### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 1/16

2006.11.23 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE C EDEX F RANCE



# EMERGENCY



# ALERT SERVICE BULLETIN

DAUPHIN NUMBER VERSIONS

Civil: N, N1, N2, N3 

# 365 62.00.24 Military: F, Fs, Fi, K

AA, MA, MB, SA, SB, 

# 565 62.00.10 Military: UB

Civil : G1 

# 366 62.14 Military: GA


# 365 65.45 Civil : C, C1, C2, C3



### SUBJECT: MAIN ROTOR

Frequency Adapter with Ventilation Holes

Corresponds to MOD 0762C39

REVISION NUMBER DATE OF APPROVAL DATE OF ISSUE

Revision 0 On: November 23, 2006 2006.11.23

### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 2/16

2006.11.23 

### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters / Installed equipment

a) On helicopters with a main rotor head fitted with frequency adapters pre MOD 0762C39 (see NOTE 3) and operated in hot climatic conditions and/or tropical and damp atmosphere, see NOTE 1. Refer to the part numbers of frequency adapters pre MOD 0762C39 listed in paragraph 2.B.2.v.



### NOTE 1

1) The operating conditions of helicopters operated in tropical and damp atmospheric conditions are defined in the “GENERAL” chapter of the Maintenance Program (PRE). 2) The operating conditions of helicopters operated in

hot climatic conditions are defined as follows: - Helicopter operated in areas with high solar radiation

temperatures above 40°C.

b) On helicopters with a main rotor head fitted with frequency adapters post MOD 0762C39,

see NOTE 2. Refer to the part numbers of frequency adapters post MOD 0762C39 listed in paragraph 2.B.2.v.



### NOTE 2

For helicopters with a main rotor head fitted with frequency adapters post MOD 0762C39, only the instructions in paragraph 1.E.2.a.2 of this ALERT SERVICE BULLETIN are applicable.



### NOTE 3

SA 366 GA helicopters modified per OP 62C36 (modification equivalent to MOD 0762C39) are not concerned by the instructions in this ALERT SERVICE

BULLETIN.

1.A.2. Non-installed equipment

On equipment designed to operate in hot climatic c onditions and / or tropical and damp atmosphere: - On main rotor heads fitted with frequency adapters pre MOD 0762C39. - On frequency adapters pre MOD 0762C39. - On frequency adapter bushes pre MOD 0762C39 (non-drilled bushes).

### T.F.S. No. 00000338

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2006.11.23 

### 1.B. ASSOCIATED REQUIREMENTS

Not applicable.



### 1.C. REASON

To reduce the operating temperature of the Starflex star arm end by im proving the air flow, by locally drilling 4 holes in the frequency adapters and in the bushes that secure the bearing.

This ALERT SERVICE BULLETIN will form the subject of an EASA Airwor thiness Directive.



### 1.D. DESCRIPTION

On October 12, 2006, following some reports of deterior ation and two reports of fa ilure of Starflex star arm ends, EUROCOPTER issued ALERT SER VICE BULLETINS No. 05.00.51R1/AS365, 05.00.21R1/AS565, 05.35R1/SA366 and 05.28R1/SA365, in or der to render the monitoring of the integrity of the bush-to-star arm end attachment mandatory. At the same time, in order to identify the reason for these deteriorations, EUROCOPTER has conducte d complementary analyses and tests which have revealed that temperature has a stro ng effect on the strength of this attachment and that this temperature can be reduced significantly by improving the air flow in this area.

EUROCOPTER has defined modification 0762C39 which re duces the operating temperature in this area and thus improve the behavior of the Starflex star arm end. This modification can be embodied by Customers and co nsists in improving the air flow in this area by drilling two holes on both sides of the armature of th e frequency adapter and in the bush that secures the bearing.

### T.F.S. No. 00000338

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2006.11.23 

### 1.E. COMPLIANCE

EUROCOPTER renders compliance with th is ALERT SERVICE BULLETIN mandatory.

1.E.1. Compliance at the works

1.E.1.a.On helicopters: MOD 0762C39 will be embodied from November 27, 2006.

1.E.1.b. On non-installed equipment:

MOD 0762C39 will be embodied from February 1, 2007.

1.E.2. Compliance in operation: By the operator:

1.E.2.a. On helicopters / installed equipment used in hot climatic conditions and/or in tropical and damp atmosphere:

1.E.2.a.1. On main rotor heads fitted with frequency adapters pre MOD 0762C39: - Comply with paragraphs 2.B.1. to 2.B.3. within 110 flying hours following receipt of this ALERT

SERVICE BULLETIN, issued on the date i ndicated at the foot of the page.

1.E.2.a.2. On main rotor heads fitted wi th frequency adapters post MOD 0762C39: - Comply with paragraph 2.B.6. every 10 flying hours.



### CAUTION

EACH TIME A FREQUENCY ADAPTER OR FREQUENCY ADAPTER BUSH POST MOD 0762C39 IS INSTALLED, DO NOT FORGET TO FIT THE LOCKWIRE (5).

1.E.2.b. On non-installed equipment

On equipment designed to operate in hot climatic c onditions and/or in tropical and damp atmosphere:

- On main rotor heads fitted with frequency adapters pr e MOD 0762C39, comply with paragraph 2.B.2.

of this ALERT SERVICE BULLETIN. - On frequency adapters pre MOD 0762C39, comply with paragraph 2.B.4. of this ALERT SERVICE

BULLETIN. - On frequency adapter bushes pre MOD 0762C39 (n on-drilled bushes), comply with paragraph

2.B.5. of this ALERT SERVICE BULLETIN.

### T.F.S. No. 00000338

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2006.11.23 

### 1.F. APPROVAL

Approval is limited to civil version helicopte rs subject to an Airworthiness Certificate.

The information or instructions relate to cha nge: MOD 0762C39 which was approved on November 14,

2006.

The technical information given in this ALERT SERVICE BULLETIN was approved on November 23, 2006 under the authority of EASA Design Organisation A pproval No. 21J.056.



### 1.G. MANPOWER

Qualification: Mechanic to comply wi th paragraphs 2.B.1. to 2.B.3. Time for the operations: Approximately 12 hours for one main rotor head. Time for Alodine 1200 and P05 paint applic ation and drying: Approximately 4 hours.

Qualification: Mechanic or flight crew to comply with paragraph 2.B.6. Time for the operations: Approximately 5 minutes.



### NOTE 4

Compliance with the instructions in paragraph 2.B.6. can be ensured by the flight crew if appropriately trained for this

maintenance.



### 1.H. WEIGHT AND BALANCE

Not applicable.



### 1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT STATE

Not applicable.

### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 6/16

2006.11.23 

### 1.K. REFERENCES

Maintenance Manual (MET) Work Cards: 53.50.00.401 - 62. 10.00.401 - 62.20.00.402

and 62.20.00.603.

or 53.50.401 – 65.11.401 – 65.14.402 and 65.14.604.

Standard Practices Manual (MTC) Work Cards: 20.04.04.403 and 20.04.05.402.



### 1.L. OTHER DOCUMENTS CONCERNED

Maintenance Program (PRE). Maintenance Manual (MET).



### 1.M. TOOLING CONCERNED

Not applicable.



### 1.N. INTERCHANGEABILITY AND MIXABILITY OF PARTS

1.N.1. Interchangeability: Prohibited.

1.N.2. Mixability: Frequency adapt ers post MOD 0762C39 cannot be combined with frequency adapters pre

MOD 0762C39.

### T.F.S. No. 00000338

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2006.11.23 

### 2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

The operational procedure in paragraph 2.B.2. is described for one frequency adapter and must be applied to the four frequency adapters installed on the main rotor head.



### 2.B. OPERATIONAL PROCEDURE

2.B.1. Preliminary steps

- Remove the MGB cowlings as per MET Work Card 53.50.00.401 or 53.50.401. - Remove the main rotor blades as per MET Work Card 62.10.00.401 or 65.11.401.

2.B.2. Embodying MOD 0762C39 on the frequency adapters and adapter bushes

a) Remove the frequency adapters from the blade a ttach beams, as per MET Work Card 62.20.00.402

or 65.14.402. b) Identify each frequency adapter with respect to the sleeve from which it was removed. c) Remove the screws (2) and washers (3) to ease the marking of the position of the four holes (Figure 1). d) On the frequency adapter (1), mark out the positi on of the four 8 mm diameter holes (two holes on the leading edge and two holes on the trailing edge, as shown on Figure 1).

ON CERTAIN FREQUENCY ADAPTERS, WHEN DRILLING THE HOLES, THE “UP” MARKING OR THE

SERIAL NUMBER AND THE DATE OF MANUFACTURE MAY BE DEFACED. IN THIS CASE,

YOU MUST VIBRO-ETCH - THE "UP” MARKING IN AREA X (FIGURE 1),

- THE SERIAL NUMBER AND THE DATE OF

MANUFACTURE IN AREA Y (FIGURE 6). (SIZE OF THE LETTERS: 2.5 TO 4 MM)

e) Spot-drill the position of the four holes on the frequency adapter (1). 

### CAUTION

### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 8/16

2006.11.23 Figure 1

f) Fit the washers (3) and the screws (2) to hold the bush (4) in place during drilling (Figure 2). g) Mask the inside of the bush (4) with adhesive tape in order to protect the bearing from drilling chips (Figure 2).

Figure 2 4 2

3

### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 9/16

2006.11.23 

### NOTE 1

Adjust the drilling depth of the drill bit and turn the bearing to the inside of the frequency adapter, in order to avoid damaging the bearing with the protruding tip of the

drill bit. Use drill bits compatible with “aluminum” or “steel”. Do

not lubricate.

h) Drill four 4 mm diameter pilot holes in th e frequency adapter (1) and in the bush (4). i) Drill out the four 4 mm diameter pilot holes using an 8 mm drill bit (Figure 3).

Figure 3

j) Remove the adhesive tape from the frequency adapter (1) and remove any chips. k) Remove the screws (2), the washers (3) and the bu sh (4) from the frequency adapter (1) (Figure 2). 4 

### 1

### T.F.S. No. 00000338

Approved under EASA DOA No. 21J.056 Page 10/16

2006.11.23 l) Mask the bearing with adhesive tape (Figure 4).

Figure 4

m) Deburr the four holes drille d in the frequency adapter (1). n) Deburr the four holes drilled in the bush (4). o) Remove any chips and clean the bush and the frequency adapter (1). p) Protect the inner surface of the holes in the fr equency adapter (1) and in the bush (4) with ALODINE 1200, as per MTC Work Card 20.04.04.403. q) Protect the inner surface of the holes in the frequ ency adapter (1) and in the bush (4) with primer P05 as per MTC Work Card 20.04.05.402. r) Remove the adhesive tape from the frequency adapter (1). s) Remove any chips from the frequency adapter (1) and from the bearing. t) Install the bush (4), the washers (3) and the screws (2), as per MET Work Card 62.20.00.402 or

65.14.402. u) Prevent the bush (4) from turn ing by locking it with lockwire (5). Feed the lockwire through the two holes in the frequency adapter (1) and the bush (4) on the trailing edge of the frequency adapter (Figure 5).

Figure 5 5 4

### T.F.S. No. 00000338

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2006.11.23 v) Identify the part number of the frequency adapter po st MOD 0762C39, in accordance with the table below and vibro-etch this part number below the exis ting part number in AREA Z, (size of the letters: 2.5 to 4 mm) (Figure 6). After markin g, cross out the previous part numb er in such a way that it is still legible.

Figure 6

Manufacturer Part

Number EUROCOPTER Part

Number pre MOD 0762C39 EUROCOPTER Part

Number post MOD 0762C39

E1T 22305-01 704A33 640 016 365A31.1019.20

E1T 2549-01 704A33 640 029 365A31.1019.21

E1T2624-01A 704A33 640 031 365A31.1019.22

E1T 3023-01 704A33 640 046 365A31.1019.23

J 16130 10 704A33 640 087 365A31.1019.24

E 4165 F01 704A33 640 088 365A31.1019.25

J 16130 15 704A33 640 089 365A31.1019.26

x) Install the frequency adapter on the attach beams of the same sleeve as identified previously, as per

MET Work Card 62.20.00.402 or 65.14.402.

2.B.3. Final steps

- Install the main rotor blades as per ME T Work Card 62.10.00.401 or 65.11.401. - Install the MGB cowlings as per MET Work Card 53.50.00.401 or 53.50.401. - If necessary, carry out dynamic balancing of the ma in rotor head, as per MET Work Card 62.20.00.603

or 65.14.604.

### T.F.S. No. 00000338

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2006.11.23 2.B.4. On non-installed equipment , embodiment of MOD 0762C39 on the frequency adapters

a) On the frequency adapter (1), mark out the positi on of the four 8 mm diameter holes (two holes on the leading edge side and two holes on the trailing edge side, as shown on Figure 1).

ON CERTAIN FREQUENCY ADAPTERS, WHEN DRILLING THE HOLES, THE “UP” MARKING OR THE

SERIAL NUMBER AND THE DATE OF

MANUFACTURE MAY BE DEFACED. IN THIS CASE, YOU MUST VIBRO-ETCH - THE "UP” MARKING IN AREA X (FIGURE 1),

- THE SERIAL NUMBER AND THE DATE OF

MANUFACTURE IN AREA Y (FIGURE 6). (SIZE OF THE LETTERS: 2.5 TO 4 MM)

b) Spot-drill the position of the four holes on the frequency adapter (1) as shown on Figure 1.



### NOTE 2

Adjust the drilling depth of the drill bit to avoid damaging the adapter. Use drill bits compatible with “aluminum” or “steel”. Do

not lubricate.

c) Drill four 4 mm diameter pilot holes in the frequency adapter (1). d) Drill out the four 4 mm diameter pilot holes using an 8 mm drill bit (Figure 3). e) Deburr the four holes drille d in the frequency adapter (1). f) Protect the inner surface of the holes in t he frequency adapter (1) with ALODINE 1200 as per MTC

Work Card 20.04.04.403. g) Protect the inner surface of the holes in the fr equency adapter (1) with primer P05 as per MTC Work

Card 20.04.05.402. h) Remove any chips from the frequency adapter (1). i) Identify the part number of the frequency adapter po st MOD 0762C39, in accordance with paragraph

2.B.2.v. 

### CAUTION

### T.F.S. No. 00000338

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2006.11.23 2.B.5. On non-installed equipment , embodiment of MOD 0762C39 on frequency adapter bushes

a) Use a frequency adapter post MOD 0762C39, as a tool. b) Fit the washers (3) and the screws (2) to hold the bush (4) in place during drilling (Figure 2).



### NOTE 3

Adjust the drilling depth of the drill bit to avoid damaging the bearing with the protruding tip of the drill bit. Use drill bits compatible with “aluminum” or “steel”. Do

not lubricate.

c) Drill the four holes using an 8 mm drill bit (Figure 3). d) Remove the screws (2), the washers (3) and the bu sh (4) from the frequency adapter (1) (Figure 2). e) Deburr the four holes drilled in the bush (4) f) Protect the inner surface of the holes in the bush (4) with ALODINE 1200 as per MTC Work Card

20.04.04.403. g) Protect the inner surface of the holes in the bush (4) with primer P05 as per MTC Work Card

20.04.05.402.



### NOTE 4

- After rework of the bushes 350A31 1885.21, their part

number becomes 365A31 10 18 21

. - After rework of the bushes 350A31 1885.22, their part

number becomes 365A31 10 18 22

. - The part number of the new bush definitions is

365A31 1018 22

### T.F.S. No. 00000338

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2006.11.23 2.B.6. Checking that the lockwire is in place and that the holes are not blocked

As shown on Figure 5:

- Check that the lockwire (5) is in place on the trailing edge side of the frequency adapter and that the

four holes are not blocked.

. If the lockwire (5) is in place on the trailing edge side of the frequency adapter and if the four holes are

not blocked: - Leave as is and resume flights.

. If the lockwire (5) is not in place on the trailing edge side of the frequency adapter:

- Re-position the bush (4) if it has turned, and fit the lockwire (5) before resuming flights. - Inform the EUROCOPTER Technical Support Department by:

. Tel: +33 (0)4.42.85.99.67 . Fax: +33 (0)4.42.85.99.66.

. If one or more holes or more is/are blocked, unblock the hole(s) before resuming flights.



### NOTE 5

Frequency adapters post MOD 0762C39 are subject to the same scheduled checks (Maintenance Program (PRE)) and the same removal criteria as frequency adapters pre MOD 0762C39.



### 2.C. IDENTIFICATION

Record embodiment of MOD 0762C39 and compliance with this ALERT SERVICE BULLETIN on the log card (FM) of the main rotor head.



### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.

### T.F.S. No. 00000338

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2006.11.23 

### 3. MATERIAL INFORMATION

3.A. MATERIAL: COST - AVAILABILITY

Not applicable.



### 3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.



### 3.C. MATERIAL REQUIRED FOR EACH AIRCRAFT, ENGINE / COMPONENTS

3.C.1. Kit(s) or component(s) to be or dered for one helicopter or one assembly

Not applicable.

3.C.2. Items to be ordered separately

Product

Part Number Qty Item Key Word

* MIL-DTL-81706 A/R ALODINE 1200 * DHS186-111-20 A/R Primer paint P05 * EN3628-0,8 A/R 5 Lock wire, 0.8 mm dia.

The products identified by an asterisk "*" or required for compliance with the Tasks and / or Work Cards listed in paragraph 1.K., can be orde red from the INTERTURBINE company.

Website: http://www.itlogistics.de Telephone: +49.41.91.809.300

AOG: +49.41.91.809.444

### T.F.S. No. 00000338

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2006.11.23 

### 3.D. PROCUREMENT CONDITIONS

Order the required quantity (unless otherwise specified)

from

EUROCOPTER Etablissement de Marignane

Sales and Customer Relations Directorate

ECR

13725 MARIGNANE CEDEX

FRANCE



### NOTE 1

For ALERT SERVICE BULLETINS, order by:

Telex: HELICOP 410 969F Fax: +33 (0)4.42.85.99.96



### NOTE 2

On the purchase order, please specify the mode of transport, the destination and the serial numbers of the

aircraft to be modified.



### 4. APPENDIX

Not applicable.