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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.

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-2010-18

Issue Date 

 16 June 2010 

Number: CF- 2010-18 

Subject: Rudder Travel Limiter − Return Springs Failure

Effective: 7 July 2010 

Applicability: Bombardier Inc. Models: 

CL-600-2C10, serial number 10003 and subsequent 

CL-600-2D15 and CL-600-2D24, serial number 15001 and subsequent 

Compliance: As indicated below. 

Background: Rudder Travel Limiter (RTL) return spring, part number (P/N) E0650-069-2750S, failed 

prior to completion of the required endurance test. In addition, the replacement RTL 

return spring, P/N 670-93465-1 (see Note) was found to be susceptible to chafing on the 

primary actuator, which could also result in eventual dormant spring failure. There are 

two return springs in the RTL and if both springs failed, a subsequent mechanical 

disconnect of the RTL components would result in an unannunciated failure of the RTL. 

This, in turn, would permit an increase of rudder authority beyond normal structural limits 

and, in the event of a strong rudder input, controllability of the aeroplane could be 

affected. 

Note: RTL return springs, P/N 670-93465-1, were installed in production aeroplanes

serial number 10266 (CL-600-2C10) and 15182 (CL-600-2D24) respectively 

and were introduced in-service by Service Bulletin (SB) 670BA-27-047. 

SB 670BA-27-047 has since been superseded by SB 670BA-27-055. 

This directive mandates repetitive visual inspection of the RTL return springs and 

primary actuator, with replacement of parts as necessary. 

Corrective 

Actions: 

Part I: Initial Inspection 

A. For each aeroplane with 4000 or less hours air time at the effective date of this 

directive, inspect and replace, if required, the RTL return springs and primary 

actuator before the aeroplane has accumulated 6000 hours air time, in accordance 

with the Accomplishment Instructions in Bombardier Aerospace SB 670BA-27-055, 

dated 11 May 2010 or later revisions approved by the Chief, Continuing 

Airworthiness, Transport Canada. 

B. For each aeroplane with more than 4000 hours air time at the effective date of this 

directive, inspect and replace, if required, the RTL return springs and primary 

actuator within 2000 hours air time after the effective date of this directive, in 

accordance with the Accomplishment Instructions in Bombardier Aerospace SB 

670BA-27-055, dated 11 May 2010 or later revisions approved by the Chief, 

Continuing Airworthiness, Transport Canada. 
No.

 N° CF-2010-18 2/2 

Part II: Repetitive Inspection 

Within 6000 hours air time after the previous inspection (or component replacement, if 

applicable), inspect the RTL return springs and primary actuator in accordance with the 

Accomplishment Instructions in Bombardier Aerospace SB 670BA-27-055, dated 

11 May 2010 or later revisions approved by the Chief, Continuing Airworthiness, 

Transport Canada. 

Authorization: For Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY 

Robin Lau for 

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Miss Helen Tsai, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 

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