AD/CHA/24 Amdt 1 - Seat Frames

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Parliament, provide the framework for ensuring aviation safety and were amended to include the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives to address specific safety issues. One such directive, AD/CHA/24 Amendment 1, pertains to American Champion (Aeronca, Bellanca) Series Aeroplanes and specifically addresses the problem of in-flight failures of folding seat backs that have been reported both domestically and internationally. The policy objective of this amendment is to enhance aircraft safety by requiring specific placards and inspections for seat frames in the mentioned aircraft models. This directive mandates the installation of placards to warn against prohibited actions during entry or exit and to restrict acrobatic operations unless certain inspections are conducted. Additionally, it requires detailed inspections of the seat back hinges and frames to detect and rectify any structural issues that could compromise safety. Compliance with these requirements must be achieved within specified timeframes to ensure that the aircraft remain airworthy.

Scope and Application

The Civil Aviation Regulations 1998, as detailed in Part 39 - 105, mandates specific airworthiness directives for American Champion (Aeronca, Bellanca) Series Aeroplanes, particularly those fitted with folding seat back frames. This regulation applies to all aircraft of this series that meet the specified criteria. It requires the installation of placards in specific areas to highlight prohibitions against certain actions, such as pulling or pushing on seat backs during entry or exit, and operating in the acrobatic category without prior inspection. Furthermore, it mandates detailed visual and non-destructive inspections of seat back hinges and frames to ensure structural integrity. Compliance with these directives is necessary within certain time frames post-service or at specific intervals depending on the operational category of the aircraft. The directive also references related service letters and approved modifications to ensure adherence to safety standards. The regulation extends its applicability to any aircraft operator within Australian jurisdiction, ensuring that the safety measures are uniformly enforced across all relevant aircraft. It does not specify exclusions but implicitly applies to all relevant aircraft models in service. The enforcement of these directives is supported by subordinate instruments and references to relevant Federal Aviation Administration advisories and service letters, ensuring a cohesive approach to maintaining airworthiness standards.

Key Provisions

The main operative sections of the Civil Aviation Safety Authority's Airworthiness Directive AD/CHA/24 Amendment 1 pertain to the seat frames of American Champion (Aeronca, Bellanca) series aeroplanes fitted with folding seat back frames. Section 1(a) requires the installation of a placard in a prominent position facing the door opening, stating "PULLING OR PUSHING ON SEAT BACK DURING ENTRY OR EXIT IS PROHIBITED". Section 1(b) mandates a placard in full view of the pilot stating "OPERATION IN ACROBATIC CATEGORY PROHIBITED UNLESS INSPECTION IN ACCORDANCE WITH AD/CHA/24 REQUIREMENT 3 HAS BEEN CARRIED OUT". Both placards must have lettering of no less than 3.5mm height, with the word "PROHIBITED" at least 40% larger than the other lettering. Section 2 involves a visual inspection of the seat back hinges for cracks, elongation of hinge bolt holes, or deformation using 10x magnification, and ensuring that hinge bolts are hex-headed AN3-7A secured with an AN365-1032 elastic stopnut. Section 3 requires a magnetic particle or dye penetrant inspection of specific areas for evidence of cracking. The Act imposes several obligations on the parties or entities it governs. Aircraft operators must ensure the placards are correctly installed and legible, as specified in Section 1(a) and 1(b). They must also conduct the visual inspections of the seat back hinges as outlined in Section 2 and perform the magnetic particle or dye penetrant inspections in accordance with Section 3. These inspections are to be carried out within specific timeframes depending on the category of operation. For example, the placards must be installed within 10 hours of the aircraft being in service after 26 April 1989. Visual inspections must occur at each maintenance release for Normal and Utility Category operations, and at intervals not exceeding 50 hours for Acrobatic Category operations, until the seat frames are replaced or modified as per American Champion Aircraft Service Letter 401 or an approved scheme. Failure to comply with the provisions of this Airworthiness Directive can result in serious consequences. Although the specific offences, penalties, or civil/criminal consequences are not detailed within the directive itself, non-compliance with Civil Aviation Regulations could lead to enforcement actions by the Civil Aviation Safety Authority. Such actions might include fines, suspension or revocation of aircraft certificates, and potential criminal charges if the non-compliance leads to an incident or accident. The severity of the penalties would depend on the specific nature and impact of the non-compliance, as well as any resulting harm or risk to aviation safety.