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 22/2010
Landing 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 22/2010
PART

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 22/2010
The 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 22/2010
Applicable 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 22/2010
TABLE 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 22/2010
TABLE 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 22/2010
2. 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 22/2010
REFERENCE 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 22/2010
CB−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 22/2010
ba5791a01.cgm

2

1

2

B

NOTE

1 Inspection area.

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 22/2010
C. 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 22/2010
3. 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 22/2010
D. 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 22/2010
 

Jan 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 detect subsurface cracks at the internal 

thread root near the end of the 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 (NDTM 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 120 (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 can be used provided that it satisfies the 

requirements of this procedure and is capable of resolving the reference 

notch(es) in the calibration reference standard (CRS) at the required 

level of sensitivity. 

- Ultrasonic flaw detector, Sonatest Model: UFSD 

- Potted angle beam contact transducer, 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 the 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. USE 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 the manufacturer's instructions when 

operating the test equipment. 

 

NOTE: Do not allow the ultrasonic couplant to dry on the inspection surface. If 

necessary, add more couplant, to replenish the surface. 

(1) Attach the 70° angle beam transducer to coaxial cable and connect the 

cable to the ultrasonic instrument. 

(2) Turn on the power and set the ultrasonic 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 obtain a maximized amplitude signal from 

EDM notch A (NA) in the root of the thread and adjust the instrument GAIN 

control to set the signal at 80% full screen 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 the leading edge of the 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 section 3.B., apply an even layer of couplant 

to the tapered section on the accumulator 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 signal 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, determine 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 the distance between the two points. 

E. Acceptance or Rejection Criteria: 

(1) All distinct indications with an amplitude signal of 60% FSH or greater 

appearing at approximately 50% of the horizontal baseline 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 A9
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