COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Allison Turbine Engines - 250 Series
AD/AL 250/43
Amdt 3
Second Stage Turbine Nozzle 2/90
Applicability: Allison Model 250-C28B, C28C engines fitted with P/N 6898952 second stage turbine nozzles.
Requirement: Modify P/N 6898952 second stage turbine nozzles in accordance with Allison CEB- A-72-2044 Rev 4.
Note: FAA AD 89-23-12 refers.
Compliance: Prior to 31 March 1990. Background: This Directive has been amended to;
- Delete reference to CSL 2030 which has been cancelled by the manufacturer, and
2. Require compliance with the requirements of CEB-A-72-2044 Rev 4, and
3. Make reference to FAA AD 89-23-12.
The Amendment follows advice of another P/N 6898952 nozzle failure in service. Failure of the nozzle has resulted in uncontained second stage turbine wheel failure.
Overview
The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA) and overseen by the Australian Parliament, were enacted to ensure the safety and efficiency of civil aviation operations within the country. One particular legislative instrument, F2006B02255, pertains to airworthiness directives aimed at enhancing aircraft safety. This specific amendment, AD/AL 250/43 Amendment 3, addresses the modification of second stage turbine nozzles in Allison Model 250-C28B, C28C engines, following a reported instance of nozzle failure leading to an uncontained second stage turbine wheel failure. The policy objective is to mandate compliance with the updated technical specifications, CEB-A-72-2044 Rev 4, and to align with the Federal Aviation Administration's Advisory Directive 89-23-12, thereby ensuring the continued safety of aviation operations by mitigating risks associated with the identified component failure.
The legislative instrument, enacted to address critical safety concerns in civil aviation, particularly those related to engine components, requires all operators of Allison Model 250-C28B, C28C engines fitted with the specified second stage turbine nozzles to modify these components in accordance with the latest technical bulletin from Allison. The directive aims to prevent future failures and ensure that all aircraft meet stringent safety standards set by CASA. This amendment reflects a proactive approach to addressing safety issues by incorporating the most current engineering guidance and referencing relevant international directives to enhance the uniformity and effectiveness of safety measures across the industry.
Scope and Application
The Civil Aviation Regulations 1998, under the authority of the Civil Aviation Safety Authority, includes specific Airworthiness Directives that pertain to the safety and maintenance of aircraft engines. One such directive, AD/AL 250/43 Amendment 3, concerns Allison Model 250-C28B and C28C engines fitted with a particular second stage turbine nozzle, part number 6898952. This directive applies to any aircraft utilising these engine models and necessitates that the specified turbine nozzles be modified in accordance with Allison's CEB-A-72-2044 Rev 4 guidelines. The directive aims to mitigate the risk of uncontained second stage turbine wheel failure, a hazard identified through service incidents. Compliance with this directive is mandatory, with the requirement that modifications be completed prior to 31 March 1990, as referenced by FAA AD 89-23-12. This directive is part of a broader regulatory framework that ensures the safety and airworthiness of aircraft operating in Australia, overseen by the Civil Aviation Safety Authority.
Key Provisions
The Civil Aviation Regulations 1998, Part 39, specifically Section 106, includes an Airworthiness Directive (AD) concerning Allison Turbine Engines - 250 Series, AD/AL 250/43 Amendment 3. This AD pertains to the second stage turbine nozzle, particularly for Allison Model 250-C28B, C28C engines equipped with P/N 6898952 second stage turbine nozzles. The primary requirement (Section 106) mandates that these nozzles must be modified in accordance with Allison CEB-A-72-2044 Revision 4. The AD also references FAA AD 89-23-12, indicating alignment with Federal Aviation Administration directives. The directive applies to all engines that meet the specified model and nozzle criteria.
The obligations imposed by this AD on the parties and entities governed include ensuring that the specified modifications to the second stage turbine nozzles are completed prior to a specified date, in this case, before 31 March 1990. The directive removes reference to CSL 2030, a superseded part, and mandates adherence to the updated requirements of CEB-A-72-2044 Rev 4. This requirement ensures that the engines maintain their airworthiness and comply with safety standards set forth by the Civil Aviation Safety Authority (CASA) and the Federal Aviation Administration (FAA). Non-compliance with these directives could potentially lead to operational issues or safety risks.
Failure to comply with the requirements outlined in this AD could result in significant civil or criminal consequences. The severity of these consequences is underscored by the history of nozzle failures that have led to uncontained second stage turbine wheel failures. While the specific penalties are not detailed in the AD itself, the overarching Civil Aviation Regulations 1998 provide a framework under which CASA can impose fines and other penalties for non-compliance with airworthiness directives. Additionally, operational certification could be revoked for non-compliance, leading to significant operational disruptions and potential safety hazards.