COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series
AD/TFE731/17 L.P. Turbine Third Stage Rotor Disc 7/89 DM
Applicability: TFE 731 series engines which may have suspect L.P. turbine third stage rotor disc part number 3074756-1/-2 whose serial numbers are listed in the Requirement document.
Requirement: Remove from service specific serial numbered L.P. turbine third stage rotor disc P/N 3074756-1/-2 (part of rotor assy P/N 3074757-1) whose serial numbers are listed in Table 1 of Allied Signals (Garrett) S.B. TFE 731-72-3387.
Compliance: Unless already accomplished, within 100 hours time in service after 10 May 1989. Background: The manufacturer, in Service Bulletin TFE 731-72-3387, has advised that specific
S/No L.P. third stage turbine discs have been manufactured with the outside diameter
0.020 inch oversize. The inspection, rework and reidentification of oversize disc assemblies can be accomplished by fitting shorter blades. This Directive is issued to ensure that suspect assemblies are removed in a timely manner to prevent turbine failures occurring.
Overview
The Civil Aviation Regulations 1998, under Part 39, mandate specific airworthiness directives to ensure the safety of aviation operations. One such directive is AD/TFE731/17, which pertains to the AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series, specifically targeting the L.P. Turbine Third Stage Rotor Disc. This directive was enacted in response to an issue identified by the manufacturer in Service Bulletin TFE 731-72-3387, which noted that certain serial numbers of the L.P. third stage turbine discs had an outside diameter that was 0.020 inch oversize. The objective of this directive, issued by the Civil Aviation Safety Authority, is to ensure the timely removal from service of these suspect assemblies to prevent potential turbine failures. Compliance with this directive requires the removal of specific serial numbered discs within 100 hours of time in service after 10 May 1989.
Scope and Application
The AlliedSignal (Garrett/AiResearch) Turbine Engines - TFE731 Series AD/TFE731/17 L.P. Turbine Third Stage Rotor Disc applies to all TFE 731 series engines that may contain suspect L.P. turbine third stage rotor discs, specifically part number 3074756-1/-2, whose serial numbers are detailed in the requirement document. The regulation is issued under the Civil Aviation Regulations 1998, overseen by the Civil Aviation Safety Authority, and it falls within the scope of the Commonwealth of Australia's jurisdiction. The requirement mandates the removal from service of specific serial-numbered L.P. turbine third stage rotor discs whose serial numbers are listed in Table 1 of Allied Signal's (Garrett) Service Bulletin TFE 731-72-3387. Compliance is necessary within 100 hours of time in service after 10 May 1989, unless the action has already been completed. The directive aims to ensure that suspect assemblies are removed in a timely manner to prevent turbine failures, aligning with the safety standards established by the Civil Aviation Safety Authority.
Key Provisions
The Civil Aviation Regulations 1998, particularly Part 39, Section 106, include a schedule of airworthiness directives that mandate specific requirements for certain aircraft engines. One such directive, AD/TFE731/17, pertains to the AlliedSignal (Garrett/AiResearch) Turbine Engines of the TFE731 series, specifically targeting the L.P. turbine third stage rotor disc (section 1). The directive requires the removal from service of specific serial numbered L.P. turbine third stage rotor discs P/N 3074756-1/-2, which are part of rotor assembly P/N 3074757-1, whose serial numbers are listed in Table 1 of Allied Signal's (Garrett) Service Bulletin TFE 731-72-3387 (section 2). This action is necessary as the manufacturer has advised that these particular serial number discs may have been manufactured with an outside diameter that is 0.020 inch oversize, potentially leading to turbine failures if not addressed.
The obligations imposed by this directive are straightforward but critical for safety. Operators of TFE 731 series engines must ensure that the specified L.P. turbine third stage rotor discs are identified, removed from service, and replaced or reworked as necessary (section 3). This process must be completed within 100 hours of time in service after 10 May 1989 unless it has already been accomplished. The directive underscores the importance of adhering to the manufacturer's recommendations to prevent potential failures.
Non-compliance with this airworthiness directive can lead to serious consequences. The Civil Aviation Safety Authority (CASA) can impose penalties on operators who fail to adhere to the requirements outlined in AD/TFE731/17. The penalties for not complying with an airworthiness directive can include fines and, in severe cases, the grounding of the aircraft until the required actions are taken. While specific penalties are not detailed in the directive itself, the overarching regulations under which this directive operates allow for significant financial penalties and other enforcement actions to ensure compliance and maintain safety standards.