COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Pratt and Whitney Turbine Engines - PW4000 Series
AD/PW4000/2 2nd Stage HPT Rotating Airseal 1/99
Applicability: PW4000 series engines.
Requirement: 1. Inspect 2nd stage high pressure turbine rotating airseals in accordance with Pratt and Whitney Alert Service Bulletins, PW4ENG A72-628, Rev. 1, and PW4G-100- A72-80, Rev. 1, as applicable.
2. Modify 2nd stage ring segments and vane clusters, and install improved 2nd stage high pressure turbine rotating seals in accordance with Pratt and Whitney Service Bulletins PW4ENG 72-636, PW4ENG 72-637, PW4G-10- 72-93, and PW4G-100- 72-94, as applicable.
Incorporation of these modifications and installation of an improved 2nd stage HPT rotating airseal constitutes terminating action for Requirement 1 of this Directive.
Note: FAA AD 98-19-03 also refers.
Compliance: 1. At each occasion the HPT is disassembled after the effective date of this Directive.
2. Within 6 years after the effective date of this Directive.
This Airworthiness Directive becomes effective on 28 January 1999.
Background: This Directive is prompted by reports of 2nd stage HPT rotating airseal cracking which could result in an uncontained engine failure and damage to an aircraft.
Overview
The Civil Aviation Regulations 1998, as amended by the Civil Aviation (Airworthiness) Regulations 1998, form a critical part of Australian aviation safety legislation. This legislative instrument, specifically addressing Pratt and Whitney Turbine Engines of the PW4000 series, was enacted to address significant safety concerns related to the 2nd stage high-pressure turbine rotating airseals. These safety directives aim to prevent potential engine failures that could lead to severe damage and accidents. The enactment of this regulation by the Australian Civil Aviation Safety Authority under the authority of the Civil Aviation Act 1988 seeks to ensure that airworthiness standards are met and maintained, thus enhancing the safety of civil aviation. The primary objective is to mitigate the risk of uncontained engine failure by mandating specific inspections and modifications of the turbine engines, thereby safeguarding the integrity and reliability of aircraft operations.
Scope and Application
The Civil Aviation Regulations 1998, specifically under PART 39 - 106, addresses the airworthiness of Pratt and Whitney Turbine Engines of the PW4000 series through the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives. This regulation applies to all PW4000 series engines used in aircraft operations within Australia. It mandates inspections and modifications of the 2nd stage high pressure turbine rotating airseals to prevent potential uncontained engine failures. The requirement necessitates adherence to specific Pratt and Whitney Alert and Service Bulletins for inspections, modifications, and installation of improved seals. The directive requires these actions to be undertaken at each occasion the high-pressure turbine is disassembled after the directive's effective date, and within six years of its enactment. The directive is enforceable under national regulations and is aimed at ensuring the safety and airworthiness of aircraft operating within Australia. The directive explicitly references similar regulations from the Federal Aviation Administration (FAA) for consistency and compliance with international safety standards.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 106, include an Airworthiness Directive (AD) pertaining to Pratt and Whitney Turbine Engines of the PW4000 series, issued by the Civil Aviation Safety Authority. This AD, identified as AD/PW4000/2, focuses on the 2nd stage high pressure turbine (HPT) rotating airseal. The directive applies to all PW4000 series engines and became effective on 28 January 1999. It mandates two primary actions: inspection and modification of the 2nd stage HPT rotating airseals.
According to the directive, the main requirements (Section 1) involve inspecting the 2nd stage HPT rotating airseals in line with Pratt and Whitney Alert Service Bulletins, PW4ENG A72-628, Rev. 1, and PW4G-100- A72-80, Rev. 1, as applicable. Additionally, it requires modifying the 2nd stage ring segments and vane clusters, and installing improved 2nd stage HPT rotating seals as specified in Pratt and Whitney Service Bulletins PW4ENG 72-636, PW4ENG 72-637, PW4G-10- 72-93, and PW4G-100- 72-94, again as applicable. The incorporation of these modifications and the installation of improved seals is considered the terminating action for Requirement 1 of this Directive.
The obligations imposed by the AD (Section 2) are twofold. Firstly, the inspections must occur at each occasion the HPT is disassembled after the effective date of this Directive. Secondly, the modifications and installation of improved seals must be completed within 6 years from the effective date of the Directive. This timeframe ensures that all applicable engines are brought into compliance within a reasonable period, mitigating potential safety risks.
Failure to comply with the AD (Section 3) could result in severe consequences. The directive addresses the critical nature of the required actions by referencing FAA AD 98-19-03, indicating that non-compliance may lead to uncontained engine failure and subsequent damage to an aircraft. While the specific penalties are not detailed within this excerpt of the Civil Aviation Regulations 1998, non-compliance with such directives can generally lead to enforcement actions, including fines and potential grounding of non-compliant aircraft. The severity of the potential consequences underscores the importance of adhering to the AD's stipulations to ensure aviation safety.