AD/B767/112 - MLG Beam Outboard Support Fuse Pins

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to regulate civil aviation safety in Australia, ensuring compliance with international standards and the safe operation of aircraft. One of the key pieces of legislation under this regulation is PART 39 - 105, which includes a schedule of airworthiness directives specifically addressing the maintenance and safety of aircraft. One such directive, AD/B767/112, was introduced to address a significant safety issue identified in Boeing 767 series aircraft. This particular directive mandates the replacement of 4330M steel fuse pins in the outboard support of the main landing gear beam with 15-5PH CRES fuse pins, following reports of corrosion that could potentially lead to catastrophic failure during landing. The objective of this directive is to mitigate the risk of landing gear collapse by ensuring the structural integrity of the fuse pins, thus enhancing the overall safety of the aircraft. The directive became effective on 12 August 1999, and compliance is required as specified in the requirement document, with a revised effective date to ensure timely implementation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate the application of Airworthiness Directives issued by the Civil Aviation Safety Authority, and this particular regulation applies to Boeing 767 series aeroplanes, specifically line numbers 1 through 609, that are equipped with 4330M steel fuse pins in the outboard support of the main landing gear (MLG) beam. This directive is designed to ensure the continued airworthiness of these aircraft by addressing the risk of corrosion or chrome plating cracks on the fuse pins, which could potentially lead to a failure of the fuse pin and subsequent collapse of the landing gear. The requirement is for compliance with the technical specifications outlined in FAA AD 99-11-14 Amdt 39-11185, with an effective date set for 12 August 1999. Notably, the installation of newer-type 15-5PH CRES fuse pins, as specified in Boeing Alert Service Bulletin 767-57A0054 Revision 2 or Revision 3, is recognised as completing the necessary action for terminating the repetitive inspection requirements stipulated by this directive. The regulation applies nationally across Australia, overseen by the Commonwealth, ensuring that all relevant aircraft operators adhere to the specified safety measures.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, include an Airworthiness Directive (AD) concerning Boeing 767 series aeroplanes. This AD, numbered AD/B767/112, pertains to the main landing gear (MLG) beam outboard support fuse pins (section 1). The directive applies to Model 767 series aircraft, line numbers 1 through 609, which are equipped with 4330M steel fuse pins in the outboard support of the MLG beam (section 2). This AD mandates compliance with the technical requirements outlined in FAA AD 99-11-14 Amendment 39-11185 (section 3). Operators of Boeing 767 series aircraft must ensure that the specified fuse pins meet these technical requirements to maintain airworthiness. The directive also notes that installing newer-type 15-5PH CRES fuse pins, as per Boeing Alert Service Bulletin 767-57A0054 Revision 2 or Revision 3, can satisfy the repetitive inspection requirements of this directive (section 4). Compliance with this AD involves adhering to the initial and repetitive inspection requirements detailed in the Requirement Document, with an effective date of 12 August 1999. Operators must ensure their maintenance and inspection schedules are updated to reflect these compliance requirements. The AD itself becomes effective on the same date, mandating that all specified actions are completed by this time (section 5). The AD addresses a critical safety issue: corrosion or cracks in the chrome plating of the fuse pins can lead to the failure of these pins, resulting in a potential collapse of the landing gear. The directive's background highlights the importance of these measures by noting a report of corrosion on a fuse pin in the outboard support of the MLG beam, underscoring the necessity of these safety regulations (section 6). Failure to comply with the AD could result in serious safety risks and potential regulatory consequences.