Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, serve as the primary legislative instrument governing civil aviation safety in the country. Part 39 - 105, concerning the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, specifically addresses the Hawker Siddeley HS 748 Series Aeroplanes. This part was introduced to address the problem of potential structural weaknesses in the “W” frame socket fitting inspection holes of the HS 748 aircraft, which can compromise airworthiness. The legislation aims to ensure the safe operation of these aircraft by mandating detailed inspections and necessary rework of these critical components. CASA, through this regulatory framework, seeks to maintain high safety standards in civil aviation, protecting both passengers and crew from potential hazards arising from mechanical failures.

Scope and Application

The Civil Aviation Safety Authority (CASA) Regulations, particularly PART 39 - 105, addresses the maintenance and safety requirements for specific aircraft types, including the British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes. This particular legislative instrument focuses on the engine mount structure "W" frame socket fittings inspection holes, applying to all HS748 aircraft. The requirements outlined in the regulations are intended to ensure the continued airworthiness and safety of the aircraft by mandating detailed inspections and, where necessary, corrective actions on the "W" frame structure. The legislation specifies the detailed visual inspection procedures, referencing Jetstream Preliminary Technical Leaflet (PTL) 501 Issue 2, which serves as the actioning document for compliance. Compliance with these regulations is mandatory, with specific deadlines and conditions for inspections and reworks to be conducted by the relevant operators or maintenance providers. The regulations also reference relevant UK Civil Aviation Authority (CAA) directives and technical bulletins, ensuring a cohesive international approach to addressing the identified safety issues.

Key Provisions

The Civil Aviation Regulations 1998, Part 39, specifically addressing the British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes, includes an Airworthiness Directive (AD) labelled as AD/HS 748/13. This AD pertains to the inspection and potential rework of the “W” frame socket fitting inspection holes (Section 5/95). The primary requirement (Section 1) is to perform a detailed visual inspection of these holes to ascertain whether fasteners have been installed or the holes reworked. This inspection must follow the guidelines set out in Jetstream Preliminary Technical Leaflet (PTL) 501 Issue 2, specifically Para 2.1 Part One. A second inspection (Section 2) must occur with the “W” frame removed, adhering to Para 2.2 Part Two of the same leaflet. Finally, all inspection holes must undergo a Magnetic Particle inspection and be reworked if necessary, as outlined in Para 2.3 Part Three. The directive references the CAA(UK) AD 002-09-94 for additional context. Compliance with these directives involves several steps. Initially, the inspection mandated by Requirement 1 must be completed before 27 April 1996 (Section 1). The second inspection, as per Requirement 2, must be conducted before the initial installation on an aircraft or at the next “W” frame removal. Requirement 3, which calls for inspection and rework if fasteners or reworked holes are found, must be executed at the next “W” frame removal or before 27 April 1996, whichever is earlier (Section 3). Adherence to Jetstream PTL 501 Issue 2 is critical, as it serves as the actionable document for Jetstream Service Bulletin HS748-71-33. The background to these stringent inspections stems from issues highlighted in Jetstream Customer Bulletin No241C, which revealed that drive screws had been inserted into the inspection holes. These screws create sharp grooves in a highly stressed area, leading to reported cracks in “W” frames. Additionally, some holes have been reworked beyond their original diameters, underscoring the necessity for thorough and timely inspections. Failure to comply with these directives could result in serious consequences. While specific penalties are not outlined in the provided text, non-compliance with Civil Aviation Regulations can typically lead to enforcement actions, including fines and potential grounding of the aircraft. These measures are intended to ensure the safety and airworthiness of the aircraft, thereby protecting both crew and passengers. The regulatory framework is designed to prevent structural failures and ensure the longevity and reliability of the HS 748 aircraft.