AD/VAT/37 - Wing Ribs - Inspection and Modification

Overview

The Civil Aviation Regulations 1998 (Cth), specifically Part 39 - 105, addresses the safety of aircraft by providing Airworthiness Directives to ensure the safe operation of aircraft in Australia. The regulation aims to maintain the highest safety standards in civil aviation, addressing the problem of structural integrity in aircraft components, particularly the Victa and A.E.S.L. Airtourer Series aeroplanes. The Australian Parliament enacted this regulation to safeguard the public from aviation accidents by ensuring that specific parts of the aircraft, such as wing ribs, are inspected and maintained according to prescribed standards. The policy objective of these regulations is to enhance the safety and reliability of civil aviation by mandating regular inspections and necessary modifications to critical aircraft components, thereby reducing the risk of in-flight failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, mandate the Civil Aviation Safety Authority to issue Airworthiness Directives that are applicable to all Victa and A.E.S.L. Airtourer Series aeroplanes that have not been modified to AESL Service Bulletin No. 019. The directive pertains to the inspection and potential modification of certain wing ribs to ensure compliance with safety standards. The requirement mandates that the walkway top skin must be removed sufficiently to inspect wing ribs P/Nos. 10217/1 and /2 and 102109/1 for any cracks, with particular attention to the lower flange to web radius near the landing gear attachment points. Any defective ribs identified must be repaired in accordance with AESL Service Bulletin No. 019 or an approved scheme before the aircraft can be returned to service. The directive applies to aircraft based on their time in service, with those exceeding 3500 hours as at 30 June 1972 required to comply within 300 hours of that date and then at intervals not exceeding 3500 hours. Aircraft that have not exceeded 3500 hours at the specified date must comply before achieving 3800 hours and then at the same intervals. This directive forms part of the overarching regulatory framework under the Commonwealth of Australia, ensuring safety standards are met across the aviation industry.

Key Provisions

The Civil Aviation Regulations 1998 (CAR), specifically Part 39 - 105 (1)(a), mandate that Victa and A.E.S.L. Airtourer Series aeroplanes undergo inspections and modifications as outlined in Airworthiness Directive AD/VAT/37. The directive concerns the inspection and potential modification of wing ribs to prevent structural failure due to cracks. The specific requirement (3)(b) is to remove the walkway top skin sufficiently to inspect wing ribs P/Nos. 10217/1 and /2 and 102109/1 for cracks, with a focus on the lower flange to web radius near the landing gear attachment points. Compliance with these directives (5) involves two scenarios: for aircraft that have exceeded 3500 hours of time in service as of 30 June 1972, inspections must occur within 300 hours of that date and then at intervals not exceeding 3500 hours (5)(a). For aircraft that had not reached 3500 hours of time in service by 30 June 1972, inspections must occur before achieving 3800 hours of time in service and then at the same intervals (5)(b). Any defective ribs found during inspection must be repaired in accordance with AESL Service Bulletin No. 019 or an approved alternative scheme by the Secretary (6). Failure to comply with these provisions (7) can result in serious consequences. The regulations impose strict obligations on the parties governed by them, such as aircraft owners and operators, to ensure the airworthiness of their aircraft by adhering to the specified inspection and repair protocols. Breach of these obligations can lead to enforcement actions, including the imposition of fines and other penalties as stipulated by the Civil Aviation Act 1988 and other relevant legislation (8). The specific penalties for non-compliance are not detailed in the Airworthiness Directive itself but can be severe under the overarching civil aviation regulatory framework.