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)

1/1 No.

CF-2010-33

Issue Date 

 30 September 2010 

Number: CF-2010-33 

Subject: Over-torque of Tailboom Attachment Hardware 

Effective: 13 October 2010 

Applicability: Bell Helicopter Textron Canada Ltd. Model 407 helicopter serial number 53000 

through 53990. 

Compliance: As indicated, unless already accomplished. 

A. Helicopters with 7000 hours air time or less: at the next 600 hours scheduled

inspection but no later than 31 December 2010. 

B. Helicopters with more than 7000 hours air time: within 150 hours air time or 90 

days, whichever comes first after the effective date of this directive. 

Background: A review of the tailboom attachment installation has determined that the torque value of 

the tailboom attachment bolts specified in the maintenance manual and applied during 

manufacturing, exceeded the torque range recommended for the bolts.

This situation, if not corrected, can lead to bolt failure, detachment of the tailboom and 

loss of control of the helicopter. To correct the problem, the tailboom attachment 

hardware has to be replaced. 

Corrective 

Actions: 

Replace the tailboom attachment hardware and perform a torque check of the tailboom 

attaching bolts/nuts at all four attachment positions at intervals of not less than 1 but not 

exceeding 5 hours air time following hardware replacement until torque stabilizes at all 

positions. Carry out the above corrective actions in accordance with instructions outlined 

in Bell Helicopter Alert Service Bulletin 407-10-93 Rev. A, dated 30 August 2010 or later 

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

Authorization: For Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: 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.