## Messier-Dowty SA 

## SPECIAL INSPECTION

BP 10 - 78142 Vélizy Cedex - France

Tél: +33 (1) 46 29 18 00 - Fax: +33 (1) 46 29 87 70

Télex: 634156F - Sita: QBHMDCR 

# SERVICE BULLETIN

A300B4, A300-600, A300-600ST

LANDING GEAR MLG ACTUATING CYLINDER

NDT INSPECTION OF THREAD OF THE ROD

1

. P L A N N I N G INFORMATION

A. Effectivity

Unit s af f e ct ed

A300B4

Actuating cylinder assy

C23129 and derived parts

Stripped actuating cylinder

C23130 and derived parts

A300-600, A300-600ST

Actuating cylinder assy

C23129004 and derived parts

Stripped actuating cylinder

C23130004 and derived parts

B. Concurrent Requirements

None

C. Reason

To check that the thread of the rod is free from crack.

D. Description (see figures 1 to 3)

(1) The accomplishment of this Special Inspecti on Service Bulletin consists in carrying out in

the workshop an Eddy current inspection of the rod to detect any possible presence of

material defect.

October 27, 2005 Serv ice Bulletin N° 470-32-806

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# SERVICE BULLETIN

(2) Flowchart inspection

No defect

Replace the rod before the

next flight Return in s e rvic e Defect found NDT inspection of the MLG Actuating cylinder rod

E. Compliance

(1) This Service Bulletin is recommended at the first opportunity.

(2) Refer to AIRBUS Service Bulleti n N ° A 3 0 0

- 3 2

- 0 4 5 0

, A 3 0 0

- 3 2

- 6 0 9 7

, A 3 0 0

- 3 2

- 9 0 1 3

.

F. Approval

The technical content of this Vendor Servic e Bulletin has been approved under the authority of

EASA Design Organisation Approval No. EASA.21J.031.

G. Manpower

1 NDT specialist (minimum qualification equi valent to level 2 of COSAC/COFREND)

Estimated time for the Eddy current inspection: 1 hour for each leg

Estimated time required for accomplishment of this Service Bulletin :Man-hour: 2.50 hours for

each leg

NOTE : It is assumed that the equipment has been placed in a maintenance status. The manhour estimates do not include time to prepare or administrative functions.

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# SERVICE BULLETIN

H. Weight and Balance

None

I. Electrical Load Data

None

J. References

- Components Maintenance Manuals :

- Actuating cylinder

A300B4 32-34-46, 32-34-47

A300-600, A300-600ST 32-34-48

- AIRBUS Service Bulletin N° A300-32-0450, A300-32-6097, A300-32-9013.

K. Other publications affected

None

L. Interchangeability or Intermixability of Parts

None

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# SERVICE BULLETIN

2

. M A T E R I A L INFORMATION

A. Material - Price and availability

(1) Necessary parts :

Washer C69066 : Qty per actuating cylinder : 1

Cotter pin MS24665-283 : Qty per actuating cylinder : 1

Cotter pin MS24665-287 : Qty per actuating cylinder : 1

(2) The parts that are necessary to perform th is Service Bulletin are available to operators on

request from the regional Messier Dowty Customer Support Centre.

(3) The parts, are provided at no charge to the operators.

B. Material Nec e s s a ry for eac h Unit.

None

C. Tooling – Price and availability.

Complete tool box KT 69029/-1-2 including

- 1 specific probes A4A02SB806, frequency 0,5 MHz (see figure 2)

- 1 calibration block used for defect evaluation.

- Calibration block CF04C10 contains an artificial defect located on the thread to be checked.

Eddy Current equipment: Elotest B1 manufacturer: Rohmann or equivalent

connection: B1-NOB 8H – Rohmann (depend of equipment)

NOTE : For Nortec equipment, (19E, etc...) no adaptator needed. For others devices an

adaptator is mandatory.

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# SERVICE BULLETIN

3

. A c c o m p l i s h m e n t instructions

A. General

The rod is to be inspected in the workshop, t he actuating cylinder havi ng been removed from the

aircraft, Refer to airbus Service Bulle tin A300-32-0450 or A300-32-6097 or A300-32-9013.

B. Procedure (see figures 1 to 3)

Inspection of actuating cylinder in the workshop.

(1) Determination of the position of the end fitting on the rod (see figure 3).

- Record dimensions L 2 before removing the end fitting refer to CMM relevant to each

actuating cylinder (see paragraph 1.J).

(2) Partially disassemble the actuating cylinder, refer to C MM relevant to each actuating

cylinder (see paragraph 1.J) so that the thread of the rod can be inspected (see figure 1).

(3) Eddy current inspection NDT inspection

Calibration of the test equipment

The set up here after is given for example using a Rohmann machine.

- Switch on B1, and check battery level.

- Connect the probe.

- Check that alarm and gates are off

- Select frequency to 0,5 MHz.

- Select bandwidth, Y and X axis spread selected to 0 and Y/X gain selected to

minimum, and adjust the pre-amplification.

- Position the probe at the center of the slot of the calibration block.

- Adjust the spot position on the screen centre.

- Select the filter and frequency of the filter.

- Move the probe by screwing and unscrewing. Adjust X/Y gain to obtain 2 graduations

of the screen.

(4) Inspection of the thread of the rod

(a) Visual inspection

Any contamination of the surface that w ill impair Eddy current will be removed before

inspection. If the removal is not possible, mark such discrepancies on the part for the

later use during evaluation of Eddy current.

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# SERVICE BULLETIN

(b) Eddy current inspection (see figures 2)

(c) Position and screw the probe with the same scanning speed used during calibration

operation until the end of the thread.

(d) Evaluation of the indication

Evaluate the indication by first resetting the sensitivity and recalibrating using the

calibration block.

(e) Acceptance criteria. (see flowchart paragraph 1.d (2))

Any readable indication with a deviation in a defect direction shall be cause of the

rejection. Replacement of the rod before the next flight.

(f) Final operation ( Inspection report)

On attached sheet paragraph “INFORMATION ” note the indication intensity, the

location and the calibration gain or the gain used for the evaluation if the gain defect

is higher than the calibration defect.

(5) Assemble the end fitting on the rod to restor e the dimension L 2 (see figure 3), and test of

the actuating cylinder, refer to CMM relev ant to each actuating cylinder (see paragraph

1.J).

(6) Install the actuating cylinder on aircraft, Refer to airbus Service Bulletin A300-32-XXX.

October 27, 2005 Serv ice Bulletin N° 470-32-806

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## Messier-Dowty SA



# SERVICE BULLETIN

Figure 1

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## Messier-Dowty SA



# SERVICE BULLETIN

Figure 2

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## Messier-Dowty SA



# SERVICE BULLETIN

Figure 3

October 27, 2005 Serv ice Bulletin N° 470-32-806

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## Messier-Dowty SA

BP 10 - 78142 Vélizy Cedex - France

Tél: +33 (1) 46 29 18 00 - Fax: +33 (1) 46 29 87 70

Télex: 634156F - Sita: QBHMDCR 

# SERVICE BULLETIN

NDT INSPECTION OF THE MLG ACTUATING CYLINDER



### INFORMATION

AIRLINE AND A/C REGIST RATION No MSN. :

.................

P/N OF THE MLG LEG :

.................

S/N OF THE MLG LEG :

.................

P/N OF THE MLG ACTU ATING CYLI NDER :

.................

S/N OF THE MLG ACTU ATING CYLI NDER :

.................

TOTAL CYCLES OF THE MLG ACTUATING CY LINDER :

.................

P/N OF THE INSPECTED ROD :

...............

S/N OF THE INSPECTED ROD :

...............

CSN OF THE ROD :

...............



### RESULT

EDDY CURRENT INSPECTION : DEFECT YES 

### ❏ NO 

### ❏

INFORMATIONS

INDICATION INTENSITY:....................................................................................

LOCATION AND CALIBRATION GAIN:.......................................................................



### ACTION

RETURN THIS SHEET ASAP TO MESSIER-DOWTY SA PRODUCT SUPPORT

ENGINEERING

FAX 33 1 46298531

October 27, 2005 Serv ice Bulletin N° 470-32-806

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