AD/SF340/24 - Wing and Stabilizer Rework and Reinforcements

Overview

The Civil Aviation Regulations 1998, amended by F2006B06953, were enacted to ensure the safety and airworthiness of aircraft operating within Australian airspace. This specific legislative instrument addresses the identified fatigue critical issues in certain Saab SF340 series aeroplanes, particularly concerning the wing attach fastener holes and horizontal stabilizer spars. The regulation was introduced to mandate compliance with the technical requirements outlined in Swedish Airworthiness Directive No 1-035 Revision A, issued 29 June 1990, for Saab SF340 aeroplanes. The policy objective is to ensure that these aircraft remain airworthy and safe for operation by requiring specific rework and reinforcements before the aeroplanes exceed 16,000 flight cycles, thereby mitigating the risks associated with fatigue in critical structural components. This was enacted by the Australian Government to align with international safety standards and ensure the integrity of aircraft operations within Australia.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Civil Aviation Safety Authority’s schedule of airworthiness directives, which includes AD/SF340/24 for the Saab SF340 series aeroplanes. This directive applies to all model SF340 aeroplanes with serial numbers SF340A -004 through -108 for Service Bulletin SAAB 340-57-017, and serial numbers SF340A -004 through -138 for Service Bulletin SAAB 340-55-027. The directive mandates actions in accordance with the technical requirements outlined in Swedish Airworthiness Directive No 1-035 Revision A, issued on 29 June 1990. The directive is designed to address critical structural issues identified through full-scale fatigue testing, specifically focusing on the wing attach fastener holes and the front and rear horizontal stabilizer spars, which have been identified as fatigue critical. Compliance with this directive is mandatory before the aeroplane exceeds 16,000 flight cycles. The directive's reach is limited to the specified serial numbers of the Saab SF340 series aeroplanes and does not extend to other aircraft models or series, thus ensuring targeted and precise application of the necessary safety measures.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, include specific Airworthiness Directives (AD) concerning the Saab SF340 series aeroplanes. One such directive, AD/SF340/24, pertains to the wing and stabilizer rework and reinforcements (Section 5/91). This directive applies to all Saab SF340 models with specific serial numbers, namely SF340A-004 through -108 for Service Bulletin SAAB 340-57-017, and SF340A-004 through -138 for Service Bulletin SAAB 340-55-027. The requirement is for action to be taken in accordance with the technical requirements outlined in Swedish Airworthiness Directive No 1-035 Revision A, issued on 29 June 1990. These service bulletins reference specific structural components that need attention. The obligations imposed by this directive include ensuring that the specified rework and reinforcements on the wings and stabilizers are carried out before the aeroplanes exceed 16,000 flight cycles. This requirement is based on full-scale fatigue testing which identified the four referenced wing attach fastener holes and the front and rear horizontal stabilizer spars as being fatigue critical. Compliance with these directives is mandatory for the continued airworthiness of the affected aircraft. Failure to comply with the requirements of AD/SF340/24 may result in significant civil and criminal consequences. The primary civil consequence is the potential grounding of the aircraft until the required rework is completed to the satisfaction of the Civil Aviation Safety Authority (CASA). From a criminal perspective, non-compliance could result in enforcement actions against the aircraft operator, including fines and other penalties as prescribed under the Civil Aviation Act 1988. While the specific maximum penalties are not detailed in the AD itself, they could range from substantial fines to imprisonment, depending on the severity and circumstances of the non-compliance.