Overview

The Civil Aviation Regulations 1998, amended through the legislative instrument F2006B03125, introduce an Airworthiness Directive concerning Boeing 747 Series Aeroplanes. This legislation was enacted to address safety concerns related to the partial deployment of deactivated thrust reversers during landing, which can compromise the controllability of the aircraft. The Civil Aviation Safety Authority (CASA), acting through its delegate, issued this directive under the authority conferred by the Civil Aviation Act 1988. The directive mandates specific actions, including the replacement of thrust reverser components, to prevent potential failures that could lead to in-flight deployment of the thrust reversers. The policy objective is to ensure the continued airworthiness and safety of Boeing 747-400 series aircraft powered by PW4000 series engines, thereby enhancing overall aviation safety standards.

Scope and Application

This Airworthiness Directive, issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998, applies specifically to Boeing 747-400 series aircraft powered by PW4000 series engines. The directive mandates the replacement of certain components in the aircraft’s thrust reverser system to mitigate the risk of partial deployment during landing, which could potentially lead to a reduction in the aircraft's controllability if it were to occur in-flight. The required action involves replacing the deactivation pin, pin bushing in the aft cascade mounting ring, and insert flange on each thrust reverser half with new improved components as outlined in Boeing Alert Service Bulletin 747-78A2165 Revision 1 dated May 13, 1999. This action must be completed within 18 months from the effective date of the Airworthiness Directive, which is 15 June 2000. This directive applies across the Commonwealth of Australia and is enforceable under the authority of the Civil Aviation Regulations.

Key Provisions

The Airworthiness Directive (AD) B747/225 issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 (CAR 1998) applies to Boeing 747-400 series aircraft powered by PW4000 series engines. The directive mandates that the deactivation pin, pin bushing in the aft cascade mounting ring, and insert flange on each thrust reverser half must be replaced with new improved components, in accordance with Boeing Alert Service Bulletin 747-78A2165 Revision 1 dated May 13, 1999. This action is required to address instances where the thrust reversers have partially deployed during landing, which could lead to in-flight deployment and reduced controllability of the aircraft. The directive became effective on 15 June 2000, and compliance must be achieved within 18 months from this effective date. Operators of the affected Boeing 747-400 series aircraft must ensure that the specified components of the thrust reversers are replaced with the improved parts detailed in the referenced Boeing Alert Service Bulletin. This involves identifying the aircraft within the scope of this AD and scheduling the necessary maintenance actions to complete the required replacements. Operators need to document and certify that the modifications have been carried out in accordance with the AD, maintaining records to demonstrate compliance with the regulatory requirements. Failure to comply with the AD may result in the aircraft not meeting the necessary airworthiness standards. This could lead to regulatory enforcement actions, including the potential for the aircraft to be grounded until the required modifications are completed. The AD also references FAA AD 99-26-02 Amdt 39-11462, indicating that non-compliance with this directive could have broader implications, particularly if the aircraft is operated across jurisdictions that enforce similar regulations. Non-compliance may also result in civil penalties, including fines, and in more severe cases, criminal charges could be pursued against the operators or responsible parties. The AD specifies that compliance must be achieved within 18 months from the effective date of 15 June 2000. Failure to meet this deadline may result in regulatory penalties, and the aircraft may be deemed non-airworthy. The Civil Aviation Safety Authority (CASA) has the authority to enforce compliance, and operators are expected to take proactive measures to ensure adherence to the directive. The directive was published in the Commonwealth of Australia Gazette on 17 May 2000, providing official notification to all relevant parties of the new requirements and compliance timelines.