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) 222 Series Helicopters AD/BELL 222/36 Tail Rotor Driveshaft Thomas Couplings 8/2007 Applicability: Bell Helicopter Textron Canada (BHTC) Model 222 helicopters serial number (S/N) up to 47089; and Model 222B helicopters S/N up to 47156; and Model 222U helicopters S/N up to 47574. Requirement: 1. Verify Disc Assemblies for manufacturing date, proper thickness and indexing, in accordance with instructions provided in applicable Alert Service Bulletins (ASB) listed below or later NAA approved revisions. - 222 and 222B ASB-222-07-105 dated 28 March 2007. - 222U ASB-222U-07-76 dated 28 March 2007. 2. For Disc Assemblies held as spares. (a) If manufacturing date is not between 1 November 2005 and 30 November 2006, the Disc Assemblies do not require further action. (b) If required, adjust the thickness of Disc Assemblies by removing or adding a new disc. (c) If required, re-index Disc assembly in accordance with the applicable Maintenance Manual. (d) Attach to Disc Assembly a serviceable tag with inscription indicating compliance to the applicable ASB. 3. For Disc Assemblies installed in an aircraft. (a) Remove from service any Disc Assembly which is not within the required thickness as per the table below. Disc Assembly Total Thickness Part Number Minimum Maximum 36300-1 0.174 inch (4.42 mm) 0.186 inch (4.75 mm) 37855-1 0.126 inch (3.20 mm) 0.138 inch (3.50 mm) (b) Remove any Disc Assembly which is not properly indexed. (c) If Disc Assemblies do not require further action or the manufacturing date is not between 1 November 2005 and 30 November 2006, make an appropriate log book notation to this effect. Note: Transport Canada AD CF-2007-09 dated 17 May 2007 refers. Compliance: 1. Not later than 25 flight hours or 30 days from the effective date of this directive whichever occurs first. 2. Before fitment to an aircraft after the effective date of this AD. 3. a. Within 10 flight hours from the effective date of this AD. 3. b. Within 300 flight hours from the effective date of this AD or at the next scheduled inspection, whichever occurs first. 3. c. Following the verification of the Disc Assembly. This Airworthiness Directive becomes effective on 2 August 2007. Background: It has been determined that certain Disc Assemblies as listed in this AD manufactured between 1 November 2005 through 30 November 2006, may have insufficient amount of discs or may have been indexed incorrectly. David Punshon Delegate of the Civil Aviation Safety Authority 19 June 2007