Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, contain a schedule of airworthiness directives to ensure the safety of civil aviation operations within the country. One such directive, AD/APU/3, specifically addresses the issue of uncontained turbine disc failures in Garrett auxiliary power units (APUs) by incorporating a back-up plate to improve turbine wheel containment. This directive applies to Garrett Model numbers GTCP36-4A, -6, -16, -16A, and -28, with reference to Garrett Service Bulletin No. GTCP36-49-5323R2. The objective of this directive is to prevent further incidents of uncontained failed discs by ensuring compliance with the specified modifications prior to July 1st, 1984. The directive responds to recent occurrences of uncontained turbine disc failures and near misses, underscoring the importance of maintaining high safety standards in aviation.

Scope and Application

The Civil Aviation Safety Authority (CASA) has issued a specific Airworthiness Directive under the Civil Aviation Regulations 1998, which applies to Garrett model auxiliary power units (APU) specifically those identified as GTCP36-4A, -6, -16, -16A, and -28. This directive is intended to address and mitigate the risk of uncontained turbine disc failures, which have been observed locally within the specified period. The directive applies to any aircraft equipped with the aforementioned APU models and mandates compliance by operators of these aircraft. The directive applies on a Commonwealth level, with CASA exercising its regulatory authority to ensure aviation safety standards are upheld across Australia. There are no exclusions or exemptions mentioned in this directive, implying a broad application to all affected aircraft operators. The directive can be extended or restricted through subordinate instruments issued by CASA, ensuring the regulatory framework remains adaptable to evolving safety concerns.

Key Provisions

The main operative sections of AD/APU/3 are primarily concerned with ensuring the airworthiness of Garrett Model GTCP36 series Auxiliary Power Units (APU) by requiring the incorporation of a back-up plate to improve turbine wheel containment. This requirement is outlined in section 1 of the directive, which specifies the models that are subject to the directive and the Garrett Service Bulletin (SB) number GTCP36-49-5323R2, which details the modifications needed. The applicability of this directive is confined to aircraft using these specific Garrett APU models that were compliant before July 1, 1984. This directive aims to prevent incidents of uncontained turbine disc failures that have occurred over the past two years. The obligations imposed by this directive on the parties or entities it governs are clear and precise. Aircraft operators and maintenance providers must ensure that the specified Garrett APU models incorporate the back-up plate as detailed in the Garrett SB No. GTCP36-49-5323R2. This includes verifying that the modification is carried out by authorised personnel and that the modifications are properly documented. The directive mandates compliance with these specifications to ensure the safety of the aircraft and its occupants by mitigating the risk of uncontained turbine disc failures. Failure to comply with the requirements of AD/APU/3 can result in significant consequences. Under section 39.107 of the Civil Aviation Regulations 1998, non-compliance is considered an offence. The penalties for such breaches can include substantial fines and, in severe cases, imprisonment. The exact penalties are determined by the Civil Aviation Safety Authority (CASA), but they are designed to enforce adherence to the directive to prevent unsafe conditions in aviation operations. Additionally, operators found in breach of the directive may face operational restrictions or the grounding of affected aircraft until the required modifications are made. These stringent measures underscore the importance of complying with airworthiness directives to maintain high safety standards in the aviation industry.