Overview

The Airworthiness Directive (AD) issued on 25 May 2002 by the Civil Aviation Safety Authority (CASA) under subregulation 39.1(1) of the Civil Aviation Regulations 1998 (CAR 1998) addresses the identified latent failure of the thrust reverser system in Boeing 747 series aeroplanes with General Electric CF6-80C2 series engines. The directive, which became effective on 5 June 2002, aims to ensure the integrity of the fail-safe features of the thrust reverser system by preventing possible failure modes that could result in inadvertent deployment of the thrust reverser in-flight. This AD is applicable to all Boeing 747 series aeroplanes equipped with specified engines and requires the functional testing and repair of the Directional Pilot Valve (DPV) of the thrust reversers, in accordance with Boeing Service Bulletin (SB) 747-78-2151 or its production equivalent. The policy objective of this directive is to ensure the safety of air travel by mitigating the risk of thrust reverser malfunctions.

Scope and Application

This Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) applies to all Model 747 series aeroplanes equipped with General Electric CF6-80C2 series engines. The AD mandates specific actions to be taken to address potential safety issues associated with the thrust reverser Directional Pilot Valve (DPV). The directive applies to both unmodified aeroplanes and those modified in accordance with Boeing Service Bulletin (SB) 747-78-2151 or its production equivalent. The requirement section outlines several functional tests and repairs that need to be conducted to ensure the DPV operates correctly and does not pose a risk of in-flight thrust reverser deployment. The compliance section specifies the timeframes within which these requirements must be met, such as within 30 or 60 days of the AD's effective date, and at intervals not exceeding 1,000 or 6,000 flight hours. The AD does not explicitly state any exclusions, exemptions, or thresholds, but it allows for production equivalent functional tests to be considered equivalent to the initial tests specified in the directive. The AD becomes effective on 5 June 2002, as published in the Commonwealth of Australia Gazette.

Key Provisions

The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of CAR 1998 applies specifically to Boeing 747 series aeroplanes equipped with General Electric CF6-80C2 series engines. The directive mandates a series of functional tests and potential repairs to the thrust reverser Directional Pilot Valve (DPV) to ensure the detection and prevention of pneumatic leakage. For unmodified aeroplanes, a functional test must be performed to detect pneumatic leakage in accordance with Boeing Alert SB 747-78A2170 dated 21 October 1999, and if any discrepancies are detected, repairs must be made as per the Aircraft Maintenance Manual (Requirement 1). This test must be repeated within 30 days of the directive's effective date (Requirement 2). For aeroplanes that have been modified according to Boeing Service Bulletin (SB) 747-78-2151 or a production equivalent, a functional test must be conducted and successfully completed to detect pneumatic leakage, followed by the repetition of this test within 60 days of the directive's effective date (Requirement 3). If any functional test cannot be successfully carried out or if discrepancies are detected, repairs must be made before further flight (Requirement 4). Any previously detected discrepancies that have been corrected must be followed by a repeat of Requirement 1 functional tests before further flight (Requirement 5). The AD imposes several obligations on the parties it governs. Primarily, it requires operators and maintenance personnel to conduct thorough functional tests on the thrust reverser DPV to ensure there is no pneumatic leakage. This is crucial for the safety and airworthiness of the aircraft. Operators must ensure that these tests are performed within the specified timeframes: within 30 days for unmodified aeroplanes and within 60 days for those modified in accordance with Boeing SB 747-78-2151 or production equivalent. Additionally, any detected discrepancies must be repaired before the aircraft can be returned to service. Functional tests must be repeated at intervals not exceeding 1,000 flight hours and 6,000 flight hours as stipulated. Any repairs carried out under Requirement 4 must be completed before further flight, and Requirement 1 functional tests must be repeated prior to subsequent flights if any discrepancies have been corrected. Failure to comply with the AD can result in severe consequences. While the specific penalties are not detailed in the text, non-compliance with ADs generally can lead to severe civil and criminal penalties under the Civil Aviation Act 1988 and Civil Aviation Regulations 1988. Civil penalties can include substantial fines, and criminal penalties can include imprisonment, reflecting the seriousness with which regulatory authorities treat non-compliance with airworthiness directives. Non-compliance can also result in the grounding of the affected aircraft until the necessary actions are taken, potentially leading to significant operational disruptions and financial losses for the operators.