AD/BELL 407/31 - Disc Assemblies - Tail Rotor Driveshaft (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron Canada (BHTC) 407 Series Helicopters AD/BELL 407/31 Disc Assemblies - Tail Rotor Driveshaft 12/2007 DM

Applicability: Bell Helicopter Textron Canada (BHTC) Model 407 helicopters S/N up to 53709, 53711 through 53716, 53718 and 53720 through 53722 fitted with disc assemblies part number (P/N) 407-340-340-103. Requirement: 1. Verify disc assemblies P/N 407-340-340-103 for manufacturing date, proper thickness and indexing, in accordance with the instructions provided in BHTC Alert Service Bulletin (ASB) ASB-407-07-76 dated 28 March 2007 or later approved revisions.

If disc assemblies, after verification in accordance with Requirement 1, do not require any further action, or if the manufacturing date is not between 01 November 2005 and 30 November 2006, make an appropriate log book entry to this effect. No further action is required.

2. Remove any disc assembly which is not within the required thickness of 0.115 - 0.127 inch (2.921 - 3.225 mm).

3. Remove any disc assembly which is not properly indexed.

4. Do not install any disc assembly P/N 407-340-340-103 into any helicopter unless it is compliant to the ASB-407-07-76 dated 28 March 2007 or later approved revisions.