### 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 na me. 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 b y the Continuin g Airworthiness Division ( AARDG ) , National Aircraft Certification Branch, Trans p ort Canada, Ottawa, tele p hone 613 952-4357.

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 Communica tions 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 2 4-0022 ( 01-2005 ) 

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### CF-2013-22 Issue Date 

### 12 August 2013

Number: CF-2013-22 Subject: Rudder Controls - Yaw Damper Uncommanded Movement Effective: 23 August 2013 Applicability: Bombardier Inc. model CL-600- 2B16 (604 Variant) aeroplanes, serial numbers 5301 through 5665 and 5701 and subsequent. Compliance: Within 30 days from the effective date of this AD, unless already accomplished. Background: There have been several reported incidents where Bombardier Regional Jet aeroplanes experienced in-flight uncommanded rudder movements. Investigation revealed that a failure of the voltage regulator inside the yaw damper actuator could lead to uncommanded yaw movement. If not corrected, this condition could lead to structural failure and the subsequent loss of the aeroplane. Since the Challenger 604 aeroplanes have the same system, and can also experience a similar problem of uncommanded yaw movement, Transport Canada is issuing this AD that mandates the introduction of an emergency procedure to the Aeroplane Flight Manual (AFM) to address the above-mentioned unsafe condition. Corrective Actions: A. Amend the applicable AFM by incorporating the emergency procedure for uncommanded yaw motion:

Aeroplane Model AFM Procedure AFM Revision CL-600-2B16 (604 Variant) S/N 5301 through 5665 Emergency Procedures - Uncommanded Yaw Motion AFM Revision 89 dated 8 July 2013, or later revisions of this procedure approved by Transport Canada CL-600-2B16 (604 Variant) S/N 5701 and subsequent Emergency Procedures - Uncommanded Yaw Motion AFM Revision 25 dated 8 July 2013, or later revisions of this procedure approved by Transport Canada
B. Advise all flight crews of the changes introduced by AFM Revisions listed above. Authorization: For the Minister of Transport, ORIGINAL SIGNED BY Philip Tang Acting Chief, Continuing Airworthiness Contact: Gordanko Jeremic, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 613- 996-9178 or e-mail AD-CN@tc.gc.ca or any Transport Canada Centre.