AD/DHC-2/10 Amdt 8 - Lift Strut and Lift Strut Attachment Fittings

Overview

The Civil Aviation Safety Authority (CASA) established the DHC-2 (Beaver) Series Aeroplanes AD/DHC-2/10 Amendment 8, issued under the Civil Aviation Regulations 1998, to address the problem of fatigue cracking in the lift struts and their attachments of DHC-2 series aeroplanes. This legislative instrument was enacted to enhance safety by implementing specific inspection and replacement requirements based on fatigue testing and analysis conducted by the manufacturer following several in-flight failures. The policy objective is to prevent and detect fatigue cracking, thus ensuring the continued airworthiness of the aircraft. The directive includes detailed inspection intervals and retirement lives for various components, specifically tailored to whether the aircraft has been engaged in agricultural operations or not.

Scope and Application

The Civil Aviation Regulations 1998, under Part 39 - 105, apply to all DHC-2 (Beaver) Series Aeroplanes through the Airworthiness Directive AD/DHC-2/10 Amendment 8, which pertains specifically to lift strut and lift strut attachment fittings. This directive applies to all models of the DHC-2 series aeroplanes and mandates regular inspections and replacements to ensure the safety and airworthiness of the aircraft. The directive outlines the necessity for fluorescent penetrant inspections for cracking of the upper attachment fitting of each lift strut, replacement of complete lift struts, and replacement of wing/strut and fuselage/strut attachment fittings, all within specified intervals and lives detailed in the compliance table. Additionally, it requires checks for looseness of lift strut attachment bolts and any evidence of misalignment, with mandatory corrections before further flight. The directive also mandates the replacement of strut upper and lower attachment bolts. The requirements are differentiated based on whether the components have been used in agricultural operations, affecting both inspection intervals and retirement lives. This regulation extends its applicability across the Commonwealth of Australia, ensuring compliance at a national level.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, include Airworthiness Directives (AD) for specific aircraft, such as the DHC-2 (Beaver) series aeroplanes. The AD/DHC-2/10 Amendment 8 pertains to the lift strut and lift strut attachment fittings, detailing several critical requirements to ensure safety (AD/DHC-2/10, para 1). Firstly, operators must perform a fluorescent penetrant inspection for cracks on the upper attachment fitting of each lift strut as specified in the compliance table, item (1). Secondly, the complete lift struts must be replaced with new ones at the lives outlined in the compliance table, item (1). Additionally, operators are instructed to replace the wing/strut and fuselage/strut attachment fittings with new ones at the specified lives in the compliance table, items (2) and (3). Moreover, it is essential to check for looseness of the lift strut attachment bolts and any evidence of misalignment of the strut or of the wing and fuselage strut attachment fittings at intervals specified in the compliance table, item (4). Any misalignment or looseness must be corrected before further flight. Lastly, strut upper and lower attachment bolts must be replaced with new bolts at the times specified in the compliance table, item (5). The AD imposes specific obligations on the operators of DHC-2 (Beaver) series aeroplanes to ensure compliance with the outlined requirements. Operators must conduct the specified inspections and replacements at the prescribed intervals and lives as detailed in the compliance table. Failure to adhere to these requirements could lead to significant safety risks, as the directive is designed to prevent fatigue cracking in the lift strut and its attachments. Additionally, operators must also be mindful of de Havilland Aircraft Company of Canada Service Bulletin No 2/43, which cautions against using the lift strut for mooring the aircraft or attaching external loads, as such uses may reduce the fatigue life of the lift strut assembly. Failure to comply with the AD/DHC-2/10 Amendment 8 may result in severe consequences. While the Civil Aviation Regulations 1998 do not explicitly state the penalties for non-compliance, general aviation regulations often include significant civil or criminal penalties for breaches. In Australia, non-compliance with airworthiness directives can result in fines, suspension of the aircraft's certificate of airworthiness, or even criminal charges if the non-compliance leads to an accident or incident. The maximum penalties can vary, but they are designed to ensure stringent adherence to safety standards to protect public safety.