COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Short SD3-30 Series Aeroplanes
AD/SD3-30/29 Main Landing Gear - Beam Sub Assembly 5/95
Applicability: All Model SD3-30 series aeroplanes equipped with Menasco MLG beam assembly P/N 17501 serial numbers MMC-005 to MMC-068 and MMC-071 to MMC-188 inclusive.
Requirement: 1. Rework the MLG beam sub-assembly P/N 17604-9, -13, -13A/14A, -15/16 or
-17/18 in accordance with Shorts Service Bulletin SD3-32-90, Revision 2.
2. Remove from service MLG beam sub-assembly P/N 17604-9, -13 or -13A/14A.
Note: FAA AD 93-14-03 refers.
Compliance: 1. Rework in accordance with Requirement 1 before 13 500 total component landings or before 2 300 component landings from 27 April 1995, whichever occurs later.
2. Action in accordance with Requirement 2 before 20 000 total component landings.
Background: Fatigue testing has revealed that there is a stress raiser at the lower edge of the bore where the beam ID intersects with the axle hole. The rework increases the radius of the intersection. Other locations of high stress are also radiused.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 105, introduces a series of directives aimed at maintaining and enhancing the safety standards of civil aviation within Australia. One such directive, AD/SD3-30/29, targets the main landing gear beam sub-assembly of all Model SD3-30 series aeroplanes equipped with certain Menasco MLG beam assembly parts. This directive was enacted to address issues identified in fatigue testing, particularly stress raisers at the lower edge of the bore where the beam ID intersects with the axle hole. The policy objective behind this directive is to ensure that these critical components are maintained in a safe operational condition by requiring specific rework to increase the radius at the identified stress points. This is intended to mitigate the risk of structural failure due to fatigue, thereby enhancing the overall safety of civil aviation operations in Australia.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to Airworthiness Directives governing the maintenance and operational safety of civil aircraft in Australia. This legislation applies to all Model SD3-30 series aeroplanes equipped with a specific type of main landing gear beam assembly, namely the Menasco MLG beam assembly with particular serial numbers. The application is limited to these aircraft models and serial numbers, ensuring that only the specified aircraft are subject to the requirements outlined in the legislation. The geographic reach of this regulation is national, as it is a Commonwealth regulation, thereby binding across all states and territories within Australia. The regulation does not specify any exclusions or exemptions but mandates specific actions to ensure the safety and airworthiness of the affected aircraft. Compliance with the directive involves detailed rework and removal procedures for certain beam sub-assemblies, with strict landing hour thresholds for these actions to be completed. Subordinate instruments or further clarifications may be issued to ensure proper implementation and enforcement of these safety measures.
Key Provisions
The Civil Aviation Regulations 1998, particularly Part 39, Section 105, includes a specific Airworthiness Directive (AD) aimed at ensuring the safety of certain model SD3-30 series aeroplanes. The directive, identified as AD/SD3-30/29, pertains to the main landing gear beam sub-assembly of these aircraft. Specifically, it applies to all SD3-30 series aeroplanes equipped with the Menasco MLG beam assembly P/N 17501 with serial numbers ranging from MMC-005 to MMC-068 and MMC-071 to MMC-188 inclusive. The directive mandates that the main landing gear beam sub-assembly P/N 17604-9, -13, -13A/14A, -15/16 or -17/18 be reworked in accordance with Shorts Service Bulletin SD3-32-90, Revision 2. Additionally, it requires the removal from service of the MLG beam sub-assembly P/N 17604-9, -13 or -13A/14A.
The obligations imposed by this AD include specific compliance timelines and requirements. Owners or operators of the affected aircraft must ensure that the rework of the main landing gear beam sub-assembly is completed before reaching 13,500 total component landings or before 2,300 component landings from 27 April 1995, whichever occurs later. Similarly, the removal of the specified MLG beam sub-assembly from service must be executed before the aircraft accumulates 20,000 total component landings. These timelines are critical to maintaining compliance with the directive and ensuring the continued airworthiness of the aircraft.
Failure to comply with the AD could result in serious safety implications, given the identified stress raisers at the lower edge of the bore where the beam ID intersects with the axle hole. The rework, which involves increasing the radius of this intersection and other high-stress locations, is essential to mitigating these risks. Non-compliance could potentially lead to severe consequences, including the grounding of the aircraft until the required modifications are made. The directive references FAA AD 93-14-03 for further guidance, highlighting the international coordination in ensuring aircraft safety.