COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/51 Fuselage Frames - Aft Cargo Bay 12/86
Applicability: All models listed in Boeing ASB 747-53A2259. Requirement: Inspect in accordance with Boeing ASB 747-53A2259.
Compliance: Before exceeding 7,000 landings, or within the next 500 landings after 31 December 1986, whichever occurs later; and,
For those frames which have improperly tapered side guide support brackets, repeat the inspection at intervals not exceeding 3,000 landings.
If the tapered strap reinforcement is accomplished in accordance with the ASB, the repeat inspection interval may be extended to 12,000 landings for reinforced frames only.
Background: The manufacturer has advised that some aircraft may have side guide support brackets which have not been properly tapered. Those which have little or no taper cause high load transfer at the end fastener, with consequent cracking. This Directive implements the intent of the FAA AD, with some local variations. One which should be noted is the requirement to carry out precautionary inspections after reinforcement, to cover the possibility of further cracking in fatigue-damaged structure which has not been replaced.
Overview
The Civil Aviation Regulations 1998, particularly Part 39 - 105, introduces the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, aiming to ensure the safety and airworthiness of aircraft operating within Australia. One of these directives, AD/B747/51, specifically addresses Boeing 747 series aeroplanes, targeting potential structural issues in the aft cargo bay's fuselage frames. This directive was enacted to address concerns regarding improperly tapered side guide support brackets, which could lead to high load transfer and subsequent structural cracking. The Australian Civil Aviation Safety Authority, as part of its regulatory framework, implements these directives to align with international standards and address specific safety concerns highlighted by the aircraft manufacturer, in this case Boeing, while allowing for some local variations to better suit the Australian aviation context.
The directive mandates inspections in accordance with Boeing's Airworthiness Service Bulletin (ASB) 747-53A2259, requiring inspections before exceeding 7,000 landings or within 500 landings after 31 December 1986, whichever is later. For frames with improperly tapered side guide support brackets, inspections must be repeated at intervals not exceeding 3,000 landings. If the tapered strap reinforcement is performed as per the ASB, the inspection interval may be extended to 12,000 landings for reinforced frames. This approach ensures that any potential issues are identified and addressed promptly, enhancing the overall safety and reliability of the aircraft in Australian airspace.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the safety requirements for Boeing 747 series aeroplanes, focusing on the fuselage frames in the aft cargo bay. This regulation applies to all models listed in Boeing ASB 747-53A2259, mandating inspections to be conducted in accordance with the specified Boeing Airworthiness Service Bulletin. The requirement necessitates compliance with these inspections either before the aircraft exceeds 7,000 landings or within 500 landings after 31 December 1986, whichever is later. Furthermore, if the side guide support brackets are improperly tapered, the inspection must be repeated at intervals not exceeding 3,000 landings. However, if the tapered strap reinforcement is done as per the ASB, the inspection interval can be extended to 12,000 landings for frames that have been reinforced. This regulation aims to address issues arising from improperly tapered side guide support brackets, which can lead to high load transfer and subsequent cracking, thereby ensuring the continued airworthiness of the affected aircraft.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an Airworthiness Directive (AD) for Boeing 747 Series Aeroplanes, denoted as AD/B747/51, which pertains to fuselage frames in the aft cargo bay (AD/B747/51). This directive is applicable to all models listed in Boeing ASB 747-53A2259 (s.1). The primary requirement outlined in this directive is to conduct inspections in accordance with Boeing ASB 747-53A2259 (s.2). Compliance with this AD must be achieved by either exceeding 7,000 landings or within the next 500 landings following 31 December 1986, whichever comes later (s.3). Furthermore, for fuselage frames that have side guide support brackets that have been improperly tapered, repeat inspections must be conducted at intervals not exceeding 3,000 landings (s.4). If the reinforcement of the tapered strap is carried out in accordance with the ASB, the interval for repeat inspections can be extended to 12,000 landings for reinforced frames only (s.5).
This Act imposes specific obligations on the operators of Boeing 747 Series Aeroplanes. Operators must ensure that inspections are performed as required by Boeing ASB 747-53A2259, maintaining detailed records of these inspections to demonstrate compliance. For frames identified with improperly tapered side guide support brackets, additional precautionary inspections are mandated at intervals not exceeding 3,000 landings. If the reinforcement procedure is followed correctly, operators can extend the inspection interval for reinforced frames to 12,000 landings. These obligations are crucial to maintain the airworthiness of the aircraft and ensure passenger safety.
Failure to comply with the requirements set forth in AD/B747/51 may result in significant legal consequences. The AD stipulates that non-compliance could lead to civil penalties, including fines and potential grounding of the aircraft. Furthermore, continued operation of an aircraft that does not meet the inspection requirements could result in criminal charges against the operator. The maximum penalties for these offences are not explicitly stated in the directive, but they can be severe, reflecting the importance of adhering to airworthiness directives to maintain the safety of air travel.