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 by the Continuing Airworthiness Division (AARDG), National Aircraft Certification Branch, Transport Can ada, 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 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/ 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 insta llation 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 corre cted, can lead to bolt failure, detachment of the tailboom and loss of control of the helicopter. To co rrect 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 pos itions at intervals of not less than 1 but not exceeding 5 hours air time following hardware r eplacement until torque stabilizes at all positions. Carry out the above corrective actions in accordanc e 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, Conti nuing Airworthiness, Transport Canada.

Authorization: For Minister of Transport, In frastructure 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.