COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/70
Amdt 2
Nacelles/Pylons - Diagonal Brace Lugs 2/99
Applicability: Model 747 series aircraft with line positions 1 through 1046; equipped with Pratt & Whitney JT9D series engines, General Electric Model CF6-45 and -50 series engines, or Rolls Royce Model RB211 series engines; excluding those aircraft on which modifications of the strut/wing structure have been accomplished in accordance with FAA AD 95-10-16 (AD/B747/153), FAA AD 95-13-05 (AD/B747/154 Amdt 1), or
FAA AD 95-13-07, as applicable.
Requirement: Action in accordance with the technical requirements of FAA AD 99-01-10 Amdt 39- 10976.
Note: Boeing Alert Service Bulletin 747-54A2126 Revision 5, Revision 6, and Revision 7 refer.
Compliance: As specified in the Requirement Document with a revised effective date of 25 February 1999.
This Amendment becomes effective on 25 February 1999.
Background: Operators have reported ten diagonal brace lug cracks which are believed to initiate at lug bore corrosion pits and propagate by fatigue.
Amendment 1 required new repetitive inspections to detect discrepancies of the diagonal brace lugs, and rework of the diagonal brace lug, if necessary. Since issuance of AD 89-07-15, the FAA received several reports of six additional diagonal braces with cracks in one lug of the aft clevis on the affected aircraft.
Amendment 2 is issued in response to a new FAA AD which adds a requirement to repetitively inspect a new area of the diagonal brace, and for certain aircraft, adds new repetitive inspections of the subject area, while requiring that certain previously required repetitive inspections be accomplished at reduced intervals.
Amendment 1 of this Airworthiness Directive became effective on 4 December 1997.
The original issue of this Airworthiness Directive became effective on 10 August 1989.
Overview
The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, serve as a comprehensive framework for ensuring the safety and efficiency of civil aviation in the country. Specifically, Part 39 - 105 of the Civil Aviation Regulations, which includes the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, addresses critical safety issues pertaining to specific aircraft models. One such directive, AD/B747/70 Amendment 2, pertains to Boeing 747 series aeroplanes and was introduced to address a recurring issue of diagonal brace lug cracks, believed to initiate from lug bore corrosion pits and propagate through fatigue. This legislative instrument was developed in response to operator reports and subsequent findings by the Federal Aviation Administration (FAA), highlighting the need for enhanced safety measures to prevent potential structural failures. The objective of this directive is to mandate repetitive inspections and, if necessary, rework of the affected diagonal brace lugs to ensure the continued airworthiness of the specified aircraft models.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, govern the safety standards for civil aviation in Australia, including the Boeing 747 series aeroplanes. The legislation applies to all Boeing 747 series aircraft with line positions 1 through 1046, which are equipped with Pratt & Whitney JT9D series engines, General Electric Model CF6-45 and -50 series engines, or Rolls Royce Model RB211 series engines. However, it excludes those aircraft that have already undergone modifications to the strut/wing structure in accordance with specific FAA Airworthiness Directives. The Act mandates compliance with the technical requirements set out in FAA AD 99-01-10 Amdt 39-10976, which includes repetitive inspections of the diagonal brace lugs and, if necessary, rework of these components. The regulation aims to address the issue of diagonal brace lug cracks, which are believed to originate from lug bore corrosion pits and propagate through fatigue. The scope of this Act is extended through subordinate instruments, which detail the specific actions and intervals for inspections and reworks. This directive became effective on 25 February 1999, following reports of additional cracks in the diagonal braces of certain aircraft.
Key Provisions
The main operative sections of the Civil Aviation Regulations 1998, Part 39 - 105, specifically AD/B747/70 Amendment 2, pertain to the maintenance and inspection requirements for Boeing 747 series aeroplanes. The regulation applies to Model 747 aircraft with line positions 1 through 1046, equipped with Pratt & Whitney JT9D series engines, General Electric CF6-45 and -50 series engines, or Rolls Royce RB211 series engines, with certain exclusions for those aircraft that have already undergone specific strut/wing structure modifications as per FAA AD 95-10-16, FAA AD 95-13-05, or FAA AD 95-13-07 (Section 2). The requirement is for operators to implement the technical requirements outlined in FAA AD 99-01-10 Amendment 39-10976, which addresses the inspection and potential rework of diagonal brace lugs that have been found to crack due to lug bore corrosion pits and fatigue (Section 3). The compliance must align with the Requirement Document, with a revised effective date of 25 February 1999 (Section 4).
The obligations imposed by this legislation on the parties governed by it are quite specific. Operators of the specified Boeing 747 series aircraft must conduct repetitive inspections to detect any discrepancies in the diagonal brace lugs as per the outlined technical requirements. If any issues are identified, they must undertake the necessary rework of the diagonal brace lugs. These inspections must be conducted in accordance with the detailed requirements set out in the FAA AD 99-01-10 Amendment 39-10976. Additionally, operators must ensure that these actions are completed by the revised effective date of 25 February 1999. The legislation also refers to Boeing Alert Service Bulletins 747-54A2126 Revisions 5, 6, and 7, which provide further guidance and detail on the required actions.
Failure to comply with the obligations set out in this legislation can lead to significant consequences. While the Civil Aviation Regulations 1998 do not explicitly detail offences, penalties, or civil/criminal consequences for non-compliance with this specific airworthiness directive, general provisions within the Civil Aviation Act 1988 may apply. Non-compliance could result in enforcement actions by the Civil Aviation Safety Authority (CASA), which might include fines, enforcement notices, or other regulatory actions. Given the critical nature of airworthiness directives, persistent non-compliance could also lead to the grounding of the aircraft, potentially resulting in severe operational disruptions and safety risks. The precise penalties would depend on the specific circumstances and the severity of the non-compliance, but the overarching aim is to ensure the highest safety standards are maintained in civil aviation.