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.

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)

1/3 No.

CF-2011-36R1 

Issue Date 

3 October 2012 

Number: CF-2011-36R1 

Subject: Main Landing Gear – Retraction Actuator Corrosion 

Effective: 18 October 2012 

Revision: Supersedes Airworthiness Directive CF-2011-36, dated 10 September 2011 

Applicability: Bombardier Inc. Aeroplanes: 

Model CL-600-2C10, serial numbers 10002 and subsequent 

Models CL-600-2D15 and CL-600-2D24, serial numbers 15001 and subsequent 

Compliance: As indicated below, unless already accomplished.

Background: Corrosion of the main landing gear (MLG) retraction actuator components was found 

in-service, either at the interface of the rod end and the piston or at the bracket and its 

related pins. This can cause the MLG retraction actuator to disconnect, leading to an 

MLG extension without damping, and a potential for MLG structural damage and possible 

collapse during landing. 

This AD mandates the inspection and rectification of the MLG retraction actuator 

components. 

This revision is to mandate the installation of the new retraction actuator jam nut. This 

revision also corrects the background information and updates Service Bulletin (SB)

references. 

Corrective 

Actions: 

Part I - Inspection of the MLG Retraction-Actuator 

For any MLG retraction actuator assembly with part number and serial number listed in 

Paragraph 1.A. Effectivity of Bombardier SB 670BA-32-031, Revision C, dated 17 April 

2012, or later revisions approved by the Chief, Continuing Airworthiness, Transport 

Canada, perform a detailed visual inspection of the retraction actuator assembly for 

evidence of corrosion and security of jam nut, and rectify as applicable, in accordance 

with Part A of the Accomplishment Instructions of the above-mentioned SB using the 

following schedule: 

A. Initially, as of the effective date of this AD: 

1. For MLG retraction actuator assemblies that have accumulated more than 8000 

hours air time since new or since overhaul, or have been in service for more than 

4 years since new or since overhaul: within 1200 hours air time or 12 months, 

whichever occurs first, from the effective date of this AD. 

2. For MLG retraction actuator assemblies that have accumulated 8000 hours air 

time or less since new or since overhaul, or have been in service for 4 years or 

less since new or since overhaul: before reaching 9200 hours air time or 5 years 

into service, whichever occurs first. 
No.

N° CF-2011-36R1 2/3 

B. Subsequently, at intervals not to exceed 1200 hours air time or 12 months, 

whichever occurs first. 

The inspection specified in Part I of this AD is not required for any retraction actuator 

assembly identified with Mod Status “32-64” on the identification plate. 

Inspection and rectification in accordance with Bombardier SB 670BA-32-031, Revision 

B, dated 29 July 2011, Revision A, dated 09 June 2011, or Initial Issue, dated 

14 March 2011, also meet the requirements of Part I of this directive. 

Part II - Inspection of the MLG Retraction-Actuator Bracket and Related Pins 

For any MLG dressed shock strut with part number and serial number listed in Paragraph 

1.A. Effectivity of Bombardier SB 670BA-32-033, Revision B, dated 26 June 2012, or 

later revisions approved by the Chief, Continuing Airworthiness, Transport Canada, 

perform a detailed visual inspection of the retract-actuator bracket assembly, associated 

pins and the mating lugs on the outer cylinder for evidence of corrosion, and rectify as 

applicable, in accordance with the above-mentioned SB within 4400 hours air time or 24 

months, whichever occurs first, from the effective date of the original issue of this AD 

(22 September 2011). 

Inspection and rectification in accordance with Bombardier SB 670BA-32-033, Revision 

A, dated 29 July 2011, or Initial Issue, dated 14 March 2011, also meet the requirements 

of Part II of this directive. 

Note: The part numbers and serial numbers of the MLG dressed shock strut has been 

clarified in the above-mentioned service bulletin. Operators are advised to perform 

a records check to ensure all required actions have been completed. 

Part III - Replacement of the MLG Retraction Actuator 

As of the effective date of this directive, no person is permitted to install on an aeroplane, 

an MLG retraction actuator assembly with part number and serial number listed in 

Paragraph 1.A. Effectivity of Bombardier SB 670BA-32-031, Revision C, dated 

17 April 2012, or later revisions approved by the Chief, Continuing Airworthiness, 

Transport Canada, unless a detailed visual inspection of the retraction actuator assembly

has been performed, for evidence of corrosion and security of jam nut, and rectification

as 

applicable, in accordance with Part A of the Accomplishment Instructions of the abovementioned SB and the repetitive inspection of Part I of this AD is subsequently followed. 

The inspection specified in Part I of this directive is not required for any retraction 

actuator assembly identified with Mod Status “32-64” on the identification plate. 

Part IV - Replacement of the MLG Dressed Shock Strut 

As of the effective date of this directive, no person is permitted to install on an aeroplane, 

an MLG dressed shock strut with part number and serial number listed in Paragraph 1.A. 

Effectivity of Bombardier SB 6470BA-32-033, Revision B, dated 26 June 2012, or later 

revisions approved by the Chief, Continuing Airworthiness, Transport Canada, unless the 

inspection, and rectification as applicable, specified in Part II of this directive has been 

completed. 

Part V - Installation of the New Jam Nut 

For any MLG retraction actuator assembly with part number and serial number listed in 

Paragraph 1.A. Effectivity of Bombardier SB 670BA-32-031, Revision C, dated 17 April 

2012, or later revisions approved by the Chief, Continuing Airworthiness, Transport 

Canada, install the new jam nut part number 49606-5 in accordance with Part B of the 

Accomplishment Instructions of the above-mentioned SB within 20 000 hours air time or 

10 years, whichever occurs first, from the effective date of this AD. 
No.

N° CF-2011-36R1 3/3 

For any retraction actuator assembly identified with Mod Status “32-64” on the 

identification plate, the requirements of Part V of this AD is met. 

The inspection specified in Part I of this AD is not required for retraction actuator 

assembly with Part V of this AD incorporated. 

Authorization: For the Minister of Transport, Infrastructure and Communities, 

ORIGINAL SIGNED BY

David Turnbull 

Director, National Aircraft Certification 

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

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