EASA AD No.: 2009-0029 

EASA Form 110 Page 1/3 

EASA AIRWORTHINESS DIRECTIVE 

AD No.: 2009-0029 

Date: 12 February 2009 

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with Regulation 

(EC) No 216/2008 on behalf of the European Community, its Member States and of the European 

third countries that participate in the activities of EASA under Article 66 of that Regulation. 

This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the 

continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate an 

aircraft to which an Airworthiness Directive applies, except in accordance with the requirements of that Airworthiness Directive unless 

otherwise specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 

216/2008, Article 14(4) exemption]. 

Type Approval Holder’s Name : 

EUROCOPTER 

Type/Model designation(s) : 

AS 355 helicopters 

TCDS Number : EASA.R.146 

Foreign AD : Not applicable 

Supersedure: This AD supersedes EASA AD 2008-0120 dated 27 June 2008 

ATA 55 Stabilizers – Upper and Lower Fin Attachment Fitting - 

Inspection / Modification / Replacement 

Manufacturer(s): EUROCOPTER (formerly EUROCOPTER FRANCE, AEROSPATIALE). 

Applicability: AS 355 E, F, F1, F2 and N helicopters, all serial numbers, if fitted with the following 

upper and lower fins to which modification (MOD) 073330 has not been embodied: 

Upper fin assembly part number (P/N): 

355A14-0522-00XX 355A14-0522-01XX 

355A14-0522-02XX 355A14-0522-03XX 

355A14-0522-13XX 355A14-0522-14XX 

355A14-0522-15XX 

Lower fin assembly P/N: 

355A14-0521-00XX 355A14-0521-01XX 

355A14-0521-02XX 355A14-0521-03XX 

Reason: Some cracks have been discovered in the spar of the upper fin on AS 355 N 

helicopters. 

The growth of a crack in a fin attachment spar, if not corrected, may lead to the 

failure of the spar and the loss of the fin. 
EASA AD No.: 2009-0029 

EASA Form 110 Page 2/3 

EASA AD 2008-0120 rendered mandatory MOD 073330 introduced by 

EUROCOPTER AS 355 Alert Service Bulletin (ASB) No. 55.00.12, whose purpose 

was: 

- to reduce the risk of forced fitting by increasing the diameter of the holes for the 

bolts on the lower and upper fin attachment fittings on the tail boom, and 

- to improve the fatigue strength of upper and lower fin attachment by replacing 

bolts and washers currently installed with special bolts and special washers. 

Thereafter, EUROCOPTER issued Revision 1 of ASB No. 55.00.12 to add new 

upper and lower fin assembly part numbers in the applicability. 

In addition, EASA AD 2008-0120 which superseded EASA AD 2006-0097R1 

omitted to retain the initial action and repetitive checks required by EASA AD 

2006-0097R1. 

For the reasons described above, this AD retains the requirements of EASA AD 

2008-0120, which is superseded, and adds new upper and lower fin assembly part 

numbers in the applicability as well as repetitive checks until the accomplishment of 

MOD 073330. 

Effective Date: 26 February 2009 

Required action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

1. For helicopters with upper and lower fins pre MOD 073288: 

1.1. For helicopters having accumulated less than 110 flying hours (FH) after 

20 August 2006, the effective date of AD 2006-0097R1: 

 Within the next 110 FH after 20 August 2006, the effective date of AD 

2006-0097R1, replace the upper fin and lower fin attachment screws in 

compliance with the instructions specified in paragraph (§) 2.B.2. of 

EUROCOPTER AS 355 ASB No. 55.00.11 Revision 2 (MOD 073288). 

1.2 For helicopters having accumulated more than 110 FH after 20 August 

2006, the effective date of AD 2007-0097R1: 

 Within 15 FH after the effective date of this AD, replace the upper fin and 

lower fin attachment screws in compliance with the instructions specified in 

§ 2.B.2. of EUROCOPTER AS 355 ASB No. 55.00.11 Revision 2 

(MOD 073288). 

1.3 At intervals not exceeding 110 FH, check the tightening torque of the 

upper fin attachment screws and check the upper fin reinforcement splice 

for cracks and loosened rivets in compliance with the instructions specified 

in § 2.B.3 of EUROCOPTER AS 350 ASB 55.00.11 Revision 2. 

1.4 In case of cracks, loosened rivets in the reinforcement splice or if the 

tightening torque of one or both of the attachment screws is less than 80% 

of the minimum torque value, before further flight, apply the associated 

corrective actions in accordance with the instructions of § 2.B.3.a.1, 

2.B.3.a.2. or 2.B.3.a.3. (as applicable), of EUROCOPTER AS 350 ASB 

55.00.11 Revision 2. 

2. For helicopters with upper and lower fins post MOD 073288: 

2.1 For helicopters having accumulated less than 110 FH since the latest 

check performed in accordance with § 2.B.3 of EUROCOPTER AS 350 

ASB 55.00.11 Revision 0 or Revision 1 or Revision 2: 

Within 110 FH after the latest check performed in accordance with § 2.B.3 

of EUROCOPTER AS 350 ASB 55.00.11 Revision 0 or Revision 1 or 

Revision 2, check the tightening torque of the upper fin attachment screws 

and check the upper fin reinforcement splice for cracks and loosened 

rivets in compliance with the instructions specified in § 2.B.3 of 
EASA AD No.: 2009-0029 

EASA Form 110 Page 3/3 

EUROCOPTER AS 350 ASB 55.00.11 Revision 2. 

Thereafter repeat these checks at intervals not exceeding 110 FH. 

2.2 For helicopters having accumulated more than 110 FH since the latest 

check performed in accordance with § 2.B.3 of EUROCOPTER AS 350 

ASB 55.00.11 Revision 0 or Revision 1 or Revision 2: 

Within 15 FH after the effective date of this AD, check the tightening torque 

of the upper fin attachment screws and check the upper fin reinforcement 

splice for cracks and loosened rivets in compliance with the instructions 

specified in § 2.B.3 of EUROCOPTER AS 350 ASB 55.00.11 Revision 2. 

Thereafter repeat these checks at intervals not exceeding 110 FH. 

2.3 In case of cracks, loosened rivets in the reinforcement splice or if the 

tightening torque of one or both of the attachment screws is less than 80% 

of the minimum torque value, apply corrective actions in accordance with 

the instructions of § 2.B.3.a.1, 2.B.3.a.2. or 2.B.3.a.3. (as applicable) of 

EUROCOPTER AS 355 ASB 55.00.11 Revision 2. 

3. For helicopters with upper and lower fins pre MOD 073330: 

 Unless already accomplished in accordance with § 1 of EASA AD 

2008-0120, no later than 31 March 2009, remove the fins, modify the lower and 

upper fittings on tail boom by increasing the diameter of the holes for the bolts 

and replace bolts P/N 22126BV060032L and washers P/N 23112AG060LE with 

special bolts P/N 350A23-4016-20 and special washers P/N 350A23- 4017-22 in 

accordance with EUROCOPTER AS 355 ASB No. 55.00.12. Revision 1 

(MOD 073330). 

Compliance with the requirements of § 3. of this AD is considered as: 

- acceptable to comply with paragraphs 1.1 and 1.2 of this AD, 

- terminating action for the repetitive checks required by paragraphs 1.3, 2.1 

and 2.2 of this AD. 

4. After 31 March 2009, no person shall install on any helicopter spare upper and 

lower fins with part numbers as listed in the Applicability of this AD, unless 

MOD 073330 has been accomplished. 

Ref. Publications: EUROCOPTER AS 355 Alert Service Bulletin No. 55.00.11 Revision 2 

dated 28 February 2008; 

EUROCOPTER AS 355 Alert Service Bulletin No. 55.00.12 Revision 1 

dated 05 January 2009. 

The use of later approved revisions of these documents is acceptable for 

compliance with the requirements of this AD. 

Remarks: 1. If requested and appropriately substantiated, EASA can approve Alternative 

Methods of Compliance for this AD. 

2. The required actions and the risk allowance have granted the issuance of a 

Final AD with Request for Comments, postponing the public consultation 

process after publication. 

3. Enquiries regarding this AD should be referred to the Airworthiness Directives, 

Safety Management & Research Section, Certification Directorate, EASA. 

E-mail: ADs@easa.europa.eu. 

4. For any question concerning the technical content of the requirements in this 

AD, please contact: EUROCOPTER (STDI) – Aéroport de Marseille Provence 

13725 Marignane Cedex – France. 

Tel: +33(0)4 42 85 97 97 – Fax: +33(0)4 42 85 99 66, 

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