COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Robinson R44 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/R44/16 Vertical-to-Horizontal Stabiliser Attach Channel 13/2001 DM Applicability: Model R44 helicopters, with horizontal stabiliser assembly part number C044-1; horizontal stabiliser serial number 0009 through 0224, except 0018, 0090, 0094, 0111, 0129, 0144, 0161, 0178, 0201, and 0223, installed. Requirement: Remove the vertical stabiliser to inspect the nutplate on channels, part number D283- 1 and -2 in accordance with Robinson Helicopter Company Service Bulletin SB-39. If the nutplates are part number MS21086L4, no further action is required by this Directive. If the nutplates are part number NAS697A4, replace the channels with serviceable channels, part number D296-1 or -2. This AD revises the Limitations section of the maintenance manual by establishing a retirement life of 2,200 time in service for horizontal stabiliser assembly, part number C044-1, with channels part number D283-1 or -2, with nutplates, part number NAS697A4, installed. Note: FAA AD 2001-20-18 Amdt 39-12466 refers. Compliance: Before accumulating 2,200 hours time in service on the horizontal stabiliser assembly. This Airworthiness Directive becomes effective on 19 November 2001. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Background: Engineering analysis indicates that certain vertical-to-horizontal stabiliser attach channels will crack sooner than the original life limit of the horizontal stabiliser. Failure of a channel could result in separation of the stabilisers, and subsequent loss of directional control of the helicopter. David Alan Villiers Delegate of the Civil Aviation Safety Authority 31 October 2001 The above AD is notified in the Commonwealth of Australia Gazette on 7 November 2001.