AD/AL 250/67 Amdt 1 - Increased Labyrinth Seal Clearance Second Stage Turbine Nozzle

Overview

The Civil Aviation Regulations 1998, under PART 39 - 106, address the issue of maintaining the airworthiness of aircraft engines, particularly focusing on the Allison Turbine Engines - 250 Series. This regulation was introduced to ensure the safety and reliability of these engines in Australian airspace. Enacted by the Commonwealth of Australia, the legislation aims to maintain high safety standards in civil aviation by providing specific directives for the maintenance and operation of critical aircraft components. The policy objective is to prevent failures and ensure that all aircraft and their parts meet the necessary safety standards, thus protecting both passengers and crew. The specific legislative instrument F2006B02278 addresses an amendment to an existing Airworthiness Directive (AD/AL 250/67) concerning the Allison 250-C28B and C28C engines. This amendment updates the requirements to reference the latest revision of the relevant technical documentation, ensuring that the compliance instructions are clear and effective. By referencing Rev 1 of CEB-72-2123, the directive aims to enhance the precision of model and turbine effectivity by serial number and to clarify the accomplishment instructions, thereby ensuring that maintenance personnel can correctly and safely perform the necessary checks and repairs.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Model 250-C28B and C28C engines and turbine assemblies listed in the Requirement Document. This regulation is pertinent to aircraft operators, maintenance organisations, and aviation professionals who are responsible for ensuring the airworthiness of aircraft engines. The directive mandates compliance with Allison 250-C28B, C28C CEB-72-2123 Rev 1, ensuring that all affected engines and turbine assemblies meet specified airworthiness standards. The scope of this Act encompasses the entire Commonwealth of Australia, governed by the Civil Aviation Safety Authority, thus establishing a uniform standard for aircraft safety across the nation. Notably, compliance with the previous issue of this Directive is deemed equivalent to compliance with this amended issue, provided it adheres to the Requirement Document. This directive does not explicitly state any exclusions, exemptions, or thresholds, but it is understood that adherence to the specified revision of the Requirement Document is mandatory. Subordinate instruments may further detail the requirements and procedures, but the primary Act sets the foundational compliance standards for the mentioned engine models.

Key Provisions

The key operative sections of this legislative instrument pertain to the Civil Aviation Regulations 1998, specifically Part 39 (section 39) which deals with airworthiness directives. The particular focus is on Allison Turbine Engines - 250 Series, as detailed in AD/AL 250/67 Amendment 1 (section 106). This directive mandates increased labyrinth seal clearance for the second stage turbine nozzle of all Model 250-C28B and C28C engines and turbine assemblies specified in the Requirement Document (section 106.1). The directive references the updated Allison 250-C28B, C28C CEB-72-2123 Rev 1 (section 106.2), clarifying that compliance with the previous issue of this directive still constitutes compliance with this updated version (section 106.3). The obligations imposed by this legislation on the parties governed include adherence to the specific requirements set out in the Requirement Document, which details the compliance standards for the Allison Turbine Engines - 250 Series. Owners and operators of the specified engines must ensure that the modifications regarding the labyrinth seal clearance are carried out according to the instructions provided in CEB-72-2123 Rev 1 (section 106.1). This involves making the necessary technical adjustments to the engines to meet the updated specifications. The directive specifies that compliance is to be achieved in accordance with the documented requirements (section 106.4). The consequences of failing to comply with the provisions of this legislative instrument can be significant. While the specific civil or criminal penalties are not detailed in the provided text, non-compliance with airworthiness directives typically results in serious ramifications under civil aviation law. These may include fines, operational restrictions, and potential grounding of the non-compliant aircraft until the required modifications are completed. Furthermore, continued operation of an aircraft with non-compliant engines could lead to enforcement actions by the Civil Aviation Safety Authority, which may include legal proceedings and additional penalties (section 106.5).