AD/AL 250/4 - Sixth Stage Compressor Blades - Modification

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, form the regulatory framework for civil aviation safety within the country. Among these regulations, Part 39 provides for the establishment of airworthiness directives aimed at ensuring that aircraft and their components meet safety standards. One such directive, AD/AL 250/4, pertains to the modification of sixth stage compressor blades for Allison Turbine Engines - 250 Series. This directive was introduced to address the problem of ensuring that specific models of the Allison 250 turbine engines maintain operational safety and reliability. The objective of AD/AL 250/4 is to mandate compliance with the Allison CEB No. 250 CEB-48 by requiring modifications before further flight after a specified date, in this case, 19 June 1968, to mitigate potential safety risks associated with the compressor blades in certain engine models.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39, establish the scope and application of Airworthiness Directives, including AD/AL 250/4, which pertains to Allison Turbine Engines - 250 Series. This legislation applies to all model 250-C18 engines fitted with compressor assemblies before serial number CAC 20873 and model 250-C18A engines with compressor assemblies before serial number CAC 20188. The directive mandates compliance before further flight after 19 June 1968, ensuring that these particular engine models meet specified safety standards. The Civil Aviation Safety Authority oversees the implementation of these directives to maintain airworthiness, thereby protecting the safety of air travel within Australia's jurisdiction. The application of these regulations extends nationally, as they are part of the Commonwealth's overarching framework for aviation safety. While the primary focus is on ensuring the safe operation of specified engine models, the regulations do not explicitly state any exclusions, exemptions, or thresholds beyond the scope defined. Subordinate instruments may further clarify or extend the application of these directives to ensure comprehensive compliance.

Key Provisions

The key provisions of the Civil Aviation Regulations 1998, specifically under Part 39 - 106 and the Schedule of Airworthiness Directives (AD/AL 250/4), focus on the maintenance and safety requirements for Allison Turbine Engines, particularly the 250 Series. Section 39.106(6) of the Regulations mandates that certain modifications must be made to the Sixth Stage Compressor Blades of the Allison Turbine Engine models 250-C18 and 250-C18A. This requirement applies to engines fitted with compressor assemblies prior to specific serial numbers: S/N CAC 20873 for model 250-C18 and S/N CAC 20188 for model 250-C18A. Compliance with these modifications is critical before any further flight operations can occur post the effective date of 19 June 1968. The obligations imposed by these regulations are significant for the entities and individuals involved with the maintenance and operation of the specified Allison Turbine Engines. Operators and maintenance personnel must ensure that the modifications to the Sixth Stage Compressor Blades are performed in accordance with the specifications outlined in Allison CEB No. 250 CEB-48. This includes verifying that the compressor assemblies meet the serial number criteria and that the modifications are correctly and thoroughly executed before the engine is allowed to fly again. Non-compliance with these directives can lead to severe operational and safety implications, potentially grounding the aircraft until the required modifications are completed. Failure to adhere to the provisions outlined in AD/AL 250/4 can result in serious consequences. Civil Aviation Safety Authority (CASA) has the authority to enforce these regulations, and non-compliance can lead to enforcement actions. The potential penalties for breaching these directives include substantial fines and, in severe cases, the possibility of criminal charges. The exact penalties can vary based on the severity and circumstances of the breach, but they are designed to ensure that all operators and maintenance personnel strictly adhere to the safety standards set forth in the Civil Aviation Regulations. The regulatory framework is designed to ensure that all stakeholders understand their obligations and the serious repercussions of non-compliance. By clearly outlining the required modifications and the stringent compliance deadlines, the regulations aim to prevent potential safety hazards associated with the operation of non-compliant engines. The enforcement provisions are a critical component of this regulatory structure, ensuring that the safety of air travel is not compromised by outdated or improperly maintained aircraft components.