AD No.: 2010-0026-E

ATA 62 Main Rotor Head - Rotor Hub Inspection

Applicability:
Eurocopter helicopter models EC 120 B all serial numbers, if equipped with Main Rotor Head with the following Hub part numbers: C622A1002103, C622A1002104, C622A1002105

Reason:
Eurocopter has been informed that an EC 120 B helicopter has performed an emergency landing due to a set of amplitude vibrations originating from the main rotor.

As a result of the investigation, it was determined that the Main Rotor Head (MRH) hub had failed in the attachment area of one of the three drag damper fittings.

Due to the reasons described above, this Emergency AD requires a repetitive visual inspection for detecting eventual cracks to preclude any risk of MRH hub failure.

Effective Date: 21 February 2010

Required Action(s) and Compliance: Required as indicated, unless already accomplished:

Time(s):

1. Within the next 15 flight hours after the effective date of this AD and thereafter, at intervals not exceeding 15 flight hours, perform a visual inspection to detect cracks in the inspection areas of the rotor hub in accordance with the instructions of paragraph 2.B.2 of Emergency Alert Service Bulletin Eurocopter EC 120 05A012 - Revision 1 - (EASB).
2. If no crack is found, re-install the dome fairing if it was removed previously and resume flight in accordance with the instructions of § 2.B.2, of Eurocopter EASB.
3. If one or more cracks are found, before next flight, contact Eurocopter as described in the NOTE 1 of paragraph 2.A of Eurocopter EASB, and replace the affected rotor hub with a new rotor hub in accordance with § 2.B.2 of Eurocopter EASB.
4. If during inspection accomplished in accordance with § (1) of this AD local deterioration is found, remove the finish paint until the P05 primer coat become visible and visually inspect the concerned areas in accordance with § 2.B.2.b.3. Accomplish the relevant corrective actions in accordance with § 2.B.2.b.1 or § 2.B.2.b.2.
5. Replacement of the rotor hub in compliance with § (3) or § (4) of this AD does not terminate the repetitive inspection requirements of § (1) of this AD.

Ref. Publications:
Eurocopter EC 120 B EASB 05A012 – Revision 1, dated 19 February 2010.
The use of later approved revisions of this document 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 safety assessment has requested not to implement the full consultation process and an immediate publication and notification.
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
   Telephone: +33 (0) 4 42 85 97 97 - Fax +33 (0) 4 42 85 99 66
   E-mail:Directive.technical-support@eurocopter.com:

FMI: www.casa.gov.au/wcmswr/_assets/main/airworth/airwd/adfiles/rotor/ec120/2010-0026-e.pdf