AD/GAF-N22/68 - Horizontal Stabiliser - Main Spar and Upper Skin

Overview

The Civil Aviation Regulations 1998, as amended by the Legislative instrument F2006B10217, were enacted to address the issue of fatigue cracks discovered in the horizontal stabiliser upper skin and main spar of Nomad N22 and N24 series aircraft. The Australian Government, through the Civil Aviation Safety Authority, introduced this legislation to ensure the safety and airworthiness of these aircraft. The policy objective behind this directive is to mitigate the risk of structural failure by mandating regular inspections and reporting of the condition of critical components, thereby enhancing the safety standards of civil aviation. The requirement is for operators to conduct a detailed visual inspection of the specified parts and report the findings to the Civil Aviation Safety Authority, ensuring compliance with set timelines for initial and subsequent inspections. The authority of the Civil Aviation Safety Authority to issue such directives stems from its mandate to regulate and oversee civil aviation safety within Australia, ensuring that aircraft remain in a safe and airworthy condition. This legislation specifically targets the Nomad N22 and N24 series aircraft fitted with modifications N663 and N768, highlighting the need for vigilance in the maintenance and inspection processes to prevent potential safety hazards.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 105, pertains to the application of Airworthiness Directives issued by the Civil Aviation Safety Authority (CASA). This particular legislative instrument concerns the GAF N22 and N24 series aeroplanes, mandating a detailed visual inspection of the horizontal stabiliser's main spar and upper skin for all Nomad N22 and N24 series aircraft fitted with modifications N663 and N768. The requirement extends to reporting the inspection findings to CASA, including the total service time of the horizontal stabiliser and the duration since the aforementioned modifications were implemented. Compliance with this directive necessitates an initial inspection before 100 hours of service time after 13 October 1994, or before 13 November 1994, whichever is sooner, followed by annual inspections or inspections conducted every 115 hours of service time. This regulation applies across the Commonwealth of Australia, imposing mandatory safety checks on the specified aircraft to address identified fatigue issues in the horizontal stabiliser. The scope of this directive is narrowly focused on ensuring the airworthiness of specific aircraft models by mandating regular inspections and reporting to CASA. It does not explicitly state any exclusions or exemptions, but the requirements are clearly defined for the specified aircraft and modifications. The directive may be extended or further specified through subordinate instruments issued by CASA, which may provide additional guidance or clarification on compliance procedures.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, outlines the schedule of airworthiness directives, including AD/GAF-N22/68 for the Nomad N22 and N24 series aeroplanes (Section 11). This directive mandates a detailed visual inspection of the horizontal stabiliser's main spar and upper skins, as these components have been found to develop fatigue cracks over time (Section 11). The inspection must be performed in accordance with the instructions set out in Nomad Alert Service Bulletin ANMD-55-32 (Section 11). Operators must report the findings of the inspection to the Civil Aviation Safety Authority, detailing both negative and positive outcomes, along with the total time the horizontal stabiliser has been in service and the time elapsed since modifications N663 and N768 were fitted (Section 11). The Civil Aviation Regulations impose several obligations on the parties governed by AD/GAF-N22/68. Operators must ensure that the initial inspection is conducted before the aircraft reaches 100 hours of time in service after 13 October 1994, or before 13 November 1994, whichever comes first (Section 11). After the initial inspection, the horizontal stabiliser's spar and skins must be re-inspected at each maintenance release inspection but not less frequently than annually or every 115 hours of time in service (Section 11). Additionally, operators are required to submit a report to the Authority detailing the results of the inspections, including any identified issues and the relevant service times (Section 11). Failure to comply with the provisions of AD/GAF-N22/68 can lead to serious consequences. The Civil Aviation Regulations do not explicitly detail specific penalties or consequences for non-compliance with this airworthiness directive. However, non-compliance with airworthiness directives generally can lead to enforcement actions by the Civil Aviation Safety Authority, which may include fines, the grounding of the aircraft, or other regulatory measures to ensure safety. The severity of the penalties can vary depending on the nature and extent of the non-compliance and its impact on aviation safety.