AD/HS 748/8 - Engine Subframe/Wing Attachment Assembly

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, were established to ensure the safety of civil aviation within the country. This legislation is overseen by the Civil Aviation Safety Authority (CASA) and includes provisions for issuing airworthiness directives to address specific safety concerns. One such directive is AD/HS 748/8, which applies to all British Aerospace (Hawker Siddeley) HS 748 Series aeroplanes. This directive was introduced to address the potential safety risk of undetected abnormal movement and wear of the engine subframe/wing attachment assembly, which could lead to the failure of critical components such as the split bush and taper bolt, potentially resulting in severe stress and damage to the engine support structure. The policy objective of this directive is to ensure compliance with British Aerospace Mandatory Service Bulletin 54/29 and to align with the UK Civil Aviation Authority’s AD 026-11-86, thereby maintaining the airworthiness of the aircraft in question.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, which pertains to the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, applies to all British Aerospace (Hawker Siddeley) HS 748 series aeroplanes. This regulatory instrument mandates that operators of HS748 aircraft must comply with the actions detailed in British Aerospace Mandatory Service Bulletin 54/29 to address undetected abnormal movement and wear of the engine subframe/wing attachment assembly, which can lead to severe structural damage. The directive ensures that all HS748 aircraft meet the specified safety standards to prevent failure of the split bush and/or taper bolt, thereby maintaining the integrity of the engine support structure. The applicability of this directive is national, ensuring uniform safety standards across all HS748 aircraft operating within Australia. The regulations do not specify any exclusions or exemptions, thereby applying uniformly to all relevant aircraft within the jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 - 105, establish a schedule of airworthiness directives (ADs) for various aircraft types, including the British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes (sections 1-3). The directive AD/HS 748/8 pertains to the engine subframe/wing attachment assembly, mandating compliance with British Aerospace Mandatory Service Bulletin 54/29. This directive references UK Civil Aviation Authority AD 026-11-86 for further detail (section 4). The primary requirement of this directive is that all HS748 aircraft must take corrective action in accordance with the specified service bulletin to address the issue of undetected abnormal movement and wear in the engine subframe/wing attachment assembly (section 5). This can lead to the failure of the split bush and/or taper bolt, which in turn can cause severe stress and damage to the engine support structure (section 6). The obligations imposed by this directive are clear and precise. Operators and owners of HS748 aircraft must ensure that the required actions, as detailed in the British Aerospace Mandatory Service Bulletin 54/29, are carried out without delay (section 7). This involves inspecting and potentially replacing or repairing the engine subframe/wing attachment assembly to mitigate the risks associated with abnormal movement and wear (section 8). The directive specifies that compliance must be achieved in line with the instructions provided in the Requirement Document, which includes detailed procedures and specifications for the corrective action (section 9). The goal is to maintain the airworthiness of the aircraft by preventing potential catastrophic failures that could arise from the described structural issues (section 10). Failure to comply with the provisions of this airworthiness directive can lead to serious consequences. Civil Aviation Safety Authority regulations allow for enforcement actions against operators who do not adhere to the specified requirements (section 11). Non-compliance can result in penalties, including fines and potential grounding of the aircraft until the necessary actions are completed (section 12). The maximum penalties for breaches of the Civil Aviation Regulations can be severe, reflecting the critical nature of ensuring aircraft safety (section 13). In the case of this directive, the potential for severe stress and damage to the engine support structure underscores the importance of strict compliance to avoid accidents and maintain the highest safety standards in aviation (section 14).