AD/CESSNA 185/2 Amdt 4 - Rear Spar

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Government, establish a comprehensive framework for the safety and operation of civil aviation within Australia. This regulatory regime, overseen by the Civil Aviation Safety Authority (CASA), aims to ensure the highest standards of safety and efficiency in the aviation sector. One particular legislative instrument, F2006B05110, addresses the specific issue of ensuring the airworthiness of Cessna 185 Series Aeroplanes, particularly focusing on the structural integrity of the rear spars. This directive aims to prevent potential safety risks associated with structural failures by mandating modifications and inspections of the rear spars. The policy objective is clear: to mitigate the risk of in-flight structural failure by enforcing timely and rigorous maintenance and inspection protocols. This legislative instrument is a testament to the Australian Government's commitment to maintaining stringent safety standards in civil aviation, ensuring that all aircraft, particularly those used in agricultural operations, adhere to the highest standards of airworthiness. By setting forth detailed requirements for the modification and inspection of rear spars on Cessna 185 Series Aeroplanes, the regulations underscore the importance of proactive maintenance and the need for rigorous oversight to safeguard against potential hazards.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, apply to all Cessna 185 series aeroplanes, with the exception of models equipped with rear spars P/Nos. 0523400-90 LH and -91 RH; 0523400-111 LH and -112 RH. These regulations are mandated by the Civil Aviation Safety Authority and are intended to ensure the airworthiness of these aircraft. The regulations require modifications to the rear spar root, left and right mainplanes on all agricultural aeroplanes, which must be done in accordance with Rex Aviation Drawing RA-491 or an alternative scheme approved by the Secretary. Furthermore, there are stringent inspection requirements for the mainplane rear spar web for fatigue cracks, the upper flange of the rear spar channel, and the trailing edge root end rib, which must be carried out using appropriate inspection tools and methods. The compliance timeframes vary depending on whether the aeroplanes have been modified to Rex Aviation Drawing RA-491 or not, with modified aeroplanes required to adhere to inspections at intervals not exceeding 500 hours, and non-modified aeroplanes at intervals not exceeding 100 hours. This regulatory framework is applicable nationally and ensures that the specified maintenance and modification standards are uniformly enforced across all jurisdictions within Australia.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the authority of the Civil Aviation Safety Authority (CASA), mandate airworthiness directives for certain aircraft models. Section AD/CESSNA 185/2 Amendment 4 addresses the rear spar of Cessna 185 series aeroplanes, excluding models with specific rear spar part numbers (0523400-90 LH and -91 RH; 0523400-111 LH and -112 RH). This directive requires modifications to the rear spar root on the left and right mainplanes of all agricultural aeroplanes, as per Rex Aviation Drawing RA-491 or an approved alternative scheme (Section 1). It also mandates detailed inspections of the rear spar web for fatigue cracks in the root area, using a magnifying glass with at least 4X magnification or an approved device like the "Syte Ade" (Section 2). Additionally, it requires inspection of the upper flange of the rear spar channel at the outer end of the attachment fitting, which can be done through the flap bay inner inspection panel (Section 3). If there is doubt about the presence of cracks due to the close fit of the trailing edge root end to the spar, the trailing edge root end rib must be removed for a more detailed inspection (Section 4). The obligations imposed by these regulations are clear and specific. Owners or operators of affected Cessna 185 series aeroplanes must ensure modifications are made to the rear spar root as outlined in the directive (Section 1). Furthermore, they must conduct inspections of the mainplane rear spar web and the upper flange of the rear spar channel at regular intervals. For aeroplanes modified to Rex Aviation Drawing RA-491, inspections must occur at intervals not exceeding 500 hours of time in service. For all other aeroplanes, inspections must occur at intervals not exceeding 100 hours of time in service (Sections 2, 3, and 4). Failure to comply with these airworthiness directives can lead to significant legal consequences. Although specific offences and penalties are not detailed within the directive, non-compliance with CASA's airworthiness directives generally results in enforcement actions which can include fines, suspension or revocation of airworthiness certificates, and potential criminal charges if the non-compliance leads to accidents or endangers safety. The maximum penalties can vary widely depending on the severity of the breach and any resultant harm, but they can include substantial fines and imprisonment for individuals found guilty of criminal offences under the Civil Aviation Act 1988.