EASA AD No.: 2010-0078-E 

EASA Form 111 Page 1/2 

EASA EMERGENCY AIRWORTHINESS 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.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 

operate 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]. 

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 Serial 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 that 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 revealed that cross-wiring at the "EMER 

SW" switch caused the malfunction. In this configuration, the "smoke in the 

cockpit/cargo" procedure described in the 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 2010 
EASA 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 instructions of § 2.B of Eurocopter 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 Emergency 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 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. Email: 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 10; fax: +33 (0) 4 42 85 99 66; 

E-mail: Airframe.technical-support@eurocopter.com