AD/APU/8 - Garrett APU Compressor Rotating Group

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to ensure the safety of air travel and to address gaps in the regulation of civil aviation within Australia. Specifically, Part 39 of these regulations, which includes AD/APU/8, targets the maintenance and safety of Auxiliary Power Units (APU) in aircraft. This directive was introduced to address the problem of rim separation in the dampening groove of the load compressor, which has led to severe unbalance and subsequent failures. The Garrett APU Compressor Rotating Group directive aims to prevent such incidents by requiring maintenance actions according to specified service bulletins, ensuring compliance by a specified deadline. The policy objective is to maintain the airworthiness of aircraft by implementing necessary safety measures to prevent potential catastrophic failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 107, applies to all aircraft operators and maintenance personnel within Australia and its territories, ensuring compliance with safety directives issued by the Civil Aviation Safety Authority (CASA). This regulation mandates adherence to Airworthiness Directives concerning auxiliary power units (APUs), particularly focusing on the Garrett APU Compressor Rotating Group. The directive applies to Garrett Model GTCP 36-300, -280[B] and -280[D] units installed on aircraft within the Australian jurisdiction. Compliance with Garrett Service Bulletins GTCP36-49-A6642 and GTCP36-49-A6653 is required, with actions to be completed by 30 September 1995. These measures are in response to incidents where rim separation in the dampening groove of the load compressor caused severe unbalance, leading to tieshaft failure and subsequent penetration of the aircraft firewall. The directive includes specific actions such as rework of the load and engine compressors and replacement of the compressor shaft, ensuring the safety and airworthiness of affected aircraft.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 107, outlines the Airworthiness Directives (AD) concerning auxiliary power units (APU) for certain Garrett models. Section AD/APU/8 addresses the Garrett APU Compressor Rotating Group, applicable to Garrett Model GTCP 36-300, -280[B], and -280[D]. The directive mandates action in accordance with Garrett Service Bulletins, with specific dates and references provided for each model (section 4/93). The directive notes that FAA AD 92-21-05 is related, and it sets a compliance deadline of 30 September 1995 (section A and B). Entities governed by this directive must adhere to the specific service bulletins provided, ensuring that the actions outlined are completed within the stipulated timeframe. This includes performing the necessary rework on the load and engine compressors, as well as replacing the compressor shaft as specified. These actions are necessary to mitigate the risk of rim separation in the dampening groove of the load compressor, which has previously led to severe unbalance, tieshaft failure, and subsequent penetration of the aircraft firewall (section 4/93). Failure to comply with the provisions of this directive can result in serious safety risks and non-compliance with aviation safety standards. The consequences for non-compliance are significant, as the directive is designed to address known safety issues that could lead to catastrophic failure during operation. The exact penalties for non-compliance are not specified within the directive itself but would typically involve enforcement actions by the Civil Aviation Safety Authority, potentially leading to fines, operational restrictions, or other regulatory penalties (section A and B). In summary, the directive under Part 39 - 107 of the Civil Aviation Regulations 1998 is crucial for ensuring the airworthiness of certain Garrett APU models. It requires specific actions to be taken by the relevant entities, with a strict compliance deadline. Non-compliance could have severe safety and regulatory repercussions, underscoring the importance of adhering to these directives.