AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/232 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/B747/232
Amdt 1
Crew Rest Area Heat Exchanger - 2 13/2001
Applicability: Model 747-400 series aircraft, line numbers 1 through 1205; equipped with dual crown skin heat exchangers.
Requirement: Inspect in accordance with the technical requirements of FAA AD 2001-18-04 Amdt 39-12430.
Note: Boeing Alert Service Bulletins 747-21A2412 and 747-21A2412 Revision 2 refer.
Compliance: As specified in the Requirement document with a revised effective date of 27 December 2001.
This amendment becomes effective on 27 December 2001.
Background: The FAA received reports of cracking and buckling of the front edge of the crew rest heat exchanger on several aircraft. Investigation revealed that certain heat exchangers were manufactured with material that is too thin. On one aircraft, the heat exchanger buckled and bulged enough to make contact with the rudder and elevator cables located below the heat exchanger.
Amendment 1 is issued in response to a new FAA AD which adds a new requirement for a one-time inspection to determine the part number and shop code of the shell of the crew rest heat exchanger, and follow-on actions if necessary, which terminate the currently required repetitive inspections.
The original issue of this Airworthiness Directive became effective on 10 August 2000.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 8 November 2001
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The above AD is notified in the Commonwealth of Australia Gazette on 5 December 2001.
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Overview
The Airworthiness Directive AD/B747/232 Amdt 1 was issued by the Civil Aviation Safety Authority (CASA) in 2001 to address a safety concern identified by the Federal Aviation Administration (FAA) regarding cracking and buckling of the front edge of the crew rest heat exchanger in Boeing 747-400 series aircraft equipped with dual crown skin heat exchangers. This safety issue was traced to certain heat exchangers being manufactured with material that was too thin, posing a potential risk of the heat exchanger making contact with rudder and elevator cables, which could compromise the aircraft’s control systems. The directive revokes the previous AD/B747/232 and mandates a one-time inspection in accordance with FAA AD 2001-18-04 Amdt 39-12430 to ascertain the part number and shop code of the heat exchanger shell, with necessary follow-on actions if required, thereby replacing the previously required repetitive inspections. The policy objective is to ensure the continued airworthiness and safety of the affected aircraft by implementing corrective measures based on findings from the inspection.
Scope and Application
The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 applies specifically to Model 747-400 series aircraft with line numbers ranging from 1 through 1205 that are equipped with dual crown skin heat exchangers. This AD mandates that a specific inspection be conducted in accordance with the technical requirements outlined in FAA AD 2001-18-04 Amdt 39-12430. The requirement is triggered by reports of cracking and buckling of the front edge of the crew rest heat exchanger, an issue identified to be due to certain heat exchangers being manufactured with material that is too thin. Boeing Alert Service Bulletins 747-21A2412 and 747-21A2412 Revision 2 provide additional reference material. The directive is effective as of 27 December 2001, replacing the previous AD/B747/232 and mandating a one-time inspection to determine the part number and shop code of the shell of the crew rest heat exchanger, with follow-on actions if necessary, thereby terminating the previously required repetitive inspections. This directive is applicable across the Commonwealth of Australia and is communicated through the Commonwealth of Australia Gazette.
Key Provisions
The Airworthiness Directive (AD) AD/B747/232 Amdt 1, issued under the authority of the Civil Aviation Safety Authority (CASA), pertains specifically to the Boeing 747-400 series aircraft with line numbers 1 through 1205 that are equipped with dual crown skin heat exchangers. This AD mandates an inspection of the crew rest area heat exchanger in accordance with the technical requirements outlined in FAA AD 2001-18-04 Amdt 39-12430. Boeing Alert Service Bulletins 747-21A2412 and its Revision 2 provide additional context and reference material. The requirement for this inspection is a direct response to reports of cracking and buckling of the heat exchanger's front edge, which were traced back to issues with the material thickness of certain heat exchangers. This inspection is intended to identify and address potential safety issues before they escalate.
The AD imposes specific obligations on the owners and operators of the affected aircraft. They are required to ensure that the inspection is conducted by qualified personnel in adherence with the technical specifications provided in FAA AD 2001-18-04 Amdt 39-12430. Additionally, operators must maintain records of the inspection and any subsequent actions taken as a result of the findings. This includes following up on any necessary repairs or replacements of the heat exchanger if the inspection reveals issues. Failure to comply with these requirements can lead to significant safety risks, including the potential for in-flight incidents.
The AD specifies a compliance date of 27 December 2001, which is when the amendment became effective. Any non-compliance with the directive's requirements can result in severe consequences. Under the Civil Aviation Regulations 1998, failure to adhere to an Airworthiness Directive can be considered an offence, leading to potential civil or criminal penalties. Civil penalties can include fines, while criminal penalties may involve imprisonment. The specific penalties are determined based on the nature and severity of the breach, and in some cases, can result in substantial financial and reputational damage to the operators involved. Therefore, it is imperative that aircraft owners and operators take the directive seriously and ensure full compliance by the stipulated date.