AD/STRIKEMASTER/4 - Port and Starboard Mainplane Spar Upper Attachment Lugs

Overview

The Civil Aviation Regulations 1998, as amended, provide a framework for ensuring the safety of civil aviation in Australia. Part 39 - 105 of these regulations specifically addresses the issue of airworthiness directives for particular aircraft types. The problem this legislation seeks to address is the occurrence of cracking in the port and starboard mainplane spar upper attachment lugs of BAC 167 Strikemaster Series Aeroplanes. This issue was identified through prior incidents where such cracks could not be reliably detected using existing ultrasonic techniques, necessitating more stringent and invasive inspection procedures to ensure safety. The regulations were enacted by the Australian Parliament and aim to ensure that the aviation industry maintains the highest safety standards. The policy objective is to mitigate the risk of in-flight structural failure by enforcing regular and thorough inspections of specified aircraft components. The Civil Aviation Regulations 1998 are administered by the Civil Aviation Safety Authority (CASA) under the authority granted by the Australian Parliament. These regulations include specific airworthiness directives that address identified safety concerns for particular aircraft models. For the BAC 167 Strikemaster Series Aeroplanes, the regulations mandate inspections of the mainplane spar upper attachment lugs at specified intervals to detect any cracking. The directive requires inspections to occur at intervals not exceeding 150 flying hours after achieving certain flight intervals or hours in service, and following specific events such as heavy landings or excessive "g" loading. The intention behind these measures is to ensure that the identified safety issues are promptly and effectively addressed, thereby maintaining the airworthiness and safety of the aircraft.

Scope and Application

The Civil Aviation Regulations 1998, as amended, specifically within Part 39 - 105, pertains to airworthiness directives, including those issued for the BAe (BAC 167) Strikemaster Series Aeroplanes. This legislation applies to all BAC 167 aircraft models, both pre-modification 7061 that have completed 15 flight inspections (F.I.) or 1000 hours of time in service, and post-modification 7061 aircraft that have completed 40 F.I. The directive is a Commonwealth regulation under the Civil Aviation Act 1988, exercising the safety oversight responsibilities of the Civil Aviation Safety Authority (CASA). It is designed to address a specific safety concern related to the upper attachment lugs of the port and starboard mainplane spars, which have exhibited a tendency to crack, a condition not reliably detectable via existing ultrasonic techniques. Compliance with this directive mandates an inspection of these lugs for cracking, as specified in BAe CSI/STRIKEMASTER/50, at the next service interval of 150 flying hours after 5 December 1996, and subsequently at intervals not exceeding 150 flying hours. The requirement also applies to inspections following each heavy landing or excessive "g" loading after 07 November 1996. This directive extends its reach nationally, ensuring uniform safety standards across the Australian aviation industry.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, include a Schedule of Airworthiness Directives pertinent to the BAe (BAC 167) Strikemaster Series Aeroplanes. One such directive, AD/STRIKEMASTER/4, addresses the inspection of the port and starboard mainplane spar upper attachment lugs for cracking (section 1). This directive applies to all BAC 167 marks that have either achieved 15 flight inspections (F.I.) or 1000 hours of time in service if pre-modification 7061, and 40 flight inspections or if post-modification 7061 (section 2). The directive references BAe CSI/STRIKEMASTER/50 for the inspection protocol and notes the UK CAA MPD 1995-109 for background information (section 3). Under the Civil Aviation Regulations 1998, operators of BAC 167 aeroplanes are required to comply with AD/STRIKEMASTER/4 by conducting inspections as stipulated. Specifically, inspections must be carried out at the next 150 flying hour service after 5 December 1996, at intervals not exceeding 150 hours of time in service thereafter, and at each heavy landing or excess “g” loading after 7 November 1996 (section 4). The inspections must be performed by removing the wings and following the technique specified in the Requirement Document, as existing ultrasonic techniques cannot reliably detect the cracking in-situ (section 5). Failure to comply with the airworthiness directive may lead to non-compliance with civil aviation safety standards. This non-compliance could potentially result in aircraft being deemed unairworthy, leading to grounding and possibly severe regulatory actions. The specific penalties or consequences for non-compliance are not detailed within the text of this directive; however, they would typically align with broader provisions within the Civil Aviation Regulations 1998, which may include fines, enforcement actions, or other regulatory measures. The regulations emphasise the importance of adherence to such directives to ensure the safety and airworthiness of the aircraft involved.