March 12/10 Service Bulletin 215-4414

ATA Ref: 27-10

Page 1 of 1 32-40

MODEL CL-215-6B11 (415)

REVISION TRANSMITTAL SHEET

FLIGHT CONTROLS / LANDING GEAR

SPECIAL INSPECTION OF THE ACCUMULATOR SCREW CAPS P/N 08−8425−014

ON TACTAIR OR YORK ACCUMULATOR P/N 08−8423−010 (MS28700−3)

Service Bulletin No.: 215−4414 Date of Original Issue: July 9/09

Revision No.: 1 Date of Issue: March 12/10

NOTES: 1. NO RETROACTIVE ACTION IS REQUIRED ON AIRCRAFT

MODIFIED TO THE PREVIOUS ISSUE OF THIS SERVICE

BULLETIN.

2. This revision supersedes the previous issue of this Service Bulletin.

3. Black bars in the left margin of this Service Bulletin and the details on

this Revision Transmittal Sheet refer to changes made since the

previous issue.

This Revision is issued to:

1. Add “York” after the name Tactair to make the accumulators “Tactair or York” in the title and

throughout the Service Bulletin.

2. Change the revision of Bombardier Aerospace Restriction and/or Special Instruction (RSI)

C-3817, from Revision B to B-1.
Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 1 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

MODEL CL-215-6B11 (415)

SERVICE BULLETIN

FLIGHT CONTROLS / LANDING GEAR

SPECIAL INSPECTION OF THE ACCUMULATOR SCREW CAPS P/N 08−8425−014

ON TACTAIR OR YORK ACCUMULATOR P/N 08−8423−010 (MS28700−3)

1. Planning Information

A. Compliance

The inspections described in this Service Bulletin is mandatory.

Time limitation for the visual inspection, PART A of this service Bulletin.

For hydraulic accumulator assemblies that have less or equal to 750 flight cycles, the

visual inspection as described in this Service Bulletin must be performed before the

accumulator reaches 1000 flight cycles, unless otherwise directed by the airworthiness

authority of the operator.

For hydraulic accumulator assemblies that have more than 750 flight cycles, the visual

inspection must be performed within 250 flight cycles upon receiving this Service Bulletin.

The visual inspection must be repeated every 250 flight cycles until the first ultrasonic

inspection (PART B of this service Bulletin) has been completed at which point the visual

inspection may be discontinued.

Time limitation for the first ultrasonic inspection, PART B of this service Bulletin.

For hydraulic accumulator assemblies that have less or equal to 750 flight cycles,

Bombardier Aerospace recommends to perform the ultrasonic inspection as described in

this Service Bulletin before the accumulator reaches 1000 flight cycles, unless otherwise

directed by the airworthiness authority of the operator.

For hydraulic accumulator assemblies that have more than 750 flight cycles, the

ultrasonic inspection must be performed within 250 flight cycles upon receiving this

Service Bulletin.

The ultrasonic inspection must be repeated every 750 flight cycles.

NOTE: This Service Bulletin is applicable only to aircraft in the condition as originally

delivered by Canadair and/or Bombardier Aerospace or as subsequently modified by

Canadair and/or Bombardier Aerospace Service Bulletin(s). Prior to incorporation of

this Service Bulletin, the status of any related systems or structural modification(s)

introduced by Supplementary Type Approval (STA) or equivalent action must be

examined for compatibility with the modifications and test procedures (if applicable)

detailed in this Service Bulletin. 
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 2 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

B. Approval

The technical content of this Service Bulletin has been approved under the authority of the

Design Approval Organization No: DAO #93-Q-02.

C. Effectivity

CL-215-6B11 (415) turboprop aircraft Serial Nos. 2001 to 2990.

D. Reason

Several accumulator screw cap failures have been reported since 2000 on the Bombardier

CRJ-200. Although the Bombardier 415 aircraft uses similar hydraulic accumulators from the

same vendor, there have been no reports of accumulator failure from any Bombardier 415

operator. The specific cause of the failure was linked to fatigue in the filet radius of the screw

cap shoulder with other failures originating at the thread runout.

E. Description

This Service Bulletin gives instructions to:

− Clean the inspection area on the accumulator screw caps in preparation to perform the

visual or ultrasonic inspection

− Perform a visual inspection of the screw caps on the four accumulator for indications

of cracks

− Calibrate the ultrasonic test equipment

− Perform the ultrasonic inspection of the suspect accumulator screw caps.

NOTE: The inspection requirement is split into two parts; PART A and PART B.

− PART A is for the visual inspection of the accumulator screw caps

− PART B is for the ultrasonic inspection of the accumulator screw caps.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 3 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

F. Manpower

For PART A

We estimate that it will take 1 technician approximately 3 hours to complete this Service

Bulletin.

For PART B

We estimate that it will take 1 technician approximately 4 hours to complete this Service

Bulletin.

NOTE: Only qualified ultrasonic inspectors certified with a level I, II, or III category per the

following specifications are authorized to perform the special inspections described in

this Service Bulletin:

− MIL−STD−410

− CDN/CGSB-48.9712-95

− COFREND (COnfederation FRançaise pour les Essais Non Destructifs)

− CoSAC (Computational Structural Analysis Committee)

− ISO 9712

− or equivalent.

G. Material Availability

This Service Bulletin contains no kit. Tactair or York Calibration Reference Standard (CRS)

T11651 is available upon request from Bombardier Aerospace, contact your Amphibious

Aircraft Technical Representative for details.

H. Tool Availability

For PART B

− Ultrasonic Flaw Detector, Sonatest Model: UFSD

− Potted angle beam contact transducer

− For accumulator screw caps P/N 08-8425-104

45 degrees refractive angle in aluminum, 5.0 MHz frequency, contact surface 0.33-inch

(8.38 millimeters) by 0.70-inch (17.78 millimeters), 0.57-inch (14.48 millimeters) high

Harisonic Model: PAB-0504,45AL

− Microdot to BNC coaxial cable

− Tactair or York CRS T11651

− Gorptech, Industrial ultrasonic couplant gel (available from Inspectech Ltd.) or equivalent.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 4 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

I. Weight and Balance

Not affected.

J. Electrical Load Data

Not affected.

K. References

Bombardier Aerospace Restriction and/or Special Instruction (RSI) C-3817, Revision B-1.

L. Publications Affected

None.

M. Related Service Bulletin

None.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 5 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

2. Accomplishment Instructions

NOTE: For this modification, it is assumed that standard maintenance and repair practices will be

applied in accordance with applicable Product Support Publications (PSP).

A. Preparation

WARNING: MAKE SURE THAT PERSONNEL AND EQUIPMENT ARE A SAFE DISTANCE

AWAY FROM ALL HYDRAULICALLY OPERATED SYSTEMS BEFORE YOU

REMOVE THE ELECTRICAL POWER. IF YOU DO NOT DO THIS, INJURIES

TO PERSONNEL AND DAMAGE TO EQUIPMENT CAN OCCUR.

(1) Remove the electrical power. Refer to PSP 492, Maintenance Manual, Chapter 24-00-00,

ELECTRICAL POWER − MAINTENANCE PRACTICES.

(2) Release the hydraulic pressure. Refer to PSP 492, Maintenance Manual, Chapter

29-00-00, HYDRAULIC POWER − MAINTENANCE PRACTICES.

(3) Release the nitrogen pressure from the accumulators. Refer to PSP 492, Maintenance

Manual.

(4) Gain access to the brake, rudder, elevator, and aileron accumulators. Refer to FIGURE 1

for accumulator locations.

(5) Clean the entire (360 degrees around) tapered section of the accumulator screw cap with

isopropyl alcohol and a clean cloth/rag free of dirt and grease.

3. PART A: Visual Inspection Procedures

Refer to the shaded area in FIGURE 2 for the location to be inspected.

A. Inspection Procedure

(1) With the aid of a light source and an inspection mirror, visually inspect the full

circumference of the two accumulator screw caps for evidence of cracks.

(2) Acceptance/Rejection Criteria

(a) If no crack is found, the accumulator can be returned to service. Refer to Chapters

27 and 32 of PSP 492.

1 Go to Section 6. RECORDING and record the incorporation of PART A of this

Service Bulletin.

(b) If a crack is found or suspected after the visual inspection, the effected accumulator

must be replaced before the next flight.

1 Return the complete accumulator to bombardier Aerospace for further

investigation OR:

2 Perform an ultrasonic inspection in accordance with PART B of this Service

Bulletin.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 6 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

0

FIGURE 1

BRAKE

ACCUMULATOR

AILERON

ACCUMULATOR
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 7 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

HIGH PRESSURE

GAUGE

0

FIGURE 1

ELEVATOR

ACCUMULATOR

RUDDER

ACCUMULATOR

AIR (HIGH 

PRESSURE 

CHARGING) 

VALVE 

ACCUMULATOR

SCREW CAP

ACCUMULATOR

SCREW CAP
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 8 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

POTENTIAL CRACK LOCATION

FIGURE 2

CLEAN ENTIRE TAPERED SECTION (SHADED) ON SCREW 

CAPS WHERE TRANSDUCER WILL BE PLACED FOR

SCANNING, APPLY SOLVENT TO THIS AREA 1

NOTE

Clean entire tapered section 

(shaded) on screw

caps where transducer will 

be placed for scanning,

apply solvent to this area.

EXTERNAL

SHOULDER

POTENTIAL CRACK AT

INTERNAL SHOULDER

1

ACCUMULATOR

SCREW CAP
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 9 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

4. PART B: Ultrasonic Inspection Procedure

NOTE: Tactair or York CRS T11651 is available upon request from Bombardier Aerospace,

contact your Amphibious Aircraft Technical Representative for details.

Refer to the shaded area in FIGURE 2 for the location to be inspected.

A. Equipment Calibration

(1) If not already accomplished do the two steps that follow:

WARNING: MAKE SURE THAT PERSONNEL AND EQUIPMENT ARE A SAFE DISTANCE

AWAY FROM ALL HYDRAULICALLY OPERATED SYSTEMS BEFORE YOU

REMOVE THE ELECTRICAL POWER. IF YOU DO NOT DO THIS, INJURIES

TO PERSONNEL AND DAMAGE TO EQUIPMENT CAN OCCUR.

(a) Remove the electrical power. Refer to PSP 492, Maintenance Manual, Chapter

24-00-00, ELECTRICAL POWER − MAINTENANCE PRACTICES.

(b) Release the hydraulic pressure. Refer to PSP 492, Maintenance Manual, Chapter

29-00-00, HYDRAULIC POWER − MAINTENANCE PRACTICES.

(c) Release the nitrogen pressure from the accumulators. Refer to PSP 492,

Maintenance Manual.

Refer to FIGUREs 3, 4, and 5.

(2) Remove the suspected accumulator from the aircraft. Refer to PSP 492, Maintenance

Manual, Chapter 27 and/or Chapter 32 for accumulator removal procedures.

(3) Attach the angle beam transducer (45° angle) to coaxial cable and connect the cable to

the ultrasonic instrument.

(4) Set the ultrasonic instrument to PULSE-ECHO test mode and 5 MHz test frequency.

(5) Apply an even coat of couplant gel on the tapered surface of the CRS.

(6) Place the transducer firmly to the tapered section on the CRS such that the sound beam

is directed towards the internal shoulder of the screw cap.

(7) Manipulate the transducer to obtain a maximized amplitude signal from the EDM notch A

(NA) and adjust the instrument GAIN control to set the signal to 80% Full Screen Height

(FSH).

(8) Adjust and position the leading edge of the notch signal at 50% of the horizontal baseline

and the signal from the external shoulder at approximately 90% for the CRS T11651.

Refer to Figures 4.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 10 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

B. Inspection Procedure

Refer to FIGURE 2 and 5.

(1) Apply an even coat of couplant gel on the tapered surface on the accumulator screw cap

to be inspected.

(2) Place the transducer firmly to the tapered section on the screw cap such that the sound

beam is directed towards the internal shoulder of the screw cap.

(3) Manipulate the transducer towards and away from the shoulder with a slight swiveling

motion.

(4) Inspect the entire 360 degrees around the screw cap for cracks.

C. 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) Verify and make sure that the indication is not from the external shoulder i.e. the

transducer moved too much forward on to the edge or the baseline has shifted

accidentally.

(3) If the indication is a crack, determine the approximate length of the crack by scanning it in

both directions from the peak signal until the signal has dropped to 40 % FSH and mark

the centre point of the transducer. The circumferential crack length is the distance

between the two points.

D. 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

cause for rejection.

(2) Record and report the results of the ultrasonic inspection to your Amphibious Aircraft

Technical Representative.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 11 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

5. Installation

If an accumulator was remove for an ultrasonic inspection and determined to be serviceable or a

new accumulator is required, refer to PSP 492, Maintenance Manual, Chapter 32 for installation

and test procedures for the break accumulators and Chapter 27 for installation and test procedures

for the rudder, elevator, or aileron accumulators.

6. Recording

When this Service Bulletin is completed, make the entry in the aircraft log book and send back the

attached Incorporation Notice to Amphibious Aircraft Technical Publications.

7. Material Information

This Service Bulletin contains no kit. Tactair or York CRS T11651 is available upon request from

Bombardier Aerospace, contact your Amphibious Aircraft Technical Representative for details.
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 12 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

TACTAIR OR YORK CALIBRATION REFERENCE STANDARD DETAILS (T11651)

FIGURE 3

NOTCH B

R 0.080

45o

45o

NOTCH A

R 0.050

NOTCH C

R 0.121

3/16 MAX

1.127

1.093

1.524

1.127

1.098

3X 0.0055 MAX
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 13 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

100%

50%

0 50 100

IP

EES

100%

50%

0 50 100

IP

EES

IP = INITIAL PULSE

EES = ECHO FROM EXTERNAL SHOULDER

ENA = ECHO FROM NOTCH A

TRANSDUCER

PLACEMENT EXTERNAL

SHOULDER

CRT DISPLAY CALIBRATION AND FAMILIARIZATION (T11651)

FIGURE 4

INTERNAL

SHOULDER

0.25 INCH REF

TRANSDUCER

SOUND EXIT POINT

EDM NOTCH A

CRS T11651

END OF TAPERED

ENA
MODEL CL-215-6B11 (415)

SERVICE BULLETIN

Bombardier 415

Service Bulletin 215-4414

July 9/09 ATA Ref: 32-40

Page 14 of 14 ATA Ref: 27-10

Rev. 1 March 12/10

TRANSDUCER PLACEMENT AND SCANNING MOVEMENT

FIGURE 5

EXTERNAL

SHOULDER

TRANSDUCER

PLACEMENT AND

SCANNING MOVEMENT

POTENTIAL CRACK AT

INTERNAL SHOULDER
Upon completion of Service Bulletin(s), please fill in and return by fax to:

Service Bulletin Number(s) Rev.

Aircraft Serial No.

Date of Incorporation

Aircraft Reg. No.

Technical Publication,

Dept. 649-DBF−(9)

Bombardier Aerospace

Amphibious Aircraft

St. Laurent, Quebec

Fax No.: (514) 855−7602

Airframe Hours

Remarks

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SERVICE BULLETIN

INCORPORATION NOTICE

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