EASA AD No : 2009-0114

EASA Form 110 Page 1/2 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2009-0114

Date: 28 May 2009

Note: This 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 th e 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 s hall be ensured by accomplishing any applicable ADs. Consequently, no person may opera te an aircraft to which an AD applies, except in accordance with t he requirements of that AD, unless otherwise specified by the Ag ency [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) exemptio n]. 

### Type Approval Holder’s Name : GE Aviation Systems Limited, trading as Dowty Propellers Type/Model designation(s) :
R408/6-123-F/17 propellers

TCDS Number: EASA.P.002

Foreign AD : Not applicable

Supersedure : None



### ATA 61 Propellers – Backplate Assembly – Sealant Application

Manufacturer(s): Dowty Propellers

Applicability: Model R408/6-123-F/17 propellers, all serial numbers (s/n). These propellers are known to be instal led on, but not limited to, Bombardier DHC-8-400, DHC-8- 401 and DHC-8-402 aeroplanes.
Note: Transport Canada AD CF-2009-01, applicable to Bombardier DHC-8 Series 400 aeroplanes, was issued on 19 January 2009 for the same unsafe condition that is addressed by this AD.

Reason: Friction or contact between a propeller de-ice bus bar and the backplate assembly can cause failure of the bus bar and a consequent intermittent short circuit. Such a short circuit can cause a dual AC generator shutdown that, particularly in conjunction with an engine failure in icing conditions, could result in reduced controllability of the aeroplane. For the reason described above, this AD requires initial and repetitive application of sealant between the prop eller bus bar assemblies and the backplate assembly.

Effective Date: 11 June 2009EASA AD No : 2009-0114

EASA Form 110 Page 2/2 Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previously: (1) Within the next 5 000 flight hours (FH) after the effective date of this AD, apply sealant between the bus bar assemblies and the backplate assembly in accordance with the instructions of Dowty Propellers Alert Service Bulletin (ASB) D8400-61-66. (2) All affected Hub, Actuator and Ba ckplate Assembly Line-Replaceable Units (LRU) with s/n DAP0347 and higher have received the initial sealant application prior to delivery/ installation and are therefore already compliant with the requirement of paragraph (1) of this AD. (3) Prior to accumulating 10 000 FH after the initial sealant application and thereafter at intervals not to exceed 10 000 FH, re-apply sealant between the bus bar assemblies and the backplate assembly in accordance with the instructions of Dowty Propellers ASB D8400-61-66. (4) After modification of all propellers on an aeroplane as required by paragraph (1) of this AD, do not install any Dowty R408/6-123-F/17 propeller on that aeroplane, unless sealant has been applied between the bus bar assemblies and the backplate assembly of that propeller in accordance with the requirements of this AD.

Ref. Publications: Dowty Propellers ASB D8400- 61-66 dated February 2007. The use of later approved revisions of this document is acceptable for compliance with requirements of this AD.

Remarks: 1. If requested and appropriately substantiated, EASA can approve Alternative Methods of Compliance for this AD. 2. The required actions and the risk a llowance have granted the issuance of a Final AD with Request for Comments, postponing the public consultation process after publication. 3. Enquiries regarding this AD should be referred to the Airworthiness Directives, Safety Management & Re search Section, Certification Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any question concerning the tec hnical content of the requirements in this AD, please contact: Dowty Propellers, Anson Business Park, Cheltenham Road East, Gloucester GL2 9QN, United Kingdom Tel +44 (0) 1452 716067 – Fax +44 (0) 1452 716001 E-mail Mike.Towkan@ge.com