AD/BN-2/62 - Wing Spar Cap

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, aim to ensure the safety and integrity of civil aviation operations within the country. Among its various provisions, Part 39 - 105 pertains to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, addressing specific safety concerns for certain aircraft types. One such directive, AD/BN-2/62, targets the Pilatus Britten-Norman BN-2 Series Aeroplanes, specifically the BN2, BN2A, BN2B, and BN2T Islanders. This directive was introduced to address the issue of cracks in the wing spar caps, which could compromise the structural integrity of the aircraft if left unaddressed. The policy objective behind this directive is to mandate regular inspections and repairs to maintain the safety standards of these aircraft, thereby preventing potential accidents and ensuring the continued safety of passengers and crew. The directive requires a thorough inspection of the top rear-spar cap, the web plates, and the support brackets for any signs of cracks around bolts, fasteners, and rivets. The inspection can be conducted using either a flexible fiberscope or visual aids like a torch and mirror. Any aircraft found with vertical cracks or horizontal cracks longer than 6.35 mm must be repaired immediately. Furthermore, the directive specifies compliance requirements, including inspection intervals and conditions for continued airworthiness. The directive became effective on 7 January 1998, highlighting the urgency and importance of adhering to these safety measures.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Pilatus Britten-Norman BN2, BN2A, BN2B and BN2T Islanders registered in Australia. This legislation mandates the inspection of the top rear-spar cap, the web plates, and the support brackets for any cracks around bolts, fasteners, and rivets. The inspections can be conducted either through the use of a flexible fiberscope or visually with a torch and mirror, as per the instructions provided in Pilatus Britten Norman Service Bulletin BN2/SB.237. Any aircraft found with vertical cracks of any length or horizontal cracks longer than 6.35 mm (0.25 inch) must be repaired. The directive also specifies inspection intervals and conditions for aircraft that have previously been inspected without cracks detected, ensuring ongoing compliance with safety standards. This directive became effective on 7 January 1998 and applies to all aircraft found to have horizontal cracks less than 6.35 mm (0.25 inch) at intervals not exceeding 50 landings, or aircraft last inspected visually at intervals not exceeding 500 landings or 250 hours time in service, whichever occurs first, or aircraft last inspected using a flexible fiberscope at intervals not exceeding 500 hours time in service.

Key Provisions

The main operative sections of this Civil Aviation Safety Authority directive (AD/BN-2/62) pertain to the inspection and repair of specific parts of Pilatus Britten-Norman BN-2 Series aeroplanes. Specifically, Section 1 requires an inspection of the top rear-spar cap, the web plates, and the support brackets for cracks around the bolts, fasteners, and rivets as detailed in Pilatus Britten Norman Service Bulletin BN2/SB.237. This inspection can be conducted either by using a flexible fiberscope or visually with a torch and mirror. Section 2 mandates that any aircraft found with vertical cracks of any length and/or horizontal cracks exceeding 0.25 inches (6.35 mm) must be repaired. Compliance with these sections is critical for ensuring the aircraft's airworthiness. The obligations and requirements imposed by this directive on the parties or entities it governs are primarily concerned with the regular inspection and maintenance of the specified parts of the aircraft. Section 1 of the directive stipulates that inspections must be carried out before 30 January 1998, and thereafter at specified intervals based on the aircraft's previous inspection methods and findings. For aircraft found with horizontal cracks less than 0.25 inches (6.35 mm), inspections must be conducted at intervals not exceeding 50 landings. For aircraft last inspected visually with no cracks detected, inspections must occur at intervals not exceeding 500 landings or 250 hours of service, whichever comes first. For aircraft last inspected using a flexible fiberscope with no cracks detected, inspections must occur at intervals not exceeding 500 hours of service. Furthermore, inspections must be completed before any further flight. Failure to comply with this airworthiness directive can result in significant consequences. Section 3 of the directive indicates that non-compliance could lead to the aircraft being deemed unairworthy, thereby preventing it from further operation until the required inspections and repairs are conducted. While the specific penalties for non-compliance are not detailed in the directive, the overarching legal framework under which the Civil Aviation Regulations operate provides for both civil and criminal penalties. For instance, in the civil context, breaches of aviation safety regulations can lead to fines and other financial penalties. In the criminal context, serious breaches may result in imprisonment. The exact penalties would depend on the nature and severity of the breach, as well as other relevant circumstances.