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. Sikorsky S-62 Series Helicopters AD/S-62/11 Main Rotor Brake Disc 4/2005 Applicability: Model S-62 series helicopters, equipped with part number S6235-20213 or part number 62350-22013-101 rotor brake discs. Requirement: 1. Replace part number S6235-20213 rotor brake disc with part number 62350-22013 -101 rotor brake disc in accordance with Paragraph 2 of Sikorsky Service Bulletin (SB) 62B35-13 or SB 62B35-13A. 2. Accomplish a detailed inspection of the part number 62350-22013-101 rotor brake disc installation and a dye penetrant inspection of the rotor brake disc for cracking; in accordance with Paragraph E (2) of Sikorsky Alert Service Bulletin 62B35-12 (except that the minimum thickness for the new disc is .449 inches and the attachment bolt torque is changed per Figures 1 and 2 of SB 62B35-13. If cracks are evident during any Requirement 2 inspection, before further flight, replace the disc in accordance with the applicable maintenance manual, and resume the Requirement 2 inspections. Note: FAA AD 81-06-53 R1 Amdt 39-4303 refers. Compliance: 1. Unless already accomplished, before 30 April 2005. 2. Before the accumulation of 120 flight hours since new or the last inspection. Inspect thereafter at intervals not to exceed 120 flight hours. This Airworthiness Directive becomes effective on 14 April 2005. Background: The FAA requires certain actions to prevent operation with cracked rotor brake discs. David Villiers Delegate of the Civil Aviation Safety Authority 2 March 2005