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This document is available on the internet: www.eurocopter.com/techpub 

EUROCOPTER 

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE 

EMERGENCY

ALERT SERVICE BULLETIN 

DAUPHIN NUMBER VERSIONS 

EC155 05A017 Civil: B-B1 

SUBJECT: TIME LIMITS – MAINTENANCE CHECKS 

Fittings Attaching the Upper Fin on the Fenestron 

ATA: 53 

REVISION No. DATE OF APPROVAL DATE OF ISSUE 

 

Revision 0 On: September 28, 2007 2007.09.28 

Revision 1 On: January 26, 2010 2010.01.27 

Revision 2 On: December 03, 2010 2010.12.09 

 
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1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters/Installed equipment 

Upper and lower fittings P/N 365A234242-01, 365A234243-01, 365A234240-01 and 365A234241-01, 

attaching the upper fin on the Fenestron pre MOD 0754B40. 

NOTE 1

The purpose of modification MOD 0754B40 is to increase the 

strength of the shroud/fin junction fittings. 

Modification 0754B40 is embodied on new helicopters or as a 

retrofit action in accordance with Service Bulletin 53-029. 

Refer to the aircraft individual inspection record (MOD record), 

to identify the actual configuration of the helicopter.

1.A.2. Non-installed equipment 

Not applicable. 

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 
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1.C. REASON 

To make sure that there is no crack in the upper and lower fittings attaching the upper fin on the 

Fenestron. 

Revision 0 of this ALERT SERVICE BULLETIN formed the subject of EASA Airworthiness Directive 

No. 2007-0259-E. 

The purpose of Revision 1 of this ALERT SERVICE BULLETIN which formed the subject of Revision 1 

of EASA Airworthiness Directive No. 2007-0259-E, was to: 

- cancel the compliance instructions in paragraph 1.E.2.a. for AS365 (N1, N2, N3, F, Fi and K), AS565 

and SA366 helicopter versions, and reference made to the associated Work Cards, 

- modify the time requirement for initial compliance with paragraph 1.E.2.a. for EC155 helicopters, 

- specify the inspection areas and add the e-mail contact address to paragraph 2.B.2. 

Revision 1 of this ALERT SERVICE BULLETIN did not affect compliance with Revision 0. 

The purpose of Revision 2 of this ALERT SERVICE BULLETIN is to: 

- Prohibit flight with fittings P/N 365A234242-01, 365A234243-01, 365A234240-01 

and 365A234241-01 (PRE MOD 0754B40) on EC155 version B and B1 helicopters, 

from December 31, 2011. 

- To inform the operators that compliance with Service Bulletin No. 53-029 make possible to overcome 

the restriction prohibiting flight with fittings P/N 365A234242-01, 365A234243-01, 365A234240-01 

and 365A234241-01 and relieves from obligation of compliance to this ALERT SERVICE BULLETIN. 

Revision 2 of this ALERT SERVICE BULLETIN will form the subject of an EASA Airworthiness 

Directive. 

Revision 2 of this ALERT SERVICE BULLETIN does not affect compliance with Revision 1. 

1.D. DESCRIPTION 

Revision 0: 

In TELEX INFORMATION No. 00000414, dated September 13, 2007, EUROCOPTER informed you of 

the loss of a fin from an EC155 B1 helicopter in flight, as well as of a crack discovered recently in the 

fittings attaching the fin on the Fenestron. 

Pending the results of the analysis of these incidents, EUROCOPTER had introduced a periodic 

condition check of the fittings attaching the upper fin on EC155 helicopters, as well as on AS365, 

AS565 and SA366 helicopters which are fitted with the same fin definition, although they are subject to 

lower loads than those on the EC155. 

Revision 1: 

Given the results of the analyses of the causes of this incident, conducted at EUROCOPTER, AS365, 

AS565 and SA366 helicopter versions can be deleted from this ALERT SERVICE BULLETIN. 

Consequently, only EC155 helicopters are concerned by the instructions given in Revision 1 of this 

ALERT SERVICE BULLETIN. 

EUROCOPTER is currently studying an improvement of the design of the fittings attaching the upper 

fin, in order to cancel the check carried out on EC155 helicopters. 
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Revision 2:

EUROCOPTER has now defined new shroud/fin junction fittings through modification MOD 0754B40 

whose purpose is to increase the strength of the fittings. 

This modification creates new fitting part numbers and makes it possible to overcome the restriction 

prohibiting flight with fittings 365A234242-01, 365A234243-01, 365A234240-01 and 365A234241-01 

from December 31, 2011, stipulated by Revision 2 of this ALERT SERVICE BULLETIN. 

Revision 2 of this ALERT SERVICE BULLETIN specifies that helicopters post MOD 0754B40 are not 

concerned by the instructions of this ALERT SERVICE BULLETIN 

EUROCOPTER renders compliance with the instructions of Revision 2 of this ALERT SERVICE 

BULLETIN, mandatory. 

1.E. COMPLIANCE 

EUROCOPTER renders compliance with this ALERT SERVICE BULLETIN mandatory. 

1.E.1. Compliance at the works 

1.E.1.a. On helicopters: 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: 

1) From receipt of Revision 1 of this ALERT SERVICE BULLETIN which was issued 

on January 27, 2010: 

a) On helicopters with less than 40 flying hours: 

- Comply with paragraph 2.B. of this ALERT SERVICE BULLETIN when the helicopter 

reaches 55 flying hours following receipt of Revision 1 which was issued 

on January 27, 2010, 

Then, 

- Comply with paragraph 2.B. at intervals not exceeding 55 flying hours. 

b) On helicopters with 40 flying hours or more:

- Comply with paragraph 2.B of this ALERT SERVICE BULLETIN within 15 flying hours 

following receipt of Revision 0 which was issued on September 28, 2007, 

Then, 

- Comply with paragraph 2.B. at intervals not exceeding 55 flying hours. 

NOTE 1

If the operating hours of the fittings are unknown, take into 

account the hours logged by the airframe of the helicopter. 
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2) To prohibit flight with fittings P/N 365A234242-01, 365A234243-01, 365A234240-01 

and 365A234241-01 from December 31, 2011. 

NOTE 2 

Compliance with Service Bulletin No. 53-029 enables the 

operators to overcome the restriction prohibiting flight with the 

fittings referenced above. 

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

1.F. APPROVAL 

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on September 28, 2007 under the authority of EASA Design Organisation Approval No. 21 J.056 for 

civil version helicopters subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 1 was approved 

on January 26, 2010 under the authority of EASA Design Organisation Approval No. 21 J.056 for civil 

version helicopters subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 1 was approved 

on January 26, 2010 by the EUROCOPTER Airworthiness Department for military version helicopters. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 2 was approved 

on December 03, 2010 under the authority of EASA Design Organisation Approval No. 21 J.056 for 

civil version helicopters subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 2 was approved 

on December 03, 2010 by the EUROCOPTER Airworthiness Department for export military versions. 

1.G. MANPOWER 

Qualification: Mechanic or aircraft structure technician. 

Time for the operations: Approximately 1 hour. 

1.H. WEIGHT AND BALANCE 

Not applicable. 
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1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable. 

1.J. SOFTWARE MODIFICATION EMBODIMENT STATE 

Not applicable. 

1.K. REFERENCES 

Aircraft Maintenance Manual (AMM), Tasks: 53-91-00-061, 53-91-08-961 and 53-91-08-962. 

Standard Practices Manual (MTC), Work Card: 20.02.09.601. 

1.L. OTHER DOCUMENTS CONCERNED 

EUROCOPTER will modify the Aircraft Maintenance Manual (AMM) and the Illustrated Parts 

Catalogue (IPC) with respect to this ALERT SERVICE BULLETIN. 

These documents will be issued later. 

1.M. TOOLING CONCERNED 

Not applicable. 

1.N. INTERCHANGEABILITY AND MIXABILITY OF PARTS 

Not applicable. 
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2. ACCOMPLISHMENT INSTRUCTIONS 

2.A. GENERAL 

NOTE 

Please feel free to contact EUROCOPTER should you need 

any further information or support when complying with the 

instructions described in this ALERT SERVICE BULLETIN. 

Contact the EUROCOPTER Customer Service Technical 

Support Department by: 

Tel: +33 (0)4.42.85.97.10 

Fax: +33 (0)4.42.85.99.66 

Email: Airframe.technical-support@eurocopter.com

2.B. OPERATIONAL PROCEDURE 

2.B.1. Preliminary steps: 

Install the equipment giving access to the upper fin. 

2.B.2. Check of the upper fin forward and aft upper and lower attachment fittings: 

As per Figure 1: 

- Remove the forward (a) and aft (b) strips on the upper fin (h). 

- Make sure that there is no crack in the forward (c) and aft (d) upper fittings and in the forward (e) and 

aft (f) lower fittings. Inspect the hatched areas shown in red on Figure 2 - DETAILS B, C and D (a 

tenfold magnifying glass or a high-resolution (more than 2 million pixels) digital camera can be used 

to facilitate the crack inspection). 

. If in doubt, perform a dye penetrant crack detection inspection in accordance with MTC Work 

Card 20.02.09.601. 

a) If no crack is found in the forward (c) and aft (d) upper fittings and in the forward (e) and aft (f) 

lower fittings: 

- Leave as is. 

- Install the forward (a) and aft (b) strips on the upper fin (h). 

. Before assembly, replace any damaged bolt(s) (g) and nut(s) (i). 

- Return the helicopter to flight configuration as per paragraph 2.B.3. 
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b) If a crack is found in a forward (c) and / or aft (d) upper fitting and / or in a forward (e) and / or aft (f) 

lower fitting: 

- Remove the upper fin in accordance with AMM Task 53-91-00-061. 

- Remove and discard any cracked fitting(s) in accordance with AMM Task 53-91-08-961 and/or 

 Task 53-91-08-962. 

- Inform the Customer Service Technical Support Department by: 

Fax: +33(0)4.42.85.99.66 

Tel: +33(0)4.42.85.97.10. 

E-mail: Airframe.technical-support@eurocopter.com

- Install the upper fitting(s) (1) and/or (2) and/or the lower fitting(s) (3) and/or (4) as per AMM 

Task 53-91-08-961 and/or AMM Task 53-91-08- 962, or comply with Service Bulletin No. 53-029 

which deals with the embodiment of modification 0754B40. 

- Install the upper fin in accordance with AMM Task 53-91-00-061. 

- Install the forward (a) and aft (b) strips on the upper fin (h). 

 . Before assembly, replace any damaged bolt(s) (g) and nut(s) (i). 

- Return the helicopter to flight configuration as per paragraph 2.B.3. 

2.B.3. Final steps 

- Remove the equipment giving access to the upper fin. 

- Resume flight. 

2.C. IDENTIFICATION 

Record compliance with this ALERT SERVICE BULLETIN in the helicopter documents. 

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

Not applicable. 
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Figure 1 
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Figure 2 

Areas to be inspected with 

magnifying glasses 

B C

D 
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3. MATERIAL INFORMATION

3.A. MATERIAL: COST - AVAILABILITY 

3.A.1. Cost 

For any information concerning kits and/or components, contact the Sales and Customer Relations 

Department of the EUROCOPTER Network. 

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

3.C. MATERIAL REQUIRED FOR EACH HELICOPTER / ENGINE / COMPONENT 

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

Material Part Number Qty Item Key Word Remark

365A234242-01 1 1 Upper fitting, FWD

365A234243-01 1 2 Upper fitting, AFT 

365A234240-01 1 3 Lower fitting, FWD 

365A234241-01 1 4 Lower fitting, AFT 

3.C.2. Item(s) to be ordered separately 

The products identified by an asterisk "*" or required for compliance with the Tasks and / or Work 

Cards listed in paragraph 1.K., can be ordered from the INTERTURBINE company. 

Website: http://www.itlogistics.de

Telephone: +49.41.91.809.300 

AOG: +49.41.91.809.444 
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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

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 helicopters to be 

modified. 

4. APPENDIX 

Not applicable.