COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.
AD/B747/236 Honeywell Inertial Reference Units 12/2000
Applicability: Model 747-400 series aeroplanes with line numbers 696 through 1187 inclusive equipped with Honeywell inertial reference units (IRU).
Requirement: 1. Remove the left, centre and right IRUs and install modified IRUs in accordance with Boeing Alert Service Bulletin (ASB) 747-34A2638 Revision 1 dated 8 April 1999.
Removal and replacement of the IRUs previously carried out in accordance with ASB 747-34A2638 dated 29 January 1999 is an acceptable method of compliance for this Requirement.
2. IRUs having Boeing Part Number S242T101-110, S242T101-111 or S242T101- 112 may not be installed on any Boeing 747-400 series aeroplane.
Note: FAA AD 2000-20-20 Amdt 39-11932 refers.
Compliance: For Requirement 1 - Before 30 May 2002.
For Requirement 2 - As of the effective date of this Directive.
This Airworthiness Directive becomes effective on 30 November 2000.
Background: Boeing received a report of the failure of the left and centre IRUs on a single flight. The failure of multiple IRUs could result in the loss of navigation data during flight which could compromise the ability of the flight crew to maintain the safe flight and landing of the aeroplane.
This Directive requires removal of existing IRUs and installation of modified IRUs. These actions are intended to prevent loss of multiple IRUs in flight.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 20 October 2000
The above AD is notified in the Commonwealth of Australia Gazette on 1 November 2000.
Overview
The Civil Aviation Regulations 1998 were enacted to regulate civil aviation safety in Australia, ensuring that all civil aviation operations meet necessary safety standards. This legislation is administered by the Civil Aviation Safety Authority (CASA), which has the authority to issue airworthiness directives to address specific safety concerns. One such directive, AD/B747/236, was issued under the authority of the CASA to address the risk of failure in the Honeywell inertial reference units (IRU) on Boeing 747-400 series aeroplanes with line numbers 696 through 1187 inclusive. This Airworthiness Directive was introduced in response to a reported failure of the left and centre IRUs on a single flight, which could potentially compromise the safe flight and landing of the aeroplane. The directive mandates the removal and replacement of the existing IRUs with modified ones to prevent multiple IRU failures in flight, thereby ensuring the continued airworthiness and safety of the aircraft.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105, mandates the Civil Aviation Safety Authority (CASA) to issue Airworthiness Directives (AD) to ensure the safety of civil aviation. This particular AD, issued by the CASA delegate, applies to Boeing 747-400 series aeroplanes with line numbers 696 through 1187 inclusive, which are equipped with Honeywell inertial reference units (IRU). The AD requires specific actions to be taken to address identified safety issues, including the removal and replacement of IRUs in accordance with specified Boeing Alert Service Bulletins. The directive applies across the Commonwealth of Australia and is intended to ensure the continued airworthiness of affected aircraft by mitigating the risk of multiple IRU failures during flight, which could jeopardise flight safety. The AD becomes effective from 30 November 2000, and compliance must be achieved by specific dates outlined in the directive, with certain actions required before 30 May 2002, and others taking effect immediately upon the directive's issuance.
Key Provisions
The Civil Aviation Regulations 1998, particularly Part 39 - 105, establish the framework for ensuring the airworthiness of aircraft within Australia. This legislation mandates that certain actions must be taken to maintain or restore airworthiness, as outlined in specific Airworthiness Directives (ADs). For instance, AD/B747/236, issued by the Civil Aviation Safety Authority (CASA) delegate, pertains to Boeing 747-400 series aeroplanes with specific line numbers and requires modifications to the inertial reference units (IRU) to prevent the risk of multiple IRU failures during flight. The directive mandates that the left, centre, and right IRUs be removed and replaced with modified units as per Boeing Alert Service Bulletin (ASB) 747-34A2638 Revision 1 dated 8 April 1999. The compliance date for this directive is set before 30 May 2002, with the directive becoming effective on 30 November 2000. The directive also prohibits the installation of certain IRUs identified by specific part numbers.
Under the Civil Aviation Regulations, operators of Boeing 747-400 series aeroplanes are required to adhere to the ADs issued by CASA. For this particular AD, operators must ensure that the specified IRUs are removed and replaced according to the instructions provided. Additionally, they must verify that no IRUs with the specified part numbers are installed on their aircraft as of the directive's effective date. Failure to comply with these requirements could result in the aircraft being deemed unairworthy, thereby posing significant safety risks.
Failure to comply with the provisions of an Airworthiness Directive can lead to severe consequences. Civil Aviation Regulations 1998 stipulate that non-compliance with ADs can result in the aircraft being considered unairworthy. In the context of AD/B747/236, operators who do not adhere to the removal and replacement requirements within the specified timeframe could face penalties. These could include fines, operational restrictions, or even the grounding of the affected aircraft until the required modifications are made. The specific penalties are determined by CASA, but they are designed to ensure strict adherence to air safety standards.