EASA AD No.: 2009-0035-E 

EASA Form 111 Page 1/2 

EASA EMERGENCY AIRWORTHINESS DIRECTIVE 

AD No.: 2009-0035-E 

Date: 18 February 2009 

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 155 helicopters 

TCDS Number : France No 159 

Foreign AD : Not applicable 

Supersedure : None 

ATA 34 Navigation – UNS-1D Navigation System – Limitation 

Manufacturer(s): EUROCOPTER 

Applicability: EUROCOPTER EC 155 B and B1 helicopters, all serial numbers, if equipped with 

the UNS-1D navigation system. 

Reason: 

During test flights carried out by Eurocopter, the flight crew noted freezing of the 

route display on the navigation display (ND) screen in Sector mode. 

The investigations have revealed that the route display on the ND in Sector mode 

is no longer refreshed if the flight plan, processed and transmitted by the UNS-1D, 

contains a procedure that includes a holding pattern or a DME (Distance 

Measurement Equipment) arc. Only the route display on the ND in Sector mode is 

affected. The navigation and guidance parameter displays on the ND, the flight 

plan display on the UNS-1D and the coupling to the autopilot are not affected. 

Freezing of the route display only occurs for flight plans which include procedures 

in the terminal zone (departure or arrival). 

If not corrected, freezing of the route display during single-pilot operation under 

IFR conditions would likely result in a significant increase in flight crew workload, 

possibly causing pilot confusion, affecting the safety of the helicopter and its 

occupants. 

For the reasons described above, this AD prohibits the use of the UNS-1D 

navigation system for SID and STAR procedures. The Flight Manual currently 

prohibits the use of GPS for approach procedures. 

Effective Date: 20 February 2009 
EASA AD No.: 2009-0035-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, amend Flight Manual 

Supplement 52 to incorporate the following limitation: 

"USING FMS FOR SIDS-STARS AND INSTRUMENT 

APPROACHES IS PROHIBITED" 

 This may be accomplished by inserting a copy of this AD into Flight Manual 

Supplement 52. 

(2) Concurrent with the action as required by paragraph (1) of this AD, install a 

placard on the console, with the same wording as specified in paragraph (1) 

of this AD, in accordance with the instructions of paragraph 2.B of Eurocopter 

EC155 Alert Service Bulletin (ASB) 04A008. 

Ref. Publications: 

EUROCOPTER EC155 ASB No. 04A008 original issue dated 17 February 2009. 

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.