AD/DHC-2/13 - Wing - Inspection and Modification

Overview

The Civil Aviation Regulations 1998, as amended, were enacted to regulate civil aviation activities and ensure safety within Australia. Part 39, specifically, includes safety directives for various aircraft, with one such directive being AD/DHC-2/13 concerning DHC-2 (Beaver) Series Aeroplanes used in agricultural operations. This directive was introduced to address potential safety risks associated with wing integrity in these aircraft, particularly those engaged in agricultural activities, where the wings might be subject to undue stress and wear. The policy objective is to ensure that these aircraft remain airworthy by mandating regular inspections and, where necessary, modifications to critical components such as the wing lower surface to prevent structural failure. Compliance with these directives is overseen by the Civil Aviation Safety Authority and is mandatory for maintaining airworthiness before each wing attains a total of 10,000 hours of service time.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the inspection and modification of the wing lower surface for DHC-2 (Beaver) Series aeroplanes involved in agricultural operations. This applies to all models of these aeroplanes that have been engaged in such operations at any point. The requirement entails conducting an internal inspection for cracking in the wing lower surface, specifically at Rib Station 110 (Wing Station 137). The inspection must focus on the wing skin at the outboard rivet line of the chordwise skin joint and the lower aft flange of the spar, employing visual and fluorescent penetrant methods. If any cracks are detected, the wing must be repaired according to an approved repair scheme. Additionally, for wings that do not exhibit cracks in the specified area, reinforcement of the wing lower surface is mandated in accordance with DH Canada Drawing C2Z-3111, with advice and drawing copies available from Hawker De Havilland Australia. Compliance with these requirements is necessary before each wing accumulates a total of 10,000 hours of service time. This regulation extends throughout the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority, and applies uniformly across all states and territories.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, address the requirements for ensuring the airworthiness of DHC-2 (Beaver) Series Aeroplanes engaged in agricultural operations. The regulation, AD/DHC-2/13, mandates critical inspections and modifications to ensure the safety of these aircraft (section 3/66). The main requirement is an internal inspection of the wing lower surface in the region of Rib Station 110 (Wing Station 137) to detect any cracking (section 3/66). This inspection must focus on two key areas: the wing skin at the outboard rivet line of the chordwise skin joint for a distance of 10 inches forward and aft of the spar, and the lower aft flange of the spar and the spar boom on the lower forward face of the spar (section 3/66). The inspection must be conducted using visual and fluorescent penetrant methods (section 3/66). Operators of DHC-2 (Beaver) Series Aeroplanes must ensure compliance with these inspection requirements before each wing reaches a total of 10,000 hours of time in service (section 3/66). If cracks are identified during the inspection, the wing must be repaired according to an approved repair scheme (section 3/66). For wings that do not show signs of cracking, a modification must be performed to reinforce the wing lower surface in accordance with DH Canada Drawing C2Z-3111 (section 3/66). This reinforcement is critical to maintaining the structural integrity of the wing. To facilitate the inspection and modification, operators should contact Hawker De Havilland Australia for guidance and access to the necessary reference drawing (section 3/66). Failure to comply with these provisions may result in significant consequences. The regulations do not explicitly detail the penalties for non-compliance; however, breaches of airworthiness directives typically result in enforcement actions that can include fines, operational restrictions, or the grounding of the affected aircraft until the required inspections and modifications are completed. These actions are designed to ensure that the aircraft maintain the highest standards of safety and airworthiness, protecting both the operators and the public from potential hazards.