AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/172 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Boeing 747 Series Aeroplanes
AD/B747/172
Amdt 1
Nose Wheel Well Vertical Beams and Fuselage Frames
11/2001
Applicability: Model 747 series aircraft, line numbers 1 through 685; except for aircraft excluded by the applicability table specified in the Requirement document.
Requirement: Inspect in accordance with the technical requirements of FAA AD 2001-14-18 Amdt 39-12329.
Replacement of vertical beams and frames, as applicable, in accordance with the applicable procedure in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2293 Revision 8, constitutes terminating action for the requirements of this Directive.
Compliance: As specified in the Requirement document with a revised effective date of 1 November 2001.
This Amendment becomes effective on 1 November 2001.
Background: The FAA received a report of severed fuselage frames at BS 300 and BS 320 approximately 10 inches outboard of the nose wheel well side panel, which resulted in accelerated fatigue cracking and subsequent failure of the adjacent nose wheel well vertical beams.
Amendment 1 is issued in response to a new FAA AD which expands applicability to include additional aircraft, and adds new requirements for repetitive inspections to detect fatigue cracking of the webs and frames from BS 260 to BS 320. The AD also provides for optional terminating action.
Boeing 747 Series Aeroplanes
AD/B747/172 Amdt 1 (Continued)
The original issue of this Airworthiness Directive became effective on 27 March 2001.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 19 September 2001
The above AD is notified in the Commonwealth of Australia Gazette on 10 October 2001.
Overview
The Civil Aviation Safety Authority (CASA) enacted the Airworthiness Directive (AD) AD/B747/172 Amdt 1 in 2001 to address safety concerns related to fatigue cracking and failure of nose wheel well vertical beams in Boeing 747 series aircraft, specifically for line numbers 1 through 685. This directive was issued following a report of severed fuselage frames at specific locations, which led to accelerated fatigue cracking and subsequent failure of the adjacent nose wheel well vertical beams. The policy objective of this AD is to ensure the safety of the aircraft by mandating inspections and, if necessary, replacement of vertical beams and frames in accordance with the Federal Aviation Administration's (FAA) technical requirements and Boeing's Accomplishment Instructions. The AD became effective on 1 November 2001, superseding the previous AD/B747/172 issued on 27 March 2001, and was notified in the Commonwealth of Australia Gazette on 10 October 2001.
Scope and Application
The Airworthiness Directive (AD) AD/B747/172 Amdt 1 applies to Boeing 747 series aircraft with line numbers ranging from 1 to 685, excluding any aircraft specifically excluded by the applicability table in the Requirement document. This directive is issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 by a delegate of the Civil Aviation Safety Authority (CASA). The AD mandates inspections and corrective actions to address an unsafe condition identified in the nose wheel well vertical beams and fuselage frames of these aircraft. Compliance with this directive requires adherence to the technical inspection requirements specified in FAA AD 2001-14-18 Amdt 39-12329, as well as the replacement procedures outlined in Boeing Alert Service Bulletin 747-53A2293 Revision 8. The directive became effective on 1 November 2001, with the Amendment becoming effective on the same date, and was notified in the Commonwealth of Australia Gazette on 10 October 2001.
Key Provisions
The Airworthiness Directive (AD) AD/B747/172 Amendment 1 applies to Model 747 series aircraft with line numbers 1 through 685, excluding those specifically listed in the applicability table of the Requirement document. This AD was issued to address a safety concern involving the nose wheel well vertical beams and fuselage frames. The requirement section of the AD mandates that inspections be conducted in accordance with the technical specifications outlined in FAA AD 2001-14-18 Amendment 39-12329. Additionally, it specifies that replacement of the vertical beams and frames, as applicable, should follow the procedures detailed in Boeing Alert Service Bulletin 747-53A2293 Revision 8. This replacement action is considered to fulfill the requirements of the directive.
Operators and owners of the specified Boeing 747 series aircraft are obligated to comply with the AD by conducting the required inspections and making any necessary replacements of the vertical beams and frames. The Compliance section of the AD states that these actions must be taken according to the instructions provided in the Requirement document, with a compliance deadline of 1 November 2001. Failure to adhere to these requirements may result in the aircraft being considered non-airworthy, potentially leading to grounding or other regulatory actions.
Failure to comply with the provisions of this Airworthiness Directive can result in severe consequences. The Civil Aviation Safety Authority (CASA) may take enforcement actions against non-compliant operators, which could include fines, suspension of airworthiness certificates, or other administrative penalties. The directive does not specify monetary penalties but emphasizes the importance of adhering to safety regulations to ensure the continued airworthiness of the aircraft. Operators are urged to follow the directive meticulously to avoid these adverse outcomes.