EASA AD No.: 2015-0178

TE.CAP.00110-004 © 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.: 2015-0178

Date: 26 August 2015

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 EU 1321/2014 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

[EU 1321/2014 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:

AIRBUS HELICOPTERS

Type/Model designation(s):

AS 350 B3 helicopters

TCDS Number: EASA R.008

Foreign AD: Not applicable

Supersedure: None

ATA -

Rotorcraft Flight Manual – Chapter Normal Procedures – Engine 

Prestart Check / Run-up Check / Engine and Rotor Shutdown –

Amendment

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

Applicability: AS 350 B3 helicopters, all serial numbers, if equipped with a dual hydraulic 

system, production modification (mod) OP 3082, or mod OP 3346.

Reason: A perceived loss of tail rotor (TR) control authority, experienced as jamming, is 

possible during take-off, if the TR hydraulic run-up checks are not properly 

executed in accordance with the applicable checklist. These checks are

currently part of the pre-flight and run-up checks in the Rotorcraft Flight Manual 

(RFM) and are, sequentially, as follows:

(1) shutting off the hydraulic pressure to the TR actuator by actuating the 

Yaw Servo Hydraulic Switch on the collective grip,

(2) checking the loads on the pedals (expected low load),

(3) discharging the yaw load compensator by triggering the ‘ACCU TST’ 

push button,

(4) re-verifying the loads on the pedals (expected high load),

(5) re-engaging both hydraulic switches to restore the hydraulic pressure to 

the TR actuator and yaw load compensator. 

Improper execution of these actions degrades the TR hydraulic system 

functionality to the point of significantly increasing the TR control load which is

necessary to get sufficient TR thrust for take-off.

This condition, if not corrected, could cause the pilot to take off without 

recognising the omission, preventing safe completion of the manoeuvre, 

possibly resulting in damage to the helicopter and injury to occupants.
EASA AD No.: 2015-0178

TE.CAP.00110-004 © European Aviation Safety Agency. All rights reserved. 2/2

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

Prompted by these findings, a new procedure for the functional check of the 

Yaw Load Compensator is introduced with Airbus Helicopters Service Bulletin 

(SB) AS350-67.00.66. The advantage of the new procedure is that it is no 

longer necessary to actuate the Yaw Servo Hydraulic Switch during the run-up 

hydraulic check.

For the reason described above, this AD requires the applicable procedures of 

Airbus Helicopters SB AS350-67.00.66 to be incorporated in the normal 

procedures section of the affected Airbus Helicopters AS350 B3 RFM.

Effective Date: 31 August 2015

Required Action(s) 

and Compliance

Time(s):

Required as indicated, unless accomplished previously:

Within 7 days after the effective date of this AD, accomplish the actions as 

specified in paragraphs (1) and (2) of this AD concurrently, and, thereafter, 

operate the helicopter accordingly.

(1) Amend the applicable RFM by incorporating the operational procedures

“Chapter 4 NORMAL PROCEDURES” and “SUP.23 Dual Hydraulic 

System” as specified in, and in accordance with the instructions of, Airbus 

Helicopters SB AS350-67.00.66.

(2) Inform all flight crews concerning this RFM change.

Note: Airbus Helicopters Safety Information Notice (SIN) No. 2944-S-29

provides additional information for the subject addressed by this AD.

Ref. Publications: Airbus Helicopters SB AS350-67.00.66 original issue dated 26 August 2015.

The use of later approved revisions of this document is acceptable for 

compliance with the requirements of this AD.

Airbus Helicopters SIN No. 2944-S-29 original issue dated 26 August 2015.

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, 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:

Airbus Helicopters (ESBESB) - Aéroport de Marseille, Provence 13725 

Marignane Cedex – France

Telephone: + 33 (0) 12 85 97 97, Fax: + 33 (4) 85 99 66,

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