AD/ALF/13 - Third Stage Compressor Disc Inspection

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA) and enacted by the Australian Parliament, were established to ensure the safety of civil aviation. Specifically, Part 39 - 106 of these regulations pertains to the Schedule of Airworthiness Directives, which are legally enforceable rules related to the design, production, and maintenance of aircraft and associated equipment. One such directive, AD/ALF/13, addresses the inspection of third-stage compressor discs in Textron-Lycoming ALF 502 L and R series engines to mitigate the risk of defective Sermetel W protective coating leading to corrosion and potential engine failure. This directive was introduced to address the identified problem of improper surface preparation that can cause the protective coating on the compressor discs to fail, thereby necessitating regular inspections to maintain airworthiness and ensure flight safety. The policy objective of AD/ALF/13 is to ensure the continued airworthiness of affected engines by mandating inspections of the 3rd stage compressor discs. Compliance with this directive is mandatory, with the requirement to inspect the discs in accordance with Textron-Lycoming Service Bulletins ALF 502L 72-259 or ALF 502R 72-259, as applicable. The directive became effective on 1 January 1994, aligning with the stringent safety standards set forth by CASA to protect the integrity of civil aviation operations in Australia.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, issued by the Civil Aviation Safety Authority, applies to all Textron-Lycoming ALF 502 L and R series engines that incorporate 3rd stage compressor discs as detailed in the Requirement documents. This regulation mandates that these particular engine components undergo inspection in compliance with Textron-Lycoming Service Bulletins ALF 502L 72-259 or ALF 502R 72-259, as applicable. The requirement stems from identified issues with the Sermetel W protective coating on the 3rd stage compressor discs, which may be defective due to improper surface preparation, leading to potential flaking, corrosion, and disc failure. The regulation is effective from 1 January 1994 and references FAA AD 93-10-07 for further compliance guidelines. The geographic and jurisdictional reach of this regulation is national, applying across the Commonwealth of Australia, ensuring that all affected engines within the country adhere to these safety directives. There are no stated exclusions or exemptions within the text, and compliance is expected without deviation.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39, include detailed directives related to airworthiness and engine safety, notably in Section 106 which pertains to the Schedule of Airworthiness Directives (ADs). The AD/ALF/13 addresses inspections for AlliedSignal (Lycoming) Turbine Engines - ALF 502 and LF 507 Series, focusing on the third stage compressor disc (Section 13/93). This directive applies to all Textron-Lycoming ALF 502 L and R series engines that include third stage compressor discs as specified in the requirement documents (Section 13/93). The requirement is to inspect these compressor discs in accordance with Textron-Lycoming Service Bulletins ALF 502L 72-259 or ALF 502R 72-259, as applicable (Section 13/93). Entities and parties governed by this legislation must adhere to the outlined inspection procedures to ensure compliance with the directive. This includes following the specific guidelines set forth in the Textron-Lycoming Service Bulletins, ensuring that the inspection process is thorough and meets the standards required to prevent potential disc failure (Section 13/93). The compliance date for these inspections is set at 1 January 1994, and the details for the inspection are to be found in the requirement documents (Section 13/93). The directive references FAA AD 93-10-07, indicating a coordinated effort between Australian and U.S. aviation authorities to address this safety concern. Failure to comply with the AD/ALF/13 directive could result in significant safety risks. The background of the directive highlights that defective Sermetel W protective coating on the third stage compressor discs can lead to adhesion issues, flaking, corrosion, and potential disc failure (Section 13/93). The consequences of not adhering to the inspection requirements could include severe safety incidents, potentially leading to both civil and criminal liabilities. The specific penalties for non-compliance are not detailed in this excerpt, but it is implied that such non-compliance could result in enforcement actions, fines, or other regulatory penalties as prescribed by the Civil Aviation Regulations.