EASA AD No.: 2015

- 0178

TE. CAP.00110

- 00 4 © 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 E U 748/2012 , Part 21

. A.3B. In accordan ce 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 ope rate 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

F oreign 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 du a l hydraulic system , p roduction m odification (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

. The s e checks are currently part of the pre

- flight and run

- up checks in the Rotorcraft Flight M anual (RFM) and are , sequentially

, as follows:
(1) shutting off the hydraul ic pressure to the TR actuator by actuating the Yaw Servo Hydraulic S witch 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

n ecessary to get sufficient TR thrust for take

- off

. This condition, if not corrected, could cause the pilot to take off without recogni sing the omission, preventing safe complet ion of the manoeuvre

, possibly resulting in damage to the helicopter and injury to occupants

.EASA AD No.: 2015

- 0178

TE. CAP.00110

- 00 4 © 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 proce dure for the functional check of the Yaw Load Compensator is introduced with Airbus Helicopter s 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 A ction(s) and Compliance Time(s) : Required as indicated, unless accomplished previously:

W ithin 7 days after the effective date of this AD, accomplish the actions as specified in paragraph s (1) and (2) of this AD concurrently

, and, thereafter, ope rate the helicopter accordingly.
(1) Amend the applicable RFM by incorporating the operational procedure s “Chapter 4 NORMAL PROCEDURES” and “SUP.23 Dual Hydraulic System” as specified in

, and in accordance with the instructions of

, Ai rbus Helicopters SB AS350

- 67.00.66

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

. Note: Airbus Helicopter s Safety Information Notice (SIN) No. 2944

- S

- 29 provides additional information for the subject addressed by this AD.

Ref. Public ations: Airbus Helicopters SB AS350

- 67.00.66 original issue dated 26 August 2015

. The u se of later approved revisions of t h is d ocument is acceptable for compliance with the requirements of this AD.
Airbus Helicopter s 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 t he 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 A D 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 Telep hone: + 33 (0) 12 85 97 97, Fax: + 33 (4) 85 99 66, E

- mail: Directive.technical

- support@airbus.com

.