July 15/11 Service Bulletin 215-A4451

Page 1 of 13 ATA Ref: 32-10

MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

LANDING GEAR

INSPECTION OF THE MAIN LANDING GEAR (MLG) UPPER MEMBER FORWARD LUG

USING EDDY CURRENT METHOD

1. Planning Information

A. Compliance

The inspection described in this Service Bulletin is Mandatory and must be completed within

the next 50 flight hours upon receipt of this Service Bulletin.

The inspection described in this Service Bulletin is to be repeated at or before every 165 land

landings until a permanent solution is incorporated in the Aircraft Maintenance Manual and/or

pending further instruction from your Amphibious Aircraft Technical Representative.

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. 

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

Cracks have been detected on the forward main landing gear lugs in service.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 2 of 13 ATA Ref: 32-10

E. Description

This Service Bulletin gives instruction to do an eddy current inspection on the forward lug part

numbers 160−714−3 (LH) and 160−714−4 (RH), without removing the MLG upper member.

F. Manpower

We estimate that it will take 1 technician approximately 2 hours to complete this Service

Bulletin.

NOTE: All NDT inspections must be done by certified level 2 or 3 individuals in an NDT

standard approved by the national Airworthiness authority.

G. Material Availability

No kit is necessary for this inspection.

H. Tool Availability

REFERENCE1.9 DESIGNATION

Hocking Phasec 2200

or equivalent

Eddy Current-Instrument-Impedance-Plane Type

AL29−32 Calibration reference standard made from aluminum alloy

(29% IACS), that contains 0.008 in. (0.20 mm), 0.020 in.

(0.51 mm), and 0.040 in. (1.02 mm) deep electrical discharge machined (EDM) notches.

Commercially

available

Coaxial cable (microdot to BNC type)

Commercially

available

Surface probe, 45° tip, 500 kHz frequency, NFe/Fe, absolute,

shielded, 0.092 in. (2.34 mm) diameter, 4.50 in. (114.30 mm)

length, 0.750 in. (19.5 mm) tip length. (GE P/N 205P4XF or

equivalent)

Commercially

available

Explosion Proof Light

NOTES: 1. You can use equivalent eddy current equipment if it satisfies the requirements of

this procedure and is capable of resolving the reference notch in the calibration

reference standard at the required level of resolution and sensitivity.

2 To get access to the inspection area, it is permitted to use a surface probe of

different configuration from the one specified. The test frequency can range from

100 kHz to 500 kHz.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 3 of 13 ATA Ref: 32-10

I. Weight and Balance

Not affected.

J. Electrical Load Data

Not affected.

K. References

For Bombardier Aerospace Reference only:

(Not Supplied with Kit)

Bombardier Aerospace Restriction and/or Special Instruction (RSI) C-3892, Revision, A.

L. Publications Affected

None.

M. Related Service Bulletin

Service Bulletin 215-4450, Inspection of the Main Landing Gear Upper Member Forward Lug

Using Liquid Penetrant Inspection Method.

2. Accomplishment Instructions

NOTES: 1. For this modification, it is assumed that standard maintenance and repair practices

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

2. For parts location, refer to the illustration page in this Service Bulletin.

3. If any deviation exists, contact your Amphibious Aircraft Technical Representative for

further instructions.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 4 of 13 ATA Ref: 32-10

A. Preparation

Refer to PSP 496, Nondestructive Testing Manual, PART 1 GENERAL − EDDY CURRENT,

and Figure 2.

The procedure for the left MLG upper member forward lug is described. The procedure for the

right MLG upper member forward lug is similar.

WARNING: MAKE SURE THAT ALL PERSONNEL AND GROUND EQUIPMENT ARE A

SAFE DISTANCE AWAY FROM HYDRAULICALLY OPERATED SYSTEMS

BEFORE YOU REMOVE HYDRAULIC PRESSURE AND/OR ELECTRICAL

POWER. ACCIDENTAL SYSTEM OPERATION CAN CAUSE INJURIES TO

PERSONNEL AND DAMAGE TO THE GROUND EQUIPMENT.

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

ELECTRICAL POWER − MAINTENANCE PRACTICES.

NOTE: It is not necessary to remove the MLG upper member to do this inspection.

(2) Make sure the inspection surface is clearly visible. Refer to Figure 3.

WARNING: WEAR RUBBER GLOVES, EYE PROTECTION, AND A RESPIRATOR WHEN

HANDLING SOLVENTS, SEALING COMPOUNDS, OR ADHESIVES. CONTACT

WITH SOLVENTS, SEALING COMPOUNDS, OR ADHESIVES AND THEIR

VAPOURS MAY CAUSE IRRITATION TO THE SKIN, THE EYES, AND THE

LUNGS. FAILURE TO WEAR PROPER PROTECTION MAY CAUSE INJURIES

TO PERSONNEL.

(3) Clean the areas to be inspected thoroughly with aliphatic naphtha using a nylon bristled

brush and clean cloths in accordance with PSP 497, Chapter 51. Allow the surfaces to

dry completely.

NOTE: If the paint or primer is in good condition, it does not need to be stripped. If the

finish is damaged, the bare metal must be exposed and refinished in accordance

with PSP 497, Chapter 51.

B. Equipment Calibration

Refer to Figures 1 and 2

NOTES: 1. Make sure that you follow the manufacturer’s instrument instructions when you

operate the test equipment.

2. The values listed in Figure 1 may vary between instruments.

(1) Connect the probe 205P4XF with the coaxial cable to the eddy current instrument.

(2) Turn the instrument ON and adjust and set the instrument controls as shown in Figure 1.

(3) Put the probe (coil) tip perpendicular to the surface of the AL29−32 calibration reference

standard (CRS), away from the 0.040 in. (1,02 mm) deep EDM notch and the edge.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 5 of 13 ATA Ref: 32-10

(4) Balance (BAL) the eddy current instrument.

(a) Adjust the instrument (PHASE) control to obtain a horizontal lift−off signal moving

from right−to−left (with increasing lift−off) across the screen display.

(b) Use the (X−POS) and (Y−POS) controls to position the dot in the lower right

quadrant of the screen display.

(5) Move the probe (coil) tip across the 0.040 in. (1,02 mm) deep EDM notch, and adjust the

instrument sensitivity (gain) to obtain an amplitude signal as shown in Figure 1, Screen

Display.

(6) Differentiate between the EDM notch and the edge signals by moving the probe over the

edge of the reference standard.

(a) Make sure the signal obtained from the edge slants−off towards the upper left

quadrant as shown in Figure 1.

C. Lift−Off Compensation Verification

Refer to Figures 1 and 2

(1) Put the probe (coil) tip perpendicular to the inspection surface.

NOTE: DO NOT balance the instrument.

(2) Compare the screen displays between the operating point on the inspection surface and

the balance point on the CRS for the following conditions:

(a) If the operating point on the inspection surface matches the balance point on the

CRS, no compensation for paint thickness is required:

1 Proceed to the Inspection Procedure section.

− or −

(b) If the operating point on the inspection area does not match the balance point on

the CRS, but has moved to the LEFT, compensation for the paint thickness is

required. Do as follows:

1 Attach a strip of nonconductive tape or shim to cover the CRS surface and the

EDM notches.

2 Put the probe (coil) tip perpendicular to the surface of the CRS. DO NOT balance

the instrument.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 6 of 13 ATA Ref: 32-10

3 Compare the operating point on the inspection surface to the balance point on

the CRS for the conditions that follow:

− If the operating point on the inspection surface is still to the left of the balance

point on the CRS, add an additional strip of tape or shim until the balance

point on the CRS matches the inspection area.

− If the operating point on the CRS over the tape is to the right of the balance

point, remove a strip of tape or shim until the balance point on the CRS

matches the inspection area.

− If lift−off compensation and calibration requirements cannot be met, remove

the paint or coating prior to inspection.

(3) Slide the probe across the 0.040 in. (1,02 mm) EDM deep notch covered with tape on the

CRS.

(a) Adjust the GAIN to obtain an eddy current amplitude signal from the 0.040 in.

(1,02 mm) deep EDM notch as shown in Figure 1, Screen Display.

(b) Proceed to the Inspection Procedure section.

D. Inspection Procedure

Refer to Figure 3

NOTES: 1. Monitor the screen display carefully at all times and make a note of all distinct

relevant indications. Include the screen height of each signal and the related

location on the part being inspected.

2. A relevant crack indication is as follows:

− A fast up dot movement signal that stays at the up position for more than a

longer probe scan distance (more than one probe diameter) when a crack length

is parallel to the scan direction,

− a fast vertical deflection signal with a short probe scan distance (one probe

diameter or less) when the crack length is perpendicular to the scan direction.

3. After balancing the inspection area, if the balance point drops below the screen

display from the original balance point, it could indicate the original balance

location contains a defect. If this is true, rebalance on an adjacent area and scan

the original balance point for possible defects before continuing the inspection.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 7 of 13 ATA Ref: 32-10

4. Instrument calibration verification intervals are as follows:

− Every 30 minutes of continuous operation,

− a change to set−up parameters, and/or equipment (i.e. a different probe),

− when the inspection is completed,

− when there is any variation in the amplitude of the calibration signal, calibrate the

instrument again and repeat the inspection at all locations from the last valid

calibration point.

5. Make sure the operation point is on the screen display at all times.

6. The maximum inspection scan speed shall be equivalent or less than the

calibration probe speed.

Refer to Figure 1 for typical screen responses and Figure 3 for inspection areas and scan

paths.

(1) Put the probe (coil) tip perpendicular to the inspection area as close as possible to the

shoulder of the initial machined fillet radius on the left MLG upper member forward lug

without getting an edge signal.

(2) Balance (BAL) the instrument.

(a) If necessary, adjust the instrument (PHASE) control to obtain a horizontal lift−off

signal moving from right−to−left across the screen display.

(3) Make a series of contour scans parallel to the shoulder adjacent to the machined fillet

radius extending for 0.250 in. (6,35 mm) from the machined fillet radius juncture.

(a) Make sure you maintain a constant edge distance for the initial scan on the shoulder

adjacent to the machined fillet radius.

(b) Make sure the probe tip stays perpendicular to the inspection surface at all times

during the scan.

(c) Index one probe diameter or less from the previous scan. Refer to Figure 3 for

inspection location and for typical scan path.

(4) Repeat the inspection procedure for the opposite shoulder of the MLG upper member

forward lug.

(5) Repeat the inspection procedure for the right-hand (RH) MLG upper member forward lug.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 8 of 13 ATA Ref: 32-10

E. Evaluation of Indications

(1) Further investigation is required if:

(a) there is a distinct vertical deflection signal that occurs over a short scan distance

(one probe tip diameter), or

(b) there is a rapid up dot movement signal that stays at the up position over a longer

scan distance.

(2) If you have a suspect indication, make sure it is not caused by non-relevant factors, as

follows:

− edge effect,

− an abrupt change in geometry,

− localized variations in conductivity,

− permeability, or

− other non−relevant factors.

(3) Evaluate all suspect crack indications by comparing their phase angle, amplitude and

shape to the calibration standard EDM notch signal.

(4) If a crack is detected, determine the length and location of the crack.

F. Acceptance or Rejection Criteria

Refer to Figures 1 and 3

(1) Indications of a crack are as follows:

(a) A distinct vertical deflection signal that occurs over a short scan distance (one probe

tip diameter),

(b) a distinct vertical deflection signal which equals to 50% or greater than the response

from the 0.040 in. (1,02 mm) deep EDM notch as shown in Figure 1,

(c) a rapid upward dot movement signal which equals to 50% or greater than the

response from the 0.040 in. (1,02 mm) deep EDM notch as shown in Figure 1 and

remains at the upward position momentarily (or over a longer period of time).

(2) If there are no cracks,

− repeat the Eddy Current Inspection every 165 Land Landings.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 9 of 13 ATA Ref: 32-10

(3) If there is a crack,

− provide details of findings to your Amphibious Aircraft Technical Representative,

− replace the forward lug (160−714−3 or 160−714−4), as per PSP 498, MAIN

LANDING-GEAR UPPER-MEMBERS − DISASSEMBLY/ASSEMBLY, and

− repeat the Eddy Current Inspection every 165 Land Landings.

G. Close−Out

(1) Replace any finish that was removed from the inspection area. Refer to PSP 497,

Structural Repair Manual, Chapter 51−71−02, CORROSION PREVENTIVE TREATMENT

− GENERAL PROCEDURES.

(2) Remove all tools, equipment, and unwanted materials from the work area.

(3) Restore the electrical power. Refer to PSP 492, Maintenance Manual, Chapter 24−00−00,

ELECTRICAL POWER − MAINTENANCE PRACTICES.

H. Recording

When this Service Bulletin is completed, make the entry in the aircraft technical record and

send back the attached Incorporation Notice to Amphibious Aircraft Technical Publications.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 10 of 13 ATA Ref: 32-10

AND PROBE 205P4XF)

FIGURE 1

. .

.

. . . . .. . . .

. . . . . .. . . .

.

.

.

... . . . . . .

. . . . . .. . . .

. . . . . .. . . .

. . . . . . .

.

.

.

.

SCREEN DISPLAY

EDGE SIGNAL

INSTRUMENT SETTINGS

SIGNAL FROM 0.040−in. (1,02−mm)

DEEP EDM NOTCH

LIFT−OFF SIGNAL

BALANCE POINT

100%

0%

80 % FSH

MODE

DISPLAY

VIEW

CH 1 FREQ

CH 1 PHASE

GAIN

X:Y

HI−PASS

LO−PASS

BAL. LOAD

X−POS

Y−POS

ABS CH1

XY

CH 1

500 kHz

342.0

44.5 dB

X −8 dB

DC

200 Hz

47 H

40

−40

. . . ...

CALIBRATION DATA (HOCKING PHASEC 2200 EDDY CURRENT INSTRUMENT

μ
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 11 of 13 ATA Ref: 32-10

3.75 in.

0.75 1.00

1.50 in.

(1,02 mm)

NOTES

4

2.

0.005 in. +0.000/−0.002 in.

(0,127 mm +0,000/−0,051 mm)

(0,51 mm) (0,20 mm)

0.040 0.020 0.008

AL 29.32 4

0.75

0.25 in.

1. Material: 2024−T3, QQ−A−250/4

Finish surface 125 RMS or better.

(19,05 mm)(19,05 mm) (25,40 mm)

(95,25 mm)

WIDE X 1.50 in. (38,10 mm)

LONG EDM NOTCH

(38,10 mm)

(TYPICAL)

0.040 in. 0.020 in. 0.008 in.

(6,35 mm)

3. Penetrant inspect as per BAPS 176−002.

4. Identification sticker, 0.125 in (3,175 mm) letters black colour.

5. Conductivity test as per BAPS 168−013.

6. EDM notches shall have a tolerance of 0.001 in. ( 0.025 mm)

for depth and +0.000/0.002 in. (+0,000/−0,051 mm) for width.

−

+ −

+

CALIBRATION REFERENCE STANDARD AL 29−32

FIGURE 2
MODEL CL-215-6B11 (415)

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SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 12 of 13 ATA Ref: 32-10

INSPECTION LOCATION OF THE MAIN LANDING GEAR (MLG) FORWARD LUG SHOULDERS

FIGURE 3

LH MLG

UPPER MEMBER

Inspect 0.250 in. (6,35 mm) from the

Machined Filet Radius Juncture

0.250 in.

0.250 in.

0.250 in.

Reference: Machined Filet Radius

Typical for Both Sides

Typical Inspection Area for

Both Shoulders adjacent to

the Machined Filet Radius

NOTES

Dash Lines Represent

Typical Scan Paths

Typical Crack Location

0.250 in.
MODEL CL-215-6B11 (415)

ALERT

SERVICE BULLETIN

Bombardier 415

July 15/11 Service Bulletin 215-A4451

Page 13 of 13 ATA Ref: 32-10

3. Material Information

This Service Bulletin contains no kit.

A. The following materials, or equivalent, are necessary to do this Service Bulletin. You can buy

them locally:

DESCRIPTION PART NO./NAME SPECIFICATION QUANTITY

Alodizing Solution Alodine 1200S MIL-C-81706 

Class 1A

A/R

Aerodynamic 

Sealant

Pro Seal 870

Class B−2

MIL-S-81733 

Type 2

A/R

Aliphatic Naphtha TT-N-95 Type 2

Faying Surface

Sealant

Pro Seal 870

Class C

MIL-S-81733 

Type 4

A/R

Humiseal 1B15 A/R

Fluid Resistant Epoxy

Primer

BAMS 565-01 A/R

Fluid Resistant Epoxy

Topcoat

BAMS 565-02 A/R
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

Name

SERVICE BULLETIN

INCORPORATION NOTICE

REPLY FAX

Customer/Operation

(Please Print)