EASA AD No.: 20 14

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TE.CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 1 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 20 1 4

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Date: 24 September 2014

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 EU 748/2012, Part 21.A.3B. In accordan ce 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 ope rate 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]

. 

### Design Approval Holder’s Name:

AIRBUS HELICOPTERS Type/Model designation (s):

SA 341 G and SA 342 J helicopters

TCDS Number: EASA.R.125

Foreign AD: Not applicable

Supersedure: None



### ATA 65 Main R otor

– Main R otor Hub Torsion B ars

– Inspection

Manufacturer(s): Aerospatiale

Applicability: SA 341 G and SA 342 J helicopters , all manufacturer serial numbers

.

Reason: Several cases of cracks were found on the polyurethane (PU) coating of the

m ain r otor h ub (MRH) torsion bars P/N 704A33633274 installed on military SA 341 helicopters . These parts can also be installed on civilian SA 341 and SA 342 helicopters

. In addition

, analysis of the cracked torsion bars has shown that small areas of superficial corrosion on the strands inside the bars can also develop during the manufacturing process. The cracking of the PU coating near these areas and the associated penetration of w ater can lead to further and deepe r development of the corrosion.
This condition, if not detected and corrected, allow s water to penetrat e into the torsion bar

, causing corrosion and failure of the metal strands inside the bar, which could lead to torsion bar failure , resulting in in

- flight loss of a main rotor blade and consequent loss of control of the helicopter

. To address this unsafe condition, Airbus Helicopters issued Alert Service Bulletin ( ASB) SA341/SA342

- 05.40 , providing instruct ions for reducing the interval s of the existing repetitive inspection of the torsion bars

, which are described in the applicable maintenance manual ( document identified as MDE) and currently required through the existing instructions for continued airworthiness ( document identified as PRE). For the reasons described above, this AD requires reduced interval s for the repetitive inspection of the torsion bars compared to the existing interval s indicated in the current PRE document

.

Effective Date: 0 8 October 2014EASA AD No.: 20 14

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TE.CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 2 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously:
(1) Initially, within the compliance time specified in Table 1 or Table 2 of this AD, as applicable

, and, thereafter, at intervals not to exceed the value s as specified in Table 3 of this AD, as applicable, inspect the MRH torsion bars P/N 704A33633274 in accordance with the instructions of A irbus H elicopters MDE Work Card n° 65.12.607

.

Table 1

– Initial Inspection of T orsion B ars installed less than 5 years

Flight Hours (FH) accumulated by the helicopter (on the effective date of this AD) since last inspection of the torsion bar Compliance Time

l ess than 320 FH B efore exceeding 420 FH or 24 months, whichever occurs first since last inspection

320 FH or more W ithin 100 FH , or within the scheduled inspection time limit for the torsion bars as indicated in the current PRE

, whichever occurs first after the effective date of this AD

.

Table 2

– Initial Inspection of Torsion Bars installed 5 years or more
Service life (FH or calendar time) accumulated by the helicopter on the effective date of this AD since last inspection of the torsion bar Compliance Time

less than 320 FH

, and last inspection performed less than 6 months before the effective date of this AD Before exceeding 420 FH or 12 months

, whichever occurs first since last inspection

320 FH or more , or last inspection performed 6 months or more before the effective date of this AD Within 100 FH, or within 6 months, or within the scheduled inspection time limit for the torsion bars as indicated in the current PRE, whichever occurs first after the effective date of this AD

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Table 3

– Repetitive Inspection s of Torsion Bars

Duration of installation of the torsion bar on a helicopter Inspection Intervals (not to exceed)

less than 6 years 420 FH or 24 months

, whichever occurs first , until reaching the limit of 6 years after fir st installation on a helicopter
6 years or more 420 FH or 12 months

, whichever occurs first, without exceeding the existing service life limits indicated in the airworthiness limit section of the current PRE.

(2) If

, during any inspection a s required by paragraph (1) of this AD, a crack in the PU coating of a torsion bar is found which match es or exceeds the criteria defined in MDE Work Card n° 65.12.607, before next flight, replaceEASA AD No.: 20 14

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TE.CAP.0011 0

- 00 4 © European Aviation Safety Agency. All rights reserved. 3 / 3 Proprietary document. Copies are not controlled. Confirm revision status through the EASA

- Internet/Intranet. the affected torsion bar with a serviceable one in accordance with the instruction s of A irbus H elicopters ASB SA341/SA342

- 05.40

. (3) Replacement of a torsion bar on a helicopter as required by paragraph (2) of this AD does not constitute terminating action for the repetitive inspections as required by paragraph (1) of this AD for that helicopter.
(4) From the effective date of this AD, installation on a helicopter of MRH torsion bars P/N 704A33633274 is allowed

, provided th at, following installation, the h e licopter is inspected and , depending on findings, corrected

, as required by this AD.

Ref. Public ations: Airbus Helicopters ASB SA341/SA342

- 05.40 original issue dated 28 April 2014

. Airbus Helicopters MDE Work Card n° 65.12.607

. 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. This AD was posted on 20 August 201 4 as PAD 14

- 1 32 for consultation until 17 September 2014

. No comments were received during the consultation p eri o d

. 3. Enquiries regarding this AD should be referred to the Safety Information Section, Certification Directorate, EASA. E

- mail: ADs@easa.europa.eu

. 4. For any question concerning the technical content of the requireme nts in this AD, please contact : Airbus Helicopters (STDI)

– Aéroport de Marseille Provenc e 13725 Marignane Cedex, France

, Telephone +33 (4) 42 8 5 97 97; F ax +33 (4) 42 85 99 66, E

- mail: Directive.technical

- support@eurocopter.com

.