EASA AD No.: 2011-0156-E 

EASA EMERGENCY AIRWORTHINESS DIRECTIVE 

AD No.: 2011-0156-E 

Date: 25 August 2011 

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 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 : 

Agusta S.p.A. 

Type/Model designation(s) : 

AB139 and AW139 helicopters 

TCDS Number: EASA.R.006 

Foreign AD: Not applicable 

Supersedure: This AD supersedes EASA AD 2011-0081 dated 09 May 2011. 

ATA 64 Tail Rotor – Tail Rotor Blades – Inspection / Replacement 

[Reduced Life Limitation] 

Manufacturer(s): Agusta S.p.A., Agusta Aerospace Corporation (USA) 

Applicability: AB139 and AW139 helicopters, all serial numbers. 

Reason: In early 2011, an occurrence was reported of tail rotor (T/R) dynamic 

unbalance on an AW139 helicopter. 

Pending the results of the investigation into that occurrence, EASA issued AD 

2011-0081 to require, as a precautionary measure, repetitive inspections of 

the T/R blades and, in case of findings, the accomplishment of applicable 

corrective actions. 

After that AD was issued, on 19 August 2011, a fatal accident occurred with 

another AW139 helicopter, possibly caused by cracks in a T/R blade. 

This condition, if not detected and corrected, could lead to a T/R structural 

failure, resulting in loss of control of the helicopter. 

For the reasons described above, this AD, which supersedes AD 2011-0081, 

retains the repetitive inspections of the T/R blades, to be applied to all T/R 

blades, irrespective of accumulated FH, and imposes a reduced life limit of 

600 flight hours (FH) / 1500 FC to the T/R blades. 

This AD is considered to be an interim action and further AD action may follow.

Effective Date: 25 August 2011 

EASA Form 111 Page 1/2 
EASA AD No.: 2011-0156-E 

EASA Form 111 Page 2/2 

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless already accomplished: 

(1) Within 25 FH after the effective date of this AD, and thereafter at intervals 

not to exceed 25 FH, inspect the T/R blades Part Number (P/N) 

3G6410A00131 or P/N 4G6410A00131, as installed on the helicopter, in 

accordance with the instructions of Part I of Agusta Alert Bollettino 

Tecnico (BT) 139-265. 

(2) From the effective date of this AD, for T/R blades that have not yet 

accumulated 600 FH or 1 500 flight cycles (FC), whichever occurs first 

since first installation on a helicopter, prior to, or upon, accumulation of 

600 FH or 1 500 FC by the blade, whichever occurs first, replace each 

T/R blade with a serviceable unit. 

Note: For the purpose of this AD, a serviceable T/R blade is one that has not 

yet accumulated 600 FH or 1 500 FC since first installation on a helicopter. 

(3) For any T/R blade that, on the effective date of this AD, has already 

accumulated or exceeded 600 FH or 1 500 FC, whichever occurs first 

since first installation on a helicopter, within 5 FH or 30 days, whichever 

occurs first after the effective date of this AD, replace the T/R blade with a 

serviceable unit. 

(4) For any T/R blade where the FC, accumulated since first installation on a 

helicopter, cannot be determined, the FH accumulated by the T/R blade 

since first installation on a helicopter must be multiplied by a factor of 4 

(four), as described in Agusta Alert BT 139-265, to determine the 

replacement time for that blade, as required by paragraph (2) or (3) of this 

AD, as applicable. 

(5) From the effective date of this AD, do not install on any helicopter a T/R 

blade P/N 3G6410A00131 or P/N 4G6410A00131 having accumulated or 

exceeded 600 FH or 1 500 FC, whichever occurs first since first 

installation on a helicopter. 

Ref. Publications: Agusta Alert BT 139-265, original issue dated 25 August 2011. 

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 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 Agusta S.p.A. 

E-mail: aw139.mbx@agustawestland.com .