COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Percival Proctor Series Aeroplanes
AD/PROCTOR/11
(Re-Issue)
Applicability: All models.
Airframe Structure - Inspection 1/73
Requirement: 1. Preparation: Prepare the aeroplane for inspection by removing all removable equipment, cabin linings, seats, inspection access panels, fairings, fabric patches, tape sealing and sufficient fabric and secondary structure to enable an inspection of the airframe in accordance with these requirements.
2. Inspection Procedure:
- Inspect all fabricated structural components such as box spars, wooden ribs, bulkheads and braces, and all glued connections between these components for the following defects:-
(1) Cracks, cuts, splits, bruises, compression shakes, warping, contamination by foreign matter such as oil, attack by fungus in the wood, shrinkage of the timber at bolt holes.
(2) Separation or sponginess in the glued joints and plywood. A 0.005 in. feeler gauge should be used to determine separation of glued joints and the depth of glue failure.
b. Inspect all plywood skin for the following defects:-
(1) Cracks, splits, cuts, bruises and shakes in the surface of the wood, deterioration and contamination by foreign matter.
(2) Separation of the glue where skin connects to the skiletal structure beneath. Particular attention should be paid to the flaps since they are exposed to moisture, and also subject to contamination by oil.
Note: Load carrying wooden skin becomes inefficient and the complete structure loses strength when adhesion to the structure beneath has failed. Consequently, all structural connections and joints must be thoroughly inspected for deterioration and defects. When carrying out an inspection the following may prove helpful in detecting defects.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Separation from the structure is often detectable from the exterior in several ways. It is likely to appear as a local discontinuity in the skin contour which can be pressed down without the immediate firm resistance anticipated. When the structure is flexed the skin will tend to take up waves. If these waves do not pass across the lines of gluing to the structure beneath, adhesion may be taken as sound. Oblique lighting of the surface will be found helpful in studying surface waves and contour discontinuities. Timber shakes appear as thin lines across the timber on the varnish later. By sponging ink on the varnish and subsequently wiping off, a line where the shake exists should be apparent. Where there are signs of failure in the protective coating it should be removed to inspect the wood beneath. Special attention is to be paid to points in the structure where liquids can collect or oil contamination can occur. Casein glue deteriorates if repeatedly exposed to moisture or oil. Where possible the inspection should be made from the interior. However, for wings, initial inspection may be made from the exterior. When inspecting the interior structure of the wings it may be necessary to cut holes in load carrying covering. In these instances reference should be made to the Director- General for an approved scheme for the incorporation of inspection holes.
or DCA/PROCTOR/11.
Compliance: (a) Within 12 months of last inspection in accordance with AD/GENERAL/29 and thereafter at intervals not exceeding 12 months.
(b) For aircraft which have not been inspected in accordance with AD/GENERAL/29 in the 12 months prior to 31 January 1973 - inspect within three months after 31 January 1973 and thereafter at intervals not exceeding 12 months.
Overview
The Civil Aviation Regulations 1998 were enacted by the Australian Parliament to establish and maintain the safety standards for civil aviation in Australia, thereby addressing the need for stringent regulatory oversight in the aviation industry to ensure the safety of passengers and crew, as well as the general public. The Civil Aviation Safety Authority, under the Department of Infrastructure and Transport, is the enacting body responsible for administering these regulations. This legislation aims to ensure that all aspects of civil aviation operations, including aircraft maintenance and airworthiness, comply with internationally recognised safety standards. The specific airworthiness directive AD/PROCTOR/11, which concerns the Percival Proctor Series Aeroplanes, was issued to address the problem of maintaining the structural integrity of older aircraft models through regular and thorough inspections, ensuring that any potential defects are identified and rectified to prevent in-flight failures.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 pertaining to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives for the Percival Proctor Series Aeroplanes, applies to all models of the specified aircraft. This regulation outlines the inspection requirements for the airframe structure, ensuring the aircraft's airworthiness and safety. The inspection mandate includes detailed procedures for preparing the aircraft, such as removing removable equipment and access panels to enable thorough examination of the airframe. The directive mandates that all fabricated structural components and glued connections be inspected for various defects, including cracks, cuts, and contamination, with specific attention to areas prone to moisture and oil exposure. Compliance with these regulations is crucial for maintaining the structural integrity of the aircraft, with inspections required within 12 months of the last inspection or within three months for aircraft not inspected prior to a specific date. This legislation underscores the importance of regular and meticulous inspection protocols to ensure the safety and reliability of the Percival Proctor Series Aeroplanes within Australian airspace.
Key Provisions
The Civil Aviation Regulations 1998, specifically within Part 39 - 105, detail the requirements for airworthiness directives concerning the Percival Proctor series aeroplanes. The key operative sections of this directive (AD/PROCTOR/11) mandate a thorough inspection of the airframe structure, with particular attention to the fabricated structural components and plywood skin. Section 1/73 requires the aeroplane to be prepared for inspection by removing various equipment and panels to ensure full access to the airframe (section 1(1)). The inspection itself must focus on identifying defects such as cracks, cuts, splits, and warping in both the structural components and the glued joints, as well as contamination and deterioration in the plywood skin (section 1(2)).
The obligations imposed by this directive are stringent and require compliance with specific timelines. Aircraft owners and operators must ensure that inspections are conducted within 12 months of the last inspection in accordance with AD/GENERAL/29, and thereafter at intervals not exceeding 12 months (section (a)). For aircraft that have not been inspected within the previous 12 months prior to 31 January 1973, an inspection must be completed within three months after this date, followed by inspections at intervals not exceeding 12 months thereafter (section (b)). Detailed guidance on the inspection process and acceptable practices, such as using a 0.005 in. feeler gauge and employing oblique lighting to detect defects, is provided to aid inspectors in their work.
Failure to comply with the requirements set out in AD/PROCTOR/11 can result in significant consequences. The regulations do not explicitly state specific penalties for non-compliance in this directive; however, non-compliance with airworthiness directives generally can lead to severe repercussions. These may include the grounding of the aircraft, fines, and potential criminal charges for operators who fail to adhere to these safety standards. The exact penalties can vary based on the severity of the breach and the jurisdiction under which the offence is prosecuted, but the overarching principle is to ensure the safety and airworthiness of the aircraft are maintained at all times.