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 222/29 Drive Hub Studs 8/2005 Applicability: All Bell Helicopter Textron Canada (BHTC) (previously manufactured by Bell Helicopter Textron, Inc. (BHTI)) Model 222 helicopters, with drive hub assembly, part number (P/N) 222-010-417-009, installed. Requirement: 1. (a) Remove nuts and washers from the studs which attach spline plate, P/N 222-310-418-105/-107, to the drive hub assembly, P/N 222-010-417-009. (b) Visually inspect washers, P/N AN960-416, and mating surface on the spline plate, P/N 222-310-418-105/-107, for any signs of fretting, cracking, or wear. (c) If any fretting or wear is found, replace spline plate, P/N 222-310-418-105/-107, and drive hub assembly, P/N 222-010-417-009. (d) If no fretting or wear is found, install new nuts, P/N MS21042L4, and washers, P/N AN960-416, and torque nuts to 100 inch pounds plus friction (tare) torque. 2. (a) apply 50 inch-pounds of torque to the spline plate P/N 222-310-418-105/-107 retaining nuts. (b) If the nuts do not move, the nut torque is sufficient. (c) If, while performing step (a), one or more of the spline plate P/N 222-310-418-105/-107 retaining nuts move prior to reaching 50 inch-pounds, replace spline plate, P/N 222-310-418-105/-107, and drive hub assembly, P/N 222-010-417-009. Note: FAA AD 87-09-02 R2 Amendment 39-6399, refers. Compliance: 1. Unless already accomplished, within 7 days of effective date of this AD. 2. After completing the requirements of paragraphs 1 (a) and 1 (b) and then repetitively at intervals not to exceed 50 hours time in service. This Airworthiness Directive becomes effective on 4 August 2005. Background: To prevent possible failure of the drive hub studs which could result in loss of flight control and subsequent loss of the helicopter. James Coyne Delegate of the Civil Aviation Safety Authority 18 June 2005