EASA AD No.: 2010-0078-E

EASA Form 111 Page 1/2 

## EASA EMERGENCY AIRW ORTHINESS DIRECTIVE

AD No.: 2010-0078-E

Date: 23 April 2010

Note: This Emergency 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 EC 1702/2003, Part 21A.3 B. 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 operate an aircraft to which an AD applies, except in accordance wi th 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) :

EC 120 B helicopters

TCDS Number : DGAC France No.189

Foreign AD : Not applicable

Supersedure : None



### ATA 24 Electrical Power – Emergency Switch (EMER SW) Wiring – Modification

Manufacturer(s): Eurocopter (formerly Eurocopter-France)

Applicability: EC 120B Helicopters with Se rial Number (S/N) 1500, S/N 1511 through 1630 (inclusive), S/N 1632, 1634 and 1636, equipped with "EMER SW" switch.

Reason: As part of a test conducted at EUROCOPTER, the "smoke in the cockpit" procedure was applied. It was found t hat setting the "EMER SW" switch to "CUT-OFF" (low position) and the "GENE" pushbutton to "OFF" at the same time, caused the aircraft starter-generator to cut-in again.

The technical investigations conducted re vealed that cross-wi ring at the "EMER SW" switch caused the malfunction. In th is configuration, the "smoke in the cockpit/cargo" procedure described in th e flight manual does not isolate the equipment electrical power supply.

This condition, if not corrected, could result a non-isolation of electrical equipment
, creating the risk of an uncontrolled electrical fire.
For the reason described above this Emergency AD requires the modification of the "EMER SW" switch wiring.

Effective Date: 26 April 2010EASA AD No.: 2010-0078-E

EASA Form 111 Page 2/2 Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously:
(1) Before next flight after the effective date of this AD, pending compliance with Paragraph (2) of this AD, update the Rotorcraft Flight Manual (RFM) with the procedure appended in the Eurocopter Emergency Alert Service Bulletin (ASB) EC 120 No 24A012 and during flight operations, the flight crew must follow the appended procedure.
(2) Within the next 15 flight hours or 30 days, whichever occurs first after the effective date of this AD, modify the “EMER SW” wiring and perform test in accordance with instruct ions of § 2.B of Euro copter Emergency ASB EC120 No 24A012.
(3) After modification of the helicopter as required by Paragraph (2) of this AD remove the up-date introduced by paragraph (1) of this AD from the RFM.

Ref. Publications: Eurocopter Emerge ncy ASB EC120 No 24A012.dated 22 April 2010;
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 subs tantiated, 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 pub lication and notification.
3. Enquiries regarding this AD should be referred to the Airworthiness Directives, Safety Management & Research Section, Certification Directorate, EASA. Email: ADs@easa.europa.eu

. 4. For any question concerning the technica l 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 10; fax: +33 (0) 4 42 85 99 66; E-mail: Airframe.technical-support@eurocopter.com