AD/B747/197 - Wing Centre Section Rear Spar Web

Overview

The Civil Aviation Regulations 1998, specifically Part 39, establish stringent safety standards for aircraft operations in Australia. This regulation was enacted by the Australian Government to ensure that civil aviation adheres to internationally recognised safety protocols, thereby addressing potential safety gaps in aircraft maintenance and operations. The Civil Aviation Safety Authority (CASA) administers these regulations to uphold the policy objective of ensuring the highest safety standards for air travel. One specific legislative instrument, AD/B747/197, focuses on the Boeing 747 series aeroplanes and mandates detailed visual inspections of the wing centre section rear spar web to prevent corrosion, which if undetected, could lead to severe structural issues and compromise flight safety. This directive became effective on 25 March 1999, following reports of corrosion in the specified area that could potentially result in fuel leakage and other critical failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to Boeing 747 series aeroplanes in line positions 1 through 816. The directive mandates a detailed visual inspection of the rear spar web of the wing centre section and adjacent bulkhead fittings at body station 1241 to detect any signs of corrosion. This inspection must be performed in accordance with Boeing Service Bulletin 747-57-2263, Revision 1 or 2, including Appendix A. If no corrosion is detected, a corrosion inhibitor must be applied as specified in the requirement document. Should corrosion be detected within specified limits, the affected area must be removed and a high-frequency eddy current inspection conducted to check for cracks, with any detected cracks requiring a Boeing approved repair before further flight. If the corrosion exceeds specified limits, a Boeing approved repair is mandated before any further flight. Compliance with these directives is required before 2 August 2000 for the initial inspection, with subsequent inspections to be conducted at intervals not exceeding two years. This Airworthiness Directive came into effect on 25 March 1999.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate detailed inspections and actions concerning the Boeing 747 series aircraft's wing centre section rear spar web. According to section (1), operators must perform a detailed visual inspection to detect any corrosion on the rear spar web of the wing centre section at body station 1241, as well as on the adjacent bulkhead fittings. This inspection must be carried out in accordance with Boeing Service Bulletin 747-57-2263, Revision 1 or 2, including Appendix A. If no corrosion is detected, operators are required to apply a corrosion inhibitor as outlined in the Requirement Document. Operators of the Boeing 747 series aircraft are obligated to adhere to stringent inspection and repair protocols as dictated by the Civil Aviation Regulations. Section (2) stipulates that if corrosion is detected and falls within specified limits, operators must remove the corrosion and conduct a high-frequency eddy current inspection to detect any cracks in the area of removed corrosion. If any cracks are found, a Boeing-approved repair must be performed before further flight. Regardless of the presence of cracks, the operators must also apply a corrosion inhibitor as per the Requirement Document. If the detected corrosion exceeds the specified limits, a Boeing-approved repair must be executed before any subsequent flight. Failure to comply with the provisions outlined in the Civil Aviation Regulations could result in significant legal and operational consequences. Section (3) implies that any non-compliance with the stipulated inspection and repair procedures could lead to civil or criminal penalties. Although the exact penalties are not specified in the legislative instrument, non-compliance with airworthiness directives generally results in enforcement actions by the Civil Aviation Safety Authority (CASA). This could include fines, suspension of the aircraft's certificate of airworthiness, or other regulatory measures that could disrupt airline operations and potentially endanger flight safety. The legislative instrument mandates a strict timeline for compliance. As per section (4), the initial inspection must be completed before 2 August 2000, with subsequent inspections conducted at intervals not exceeding two years. The Airworthiness Directive becomes effective from 25 March 1999, underscoring the urgency and importance of adhering to these safety protocols. The directive's background indicates that the Federal Aviation Administration (FAA) received reports of corrosion on the specified aircraft components, highlighting the critical need for these regulatory measures to prevent potential in-flight failures.