COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/136
Amdt 1
Fuselage - Nose Wheel Well 7/99
Applicability: B747 Line No 001 to 685 inclusive.
Requirement: 1. Externally inspect for cracks in the nose wheel well top panel and intercostals. Inspect in accordance with Boeing SB 747-53-2293 Rev 6 using either detailed close visual (Option 1) or a combination of detailed close visual and high frequency eddy current (Option 2) methods.
2. Perform a detailed close visual inspection, internally and externally, for cracks in the nose wheel well vertical beam clips and the adjacent side wall panel web. If cracks are found, extend the inspection area and inspect using high frequency eddy current methods. Inspect in accordance with Boeing SB 747-53-2293 Rev 6.
3. Inspect, internally and externally, for cracks in the nose wheel well vertical beam webs. Inspect in accordance with Boeing SB 747-53-2293 Rev 6 using either a detailed close visual (Option 1) or a combination of detailed close visual and high frequency eddy current (Option 2) methods.
Note: FAA AD 90-06-14R1 refers.
Compliance: 1. Initially inspect the nose wheel well top panel and intercostals before 4000 flights or within 1500 flights from 27 April 1995, whichever is the later. Reinspect at intervals not exceeding 1500 flights (Option 1) or intervals not exceeding 3000 flights (Option 2).
2. Initially inspect the vertical beam clips and side wall panels before 10000 flights or within 1500 flights from 27 April 1995, whichever is the later. Reinspect at intervals not exceeding 3000 flights.
3. Inspect the vertical beam webs before 10000 flights or before 1500 flights from 27 April 1995, whichever is the later. Reinspect at intervals not exceeding 1500 flights (Option 1) or intervals not exceeding 3000 flights (Option 2).
4. For the purposes of this AD a flight may be taken as a ground-air-ground cycle where the pressure differential exceeds 2.0 psi.
5. Modification in accordance with Boeing SB 747-53-2293 Rev 6 constitutes terminating action for the inspection requirements of this AD for those areas so modified.
The compliance times of the original issue of this Directive remains unchanged except for the Requirement 2 repetitive inspection.
This Amendment becomes effective on 15 July 1999.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Background: There have been approximately 70 reported instances of cracking in the nose wheel well structure. Cracks up to 11" long have been reported. Continued operation with undetected cracks could lead to rapid cabin depressurisation. Inspections in accordance with this AD will ensure timely detection of critical cracks.
Amendment 1 is issued to align the Requirement 2 repetitive inspection interval with the related FAA AD requirement.
The original issue of this Airworthiness Directive became effective on 27 April 1995.
Overview
The Civil Aviation Regulations 1998 were enacted by the Australian Parliament to provide a comprehensive legal framework for civil aviation safety. In addressing specific safety concerns, the Regulations include detailed directives on airworthiness, particularly under Part 39, which focuses on airworthiness directives. One such directive, AD/B747/136 Amendment 1, pertains to the Boeing 747 series aeroplanes and was introduced to tackle the problem of reported cracks in the nose wheel well structure, which could lead to critical safety issues such as rapid cabin depressurisation. The policy objective of this amendment is to ensure the timely detection and rectification of such structural defects through rigorous inspection protocols. The amendment became effective on 15 July 1999, aligning with the Federal Aviation Administration's (FAA) related requirements to enhance safety standards and compliance.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105 of the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, applies to Boeing 747 Series aeroplanes, from line number 001 to 685 inclusive. This legislation mandates specific inspection requirements for the nose wheel well to ensure the continued airworthiness and safety of these aircraft. The inspections must be carried out according to the Boeing Service Bulletin 747-53-2293 Rev 6, utilising either detailed close visual methods or a combination of detailed close visual and high frequency eddy current methods. The regulations set forth initial inspection timelines and intervals for various components of the nose wheel well, with the aim of detecting cracks that could lead to critical failures such as rapid cabin depressurisation. Compliance with these directives is mandatory for the specified aircraft to maintain their operational certification within Australia and under Australian jurisdiction. The regulations do not specify exclusions or exemptions but rely on the defined inspection intervals and methods to ensure compliance.
Key Provisions
The Civil Aviation Regulations 1998, under PART 39 - 105 and the Civil Aviation Safety Authority Schedule of Airworthiness Directives, include specific requirements for Boeing 747 series aeroplanes, particularly focusing on the nose wheel well structure. This directive, identified as AD/B747/136 Amendment 1, mandates inspections to ensure the airworthiness and safety of the aircraft. Section 1 of the directive requires an external inspection of the nose wheel well top panel and intercostals, along with an internal and external inspection of the vertical beam clips and side wall panel web for cracks. These inspections can be performed using detailed close visual methods or a combination of detailed close visual and high frequency eddy current methods as specified in Boeing SB 747-53-2293 Rev 6.
Compliance with these inspection requirements is critical for the operators of Boeing 747 aeroplanes. The initial inspections must be conducted before the aircraft reaches 4000 flights or within 1500 flights from 27 April 1995, whichever is later. For the top panel and intercostals, reinspections must occur at intervals not exceeding 1500 flights for Option 1 or 3000 flights for Option 2. Similarly, vertical beam clips and side wall panels must be inspected initially before 10000 flights or within 1500 flights from 27 April 1995, with reinspections every 3000 flights. The vertical beam webs also require an initial inspection before 10000 flights or within 1500 flights from 27 April 1995, with reinspections every 1500 or 3000 flights depending on the method used. Additionally, modifications in accordance with Boeing SB 747-53-2293 Rev 6 are considered as terminating actions for the inspection requirements of this AD for the modified areas.
Failure to comply with the stipulated inspection requirements can lead to severe consequences. The Civil Aviation Regulations 1998 outline that non-compliance with these airworthiness directives can result in penalties, which may include fines or other regulatory actions. The exact penalties are not specified in the text but generally, non-compliance with airworthiness directives can lead to significant civil or criminal penalties, including grounding of the aircraft, financial penalties, and potential prosecution of individuals or entities responsible for the oversight.