EASA AD No.: 2011-0104 

EASA Form 110 Page 1/2 

EASA AIRWORTHINESS DIRECTIVE 

AD No.: 2011-0104 

Date: 27 May 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 : 

EUROCOPTER 

Type/Model designation(s) : 

AS 350 and AS 355 helicopters 

TCDS Number : EASA.R.008, EASA.R.146 

Foreign AD : Not applicable 

Supersedure : None 

ATA 65 Tail Rotor Drive – Tail Gearbox (TGB) Casing Assembly – 

Inspection / Replacement 

Manufacturer(s): Eurocopter (formerly Eurocopter France, Aerospatiale) 

Applicability: AS 350 B, BA, BB, B1, B2, B3 and D helicopters and AS 355 E, F, F1, F2, N 

and NP helicopters, all serial numbers. 

Reason: Following repair of the manufacturing mould for the TGB casing assemblies, 

the dye-penetrant inspection performed after machining of the attachment 

yokes of the control lever has revealed cracks on some TGB casing 

assemblies. 

EUROCOPTER identified the TGB casing assemblies which may show 

cracks. 

This condition, if not detected and corrected, could lead to a crack on the 

attachment yokes of the control lever, possibly resulting in the loss of tail 

rotor pitch control and subsequent loss of control of the helicopter. 

For the reasons described above, this AD requires an inspection for cracks 

and, depending on findings, replacement of the TGB.

Effective Date: 10 June 2011 
EASA AD No.: 2011-0104 

EASA Form 110 Page 2/2 

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

(1) Within the time indicated in Table 1 of this AD, identify the serial number 

of the TGB casing assembly P/N 350A33-1090-02 installed on the 

helicopter and, if the TGB casing assembly has a serial number as 

specified in Table 2 of this AD, inspect the attachment yokes of the 

control lever of the TGB casing assembly for cracks in accordance with 

the instructions of paragraph 3 of Eurocopter AS350 Alert Service 

Bulletin (ASB) 65.00.46 or AS355 ASB 65.00.22, as applicable to 

helicopter type. 

Table 1 

Flight Hours (FH) 

accumulated by the TGB 

casing since new, on the 

effective date of this AD 

Compliance Time 

Less than 550 FH Within 26 months or 660 FH 

accumulated by the TGB casing 

since new, whichever occurs first 

550 FH or more Within 110 FH or 13 months, 

whichever occurs first after the 

effective date of this AD 

Table 2 – Affected Serial Numbers TGB Casings 

MA47577, MA47585, MA47587, MA47588, MA47589, MA47590, 

MA47591, MA47592, MA47593, MA47597, MA47598, MA47599, 

MA47600, MA47602, MA47604, MA47606, MA47610, MA47613, 

MA47615, MA47617, MA47619, MA47620, MA47621, MA47622, 

MA47623, MA47624, MA47626, MA47628, MA47631.

(2) If, during any inspection required by paragraph (1) of this AD, any crack 

is detected on at least one of the control lever yokes of the TGB casing 

assembly, before next flight, replace the TGB with a serviceable unit in 

accordance with the requirements of the Eurocopter AS350 ASB 

65.00.46 or AS355 ASB 65.00.22, as applicable to helicopter type. 

(3) After the effective date of this AD, do not install a TGB casing with a 

serial number as listed in Table 2 of this AD on any helicopter, unless 

the attachment yokes of the control lever of the TGB casing assembly 

have passed the inspection as required by paragraph (1) of this AD.

Ref. Publications: EUROCOPTER AS350 ASB No. 65.00.46 Revision 0, dated 18 May 2011, 

EUROCOPTER AS355 ASB No. 65.00.22 Revision 0, dated 18 May 2011. 

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 accept Alternative 

Methods of Compliance for this AD. 

2. The required actions and the risk allowance 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 & 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 - Customer Service Technical Support 

Department - Aéroport de Marseille Provence 13725 Marignane Cedex - 

France. Tel: + 33 (0)4 42 85 99 51 - Fax: + 33 (0)4 42 85 99 66. 

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