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 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-76 Series Helicopters AD/S-76/72 Main Landing Gear Brake Discs - Replacement 10/2003 DM Applicability: Model S-76A, B and C series helicopters, with main landing gear brake (MLG) assembly part number (P/N) 5007555, 5007555-1, or 5007555-2 installed. Requirement: 1. Determine if a MLG brake disc P/N 5014067 is installed in the braking assembly in accordance with: (a) For brake assembly P/N 5007555 and P/N 5007555-1: Section 111-Acommplishment Instructions, paragraph 1.A. to 1.D., of Aircraft Braking Systems Corporation Alert Service Bulletin (ASB) S76-32-A24, dated 10 April 2002; and (b) For brake assembly P/N 5007555-2: Section 111-Acommplishment Instructions, paragraph 1.A. and 1.B., of Aircraft Braking Systems Corporation ASB S76-32-A25, dated 15 May 2002. 2. If it is determined, in compliance with Requirement 1, that a disc P/N 5014067 is installed, remove that disc and replace with disc P/N 5007672 and re-identify brake assembly: (a) P/N 5007555 and P/N 5007555-1 as brake assembly P/N 5007555-3, in accordance with the conversion of brake assembly instructions on page 6 of ASB S76-32-A24, dated 10 April 2002; and (b) P/N 5007555-2 as brake assembly P/N 5007555-4, in accordance with the conversion of brake assembly instructions on page 6 of ASB S76-32-A25, dated 15 May 2002. 3. Increase the Category A - Rejected Takeoff Distance, the Category A-Landing Distance, and the Category B - Landing Distance, as stated in the current Rotorcraft Flight Manual (RFM) for the helicopter, by multiplying these rejected takeoff and landing distances by a factor of 1.67. This can be accomplished by inserting into the helicopter flight manual a copy of this Directive, or the helicopter manufacturers temporary revision to the RFM reflecting increased rejected takeoff and landing distances. Sikorsky S-76 Series Helicopters AD/S-76/72 (continued) 4. MLG brake discs having P/N 5014067 shall not be installed on any aircraft. Note 1: Temporary revisions to the RFM reflecting increased rejected takeoff and landing distances can be obtained from the helicopter manufacturer. Note 2: Sikorsky Aircraft Corporation ASB 76-32-27 dated 30 April 2002 contains Aircraft Braking Systems Corporation ASB S76-32-A24, dated 10 April 2002, and Sikorsky Aircraft Corporation ASB 76-32-28 dated 17 May 2002 contains Aircraft Braking Systems Corporation ASB S76-32-A25, dated 15 May 2002. Note 3: FAA AD 2003-14-18 Amdt 39-13237 refers. Compliance: For Requirement 1: Within 60 days from the effective date of this Directive. For Requirement 2: Within 90 days from compliance with Requirement 1 of this Directive. For Requirement 3: Before further flight after the effective date of this Directive, until all installed discs P/N 5014067 on the helicopter are replaced with disc P/N 5007672, and all brake assemblies are re-identified in accordance with Requirement 2 of this Directive. For Requirement 4: Following compliance with Requirement 1 of this Directive. This Airworthiness Directive becomes effective on 25 August 2003. Background: This Directive is issued after it was been found that some MLG brake discs have been manufactured using inferior materials. To rectify this condition, it is required to replace any non-conforming discs with different part-numbered airworthy discs, and to revise the helicopter flight manual to adjust the rejected takeoff and landing distances until the discs are replaced. Jim Coyne Delegate of the Civil Aviation Safety Authority 6 August 2003 The above AD is notified in the Commonwealth of Australia Gazette on 13 August 2003.