EASA AD No : 2011-0127

EASA Form 110 Page 1/4 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2011-0127

Date: 01 July 2011

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 participat e 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 aircra ft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate an aircraft to which an AD applies, except in accordance with the requirements of that AD 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 365, EC 155, SA 365 and SA 366 helicopters

TCDS Number: France No. 159

Foreign AD: Not applicable

Supersedure: This AD supersedes DGAC France AD F-2008-004 dated 04 June 2008.



### ATA 63 Main Rotor Drive - Main Gearbox Casing – Inspection / Repair

Manufacturer(s): Eurocopter (formerl y Eurocopter France, Aérospatiale)

Applicability: EC 155 B, EC 155 B1, SA 365 N, SA 365 N1, AS 365 N2, AS 365 N3, SA 366 G1, SA 365 C, SA 365 C1, SA 365 C2 and SA 365 C3 helicopters, all serial numbers, if equipped with Main Gearboxes (MGB), as defined in table 1 hereunder:
Table 1

MGB, all part numbers (P/N), delivered before 5 December 2007 (inclusive), or
MGB, all P/N, installed on helic opters delivered before 5 December 2007 (inclusive); and
MGB, all P/N, overhauled or repaired before 30 September 2008 (inclusive).

2 Reason: In 2008, two reports were received of atmospheric corrosion on the MGB casing lower area of two helicopters, between the two servo-control anchoring fitting attachment ribs. The investigation showed that initiation of corrosion in this area is due to a confined area under the anchoring fitti ngs, associated with PR sealing compound on the lower part of the fitting/casing attachment.

This PR sealing compound may have been applied on some helicopters dueEASA AD No : 2011-0127

EASA Form 110 Page 2/4 to a misinterpretation of the EUROCOPTER documentation during installation. This condition, if not detected and correc ted, could lead to crack initiation and crack growth in the affected area of t he casing which could cause this area to fail and consequent loss of control of the helicopter. This unsafe condition, which is unrelat ed to design approval, was addressed in June 2008 by DGAC France AD F-2008-004. Later, in July 2008, EASA issued the EA SA Airworthiness Directive Policy, (referenced C.Y001-01) which allowed the agency to issue Airworthiness Directives to addres s non-conformities of aircraft with the EASA approved design, due to manufacturing or maintenance deficiencies.
For the reasons describ ed above and in the frame of an EASA Airworthiness Directive Policy catch-up pr ocess for this type of Airworthiness Directives, this EASA AD supersedes DGAC France AD F-2008-004 retaining all its requirements although it does not introduce any new requirement.

Effective Date: 15 July 2011

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously: (1) Within 15 Flight Hours (FH) afte r 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004] , inspect all the lower parts of the MGB servo-control anchoring fitti ngs to detect the presence of PR sealing compound in accordance with the instructions of paragraph 2.B.2. of EUROCOPTER EC 155 Al ert Service Bulletin (ASB) No. 63A011 or AS 365 ASB No. 63.00.17 or SA 360/365 ASB No. 65.47, or SA 366 ASB No. 65.03, as applicable to helicopter type. (2) If, during the inspection required by paragraph (1) of th is AD, PR sealing compound is found on any lower part of the MGB servo-control anchoring fittings, before next flight, inspect the affected area for corrosion in accordance with the in structions of paragraph 2.B.3. of EUROCOPTER EC155 ASB No. 63A011 or AS365 ASB No. 63.00.17 or EUROCOPTER SA360/365 ASB No. 65.47, EUROCOPTER SA366 ASB No. 65.03, as applicable to helicopter type. (3) If, during the inspection required by pa ragraph (2) of this AD, corrosion is found, within the compliance time indicated in Table 1 in Appendix 1 of this AD, as applicable, accomplish corrective actions in accordance with the instructions of paragraph 2.B.3. EUROCOPTER EC155 ASB No. 63A011 or AS365 ASB No. 63.00.17 or EUROCOPTER SA360/365 ASB No. 65.47, EUROCOPTER SA366 ASB No. 65.03, as applicable to helicopter type, and, depending on fi ndings, accomplish a repair in accordance with EUROCOPTER R epair Sheet No. 365-63-36-08. (4) After 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004], do not install MGB listed in Table 1 in Appendix 1 of this AD on a helicopter, unless in compliance with the inspections and corrective actions, if any, of paragra phs (1), (2) and (3) of this AD.

Ref. Publications: EUROCOPTER EC155 ASB No. 63A011 dated 7 May 2008. EUROCOPTER AS365 ASB No. 63.00.17 dated 7 May 2008. EUROCOPTER SA360/365 ASB No. 65.47 dated 5 May 2008. EUROCOPTER SA366 ASB No. 65.03 dated 7 May 2008. EUROCOPTER Repair Sheet No. 365-63-36-08 dated 4 April 2008. The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.EASA AD No : 2011-0127

EASA Form 110 Page 3/4 Remarks : 1. If requested and appropriately substantiated, EASA can approve Alternative Methods of Compliance for this AD. 2. This AD was posted on 05 May 2011 as PAD 11-045 for consultation until 02 June 2011. No comments were re ceived during the consultation. 3. Enquiries regarding this AD should be referred to the Safety Information Section, Executive Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any question concerning the tec hnical content of the requirements in this AD, please contac t: EUROCOPTER (STDI) - Aéroport de Marseille Provence 13725 Marignane Cedex, France. Telephone +33 (0) 4 42 85 97 97, Fax +33 (0) 4 42 85 99 66. E-mail: Directive.technical-support@eurocopter.com

.EASA AD No : 2011-0127

EASA Form 110 Page 4/4 

### APPENDIX 1

Table 1 Helicopter operating conditions: MGB operating time accumulated since new or since last complete overhaul: Compliance time, in accumulated MGB operating time :

Less than 30 months. 33 months.

Between 30 and 33 months. 33 months, or within 3 months after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004], without exceeding 55 FH after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004]. Helicopters that have been operated in one of the following conditions: - Helicopters based onboard a ship and operated off-shore, and/or - Helicopters operated less than 1 kilometre from the coast, and/or - Helicopters operated at low altitude (less than 1 000 feet) over the sea. More than 33 months. Within 3 months after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004], without exceeding 55 FH after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004].
Less than 54 months. 60 months.

Between 54 and 60 months. 60 months, or within 6 months after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004], without exceeding 110 FH after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004]. All other helicopters

More than 60 months. Within 6 months after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004], without exceeding 110 FH after 14 May 2008 [the effective date of the French superseded DGAC AD F-2008-004].