COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 747 Series Aeroplanes
AD/B747/199 Cabin Pressure Control System 6/99
Applicability: Model 747-400, -400D and -400F series aeroplanes identified in Boeing Alert Service Bulletin (ASB) 747-21A2381 dated 27 June 1996 and Service Bulletin (SB) 747-24- 2193 dated 26 January 1995.
Requirement: 1. Modify the P212 and P213 panels of the cabin pressure control system in accordance with Boeing ASB 747-21A2381 as follows:
- For Groups 1 through 7 aeroplanes, as identified in the ASB - Change the wiring in the P212 and P213 panels, replace the existing two-pole relays with new four-pole relays and perform a test of both panels.
b. For Group 8 aeroplanes, as identified in the ASB - Change the wiring in the P212 panels, replace the existing two-pole relays with new four-pole relays, replace the existing P213 panel with a new P213 panel and perform a test of both panels.
2. For aeroplanes having line positions 696 through 1021 inclusive modify the P5, P6 and P7 panels, together with wire bundles W4701, W4703 and W4908, as applicable, in accordance with either SB 747-24-2193, as revised by Notices of Status Change (NSC) 747-24-2193 NSC 1 dated 13 April 1995, NSC 2 dated
5 October 1995, NSC 3 dated 22 November 1995, NSC 4 dated 21 December
1995, NSC 5 dated 2 May 1996 and NSC 6 dated 13 March 1997; or ASB 747-
24A2193 Revision 1 dated 19 June 1997, as follows:
- For all aeroplanes identified above - modify the wiring in the P5, P6 and P7 panels together with the wiring in the W4701 and W4908 wire bundles and install diodes in the P6 panel.
b. For Group 1 and 2 aeroplanes, as identified in the Accomplishment Instructions, paragraph I, of the SB or ASB - modify the wiring in the W4703 wire bundle.
Note: FAA AD 99-06-18 Amdt 39-11082 refers.
Compliance: 1. Within 12 months after the effective date of this Directive.
2. Within 12 months after the effective date of this Directive. This Airworthiness Directive becomes effective on 17 June 1999.
Background: The FAA has received a report of an in-flight loss of cabin pressurisation control due to a single failure of the auxiliary power unit battery. This directive introduces measures which are intended to prevent loss of the cabin pressurisation system, which could result in rapid depressurisation of the aeroplane.
Overview
The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, were introduced to address the need for stringent aviation safety standards. The Regulations, particularly Part 39, aim to ensure that aircraft maintain the highest levels of safety and airworthiness. One specific measure under these regulations is the Airworthiness Directive AD/B747/199, which was introduced to address the problem of cabin pressure control system failures in Boeing 747 Series aeroplanes. This directive was developed in response to a reported incident involving an in-flight loss of cabin pressurisation control due to a single failure of the auxiliary power unit battery. The policy objective of this directive is to prevent the loss of cabin pressurisation, thereby avoiding potential rapid depressurisation of the aeroplane, which could compromise the safety of passengers and crew.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Airworthiness Directives issued by the Civil Aviation Safety Authority (CASA) in relation to the Boeing 747 Series Aeroplanes. This regulation applies to specific models of Boeing 747 aeroplanes, namely the 747-400, -400D, and -400F series, as identified in Boeing Alert Service Bulletin (ASB) 747-21A2381 dated 27 June 1996 and Service Bulletin (SB) 747-24-2193 dated 26 January 1995. The directive mandates modifications to the cabin pressure control system, requiring changes to the wiring and relay components of the P212 and P213 panels for certain groups of aeroplanes, as well as modifications to the P5, P6, and P7 panels and associated wire bundles for aeroplanes with specific line positions. Compliance with these requirements is mandated within 12 months from the effective date of the directive, which was 17 June 1999. The directive was issued in response to reports of in-flight loss of cabin pressurisation control due to a single failure of the auxiliary power unit battery, aiming to prevent rapid depressurisation of the aeroplane.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate that Boeing 747-400, -400D, and -400F series aeroplanes identified in certain Boeing bulletins must undergo specific modifications to their cabin pressure control systems. Section 1 of the regulation requires operators to modify the P212 and P213 panels according to Boeing ASB 747-21A2381. For aeroplanes in Groups 1 through 7, this involves changing the wiring in the P212 and P213 panels, replacing the existing two-pole relays with new four-pole relays, and conducting a test of both panels. For aeroplanes in Group 8, the modifications are slightly different, involving similar changes to the P212 panel wiring and relays, but also requiring the replacement of the P213 panel with a new one and subsequent testing. Additionally, for aeroplanes with line positions 696 through 1021, modifications must be made to the P5, P6, and P7 panels, as well as the W4701, W4703, and W4908 wire bundles, following either Boeing SB 747-24-2193 or ASB 747-24A2193 Revision 1.
Operators of the specified Boeing 747 series aeroplanes must ensure compliance with these modifications within 12 months of the effective date of this directive, which is 17 June 1999. This requirement applies to all aeroplanes identified in the relevant Boeing bulletins. Compliance involves detailed technical work, including precise wiring changes, relay replacements, and the installation of diodes, ensuring that the aeroplanes meet the updated safety standards outlined in the directive.
Failure to comply with the requirements of this Airworthiness Directive may result in serious safety consequences, potentially leading to a loss of cabin pressurisation control and subsequent rapid depressurisation of the aeroplane. The Civil Aviation Regulations 1998 do not explicitly detail penalties for non-compliance in this context, but failure to adhere to such directives can result in severe regulatory consequences, including potential grounding of the aeroplane, fines, and other enforcement actions by the Civil Aviation Safety Authority (CASA).
Furthermore, the directive references FAA AD 99-06-18 Amdt 39-11082, indicating a collaborative effort between Australian and U.S. aviation authorities to ensure safety standards are met across both jurisdictions. The directive aims to prevent incidents of in-flight loss of cabin pressurisation control, which could endanger the safety of passengers and crew.