AD/AL 250/33 - Fourth Stage Compressor Wheel - Retirement

Overview

The Civil Aviation Regulations 1998, as amended through the legislative instrument F2006B02250, address specific safety concerns related to the Allison Turbine Engines, particularly the 250 Series, by establishing Airworthiness Directives. This piece of legislation was enacted by the Parliament of the Commonwealth of Australia and is administered by the Civil Aviation Safety Authority (CASA). The primary objective of this regulation is to ensure the safety and reliability of aircraft operations by mandating the retirement of certain fourth stage compressor wheels in specified Allison Turbine Engines to mitigate potential risks associated with their continued use. The directive applies to all 250-C18 and 250-B15G series engines fitted with particular compressor wheels and requires compliance within a specified timeframe following the issuance of the directive.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 106, which pertains to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, governs the applicability and compliance requirements for Allison Turbine Engines of the 250 Series, focusing on the Fourth Stage Compressor Wheel. This regulation applies to all 250-C18 and 250-B15G series engines that are fitted with compressor wheels bearing the part numbers 6856754 or 6871444. The directive mandates compliance within 100 hours of time in service after 31 May 1979, as outlined in the Allison 250-C18 CSL-96 or the Allison B15G TP CSL-36 documents. The legislation's jurisdictional reach is Commonwealth-wide, affecting all aviation entities operating within Australia that use these specified engines. The directive does not specify exclusions or exemptions, but its application may be extended or restricted through subordinate instruments issued by the Civil Aviation Safety Authority.

Key Provisions

The primary sections of the Civil Aviation Regulations 1998 relevant to the Allison Turbine Engines - 250 Series are those under Part 39, specifically the Airworthiness Directives (ADs). Section 39.106 pertains to the schedule of airworthiness directives, which includes AD/AL 250/33 concerning the retirement of the Fourth Stage Compressor Wheel. This directive applies to all 250-C18 and 250-B15G series engines fitted with specific compressor wheels (P/N 6856754 or 6871444). Compliance is mandated within 100 hours of time in service after 31 May 1979, as referenced in the Allison 250-C18 CSL-96 or Allison B15G TP CSL-36 documents. The Act imposes several obligations and requirements on the parties governed by this legislation. Primarily, it mandates that the owners or operators of the specified Allison turbine engines must ensure that the Fourth Stage Compressor Wheel is retired within the specified timeframe. This involves adhering to the instructions provided in the Allison 250-C18 CSL-96 or Allison B15G TP CSL-36 documents, which detail the technical specifications and procedures for the retirement of the compressor wheels. Non-compliance with these directives can result in the engine being deemed non-airworthy, potentially leading to grounding of the aircraft until the directive is complied with. Failure to adhere to the provisions of AD/AL 250/33 can result in significant legal consequences. The Civil Aviation Regulations 1998 outline penalties for non-compliance with airworthiness directives. Specifically, breaches of these directives may be subject to administrative penalties, including fines. While the exact monetary penalties are not detailed in the provided excerpt, the potential consequences of non-compliance could include civil penalties under the Civil Aviation Act 1988, which can amount to substantial fines. Additionally, continued operation of a non-compliant aircraft could result in criminal charges, which may carry more severe penalties, including imprisonment.