Transport Transports 

Canada Canada

 TP 7245E

 

AIRWORTHINESS DIRECTIVE

The following airworthiness directive (AD) may be applicable to an aircraft which our records indicate is registered in your name. ADs are issued pursuant to Canadian Aviation 

Regulation (CAR) 521 Division X. Pursuant to CAR 605.84 and the further details of CAR Standard 625, Appendix H, the continuing airworthiness of a Canadian registered aircraft is contingent upon compliance with all applicable ADs. Failure to comply with the requirements of an AD may invalidate the flight authorization of the aircraft. Alternative means of compliance shall be applied for in accordance with CAR 605.84 and the above-referenced Standard. 

This AD has been issued by the Continuing Airworthiness Division (AARDG), National Aircraft Certification Branch, Transport Canada, Ottawa, telephone 613 952-4357.

URGENT URGENT URGENT URGENT URGENT URGENT URGENT URGENT URGENT 

TRANSPORT CANADA EMERGENCY AIRWORTHINESS DIRECTIVE 

PLEASE FORWARD IMMEDIATELY TO THE PERSON RESPONSIBLE FOR THE OPERATION 

AND MAINTENANCE OF YOUR AIRCRAFT

Pursuant to CAR 202.51 the registered owner of a Canadian aircraft shall, within seven days, notify the Minister in writing of any change of his or her name or address. 

To request a change of address, contact the Civil Aviation Communications Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8, or 1-800-305-2059, or www.tc.gc.ca/civilaviation/communications/centre/ address.asp 

24-0022 (01-2005)

1/2 No.

CF-2011-17R1

Issue Date 

 19 December 2011 

Number: CF-2011-17R1 

Subject: Incorrect Assembly of Hydraulic Servo Actuators 

Revision: Supersedes Airworthiness Directive CF-2011-17 

Effective: 22 December 2011 

Applicability: Bell Helicopter Textron Canada helicopters: 

Model 407, serial numbers 53000 through 53900, 53911 through 53999 and 54000 

through 54081 equipped with servo actuators part number 206-076-062-105 or 

206-076-062-107. 

Model 427, serial numbers 56001 through 56077, 58001 and 58002 equipped with 

servo actuators part number 206-076-062-109 or 206-076-062-111. 

Compliance: As indicated below, unless already accomplished. 

Background: Transport Canada was advised that a quality escape by a supplier has occurred and a 

number of Bell Helicopter hydraulic servo actuators may have a loose nut, shaft, and 

clevis assembly. The loose connection is due to improper lock washer installation. This 

discrepancy is not traceable or identifiable except by inspection. A disconnect of the 

affected components may lead to loss of control of the helicopter. 

The original issue of this directive mandates inspections and rectification of the nut, shaft 

and clevis assembly for all affected components identified when the directive was issued.

Since the publication of the original issue of this directive, it has been discovered that 

additional servo actuator serial numbers may be affected. Therefore, Revision one (R1) 

of this directive is issued to extend the coverage of the one-time inspection to all installed 

actuators. Those actuators already inspected according to the original issue of this 

directive are to be re-identified with the letter “V” at the end of the part number. 

Corrective 

Actions: 

A. Before next flight perform a one-time visual inspection and the applicable 

rectifications on the hydraulic servo actuator, in accordance with the Accomplishment 

Instructions of the applicable Alert Service Bulletin (ASB) listed below, or later 

revisions approved by the Chief, Continuing Airworthiness, Transport Canada:
No.

N° CF-2011-17R1 2/2 

Helicopter Model Alert Service Bulletin Date 

407 407-11-96 Revision B 22 August 2011 

427 427-11-35 Revision B 22 August 2011 

Previous inspections and rectifications carried out in accordance with the original 

issue of this directive meet the requirements of this paragraph. 

B. For actuators which have already been inspected and have incorporated the 

applicable rectifications in accordance with the original issue of this directive and 

those actuators that have met the requirements of paragraph A above, within the 

next 110 hours air time, re-identify the actuator data plate by adding the letter “V” at 

the end of the part number, in accordance with the applicable ASB listed in the above 

table. 

As of the effective date of this directive, servo actuators with part numbers listed in the 

applicability section of this directive shall not be installed on Bell Helicopter Textron 

Canada helicopter Models 407 and 427, unless the actuator complies with the 

requirements of this directive and is identified with the letter “V” after the part number. 

Authorization: For the Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY 

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Mr. Bogdan Gajewski, Continuing Airworthiness, Ottawa, telephone 613-952-4357, 

facsimile 613-996-9178 or e-mail CAWWEBFeedback@tc.gc.ca or any Transport 

Canada Centre.