AD/AL 250/58 Amdt 2 - Gearbox Assembly - PTO Helical Gearshaft Assembly - Replacement

Overview

The Civil Aviation Regulations 1998, as amended by the Legislative Instrument F2006B02269, addresses specific issues concerning the airworthiness of Allison Turbine Engines 250 Series. This regulation, enacted by the Australian Government, aims to ensure that all relevant aircraft engines maintain their airworthiness through compliance with specific directives. The amendment to Part 39 - 106, Schedule of Airworthiness Directives, particularly targets the Allison 250 Series engines, mandating the replacement of certain gearbox components to prevent potential failures due to shock loads or sudden stoppages. This legislative measure ensures that aircraft utilising these engines remain compliant with safety standards, thereby safeguarding the integrity and safety of civil aviation operations within Australia. The policy objective is clearly to enhance the safety and reliability of the specified aircraft engines through stringent compliance and maintenance directives.

Scope and Application

The Civil Aviation Regulations 1998, as detailed in Part 39 - 106 and the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, govern the airworthiness of aircraft and their components within Australia. Specifically, AD/AL 250/58 Amendment 2 pertains to Allison Turbine Engines - 250 Series, mandating the replacement of the gearbox assembly - PTO helical gearshaft assembly for certain engine models. This applies to all Model 250-C18, C20, C20B, C20F, B15G, B17, B17B, and B17C engines, with exceptions outlined in the requirement document. Compliance with this directive necessitates adherence to the requirement document's Paragraph E, particularly sub-paragraph 3, which mandates the immediate replacement of any superseded PTO shaft in the event of shockload or sudden stoppage as defined in Paragraphs 3.1 and 3.2. The directive's scope is limited to the specified engine models, and any exclusions are detailed within the requirement document itself. This regulation is applicable nationwide and extends to any aircraft operating within Australian airspace that uses the specified Allison Turbine Engines.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39, includes a schedule of Airworthiness Directives (ADs) aimed at ensuring the safety and airworthiness of aircraft and their components. One such directive is AD/AL 250/58 Amendment 2, which pertains to Allison Turbine Engines of the 250 Series (sections 106(1) and 106(2)). This directive mandates the replacement of the PTO (Power Take-Off) Helical Gearshaft Assembly in certain Allison 250 series engines, including models 250-C18, C20, C20B, C20F, B15G, B17, B17B, and B17C, with certain exceptions as outlined in the requirement document. The requirement (section 106(3)) stipulates that the affected engines must comply with the manufacturer's requirements as detailed in the Requirement Document Para E, specifically CEB-203, CEB-1150, TP CEB-71, and TP CEB-1126 Revision 7. The directive requires immediate replacement of the PTO shaft if it is superseded and in the event of shockload or sudden stoppage as defined in the requirement document (section 106(4)). This ensures that the gearbox assembly remains functional and safe for operation, mitigating the risk of mechanical failure. The obligations imposed by this directive fall on the operators and maintenance personnel of the affected aircraft. They are required to ensure that the specified engines are inspected and, if necessary, the PTO Helical Gearshaft Assembly replaced in accordance with the requirement document (section 106(5)). Compliance with this directive is crucial for maintaining the airworthiness of the aircraft and ensuring the safety of all persons on board. Non-compliance can lead to severe consequences, including the grounding of the aircraft until the required maintenance is performed. In the event of non-compliance with the AD/AL 250/58 Amendment 2, the Civil Aviation Safety Authority (CASA) has the authority to impose penalties. The specific penalties for breaches of airworthiness directives can vary, but they generally include fines, enforcement notices, or even the suspension or revocation of airworthiness certificates (section 106(6)). In severe cases, where non-compliance results in an accident or serious incident, the penalties can include significant financial penalties, imprisonment, or both. The exact penalties are determined based on the severity of the breach and the potential risk posed to aviation safety.