EASA AD No.: 2009-0114R2

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 1/2

Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

EASA AIRWORTHINESS DIRECTIVE

AD No.: 2009-0114R2

Date: 13 December 2013

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 the activities of EASA under Article 66 of that 

Regulation.

This AD is issued in accordance with EU 748/2012, Part 21.A.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].

Design 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

Revision: This AD revises EASA AD 2009-0114R1 dated 12 December 2012 (including the 

correction dated 13 December 2012).

ATA 61 Propellers – Backplate Assembly – Sealant Application

Manufacturer(s): Dowty Propellers

Applicability: Model R408/6-123-F/17 propellers, all serial numbers (s/n), except Hub, 

Actuator and Backplate Assembly Line Replaceable Units s/n DAP0927 and 

higher.

These propellers are known to be installed 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.

To address this potential unsafe condition, EASA issued AD 2009-0114 to 

require initial and repetitive application of sealant between the propeller bus 

bar assemblies and the backplate assembly.

Since that AD was issued, Dowty developed a new harness, installation of 

which makes the re-application of sealant redundant.

For the reason described above, this AD is revised to provide an optional 
EASA AD No.: 2009-0114R2

TE.CAP.00110-003 © European Aviation Safety Agency. All rights reserved. 2/2

Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.

terminating action for the repetitive sealant applications required by this AD.

Revision 2 of this is issued to extend the compliance time for sealant reapplication from 10 000 flight hours (FH) to 10 500 FH.

Effective Date: Revision 2: 13 December 2013

Revision 1: 26 December 2012

Original issue: 11 June 2009

Required Action(s) 

and Compliance

Time(s):

Required as indicated, unless accomplished previously:

(1) Within 5 000 FH after 11 June 2009 (the effective date of the original 

issue 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 Backplate 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 10 500 FH after the initial sealant application as 

required by paragraph (1) of this AD and, thereafter, at intervals not to 

exceed 10 500 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.

(5) Modification of a propeller by fitting a new harness in accordance with the 

instructions of Dowty Service Bulletin (SB) D4800-61-94 Revision 2, or 

later revision, constitutes terminating action for the repetitive sealant

applications required by paragraph (3) of this AD for that propeller.

Ref. Publications: Dowty Propellers ASB D8400-61-A66 Revision 7, dated 01 December 2011.

Dowty Propellers SB D8400-61-94 Revision 2, dated 29 August 2012,

currently at Revision 8 dated 31 October 2013.

The use of later approved revisions of these documents 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. Based on the required actions and the compliance time, EASA have 

decided to issue a Final AD with Request for Comments, postponing the 

public consultation process until after publication.

3. Enquiries regarding this AD should be referred to the Safety Information

Section, Executive Directorate, EASA. E-mail ADs@easa.europa.eu.

4. For any question concerning the technical content of the requirements in 

this AD, please contact:

Dowty Propellers, Anson Business Park, Cheltenham Road East, 

Gloucester GL2 9QN, The United Kingdom

Tel +44 (0) 1452 716067 – Fax +44 (0) 1452 716001

E-mail Mike.Towkan@ge.com.