AD/TPE 331/32 - Rear Turbine Bearing Oil Supply Tube Inspection/Replacement

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, address the critical need for stringent aviation safety standards. This legislation, administered by the Civil Aviation Safety Authority, aims to ensure that all aircraft operations meet high safety benchmarks to prevent incidents such as engine failure due to mechanical issues. Specifically, Part 39 - 106 of these regulations includes Airworthiness Directives that target particular engine models to mitigate risks. The Airworthiness Directive AD/TPE 331/32 pertains to the inspection and modification of the rear turbine bearing oil supply tube for AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series, addressing the problem of chafing that could lead to oil loss and subsequent engine failure. The directive mandates inspections and modifications to ensure the adequate clearance of the oil supply tube and compliance with specified British Aerospace standards, thereby directly supporting the overarching policy objective of maintaining aviation safety.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, addresses the Airworthiness Directives (AD) for various aircraft components, including the AlliedSignal (Garrett/AiResearch) Turbine Engines of the TPE 331 Series. This directive applies to specific Garrett Model engines that are equipped with a rear turbine oil supply tube part number 3102123-1 and are not compliant with British Aerospace Maintenance Order JM 7388 TPE 331-10UF-501H, -511H, -512H, -513H TPE 331-10UR-513H. The AD mandates an inspection for adequate clearance between the oil supply tube and the bleed air cooler as per British Aerospace Alert Service Bulletin SB 71-A-JM 7418 Part A. Furthermore, it requires a modification in accordance with the same alert bulletin Part B or Garrett Turbine Engine Company Service Bulletin TPE 331-79-0013, referencing AD/AIR-T/50. Compliance with Part 1, the inspection, must occur within 50 hours of time in service after 30 June 1984 and subsequently at intervals not exceeding 400 hours of time in service until the modification is made. Part 2, the modification, must be completed prior to 31 August 1984. It is noteworthy that for aircraft/engine combinations that incorporate British Aerospace Maintenance Order No. JM 7388, compliance with this directive is not applicable. This directive is aimed at preventing chafing of the oil supply tube, which could result in oil loss and consequent engine failure.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 106, sets forth the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, which include requirements for the maintenance and inspection of certain aircraft components to ensure they meet safety standards. The regulation in question here, AD/TPE 331/32, pertains to AlliedSignal (Garrett/AiResearch) Turbine Engines of the TPE 331 series. This directive mandates the inspection and potentially the replacement of the rear turbine bearing oil supply tube (Part No. 3102123-1) for certain Garrett Model engines, specifically TPE 331-10UF-501H, -511H, -512H, -513H and TPE 331-10UR-513H, which are not compliant with British Aerospace (BAe) Modification JM 7388 TPE 331-10UF-501H, -511H, -512H, -513H. In terms of compliance, the directive requires two main actions. First, the engine must be inspected for adequate clearance between the oil supply tube and the bleed air cooler as per BAe Alert SB 71-A-JM 7418 Part A. This inspection must occur within 50 hours of time in service after 30 June 1984 and then at intervals not exceeding 400 hours of time in service until the engine is modified. Second, the engine must be modified in accordance with BAe Alert SB 71-A-JM 7418 Part B, Garrett Turbine Engine Company SB TPE 331-79-0013, or AD/AIR-T/50, and this must be completed before 31 August 1984. For aircraft/engine combinations that incorporate BAe MOD No. JM 7388, compliance with this directive is not applicable. Operators and maintenance providers are obligated to ensure that the specified inspections and modifications are carried out on the Garrett Model engines within the stipulated timeframes. Failure to comply with these directives can lead to serious safety issues, such as chafing of the oil supply tube, which could result in loss of oil and subsequent engine failure. There are no explicit penalties mentioned in the regulation for non-compliance with these directives, but non-compliance could potentially result in enforcement actions by the Civil Aviation Safety Authority, which could include fines, suspension of airworthiness certificates, or other regulatory actions that could impact the operation of the aircraft. The safety implications of not adhering to these directives are significant, given the potential for engine failure that could lead to catastrophic outcomes.