### Approved under EASA DOA No. 21J.056. Page 1/15

2008.08.18 This document is available on t he internet: www.eur ocopter.com/techpub EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE C EDEX F RANCE



# EMERGENCY 

# ALERT SERVICE BULLETIN

DAUPHIN NUMBER VERSIONS

Civil: N, N1, N2, N3 

# 365 05.00.51 Military: F, Fs, Fi, K

AA, MA, MB, SA, SB, 

# 565 05.00.21 Military: UB

Civil : G1 

# 366 05.35 Military : GA

C, C1, C2, C3 

# 365 05.28 Civil :



### SUBJECT: TIME LIMITS - MAINTENANCE CHECKS

Check of the Bushes and Check for Ab sence of Delamination on Starflex

Star Arm Ends



### ATA : 62

REVISION No. DATE OF APPROVAL DATE OF ISSUE

Revision 0 On: March 31, 2006 2006.04.04 Revision 1 On: October 12, 2006 2006.10.12 Revision 2 On: November 16, 2007 2007.11.22 Revision 3 On: August 18, 2008 2008.08.18

### Approved under EASA DOA No. 21J.056. Page 2/15

2008.08.18 

### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/Installed equipment

Bushes and composite material on the arm ends of main rotor hub Starflex stars (all part numbers).

1.A.2. Non-installed equipment

Not applicable.



### 1.B. ASSOCIATED REQUIREMENTS

Not applicable.



### 1.C. REASON

To render inspection checks of the bushes installed on Starflex star arm ends mandatory and to reduce the

interval between successive checks in order to be able to detect any bush bonding failure or distortion of a Starflex arm end as rapidly as possible.

Revision 0 of this ALERT SERVICE BULLETIN which fo rmed the subject of an EASA Airworthiness Directive supersedes ALERT TELEX No. 05.00.51, issued on Sept ember 27, 2005, with no change to the technical

content.

Revision 1 of this ALERT SERVICE BULLETIN added to t he inspection checks of the bushes on the Starflex
star arm ends, a visual check for absence of delami nation on the star arm ends, on the horizontal center plane, flush with the bush.

Revision 1 of this ALERT SERVICE BULLETIN formed the subject of an EASA Airworthiness Directive.

Revision 2 of this ALERT SERVICE BULLETIN specifi ed that local loss of t he adhesive bead on stars fitted with shouldered bushes (post MOD 0762C 18) is no longer to be considered as a reason for removal on the condition that part of the adhesive bead remains on the leading edge thus enabling to check that there is no gap E1, as shown on Figures 1, 3 and 5.

Revision 2 of this ALERT SERVICE BULLETIN has no effect on the content of EASA Airworthiness Directive 2006-0321-E which remains unchanged and is still applicable.

The purpose of Revision 3 of this ALERT SERVICE BU LLETIN is to rewrite the “Operational Procedure” paragraph 2.B. and clearly describe in paragraph 2.B.1 a ll the various types of deterioration that may be discovered during the visual inspection of the adhesive bead on the bushes installed on Starflex star arm ends.

Revision 3 of this ALERT SERVICE BULLETIN will fo rm the subject of an EASA Airworthiness Directive.

Revision 3 of this ALERT SERVICE BULLETIN does not affect compliance with Revision 2.

### Approved under EASA DOA No. 21J.056. Page 3/15

2008.08.18 1.D. DESCRIPTION

Revision 0 :

In ALERT TELEX No. 05.00.51, EUROCOPTER inform ed you of two cases of deterioration of the

end of one of the Starflex star arms: - The first case concerns a helicopter on which high-am plitude vibrations occurred in flight, compelling the

pilot to carry out a precautionary landing. On the ground, it was then found that t he end of a Starflex star

arm had failed in line with the bush. - The second case concerns significant dragwise distor tion of a Starflex star arm end. This distortion was

discovered during a maintenance inspection and was i ndicated by a significant gap between the adhesive bead and the bush leading edge.

In both cases, the customers had discovered cracki ng or local loss of the adhesive bead during a scheduled inspection check, carried out sometime before. A photo showing an example of deterioration (existence of a gap between the adhesive bead and the bush) discovered on the bush on a Starflex star arm end, is provided on Figure 3. The check for correct bonding of the bushes installed on the Starflex star arm end was therefore required every 50 flying hours

Since the ALERT TELEX was issued, the two Starfl ex stars concerned have been received and examined by

EUROCOPTER. These examinations revealed accident al deterioration for the first case (FOD) and progressive deterioration for the second case. EUROCOPTER is currently analyzing the mode of deterio ration for the second case in order to define any possible modification(s). Pending completion of these analyses and in order to ma ke it possible to detect any bush bonding failure or Starflex star arm end distortion as rapidly as possi ble, EUROCOPTER has rendered the monitoring, defined
in ALERT TELEX No. 05.00.51, iss ued on September 27, 2005, mandatory.

Revision 1 :

EUROCOPTER informed you of a new case of failure of a STARFLEX star, flush with the bush on the star

arm end. This event was indicated by high- amplitude vibrations in flight, compelling the pilot to carry out a precautionary landing which took place with no other damage. The star concerned was returned to EUROCOPTER for investigation. Preliminary examinations revealed delam ination on the center plane, on the st ar arm end, similar to the initial case. A photo showing an example of the delaminat ion found on the arm end is provided on Figure 4. The elements currently in our possession seem to indicate that the hypothesis established in the initial case (FOD) is not confirmed. Without predicting the results of the ongoing investigations and in view of these initial findings, EUROCOPTER provides additional information concerning the star removal criteria defined in this ALERT

SERVICE BULLETIN. Given the compliance time for this additional check, EUROCOPTER issued these instructions through an

ALERT SERVICE BULLETIN.

### Approved under EASA DOA No. 21J.056. Page 4/15

2008.08.18 Revision 2 : (See Figures 1 and 5)

Since the Starflex stars post MOD 0762C18 (S tarflex stars P/N 365A31-1210 all dash numbers and P/N 365A31-1211 all dash numbers, manufactured from a new material and fitted with a shouldered bush on each star arm end) were put into service, numerous customers have reported case s of local loss of the adhesive bead (2) or the shockproof paint (3) from t he flange/shoulder of the bush (1) on the star arm end. With this design standard, the adhesive bead (2) is added after bonding the bush (1), and does not at all feature the same bonding quality as the previous desi gn standard. Consequently, with this type of stars, there is a risk of local loss of the adhesive bead (2) in operation. This, however, is not indicative of a deterioration of the bonding quality of the bush (see Figure 5). In this case, only delamination on the star arm

end (Figure 4), de-bonding of a bush or distortion of a star arm end (existence of a gap (E1) between the remaining part of the adhesive bead (2) and bush (1): Fi gures 1 and 3) must be considered as a reason for

removal. Therefore, in Revision 2 of this ALERT SERVICE BU LLETIN, EUROCOPTER modifies the removal criterion for Starflex stars post MOD 0762C18 with respect to the adhesive bead.

Revision 3 :

Revision 3 of this ALERT SERVICE BULLETIN does not m odify the previous criteria and time limits defined in the previous revisions. Revision 3 provides some additional information concerning the analysis of the various deteriorations that may be discovered at t he bonding interface between the bush (1) and the Starflex

star arm end.



### 1.E. COMPLIANCE

The following measures are mandatory from receipt of Revision 0 of ALERT TELEX No. 05.00.51, issued on September 27, 2005.

1.E.1. Compliance at the works

1.E.1.a. On helicopters/installed equi pment: Comply with paragraph 1.E.2.a.

1.E.1.b. On non-installed equipment: Not applicable.

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

1.E.2.a. On helicopters/installed equipment:

- Comply with paragraph 2.B. within the 10 flying hours following receipt of ALERT TELEX No. 05.00.51,

issued on September 27, 2005,
then, . comply with paragraph 2.B. every 10 flying hours.

1.E.2.b. On non-installed equipment: Not applicable.

### Approved under EASA DOA No. 21J.056. Page 5/15

2008.08.18 1.F. APPROVAL

Approval is limited to civil version helicopter s subject to an Airworthiness Certificate.

The technical information contained in Revision 0 of this ALERT SERVICE BULLETIN was approved on March 31, 2006 under the authority of EASA De sign Organisation Approval No. 21J.056.

The technical information contained in Revision 1 of this ALERT SERVICE BULLETIN was approved on October 12, 2006 under the authority of EASA Design Organisation Approval No. 21J.056.

The technical information contained in Revision 2 of this ALERT SERVICE BULLETIN was approved on November 16, 2007 under the authority of EASA Design Organisation Approval No. 21J.056.

The technical information contained in Revision 3 of this ALERT SERVICE BULLETIN was approved on August 18, 2008 under the authority of EASA De sign Organisation Approval No. 21J.056.



### 1.G. MANPOWER

Qualification: Mechanic.

Time for the operations: Approximately 15 minutes.



### 1.H. WEIGHT AND BALANCE

Not applicable.



### 1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT STATE

Not applicable.



### 1.K. REFERENCES

Maintenance Manual (MET) Work Card: 62.20.00.401 or 65.14.401.



### 1.L. OTHER DOCUMENTS CONCERNED

Maintenance Program (PRE).

Maintenance Manual.

### Approved under EASA DOA No. 21J.056. Page 6/15

2008.08.18 1.M. TOOLING CONCERNED

Not applicable.



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

Not applicable.

### Approved under EASA DOA No. 21J.056. Page 7/15

2008.08.18 

### 2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

Not applicable.



### 2.B. OPERATIONAL PROCEDURE

2.B.1. Visual check of the adhesive bead on the bushes on the Starflex star arm ends

As per Figures 1, 2, 3 and 5 :

On each arm of the Starflex star, check that the bonding of the bush has not failed and that the arm ends are not distorted; see the bush installation drawing on Figure 1, according to star definition. This check may reveal various types of occurrences whic h are described in paragraphs a), b) and c):

a) cracking of the shockproof paint (3) over t he circumference of the adhesive bead (2) (See Figure 2) . In this case, apply the rotor brake (braking pos ition), move the blade, by hand, in the flapping and

drag directions, in order to make sure that the bush (1) is correctly bonded.



### NOTE 1

Cracking is considered as a closed cr ack. It is distinguished by a single dimension (length). Cracking is the resu lt of a minute displacement of bush (1) and is not necessarily combined with a bonding failure of the adhesive

film between the bush and the arm end.



### CAUTION

ANY MOVEMENT OF THE BUSH WHEN A LOAD IS APPLIED MUST BE

CONSIDERED AS A REASON FOR REMOVAL.

b) a gap (E1) between adhesive bead (2) and bush (1). (See Figure 3)



### NOTE 2

A gap (E1) is considered as an open cr ack. It is distinguished by two dimensions (length and width). This gap may be due to crack growth or bonding failure of bush (1) or distorti on of the Starflex star arm end.



### CAUTION

ANY GAP (E1) MUST BE CONSIDER ED AS A REASON FOR REMOVAL

EVEN IF THE BUSH DOES NOT MOVE WHEN A LOAD IS APPLIED AND

EVEN IF THE GAP IS LOCATED ONLY ON PART OF THE

CIRCUMFERENCE.

### Approved under EASA DOA No. 21J.056. Page 8/15

2008.08.18 c) local loss of adhesive bead (2). (See Figure 5)



### CAUTION

ON STARS PRE MOD 0762C18 (STARS NOT FITTED WITH SHOULDERED BUSHES ON THE STAR ARM END), ANY LOCAL LOSS OF ADHESIVE BEAD, WHATEVER ITS LOCATION , INDICATES THAT THE BUSH HAS MOVED, AND MUST ALSO BE CONSIDERED AS A

REASON FOR REMOVAL.

LOCAL LOSS OF ADHESIVE BEAD ON STARS POST MOD 0762C18 (STARS FITTED WITH SHOULDERED BUSHES ON THE STAR ARM END) IS PERMITTED ON THE CONDITION THAT PART OF THE

ADHESIVE BEAD REMAINS ON THE LE ADING EDGE THUS ENABLING TO CHECK THAT THERE IS NO GAP E1 (SEE FIGURES 1, 3 AND 5).

2.B.2. Check for absence of delaminat ion on the Starflex star arm ends

As per Figure 4:

On each Starflex star arm and on both sides (leadi ng edge and trailing edge), make sure that there is no delamination in the composite material, in the area of the horizontal center plane, flush with the bush (zone A). If in doubt, carry out this check after havi ng removed the paint coat by light cloth sanding.



### CAUTION

ANY CRACK OR CRACKING IN THE AREA OF THE HORIZONTAL CENTER PLANE OF THE STAR ARM, FLUSH WITH BUSH (1), MUST BE

CONSIDERED AS A REASON FOR REMOVAL OF THE STARFLEX

STAR.

2.B.3. Interpretation of the results

a) If none of the removal criteria, specified in paragraphs 2.B.1. and 2.B.2. is reached: - Leave as is and resume flights.



### CAUTION

CRACK-TYPE DETERIORATIONS, CRACKING AND LOSS OF

ADHESIVE BEAD FROM THE INTERFACE BETWEEN THE BUSH AND

THE STARFLEX STAR ARM END ARE REMOVAL CRITERIA AND MUST

THEREFORE NOT BE FILLED OR SEALED.

b) If one of the removal criteria, specified in paragraphs 2.B.1. and 2.B.2. is r eached on one of the Starflex

star arms:

- Before resuming flights, remove and replace the Starflex star as per MET Work Card 62.20.00.401

or 65.14.401. - Inform the EUROCOPTER Technical Support Department ESTVM by

. Tel.: +33 (0)4.42.85.99.67 . Fax: +33 (0)4.42.85.99.66 . E-mail: DynComp.techni cal-support@eurocopter.com

- Return the Starflex star to EUROCOPTER Marignane for examination and repair where applicable.

### Approved under EASA DOA No. 21J.056. Page 9/15

2008.08.18 2.C. IDENTIFICATION

Record initial compliance with Revision 3 of this ALERT SERVICE BULLETIN in the aircraft documents.



### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.

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2008.08.18 Figure 1

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2008.08.18 Figure 2 

### Cracking Starflex star PRE MOD 07 62C18

Starflex sta r POST MOD 0762C18

### Approved under EASA DOA No. 21J.056. Page 12/15

2008.08.18 Figure 3 

# E1: Unacceptable

### Approved under EASA DOA No. 21J.056. Page 13/15

2008.08.18 Figure 4 

### Delamination in

Zone 

## A 

# : Unacceptable Zone A

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2008.08.18 Local loss of adhesive bead on stars post MOD 0762C18: Unacceptable in the leading edge (see CAUTION § 2.B.1.c)

Figure 5

### Approved under EASA DOA No. 21J.056. Page 15/15

2008.08.18 

### 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

Not applicable.



### 3.D. PROCUREMENT CONDITIONS

Order the required quantity (unless otherwise specified)

from

EUROCOPTER Etablissement de Marignane

Direction Ventes et Relations Client

ECR

13725 MARIGNANE CEDEX

FRANCE



### NOTE 1

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

aircraft to be modified.



### NOTE 2

For ALERT SERVICE BULLETINS, order by:

Telex: HELICOP 410 969F.



### 4. APPENDIX

Not applicable.