AD/F28/63 Amdt 1 - Horizontal Stabiliser Attach Fitting

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, address the maintenance and safety of aircraft by establishing Airworthiness Directives (ADs). This legislative instrument was enacted by the Commonwealth of Australia to ensure that civil aviation operations comply with safety standards and mitigate any risks that could compromise flight safety. The policy objective behind these regulations is to safeguard public safety by enforcing stringent airworthiness standards and issuing directives to address identified safety issues. In this context, AD/F28/63 Amendment 1 pertains to the Fokker F28 series aeroplanes, targeting serial numbers 11003 through 11151, and 11991 and 11992. This directive mandates actions to replace specific aluminium fittings to prevent stress corrosion, which was identified as a potential risk to the structural integrity of the horizontal stabilizer attach fittings. The amendment aims to align with the technical requirements of the new RLD AD, ensuring the aircraft meet necessary safety standards before a specified compliance date.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the application of airworthiness directives for certain aircraft, including Fokker F28 series aeroplanes. This particular regulation, AD/F28/63 Amendment 1, pertains to the horizontal stabilizer attach fitting for models F28 with serial numbers 11003 through 11151, and 11991 and 11992. The directive requires compliance with the technical requirements outlined in RLD AD 92-11-9, mandating actions to mitigate the risk of stress corrosion affecting the aluminium AL7079 material used in the horizontal stabilizer attach fittings. Compliance with this directive must be achieved prior to 1 November 1995. The amendment was prompted by a report detailing a major crack in the RH upper lug of the horizontal stabilizer attach fitting, which was attributed to stress corrosion. To address this safety concern, the directive mandates the replacement of all aluminium AL7079 fittings with units made from AL7075-T73, which exhibits lower susceptibility to stress corrosion and thus reduces the risk of hazardous movement of the horizontal stabiliser.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, includes a directive concerning the airworthiness of Fokker F28 Series Aeroplanes, identified by the Airworthiness Directive (AD) number AD/F28/63 Amendment 1. This directive applies to Fokker F28 series aeroplanes with serial numbers ranging from 11003 through 11151, and specifically to serial numbers 11991 and 11992 (section 1). The primary requirement of this directive is to comply with the technical specifications outlined in RLD AD 92-119. This includes replacing the aluminium AL7079 horizontal stabilizer attach fittings with those made from AL7075-T73, a material less susceptible to stress corrosion (section 2). Compliance with this directive is mandatory and must be achieved prior to 1 November 1995. The directive is a response to a reported major crack in the right horizontal stabilizer attach fitting, which was found to be the result of stress corrosion in the aluminium AL7079 material. This type of crack could lead to lug fracture and result in hazardous movement of the horizontal stabilizer, thereby compromising the safety of the aircraft (section 3). The directive seeks to mitigate this risk by mandating the replacement of vulnerable fittings with a more reliable material. The obligations imposed by this directive on the relevant parties include ensuring that the specified Fokker F28 series aeroplanes are inspected for the presence of aluminium AL7079 fittings and subsequently replaced with AL7075-T73 fittings if necessary. Operators of these aircraft must ensure that all required modifications are completed by the specified deadline, and must maintain records of compliance with the directive (section 4). Failure to comply with this directive can have serious consequences, as it directly affects the airworthiness and safety of the aircraft involved. There are potential civil and criminal consequences for non-compliance with this airworthiness directive. Civil penalties can include fines, and in severe cases, the grounding of the affected aircraft until the required modifications are completed. Criminal penalties may also apply, particularly if non-compliance is found to have directly contributed to an aviation incident or accident. The exact penalties are determined by the relevant authorities and can vary depending on the severity and circumstances of the non-compliance (section 5).