COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Douglas DC4 Series Aeroplanes
AD/DC4/34
Amdt 1
Electrical Distribution Bus 4/97
Applicability: All DC-4 and C-54 aeroplanes.
Requirement: 1. Inspect the electrical distribution bus to ensure that at least 12.7mm (0.5 inch) clearance is maintained between the bus and protuberances likely to “ground” the bus in the nacelle areas.
Note 1: Particular attention should be given to the areas around the engine control pulleys and the pulley guide brackets.
2. Remove the large gauge nacelle-to-bus feeder cables, that are run in metallic conduits, from the conduits and inspect them for chafing or mechanical deterioration of the insulation.
Note 2: Oil-soaked insulation alone is not considered as sufficient cause to require the replacement of the cables.
3. If any cables are found to be damaged during the Requirement 2 inspection, replace the cables with cables conforming to Douglas Aircraft Company (DAC) specification BXS7008, per MIL-L-22759 or DAC specification DMS2426, per MIL-W-81381/12.
4. If not previously accomplished, inspect the electrical distribution bus to ensure that the supporting brackets are of an approved DAC standard quality and that cushioned non grounding cable clamps are used for clamping the bus onto the brackets. Replace any substandard brackets or clamps.
Note 3: FAA AD 48-09-02 and Douglas Service Letter A214TS-1245/SRD-530 dated 10 October 1947 refer.
Compliance: For Requirement 1 - Prior to 22 May 1997 and thereafter at intervals not to exceed 400 hours time in service.
For Requirement 2 - Prior to 22 July 1997 and thereafter at intervals not to exceed 8000 hours time in service.
For Requirement 3 - Prior to further flight. For Requirement 4 - Prior to 22 July 1997.
This Amendment becomes effective on 27 March 1997.
Background: Actions mandated by this Directive are designed to preclude the possibility of short circuits occurring in the electrical distribution bus running from nacelles number one to four, which is impractical to protect by circuit protection devices.
This Directive was originally issued in 1948, this amendment both amplifies the requirements and clarifies the compliance intervals.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
The original issue date of this Airworthiness Directive is unknown.
Overview
The Civil Aviation Regulations 1998, as amended, form the legal foundation for ensuring the safety of civil aviation in Australia. The 1998 regulations were enacted by the Parliament of Australia, with the aim of providing a comprehensive framework for the regulation of civil aviation, ensuring that all aircraft operations meet stringent safety and operational standards. One of the mechanisms through which these regulations are enforced is the issuance of Airworthiness Directives (ADs), which are mandatory orders issued by the Civil Aviation Safety Authority (CASA) to address safety issues in specific types of aircraft. The problem or gap that these directives aim to address includes any identified risks to aircraft safety that require immediate action to prevent accidents or incidents. For example, the AD/DC4/34 Amendment 1 pertains to Douglas DC-4 Series aeroplanes, mandating specific inspections and maintenance actions to prevent electrical faults in the aircraft's distribution bus, which could lead to dangerous short circuits. The policy objective of these directives is to enhance the safety of air travel by ensuring that all aircraft are maintained in an airworthy condition through regular and rigorous inspections and repairs.
Scope and Application
The Civil Aviation Regulations 1998, under PART 39 - 105, issued by the Civil Aviation Safety Authority, pertains specifically to the maintenance and inspection of Douglas DC4 Series Aeroplanes, including both DC-4 and C-54 aeroplanes. The regulations mandate that these aircraft undergo specific inspections and maintenance checks to ensure airworthiness, with a focus on the electrical distribution bus and related components. The requirement to maintain a minimum clearance of 12.7mm between the electrical distribution bus and protuberances, particularly in the nacelle areas, is intended to prevent short circuits that could compromise safety. Additionally, the regulations detail inspections of the large gauge nacelle-to-bus feeder cables for any signs of chafing or mechanical deterioration, with instructions to replace damaged cables according to specific Douglas Aircraft Company specifications. Compliance with these directives is crucial, with specific intervals for inspections and replacements, such as before 22 May 1997 for certain checks and thereafter at set intervals not exceeding 400 or 8000 hours of service. These regulations apply nationally and are enforceable across all jurisdictions within Australia.
Key Provisions
The main operative sections of this Civil Aviation Safety Authority (CASA) Airworthiness Directive (AD) are the requirements for inspecting and maintaining the electrical distribution bus of Douglas DC4 Series aeroplanes, specifically focusing on clearance, inspection of cables, and the use of approved brackets and clamps. Section 1 mandates that there must be at least 12.7mm (0.5 inch) of clearance between the electrical distribution bus and any protuberances in the nacelle areas, with particular attention to the engine control pulleys and pulley guide brackets. Section 2 requires the removal of large gauge nacelle-to-bus feeder cables from metallic conduits for inspection of chafing or mechanical deterioration of the insulation. Section 3 stipulates that any damaged cables must be replaced with cables meeting specific Douglas Aircraft Company (DAC) specifications. Finally, Section 4 demands the inspection of the electrical distribution bus to ensure that it is supported by brackets of approved DAC standard quality and that cushioned, non-grounding cable clamps are used, replacing any substandard components.
The obligations imposed by the AD on the parties governed by it include thorough inspections and maintenance of the electrical distribution bus to prevent potential short circuits. Operators of DC-4 and C-54 aeroplanes must ensure that the required inspections are conducted at specified intervals. For Requirement 1, inspections must occur before 22 May 1997 and thereafter at intervals not exceeding 400 hours of service. For Requirement 2, inspections must be completed before 22 July 1997 and then at intervals not exceeding 8000 hours of service. Requirement 3 necessitates immediate action if damaged cables are found, requiring their replacement before further flight. Requirement 4 must be completed before 22 July 1997. These obligations are designed to maintain the safety and airworthiness of the aircraft by ensuring that the electrical systems are free from potential hazards.
The consequences for non-compliance with the AD are outlined within the legislative framework of the Civil Aviation Regulations 1998. Failure to adhere to the specified inspection and maintenance requirements can result in severe penalties. Although the exact penalties are not detailed in the AD, non-compliance with CASA directives can lead to enforcement actions under the Civil Aviation Act 1988. This may include fines, suspension or revocation of air operator certificates, and other regulatory actions. The seriousness of these consequences underscores the importance of strict compliance to ensure the safety of all personnel and passengers on board the aircraft.