AD/TFE 731/5 - Compressor Tie Rod - Replacement

Overview

The Civil Aviation Regulations 1998, under PART 39 - 106, addresses the issue of ensuring the airworthiness of specific turbine engines manufactured by AlliedSignal (Garrett/AiResearch) and specifically the TFE731 series. Enacted by the Australian Government, this legislation aims to fill a critical gap in aviation safety by providing clear directives for the maintenance and replacement of certain components of these engines. The objective is to mitigate potential risks associated with the use of suspect materials in the compressor tie rods, thereby enhancing overall aviation safety. The directive, AD/TFE731/5, mandates the replacement of these tie rods within specified timeframes to ensure continued compliance with airworthiness standards. This legislative instrument, issued by the Civil Aviation Safety Authority, is a response to notifications from the engine manufacturer regarding the use of potentially flawed materials during engine production or overhaul processes.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, includes a schedule of airworthiness directives that govern the maintenance and safety standards of aircraft engines operating within Australia. One such directive, AD/TFE731/5, pertains to the AlliedSignal (Garrett/AiResearch) Turbine Engines of the TFE731 series. This directive applies to specific models of these engines, including the TFE731-2-1C, -2-2B, -3-1E, -3-1G, -3-1F, -3-1C, -3-1H, -2-2J, and -3-1K. The directive mandates the replacement or change of the compressor tie rod for certain serial numbers identified in the requirement document, AiResearch Alert SB No. TFE731-A72-3140, or AD/AIR-T/37. The requirement necessitates compliance with strict timelines, with part 1 mandating action within 100 hours of time in service after 30 September 1980 for engines with specific serial numbers, while part 2 requires action at the next hot end inspection or next access to the area for another purpose for other applicable models. The directive ensures the safety and airworthiness of these engines by addressing potential issues arising from the use of suspect materials in the manufacture or overhaul of the compressor tie rods.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 106, include a schedule of airworthiness directives which cover the maintenance and safety of various aircraft components. In this context, AD/TFE731/5 pertains to the compressor tie rod of AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series. The directive mandates the replacement of the compressor tie rod for specified engine models (section 3/86). These include TFE731-2-1C, -2-2B, -3-1E, -3-1G, -3-1F, -3-1C, -3-1H, -2-2J, and -3-1K models. The directive references AiResearch Alert SB No. TFE731-A72-3140, or AD/AIR-T/37, as the requirement document. According to Part 1 of the directive, engines with serial numbers listed in paragraph "D" of the requirement document must have their compressor tie rod changed. For engines not listed in paragraph "D", any compressor tie rod of a serial number listed under the "Special Category" in paragraph "D" must be replaced (Part 2). Compliance with these directives is critical to ensure the airworthiness of the aircraft. Entities governed by this directive, such as aircraft operators and maintenance service providers, are required to adhere to the specified timelines and procedures. For engines listed in Part 1, the replacement must occur within 100 hours of time in service after 30 September 1980. For engines covered under Part 2, the replacement must be conducted at the next hot end inspection or at the next opportunity to access the area for another purpose, whichever comes first. This obligation ensures that the identified safety issue is addressed promptly and effectively. Failure to comply with these directives may result in non-compliance with the Civil Aviation Regulations, which could lead to operational restrictions or grounding of the affected aircraft until the required actions are taken. Breach of the requirements outlined in the airworthiness directive can lead to serious consequences. The Civil Aviation Safety Authority (CASA) may impose penalties for non-compliance, which can include fines and other administrative sanctions. In extreme cases, the continued operation of an aircraft with non-compliant components can result in criminal charges, particularly if such non-compliance leads to an accident or incident. The maximum penalties for such offences can be significant, reflecting the importance of adhering to safety directives to protect the public and maintain the integrity of the aviation system. It is imperative for all parties involved to ensure strict compliance to avoid these adverse outcomes.