AD/P68/22 Amdt 4 - Wing Lower Front and Rear Spar Assemblies

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, address the problem of cracks found in the front and rear lower spar cap angles of Partenavia P68 Series aeroplanes. This issue was identified in several Australian aircraft where the horizontal flange of the spar cap angles tapered down near the wing-fuselage attachment, leading to potential safety risks. The Civil Aviation Safety Authority, acting under the authority of the Australian Government, introduced these regulations to ensure the safety of aircraft operations by mandating specific inspections and modifications to the affected aircraft. The overarching policy objective is to maintain and enhance the airworthiness of aircraft through regular inspections and necessary modifications as identified by the manufacturer and endorsed by the authority. The latest amendment to the directive incorporates Partenavia Service Bulletin No. 65 Revision 2, which provides a re-designed front spar reinforcement and includes variations to the rear spar repair scheme. The regulations require inspections to be carried out at specific intervals based on the aircraft's time in service and mandate the use of approved fasteners and reinforcement techniques to prevent corrosion. Compliance with these directives is essential for all P68 series aircraft up to serial number 347, ensuring the structural integrity and safety of these aircraft in operation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to airworthiness directives issued by the Civil Aviation Safety Authority (CASA). This particular directive, AD/P68/22 Amendment 4, applies to all Partenavia P68 series aeroplanes with serial numbers up to and including S/No 347. The directive mandates inspections of the wing lower front and rear spars for cracks in accordance with Partenavia Service Bulletin No. 65 Revision 2. It applies across the Commonwealth of Australia and involves both domestic and potentially international operators of these aircraft. The directive does not specify any exclusions, but the amendment notes that later serial number aircraft are exempt from its requirements. The directive can be extended or restricted through subordinate instruments, which would be detailed in future amendments or service bulletins.

Key Provisions

The Civil Aviation Safety Authority's Airworthiness Directives (ADs) under the Civil Aviation Regulations 1998 mandate specific inspection and maintenance requirements for Partenavia P68 series aeroplanes, particularly focusing on the wing lower front and rear spar assemblies (AD/P68/22 Amendment 4). This directive applies to all P68 series aircraft up to and including serial number 347. It requires a detailed inspection of the wing front and rear spars for cracks in accordance with Partenavia Service Bulletin No. 65 Revision 2 (section 1). Aircraft that have been inspected under the initial issue of this AD must undergo further inspection as per this amendment. Importantly, inspections conducted under Amendment 1 or subsequent versions satisfy the inspection requirements of this latest amendment (section 1). To ensure compliance, the AD outlines specific obligations. Aircraft with front spar modifications per previous or current AD issues are exempt from repetitive front spar inspections (section 2). However, those with rear spar modifications prior to Amendment 3 require additional rework as specified (section 3). It is crucial that when performing modifications to the front and rear spars, reinforcement plates and fasteners are wet assembled with appropriate jointing compounds or sealants such as Hylomar SQ-32, PR1436G, PR1422, or similar to prevent corrosion (section 4). For rear spar modifications, specific rivets and bolts must be used, with substitutions requiring prior approval (section 5). Compliance with the AD mandates inspections at specific intervals. For aircraft that have logged 1800 hours of service, inspections must be conducted within 25 hours after 20 September 1984 and subsequently at intervals not exceeding 500 hours (section 1). For all other aircraft, inspections must occur before reaching 1800 hours and then at intervals not exceeding 500 hours (section 1). Additionally, aircraft with rear spar modifications prior to Amendment 3 must incorporate the variations specified in the AD before their next maintenance release after 1 December 1984 (section 3). Failure to comply with the AD can lead to serious consequences. The AD outlines potential penalties for non-compliance, although specific maximum penalties are not detailed in the provided text. Non-compliance with ADs can result in civil penalties, including fines, as well as potential criminal charges if the non-compliance leads to safety incidents. Furthermore, non-compliant aircraft may be grounded, preventing operation until the necessary inspections and modifications are completed, thereby impacting the aircraft's airworthiness and the operator's ability to fly the aircraft.