AD/BN-2/23 Amdt 1 - Woodward Propeller Governor Drive Shaft - Inspection and Replacement

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, establishes a schedule of airworthiness directives aimed at maintaining the safety and operational standards of aircraft within Australia. This legislative instrument, F2006B04734, focuses on the Pilatus Britten-Norman BN-2 Series Aeroplanes, addressing the need to inspect and replace specific components of the Woodward Propeller Governor Drive NK Shaft. The objective of this regulation is to ensure that these critical components are regularly assessed for structural integrity and replaced as necessary to prevent potential failures that could compromise aircraft safety. The enactment of these regulations by the Commonwealth of Australia is overseen by the Civil Aviation Safety Authority, with the overarching policy goal of enhancing the safety and reliability of civil aviation through stringent and proactive maintenance directives. The regulation mandates inspections of the governor drive shaft P/N 210206 for any signs of cracking at specific points, as well as the retirement of certain shafts based on their service hours and identification markers. This approach ensures that the risks associated with the identified components are managed effectively, thereby safeguarding the safety of air travel. The requirement for compliance includes a detailed schedule for inspections and replacements, reflecting a commitment to rigorous oversight and maintenance practices in the aviation sector.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates certain safety directives for Pilatus Britten-Norman BN-2 Series Aeroplanes. This particular amendment, AD/BN-2/23, pertains to the inspection and replacement of the Woodward Propeller Governor Drive NK Shaft. The directive applies to all models of the BN-2 series aeroplanes that are equipped with specific Woodward Governor parts numbers: 210275, F210444, 210655, or 210669. The requirement necessitates a detailed inspection of the governor drive shaft P/N 210206, particularly focusing on detecting any cracks at the radially disposed slots adjacent to the drive splines, using either magnetic particle inspection or an approved dye penetrant method. Additionally, it mandates the retirement from service of governor drive shafts P/N 210206, irrespective of whether they are identified with the letter "W" on the drive end. The compliance schedule stipulates inspections at specific intervals, based on the total time in service of the shafts, ensuring these critical components are maintained within safe operational parameters. The regulation's jurisdictional reach is national, applying uniformly across Australia, and it is overseen by the Civil Aviation Safety Authority (CASA).

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, contain a schedule of airworthiness directives for various aircraft, including the Pilatus Britten-Norman BN-2 Series Aeroplanes. One such directive is AD/BN-2/23 Amendment 1, which concerns the Woodward Propeller Governor Drive NK Shaft. This directive applies to all models equipped with certain Woodward Governor parts numbers: 210275, F210444, 210655, or 210669. The primary requirements set out in this directive are inspections and replacements of the governor drive shaft, particularly the P/N 210206 shaft. The AD mandates that the governor drive shaft, identified by P/N 210206, must be inspected for cracks at the radially disposed slots adjacent to the drive splines using either a magnetic particle method or an approved dye penetrant method. The inspection must not be conducted on shafts that have the letter "W" on the drive end. Furthermore, shafts without the "W" letter must be retired from service. Even those with the "W" letter must also be retired before the shaft exceeds 4600 hours of total time in service. The directive references Britten Norman Service Bulletin BN-2/SB.53 Issue 4 and Woodward Service Bulletins 33538 and 33539C for detailed instructions on how to remove the shaft. Compliance with this directive requires adherence to specific inspection and replacement schedules. Initially, an inspection must be performed within 100 hours of the aircraft's time in service after 31 March 1972 and subsequently at intervals not exceeding 200 hours. For shafts that have accumulated 1700 or more hours of total time in service, an inspection is required within 100 hours of service; for those with less than 1700 hours of total time in service, an inspection must be conducted before reaching 1800 hours. Ultimately, all shafts must be retired from service before they exceed 4600 hours of total time in service. Failure to comply with the requirements set forth in this airworthiness directive can result in serious consequences. While the Civil Aviation Regulations 1998 do not explicitly outline penalties for non-compliance with airworthiness directives in this particular section, non-compliance generally leads to significant civil and potentially criminal repercussions. Civil penalties can include fines, enforcement actions, and operational restrictions imposed by the Civil Aviation Safety Authority (CASA). In more severe cases, non-compliance may also lead to criminal charges, where individuals or entities could face imprisonment or substantial fines under the relevant aviation and safety legislation. The exact penalties would depend on the specific nature and impact of the non-compliance.