AD/ALF/9 Amdt 1 - Third Stage Turbine Rotor Assembly

Overview

The Civil Aviation Regulations 1998, specifically within Part 39 - 106, address the safety concerns associated with certain AlliedSignal (Lycoming) Turbine Engines, namely the ALF502 and LF507 series. This regulation was enacted to ensure the safety of aviation operations by imposing specific airworthiness directives. The policy objective behind these regulations is to mitigate risks associated with identified defects in aircraft components, ensuring that such components are either repaired or replaced to maintain airworthiness standards. This directive was issued by the Civil Aviation Safety Authority, reflecting amendments to Requirement Documents which identify specific turbine rotor assemblies with manufacturing defects that could lead to serious safety issues, including engine damage due to blade release caused by disc tenon deformation. The directive mandates the removal from service of certain third stage turbine rotor assemblies that have been identified as having suspect heat treatment, as detailed in Lycoming Service Bulletins. The amendment to the directive was made to incorporate updates in the Requirement Documents, particularly Revision 1, which refines the lists of affected rotor assemblies. This ensures that all relevant parties are aware of the latest safety requirements and can take appropriate action to maintain the airworthiness of the aircraft involved. By enforcing these measures, the Civil Aviation Regulations 1998 aim to uphold the highest safety standards in the aviation industry, thereby protecting passengers, crew, and the general public from potential hazards arising from aviation incidents.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 106, mandates the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives which governs the airworthiness of certain aircraft engines. The particular directive AD/ALF/9 Amendment 1 pertains to AlliedSignal (Lycoming) turbine engines of the ALF502 and LF507 series, targeting the third stage turbine rotor assembly. This directive applies to ALF 502 L and R series engines with specific serial numbers identified in the Requirement Documents, necessitating the removal from service of third stage turbine rotor assemblies with part number 2-143-040-16 whose serial numbers are listed in Lycoming Service Bulletins No. A-ALF 502L-72-0189 Rev 1 and A-ALF 507R-72-0189 Rev 1. The directive is aimed at ensuring compliance by removing rotor assemblies identified with issues related to heat treatment, which may cause disc tenon deformation and lead to blade release and subsequent engine damage. The scope of this directive is strictly within the Commonwealth of Australia, enforced by the Civil Aviation Safety Authority, and applies to all entities operating within its jurisdiction that possess the specified turbine engines. There are no stated exclusions or exemptions within the text, and compliance must be achieved as per the detailed schedules provided in Section D of the relevant Requirement Documents. This directive extends its application through subordinate instruments to ensure comprehensive enforcement and adherence by all relevant parties.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 - 106, include a Schedule of Airworthiness Directives that address the safety of AlliedSignal (Lycoming) turbine engines, particularly the ALF502 and LF507 series. Within this schedule, AD/ALF/9 Amendment 1 pertains to the Third Stage Turbine Rotor Assembly, issued in November 1988, and concerns the removal from service of specific turbine rotor assemblies. According to section 11, the directive applies to ALF 502 L and R series engines with third stage turbine rotor assemblies whose serial numbers match those listed in Lycoming Service Bulletins No. A-ALF 502L-72-0189 Rev 1 and A-ALF 502R-72-0189 Rev 1. The directive mandates the removal of third stage turbine rotor assemblies with the part number 2-143-040-16, whose serial numbers are specified in the aforementioned service bulletins. This requirement aims to ensure the safety of the engines by addressing issues related to suspect heat treatment during the manufacturing process, which can lead to disc tenon deformation and subsequent blade release, causing engine damage. Entities governed by these regulations must adhere to specific obligations. They must ensure that the affected turbine rotor assemblies are removed from service in accordance with the schedules laid out in Section D of the relevant Requirement Document. This involves identifying the affected engines, sourcing the appropriate service bulletins, and verifying the serial numbers of the turbine rotor assemblies. Once identified, these assemblies must be removed and replaced according to the specified timelines and procedures outlined in the directive. Compliance with these obligations is crucial to maintain the airworthiness of the aircraft and to prevent potential safety hazards. Failure to comply with the provisions of this Airworthiness Directive can lead to serious consequences. The regulations do not explicitly state the specific offences or penalties for non-compliance, but non-compliance with airworthiness directives is generally treated as a serious breach of aviation safety standards. Potential consequences can include enforcement actions by the Civil Aviation Safety Authority (CASA), which may result in fines, penalties, or even the grounding of aircraft until the non-compliance issues are rectified. In severe cases, repeated or significant non-compliance could lead to legal action against the responsible parties, resulting in substantial financial penalties and reputational damage. Ensuring adherence to these directives is therefore critical for maintaining the safety and integrity of civil aviation operations.