Bell Helicopter Textron 205 Series Helicopters 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 39.1 (1) of CAR 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. AD/BELL 205/68 Tail Rotor Counterweight Bellcrank Retention Nut Applicability: Model 205A-1 and 205B helicopters. Requirement: 1. For 205A-1 helicopters: 9/2001 DM 1. Remove the two existing retention nuts retaining the bellcranks, part number 212-010-709-001 or 212-011-705-001, and install zero time retention nuts, part number MS 14145L6 or MS17826-6, in accordance with paragraphs (1) through (5) of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin (ASB) 205-00-77 Revision A, dated 13 September 2000. A used nut must not be installed. b. Inspect the retention nuts and corrosion preventive compound (CPC) coating in accordance with paragraph (6) of the Accomplishment Instructions of ASB 205-00-77 Revision A. Reapply the CPC coating if deficiencies are found in the coverage and protection of the area. Replace any retention nut found with any corrosion, mechanical damage, a crack, or looseness, with a serviceable new retention nut before further flight. 2. For 205B helicopters: 1. Remove the two existing retention nuts retaining the bellcranks, part number 212-011-705-001, and install retention nuts, part number MS14145L6 or MS17826-6, in accordance with paragraphs (1) through (5) of the Accomplishment Instructions in ASB 205B-00-31 Revision A, dated 13 September 2000. A used nut must not be installed. b. Inspect the retention nuts and CPC coating in accordance with paragraph (6) of the Accomplishment Instructions in ASB 205B-00-31 Revision A. Reapply the CPC coating if deficiencies are found in the coverage and protection of the area. Replace any retention nut found with any corrosion, mechanical damage, a crack, or looseness, with a serviceable new retention nut before further flight. Note: FAA AD 2001-13-01 Amdt 39-12281 refers. Compliance: 1.a. and 2.a: Within 100 hours time in service or 90 days after 1 August 2001, whichever occurs first; unless already accomplished. 1.b. and 2.b: At intervals not to exceed 100 hours time in service after accomplishing Requirement 1.a. or 2.a., as applicable. This Airworthiness Directive becomes effective on 1 August 2001. Background: The FAA received a report of an in-flight loss of a tail rotor counterweight bellcrank due to failure of the retention nut. Failure of the retention nut could result in the bellcrank migrating off the crosshead spindle, loss of tail rotor control, and subsequent loss of control of the helicopter. David Alan Villiers Delegate of the Civil Aviation Safety Authority 25 July 2001 The above AD is notified in the Commonwealth of Australia Gazette on 1 August 2001.