### 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 ma y 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 Communicat ions Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8 , or 1-800-305-2059 , or www.tc.gc.ca/civilaviation/communications/centre/ addr ess.asp
2 4-0022 ( 01-2005 ) 

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### CF-2012-10 Issue Date 

### 12 March 2012

Number: CF-2012-10 Subject: Non-Conforming Wing-to-Fuselage Attachment Nuts
Effective: 26 March 2012 Applicability: Bombardier Inc. Aeroplanes: Model CL-600-2C10, Serial Numbers 10002 through 10999 Models CL-600-2D15 and CL-600-2D24, Serial Numbers 15001 through 15990 Model CL-600-2E25, Serial Numbers 19001 through 19990 Compliance: As indicated below, unless already accomplished. Background: The manufacturer has determined that wing-to-fuselage attachment nuts, part number (P/N) SH670-35635-1, SH670-35440-951, SH670-35440-3, SH670-35635-1 and 95136D-2412, installed at six attachment joint locations, do not conform to the certification design requirements for dual locking features. The nuts are not of the self-locking type as required and do not provide the frictional thread interference required to prevent the nut from backing off the bolt. As a result, only a single locking device, the cotter pin, is provided at these critical joints. In the case where a nut becomes loose, in combination with a missing or broken cotter pin, the attachment bolt at the wing-to-fuselage joint could migrate and fall out. Loss of two attachment joints could potentially result in the loss of the wing. This Airworthiness Directive (AD) mandates a detailed visual inspection (DVI) of each affected wing-to-fuselage attachment joint to ensure that a cotter pin is installed. Corrective Actions: A. Within 3000 hours air time or 18 months, whichever occurs first, from the effective date of this AD, perform a DVI of each affected wing-to-fuselage attachment joint, in accordance with the Accomplishment Instructions in Bo mbardier Service Bulletin (SB) 670BA-53-042, Initial Issue, dated 21 December 2011, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada.
B. Repeat the inspection specified in paragraph A of this AD at intervals not to exceed 6600 hours air time. During any required inspection, if an attachment joint is found without a cotter pin installed, before further flight, contact the Bombardier Customer Response Center for an approved disposition. The approved disposition must specifically reference this AD. Note: The compliance time in this AD differs from the recommended compliance time mentioned in the Bombardier SB.
Authorization: For the Minister of Transport, Infrastructure and Communities 

### ORIGINAL SIGNED BY Derek Ferguson Chief, Continuing Airworthiness
Contact: Mr. Robert Farinas, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 613-996-9178 or e-mail CAWWEBFeedback@tc.gc.ca or any Transport Canada Centre.