuit breakers that follow:

CB−PANEL CB NO. NAME CBP−1 F11 HYD SYST AC PUMP CONT 3B
CBP−1 F14 HYD SYST AC PUMP CONT 2
CBP−2 F14 HYD SYST AC PUMP CONT 3A 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 11 of 17 Jan 29/2010 Revision B, Dec 22/2010CB−PANEL CB NO. NAME ACPC ACPC HYD PUMP 2
ACPC ACPC HYD PUMP 3A
ACPC ACPC HYD PUMP 3B

B. Procedure Refer to Figure 1. (1) Remove the applicable inboard and/or outboard brake accumulator(s) (1) (AMM 32−43−16−000−801). (2) Do an ultrasonic inspection on the applicable inboard and/or outboard brake accumulator (1) screw−caps (2) (Refer to Appendix A). (3) If there is a crack do as follows: (a) Send the accumulator(s) to: Bombardier Aerospace CRJ In Service Engineering 13100 Boulevard Henri−Fabre, Mirabel, Quebec, Canada J7N 3C6 C/O ISE group, Dept#662 (b) Install the new applicable inboard and/or outboard brake accumulator(s) (1) (AMM 32−43−16−400−801). (4) If there is no crack, install the applicable inboard and/or outboard brake accumulator(s) (1) (AMM 32−43−16−400−801). 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 12 of 17 Jan 29/2010 Revision B, Dec 22/2010ba5791a01.cgm 2

1

2

B NOTE Inspection area. 1 LEGEND 1. Brake accumulator. 2. Screw cap. 1

1 1 B

B A A 

### SERVICE BULLETIN 670BA−32−026

Accumulator − Installation/Removal/Inspection Figure 1

S.B. 670BA−32−026 Page 13 of 17 Jan 29/2010 Revision B, Dec 22/2010C. Job Close−Out (1) Remove all tools, equipment, and unwanted materials from the work area. (2) 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−1 F14 HYD SYST AC PUMP CONT 2
CBP−2 F14 HYD SYST AC PUMP CONT 3A
ACPC ACPC HYD PUMP CONT 2
ACPC ACPC HYD PUMP CONT 3B
ACPC ACPC HYD PUMP CONT 3A
(3) Do the servicing of the removed inboard and/or outboard brake accumulator(s)(AMM 12−12−29−614−801). (4) If the outboard brake accumulator was removed, do the servicing of the No. 2 hydraulic system reservoir(AMM 12−12−29−611−801). (5) If the inboard brake accumulator was removed, do the servicing of the No. 3 hydraulic system reservoir(AMM 12−12−29−611−802). (6) If the outboard brake accumulator was removed, bleed hydraulic system No. 2 (AMM 29−10−00−870−801). (7) If the inboard brake accumulator was removed, bleed hydraulic system No. 3 (AMM 29−10−00−870−802). (8) Bleed the applicable inboard and/or outboard brake(s) (AMM 32−43−00−870−801). (9) Do an operational check of the applicable inboard and/or outboard brake accumulator(s) (AMM 32−43−16−710−801). (10) Close hydraulic access door 121AL. (11) Close main avionic−compartment door 811. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 14 of 17 Jan 29/2010 Revision B, Dec 22/2010(12) Close electrical bay door 211AL. (13) When this service bulletin is completed, make this entry in the applicable logbook(s): "Service Bulletin 670BA−32−026, Revision B, Landing Gear − Brake System − Detailed Inspection of the Accumulator Screw−Caps Threads, incorporated." 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 15 of 17 Jan 29/2010 Revision B, Dec 22/20103. MATERIAL INFORMATION A. Kit Information
Kit Content:

KIT 670BA32026K90

PART NUMBER QUANTITY NAME ALTERNATE PART(S) NOTES

T11828 1 NDT Calibration Tool Kit

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

CONSUMABLES

SPECIFICATION QUANTITY NAME REFERENCE

MIL−C−85043 As necessary Cloths, cleaning, low lint 05−001 [1]

TT−I−735 As necessary Alcohol isopropyl 05−001 [1]

[1] Refer to AMM 51−31−00−992−801.

NOTE : To complete this list of consumables, refer to the different tasks and the Tactair service bulletin 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, the Tactair service bulletin given as references in this service bulletin. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 16 of 17 Jan 29/2010 Revision B, Dec 22/2010D. Disposition of Parts Not applicable. 

### SERVICE BULLETIN 670BA−32−026

S.B. 670BA−32−026 Page 17 of 17 Jan 29/2010 Revision B, Dec 22/2010Jan 29/2010 APPENDIX A Page A1 of A9 

## PROCEDURE

The procedure contained in this appendix is given as references in the ACCOMPLISHMENT INSTRUCTIONS of Service Bulletin 670BA-32-026.

### Appendix A

Ultrasonic Inspection of the Inboard and Outboard Brake System No.2 and No.3 Accumulators – Thread of the Screw caps

1. General

A. Function Refer to Figure A1. This inspection procedure is used to det ect subsurface cracks at the internal thread root near the end of t he internal shoulder of the screw caps (gas and fluid ends) of the brake accumulator systems No. 2 and No. 3.

B. Reference Information

For additional data that is necessary to do this inspection, refer to manuals that follow: - Nondestructive Testing Manual (NDT M CSP B-010) Part 1, 51-20-004-270, General Information. - Structural Repair Manual (SRM). - Aircraft Maintenance Manual (AMM).
C. Location The inspection area is in Zone 12 0 (Refer to AMM 06-20-00-992-801).

D. Parts Examined in this procedure

DESCRIPTION ACCUMULATOR PART NUMBER SCREW CAP PART NUMBER MATERIAL

Brake Accumulator 0860204001 08-8421-104 7075-T73 Al Alloy

Jan 29/2010 APPENDIX A Page A2 of A9

### Appendix A

2. Tools and Equipment

A. Use the items that follow, or their equivalent (Refer to the NDTM Part 1, 51-20- 004-270). NOTE: Equivalent ultrasonic equipment c an be used provided that it satisfies the requirements of this procedure and is capable of resolving the reference notch(es) in the calibration refer ence standard (CRS) at the required level of sensitivity.
- Ultrasonic flaw detecto r, Sonatest Model: UFSD - Potted angle beam contact transduc er, 70 degrees refractive angle in

aluminum, 5.0 MHz frequency, contact surface 0.32-inch (8.13 mm) by 0.70-inch (17.78 mm) UTX Model: CX-118 - Microdot to BNC type coaxial cable.
- Tactair Calibration Reference Standard: T11828, similar in geometry as the

part to be inspected containing several electrical discharge machined (EDM) notches (Refer to Figure A2 ).

- Inspectech LTD: Gorptech Industrial Ultrasonic Couplant Gel.

3. Inspection for Subsurface Cracks on th e Screw-Cap Internal Thread of the Brake Accumulator

A. Cleaning Refer to Figure A1.
WARNING: OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU USE CHLORINATED OR OTHER SOLVENTS TO CLEAN THE WORK SURFACES. MAKE SURE THAT THERE IS A SUFFICIENT SUPPLY OF FRESH AIR. U SE PROTECTIVE CLOTHING AND SAFETY GLASSES. IF THIS IS NOT DONE, INJURIES TO PERSONS CAN OCCUR. (1) With solvent, clean the entire (360 degrees around) tapered section of the screw caps where the transducer is to make contact during the inspection. Refer to AMM 51-26-00-110-801.

Jan 29/2010 APPENDIX A Page A3 of A9

### Appendix A

B. Equipment Calibration Refer to Figure A2 and Figure A3. NOTE: Make sure that you follow t he manufacturer's instructions when operating the test equipment.
NOTE: Do not allow the ultr asonic couplant to dry on the inspection surface. If necessary, add more couplant, to replenish the surface. (1) Attach the 70° angle beam transdu cer to coaxial cable and connect the cable to the ultrasonic instrument. (2) Turn on the power and set the ultr asonic instrument to pulse-echo test mode and 5 MHz test frequency. (3) Apply couplant to tapered section of the calibration reference standard (CRS) T11828. (4) Place the transducer firmly to the tapered section on the CRS such that sound beam is directed up to slope of the tapered section towards the internal thread of the screw cap. (5) Manipulate the transducer to obtai n a maximized amplitude signal from EDM notch A (NA) in the root of t he thread and adjust the instrument GAIN control to set the signal at 80% full scr een height (FSH) (Refer to Figure A2 and A3).
CAUTION: THERE WILL BE A SLIGHT NOISE ARISING FROM THE THREADS DURING THE SCAN. MAKE SURE THAT IT IS NOT GREATER THAN 30% FSH. (6) Adjust range control to position t he leading edge of t he notch signal at approximately 50% of the horizontal baseline (Refer to Figure A3).
C. Inspection Procedure Refer to Figure A3. (1) After calibration as outlined in secti on 3.B., apply an even layer of couplant to the tapered section on the accumu lator screw cap to be inspected. (2) Place the transducer firmly to the tapered section of the Screw Cap such that the sound beam is directed up the slope of the tapered section towards the internal threads.

Jan 29/2010 APPENDIX A Page A4 of A9

### Appendix A

(3) Manipulate the transducer towards and away from the threads with slight swiveling motion. (4) Inspect 360 degrees around the cap for cracks.

D. Evaluation of Indications (1) Any indication with an amplitude si gnal of 60% FSH or greater at approximately 50% of the horizontal baseline limit is considered a suspect indication and is cause for further evaluation. (2) If the indication is a crack, determi ne the approximate length of crack by scanning in both directions from the peak signal until the signal has dropped to 40% FSH and mark the center point of the transducer. The circumferential crack length is t he distance between the two points.

E. Acceptance or Rejection Criteria: (1) All distinct indications with an am plitude signal of 60% FSH or greater appearing at approximately 50% of the horizontal base line is classified as a crack indication and is caused for rejection. (2) Record results.

Jan 29/2010 APPENDIX A Page A5 of A9

### Appendix A

Brake Accumulator Screw Cap Locations Figure A1

Jan 29/2010 APPENDIX A Page A6 of A9

### Appendix A

Tactair CRS Number T11828 Figure A2

Jan 29/2010 APPENDIX A Page A7 of A9

### Appendix A

CRT Display Calibration and Familiarization Figure A3 (Sheet 1 of 2)

Jan 29/2010 APPENDIX A Page A8 of A9

### Appendix A

CRT Display Calibration and Familiarization Figure A3 (Sheet 2 of 2)

Jan 29/2010 APPENDIX A Page A9 of A9THANK YOU FOR ANSWERING THIS EVALUATION FORM UPON COMPLETION OF THIS EVALUATION FORM/COMPLIANCE SHEET, FAX TO 450-476-7300 

### SERVICE BULLETIN EVALUATI ON FORM/COMPLIANCE SHEET (YOUR IDEAS WILL HELP US PROVIDE BETTER BULLETINS)

SERVICE BULLETIN : 670BA- 32 -0 2 6 ISSUE: B

STRONGLY DISAGREE NEUTRAL AGREE STRONGLY DISAGREE AGREE

• Instructions to do the Service Bulletin were accurate. Comments: 

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• Illustration(s), figure(s), picture(s) and/or kit drawing(s) were helpful to carry out instructions. Comments: 

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• If a parts kit was required, did the kit contents received agree with the contents listed in the bulletin? Comments: 

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• Aircraft hands-on work was accomplished in estimated time. Comments: 

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• Overall, I was satisfied with this Service Bulletin. Comments: 

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PLEASE SUPPLY US WITH THE FOLLOWING DATA AND FAX TO (450) 476-7300:

OPERATOR: NAME (Please print)
SERVICE CENTER: TELEPHONE:
AIRCRAFT SERIAL NO.: FACSIMILE:
DATE OF SB INCORPOARTION