Overview

The Civil Aviation Regulations 1998, under Part 39 - 105, provides specific safety directives for aircraft to ensure operational safety and compliance with airworthiness standards. One such directive, AD/MU-2/49, addresses a critical safety concern regarding the Mitsubishi MU-2 Series aeroplanes. This directive was enacted to rectify an identified issue with the underwing pressure bulkhead flange, which had the potential to lead to a sudden loss of cabin pressure if left undetected. The problem was identified through a reported 300mm long crack on an Australian registered aircraft, prompting the need for stringent inspection protocols. The objective of this legislative instrument, as overseen by the Civil Aviation Safety Authority, is to mandate regular inspections of the bulkhead to prevent such occurrences, thereby safeguarding the safety of passengers and crew. This specific amendment, effective from 15 September 1994, aims to provide clarity on the exact area to be inspected, following reports of misunderstandings in the field.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, address the maintenance and safety of aircraft with a focus on the Mitsubishi MU-2 Series aeroplanes. This particular legislation mandates the inspection of the underwing pressure bulkhead flange on all models of the Mitsubishi MU-2 aeroplanes. The requirement entails a close visual inspection for any cracks in the bend radius of the flange on both the left and right-hand sides of the bulkhead, specifically from F.Sta.3905 to F.Sta.4660. Compliance with this directive is crucial to ensure safety, requiring the inspection to be conducted prior to exceeding 5000 pressurised flights or before 11 October 1991, whichever is later. Subsequent inspections must occur at intervals not exceeding 1000 pressurised flights, and additionally at any time an unexplained difficulty in maintaining cabin pressure is encountered. This directive, as amended on 15 September 1994, seeks to address previously reported issues of undetected cracking that could lead to a sudden loss of cabin pressure in flight.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 105, establish a comprehensive framework for ensuring the airworthiness of aircraft operating in Australia. One such regulation is AD/MU-2/49 Amendment 1, which pertains specifically to Mitsubishi MU-2 series aeroplanes. According to section (1), this directive mandates a detailed visual inspection of the underwing pressure bulkhead, focusing on the bend radius of the flange between F.Sta.3905 and F.Sta.4660 on both the left and right sides. This inspection is crucial to detect any cracks that could potentially lead to a sudden loss of cabin pressure during flight, a situation that poses a significant safety risk. Operators of Mitsubishi MU-2 series aeroplanes must comply with the directive by performing the required inspection. Section (2) stipulates that the inspection must be conducted prior to exceeding 5000 pressurised flights or before 11 October 1991, whichever is later. Furthermore, the inspection must be repeated at intervals not exceeding 1000 pressurised flights, and additionally, whenever there is an unexplained difficulty in maintaining cabin pressure. The directive emphasizes that compliance with the initial directive remains unchanged, and the amendment is effective from 15 September 1994. Failure to adhere to the requirements outlined in AD/MU-2/49 Amendment 1 can result in significant legal and safety consequences. Section (3) of the regulations outlines the penalties for non-compliance. While the specific penalties are not detailed within the legislative instrument, the overarching Civil Aviation Act 1988 provides for both civil and criminal penalties for violations. Civil penalties may include fines, while criminal penalties could lead to imprisonment, reflecting the serious nature of non-compliance with airworthiness directives designed to protect public safety. The exact penalties would be determined based on the severity of the breach and any resulting harm.