AD/PT6T/9 - Reduced 2nd and 3rd Stage Compressor Disc Lives

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, establish comprehensive safety standards for civil aviation within Australia. Among these, Part 39, specifically dealing with airworthiness directives, aims to ensure that aircraft and their components meet necessary safety standards to prevent accidents and incidents. One such directive, AD/PT6T/9, addresses a critical safety concern identified in Pratt and Whitney Canada's PT6T series turbine engines. This directive was introduced in response to potential issues with certain second and third stage compressor discs, which may have been contaminated with tungsten inclusions during production, necessitating their removal and inspection to ensure compliance with safety standards. The policy objective is to maintain the highest level of safety in civil aviation by enforcing stringent checks and maintenance procedures as recommended by the manufacturer.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, applies to all PT6T series engines and spare compressor discs identified by serial number in Pratt and Whitney Canada Service Bulletin No. 5266. The directive mandates actions as outlined in the aforementioned service bulletin. The regulation applies to entities involved in the operation and maintenance of PT6T series engines within Australia and is governed under the Commonwealth jurisdiction. Compliance with this directive is essential and was made effective from 30 April 1992. The requirement is rooted in the necessity to ensure safety by removing and inspecting specified compressor discs for potential contamination with tungsten inclusions, as advised by the manufacturer. The directive ensures that the engines meet the necessary safety standards to prevent any operational hazards. Subordinate instruments may further define or extend the application of these directives to ensure comprehensive adherence to safety protocols.

Key Provisions

The primary sections of the Civil Aviation Regulations 1998, particularly Part 39 - 106, mandate specific actions regarding the Pratt and Whitney Canada Turbine Engines, specifically the PT6T Series, under the Airworthiness Directive AD/PT6T/9. This directive, identified as AD/PT6T/9, pertains to the reduced service lives of the second and third stage compressor discs, as outlined in Pratt and Whitney Canada Service Bulletin No. 5266 dated 5/92. The directive applies to all PT6T series engines and spare compressor discs listed by serial number in the aforementioned service bulletin (Sections 39-106(1) and 39-106(2)). In accordance with this directive, all PT6T series engines must undergo specific actions as per the requirements set forth in Pratt and Whitney Canada Service Bulletin No. 5266. This includes the removal from service and subsequent X-ray inspection of certain second and third stage compressor discs. These actions are necessary to ensure the safety and airworthiness of the aircraft using these engines. Compliance with this directive is mandatory, with an effective date of 30 April 1992 (Section 39-106(3)). The detailed procedures for compliance are outlined in the requirement document provided by Pratt and Whitney Canada (Section 39-106(4)). The obligations imposed by this directive are clear and precise. Operators and owners of PT6T series engines must ensure that the specified compressor discs are removed from service and inspected according to the manufacturer’s guidelines. These obligations include adhering to the serial numbers listed in the service bulletin, conducting thorough inspections, and ensuring that any identified issues are rectified before the engine is returned to service. Failure to comply with these obligations could result in the aircraft being deemed unairworthy, leading to potential grounding and significant operational disruptions (Section 39-106(5)). Failure to comply with the directives and requirements set forth in the Civil Aviation Regulations 1998 can result in severe consequences. Any breach of these regulations could be considered an offence under the Civil Aviation Act 1988, leading to potential criminal charges. Additionally, the operator or owner of the non-compliant aircraft may face substantial civil penalties. The maximum penalties for non-compliance can include fines and imprisonment, depending on the severity of the breach. Ensuring strict adherence to the regulations is therefore paramount to avoid these legal and financial repercussions (Section 39-106(6) and Civil Aviation Act 1988).