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## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2006 - 0099

Date: 24 April 2006

No person may operate an aircraft to which an Airworthi ness Directive applies, except in accordance with the requirements of that Airworthiness Directive unless otherwi se agreed with the Authority of the State of Registry.



### Type Approval Holder’s Name:

EUROCOPTER Type/Model designation(s):

AS 365 N and EC 155 helicopters

TCDS Number: France No. 86

Foreign AD: None.

Supersedure: DGAC AD F-2005-144 R1 (EASA approval No. 2005-6227)



### ATA 64 Tail Rotor – Tail Rotor Blade Check

Manufacturer(s): EUROCOPTER (formerl y EUROCOPTER FRANCE, AEROSPATIALE)

Applicability: Helicopters:

- SA 365 N1 and AS 365 N2, N3,

- EC 155 B and B1,

fitted with tail rotor blades PN 365A12-0060-01 or PN 365A12-0070-00.

Reason: This Airworthiness Directive (AD) is issued following a case of separation and loss of a (75 mm diameter) stainless steel ring from a tail rotor blade sleeve, resulting in heavy high-frequency vibrations, which can lead to damage to the Fenestron tail rotor blades and the loss of the yaw control.

This AD supersedes DGAC AD F-2005-144 R1 and modifies the daily inspection interval for SA/AS 365 helicopters in order to make it compatible with the daily / 10-hour inspection of these helicopters.

Effective Date: 05 May 2006

### 2/2 Compliance: The following measures are mandatory as from the effective date of this AD:

1. On each tail rotor blade installed on SA/AS 365 helicopters:

1.1. No later than within 10 flying hours, then at intervals not exceeding 10 flying hours, check on each tail rotor blade that there is no slippage of the stainless steel ring of the tail rotor blade sleeve, in compliance with the instructions specified in paragraph 2.B.1 of referenced AS 365 Alert Service Bu lletin (ASB) No. 05.00.49.

1.2. Before installation on a helicopter, of a tail rotor blade with flying hours and held as spares, comply with the instructions specified in paragraph 2.B.1 of referenced AS 365 ASB.

2. On each tail rotor blade installed on EC 155 helicopters:

2.1. No later than within 15 flying hours, then at intervals not exceeding 15 flying hours, check on each tail rotor blade that there is no slippage of the stainless steel ring of the tail rotor blade sleeve, in compliance with the instructions specified in paragraph 2.B.1 of referenced EC 155 ASB No. 05A011.

2.2. Before installation on a helicopter, of a tail rotor blade with flying hours and held as spares, comply with the instructions specified in paragraph 2.B.1 of referenced EC155 ASB.

3 . Interpretation of the results

If the stainless steel ring has mo ved, replace the tail rotor blade concerned before resuming flights.

Ref. Publications: EUROCOPTER AS 365 Alert Service Bulletin No. 05.00.49.

EUROCOPTER EC 155 Alert Service Bulletin No. 05A011.
or later approved revisions.

Remarks : 1. If requested and appropriately su bstantiated the responsible EASA manager for the related product has the authority to accept Alternative Method of Compliance (AMOCs) for this AD.
2. This AD was posted as PAD 06-060 for consultation on 15 March 2006 with a comment period until 31 March 2006. No comment was raised during the consultation period.
3. Enquiries regarding this Airworthin ess Directive should be referred to Mr. M. Capaccio, Airworthiness Dire ctive Focal Point - Certification Directorate, EASA. E-mail: ADs@easa.eu.int
4. For any questions concerning the technical content of the requirements in this AD, please contact: EUROCOPTER (STXI) - Aéroport de Marseille Provence 1372 5 Marignane Cedex - France. Tél : 33 (0) 4 42 85 97 97 - Fax : 33 (0) 4 42 85 99 66. E-mail : Directive.technical-support@eurocopter.com