AD/B747/175 Amdt 1 - Door Switch Replacement

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the critical safety concerns associated with the Boeing 747 series aeroplanes through the introduction of airworthiness directives. This legislative instrument was enacted to ensure the safety of civil aviation by mandating specific actions to mitigate risks identified in the aircraft's design and components. The Civil Aviation Safety Authority, acting under the authority of the Australian Parliament, issued this directive to address the problem of internal failures in specific cabin switches which could lead to short circuits, smoke, and fires. The policy objective is to prevent the installation and use of defective switches to ensure the continued airworthiness and safety of the Boeing 747 aeroplanes. This airworthiness directive, as amended, requires the replacement of certain switches in the cabin attendant's panel at specific doors to prevent potential fire hazards. The directive applies to all B747-100, -200, and -300 series aeroplanes and mandates compliance by specific dates. The directive references procedures detailed in Boeing Alert Service Bulletin 747-33A2252 Revision 2, emphasising the importance of following precise installation procedures to avoid the installation of faulty switches. The directive was introduced to respond to reports of fires caused by switch failures, thereby reinforcing the commitment to maintaining the highest safety standards in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses airworthiness directives for various aircraft, with the Boeing 747 series being a notable focus. This particular legislative instrument mandates a door switch replacement for all Boeing 747-100, -200, and -300 series aeroplanes, as referenced in Boeing Alert Service Bulletin (ASB) 747-33A2252 Revision 2 dated 4 December 1997. The directive applies to any switches identified in the bulletin and aims to replace or prohibit the installation of certain switches to mitigate the risk of fires resulting from internal failures. The directive applies nationally, under the purview of the Commonwealth of Australia, and compliance is mandatory with specific deadlines outlined in the document. The regulation does not explicitly mention any exclusions, exemptions, or thresholds, but compliance is strictly enforced to ensure the safety of air travel. The directive has been amended to include clearer procedures and references, as evidenced by FAA AD 97-08-05 Amdt 39-9993, underscoring the importance of adhering to the specified requirements.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, which pertains to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, include detailed safety requirements for specific aircraft types. For Boeing 747 series aeroplanes, Amendment 1 to Airworthiness Directive AD/B747/175 mandates the replacement of certain switches installed in the cabin attendant’s panel at Doors 4 right and 2 right (section 1). The directive explicitly states that switches identified in Boeing Alert Service Bulletin (ASB) 747-33A2252 Revision 2, particularly those listed in the 'Old Switch' column, must not be installed at these locations (section 2). Compliance with this directive is crucial for all B747-100, -200, and -300 series aeroplanes as identified in the bulletin dated 4 December 1997. The directive was amended to update the Boeing Service Bulletin reference and to detail the procedure for Door 2 Right, ensuring comprehensive safety measures. Operators and entities governed by these regulations are required to adhere to the specific timelines and procedures outlined in the Airworthiness Directive. Specifically, compliance must be achieved by 26 April 1998 for actions taken prior to 26 March 1998, with the directive becoming effective from 26 March 1998 (section Compliance). This includes replacing the specified switches with new items in accordance with Boeing ASB 747-33A2252 Revision 2. The directive is a direct response to reports of fires caused by internal failures of these switches, which can lead to short circuits, smoke, and fire on board the aircraft. By following these requirements, operators help to mitigate the risk of such incidents. Failure to comply with the Civil Aviation Regulations and the specific airworthiness directives can result in serious legal and safety consequences. The Civil Aviation Safety Authority has the authority to enforce compliance, and non-compliance can lead to severe penalties. While the specific penalties are not detailed in the provided text, the seriousness of the directive suggests that penalties for non-compliance could include fines, suspension or revocation of airworthiness certificates, and potential criminal charges in cases where negligence leads to harm. These measures are in place to ensure that aircraft maintain the highest safety standards and to protect passengers and crew from potential hazards.