AD/F50/45 - Fuselage Power Supply Box Surround Structure

Overview

The Civil Aviation Regulations 1998 were enacted to provide a comprehensive regulatory framework for civil aviation in Australia, ensuring the safety and efficiency of air operations. Specifically, Part 39 addresses Airworthiness Directives, which are mandatory orders issued by the Civil Aviation Safety Authority to ensure the continued airworthiness of aircraft. The legislation aims to mitigate safety risks by setting standards that aircraft must meet. AD/F50/45, concerning the Fokker F50 (F27 Mk 50) Series Aeroplanes, was introduced to address a specific safety issue identified during fatigue testing. The problem arose from cracks occurring in the aircraft skin near the door hinge of the external power supply box, which could compromise the structural integrity and safety of the aircraft. The policy objective behind this directive is to enhance the safety and reliability of Fokker F50 aircraft by requiring the installation of a reinforcement plate to extend the fatigue life of the affected area, thereby preventing potential failures during operation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to Airworthiness Directives for particular aircraft types, with AD/F50/45 focusing on Fokker F50 (F27 Mk 50) series aeroplanes. This directive applies to aircraft with serial numbers ranging from 20103 to 20108 inclusive and 20110 to 20131 inclusive, mandating compliance with the technical requirements outlined in RLD AD 89-130, dated 27 October 1989. The directive was informed by Fokker Service Bulletin F50-53-024, dated 25 October 1989, which references the need for action following the discovery of cracks in the aircraft skin near the door hinge of the external power supply box during fatigue testing. Compliance is required before the aircraft exceeds 15,000 pressurisation cycles, ensuring that a reinforcement plate is installed to improve the fatigue life of the skin in the affected area. This legislation is enforced by the Civil Aviation Safety Authority and applies across the Commonwealth of Australia, governing the operation and maintenance of the specified Fokker F50 series aeroplanes within its jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 under the heading "Civil Aviation Safety Authority Schedule of Airworthiness Directives," include an Airworthiness Directive (AD) concerning Fokker F50 (F27 Mk 50) Series Aeroplanes. This particular directive, AD/F50/45, pertains to the Fuselage Power Supply Box Surround Structure and is applicable to Fokker F50 aircraft with serial numbers ranging from 20103 to 20108 inclusive, and from 20110 to 20131 inclusive. The requirement outlined in this directive is that the action must be taken in accordance with the technical requirements specified in RLD AD 89-130, dated 27 October 1989, with reference to Fokker Service Bulletin F50-53-024, dated 25 October 1989. This directive mandates that the reinforcement of the fuselage power supply box surround structure must be implemented before the aircraft exceeds 15,000 pressurisation cycles. The obligations imposed by this directive are clear and specific. Operators of the affected Fokker F50 aircraft must ensure that the required modifications to the fuselage power supply box surround structure are carried out by a certified technician or engineer. This involves the installation of a reinforcement plate to the affected area to enhance the fatigue life of the aircraft skin, which was found to be prone to cracks during full-scale fatigue testing. The directive stipulates that this reinforcement must be completed prior to the aircraft reaching 15,000 pressurisation cycles, underscoring the importance of timely and proactive compliance to maintain airworthiness. Non-compliance with the requirements set forth in AD/F50/45 could result in severe consequences, both civil and criminal. Civil Aviation Safety Authority (CASA) has the authority to enforce penalties for violations of the Civil Aviation Regulations. While the specific penalties for non-compliance with this particular AD are not detailed within the text, breaches of airworthiness directives generally may lead to enforcement actions such as fines, suspension or revocation of airworthiness certificates, and potential legal action against the operators. In the most severe cases, failure to adhere to these directives can result in criminal charges, particularly if the non-compliance leads to accidents or incidents that endanger public safety. Additionally, failure to comply with airworthiness directives can also result in liability for damages if the non-compliance leads to an accident. Operators must ensure they adhere strictly to the directive to avoid these repercussions. Given the potential safety implications, operators are advised to consult with CASA and relevant technical experts to ensure that all modifications are carried out correctly and within the specified timelines. Compliance with such directives is not just a legal obligation but a critical aspect of ensuring the safety and reliability of aviation operations.