EASA AD No.: 201 3

- 0029

TE. CAP.0011 0

- 00 3 © 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
. : 201 3 - 0029

Date: 08 Febr uary 201 3

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 E U 748/2012 , Part 21

. A.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 ope rate an aircraft to which an AD applies, except in accordance with the requ irements 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: EUROCOPTER Type/Model designation(s): AS 350 B3 helicopters

TCDS Number: EASA.R.008

F oreign AD: Not applicable Supersedure: This AD supersedes EASA Emergency AD 2012

- 02 1 7

- E dated 19 October 2012

.



### ATA 64 Rotorcraft Flight Manual
– Section Limitations
– Amendment

Tail Rotor
– Laminated H alf - B earings
– Inspection / Replacement / Modification

Manufacturer(s): Eurocopter (formerly Eurocopter France, Aerospatiale) Applicability: AS 350 B3 helicopters, all serial numbers, if modified in production by incorporating Eurocopter modification (MOD) 07 5601 , except those helicopters that have been modified by incorporating Eurocopter MOD 07 5606 in production. Note : MOD 07 5601 is an integral part of a specific AS 350 B3 model configuration , commercially identified as “AS350B3e” and is not fitted on AS 350 B3 model helicopters of other configurations

. Reason: Premature failures of laminated half

- bearings , Part Number (P/N) 704A33

- 633

- 261 (supplier P/N 5791530004) , installed in tail rotors, were detected on AS 350 B3 helicopters in AS350B3e configuration. Three cases of vibrations originating from the tail rotor were also reported, detected in flight on affected helicopters, following which precautionary landings were performed. The cause of vibration has been identified as failure of the laminated half

- bearings. Subsequently , an accident occurred involving an AS 350 B3 helicopter in AS350B3e configuration. During the affected flight, the pilot felt strong vibrations originating from the tail rotor before losing control of the helicopter. It was f ound that, due to their deterioration , the laminated half

- bearings were twice replaced on this helicopter prior to the accident

. This condition, if not detected and corrected, could lead to failure of the tailEASA AD No.: 201 3

- 0029

TE. CAP.0011 0

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

- Internet/Intranet. rotor, possibly resulting in loss of control of the helicopter. To address this unsafe condition, Eurocopter issued AS350 Emergency Alert Service Bulletin (ASB) No. 01.00.65 for the affected AS 350 B3 helicopters in this particular configuration. Consequently, EASA issued Emergency AD 2012

- 0207

- E to require changes to the Rotorcraft Flight Manual (RFM), imposing limitations of the flight envelope in order to reduce the dynamic loads on the tail rotor, and a one

- time pre

- flight inspection, a one

- tim e ALF check inspection (including tail rotor disassembly), and repetitive post

- flight inspections of the laminated half

- bearings to detect damage and, depending on findings, replacement of all 4 laminated half

bearings. After that AD was issued, a discrepancy was found where, under specific altitude and temperature conditions, the new airspeed limitation (defined in True Airspeed

– TAS) and the information on one of the two related labels (defined in Indicated Airspeed

– IAS) were not compatible. Ad ditionally, Eurocopter defined a new Engine Health Check (EHC) procedure which was compatible with the new airspeed limitation. To address the discrepancy described above and to publish the new EHC procedure, Eurocopter issued AS350 EASB No. 01.00.65 revis ion 1. Prompted by these findings and actions , EASA issued AD 2012

- 0217

- E retaining partially the requirements of EASA AD 2012

- 0207

- E, which was superseded, and introduc ing a new airspeed limitation (defined in IAS only) and introduc ing the new EHC procedu re to replace the one incorporated in the AS350B3e RFM. Since EASA AD 2012

- 0217

- E was issued, Eurocopter designed a new modification MOD 07 5606 , which restores the tail rotor dynamic load level similar to that on helicopters pre MOD 07 5601, thereby eliminating the modified loading conditions of laminated half

- bearings which caused the intensified deterioration and reported failures

. For the reasons described above, this new AD retains the requirements of EASA AD 2012

- 0217

- E , which is superseded, and requires incorporation of MOD 07

- 5606 as a terminating action.
Effective Date: 01 March 2013 Required A ction(s) and Compliance Time(s) : Required as indicated, unless accomplished previously: (1) Before next flight after 05 October 2012 [the effective date of EASA AD 2012

- 0207

- E], install the VNE IAS limit vs. flight altitude placard (specified as Label (2) in Eurocopter AS350 ASB No. 01.00.65) on the instrument panel, in full view of the pilot and co - pilot, in accordance with the instructions of paragraph 3.B.1 of Eurocopter AS350 ASB No. 01.00.65. (2) Before next flight after 19 October 2012 [the effective date of EASA AD 2012

- 0217

- E], accomplish the following actions concurrently: (2.1) R emove the V NE limitation placard (specified as Label (1) in Eurocopter AS350 ASB No. 01.00.65) , as previously required by paragraph (1) of EASA AD 2012

- 0207

- E, from the helicopter, and (2.2) Replace the RFM specific pages, as previously required by paragraph (1) of EASA AD 2012

- 0207

- E, with specific pages containing the temporary V NE limitation , emergency procedure for in

flight vibrations felt in the pedals and temporary EHC procedure , which are provided in Section 4 Appendix of Eurocopter AS350 ASB No. 01.00.65 revision 1

. Concurrent with making the changes as required by paragraph s ( 1 ) and (2) of this AD, inform all flight crews and, thereafter, operate the helicopter accordingly.EASA AD No.: 201 3

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TE. CAP.0011 0

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

- Internet/Intranet. ( 3 ) Before next flight after 05 October 2012 [the effective date of EASA AD 2012

- 0207

- E ] , and thereafter, after each flight, without exceeding 3 flight hours between two consecutive inspections, visually inspect the laminated half

- bearings in accordance with the instructions of p aragraph 3.B.2 of Eurocopter AS350 ASB No. 01.00.65. ( 4 ) If, during any inspection as required by paragraph ( 3 ) of this AD, a ny deficiencies are found, defined as “ Deterioration requiring replacement ” in paragraph 3.B.3.a of Eurocopter AS350 ASB No. 01.00.65, before next flight , replace all 4 laminated half

- bearings in accordance with the instructions of AS350B3 Maintenance Manual Work Cards No. 64

- 10

- 00, paragraph 4

- 3 and No. 64

- 10

- 00, paragraph 4

- 4. ( 5 ) During the next ALF check after 05 October 2012 [the effective date of EASA AD 2012

- 0207

- E ] , disassemble the tail rotor in accordance with the instructions of paragraph 1.E.2.a.4 of Eurocopter AS350 ASB No. 01.00.65 and visually inspect the laminated half

- bearings for deficiencies

. If during this check, any separation, cracks, or extrusions in th e elastomer are found in any bearing, before next flight, replace all 4 laminated half

- bearings in accordance with the instructions of AS350B3 Maintenance Manual Work Cards No. 64

- 10

- 00, paragraph 4

- 3 and No. 64

- 10

- 00, paragraph 4

- 4. Note: Paragraph 3. B.3. b of Eurocopter AS350 ASB No. 01.00.65 instructs to replace only those half

- bearings found damaged. Instead, this AD requires r eplacement of all 4 laminated half

- bearings

. (6) Within 5 months after the effective date of this AD, modify the helicopter in accordance with instructions of Eurocopter AS350 SB No. 01.00.66 (MOD 07 5606)

. (7) Modification of a helicopter as required by paragraph (6) of this AD constitutes terminating action for the repetitive inspections of the laminated half

- bearings as require d by paragraph s (3) and (5) of this AD for that helicopter. After modification of a helicopter as required by paragraph (6) of this AD, the operating limitations placard and RFM procedures as introduced , respectively, by paragraph s (1) and (2.2) of this A D , are no longer required and must be removed from that helicopter

. Ref. Public ations: Eurocopter AS350 E mergency ASB No. 01.00.65 original issue dated 04 October 2012 , or Revision 1 dated 18 October 2012

. Eurocopter AS350 SB No. 01.00.66 original issue dated 30 January 2013. The u se of later approved revisions of th ese document s 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. Based on the required actions and the compliance time, EASA have decided to issue a Final AD with Request for Comments, postponing the public consultation process until after publication

. 3. Enquiries regarding this A D should be referred to the Safety Information Section, Executive 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 , Telephone +33 (4) 42 85 97 97 , Facsimile +33 (4) 42 85 99 66 , E

- mail: Directive.technical

- support@eurocopter.com

.