AD/BELL 412/21 - Fuel Cell Interconnect Tube

Overview

The Civil Aviation Regulations 1998 (Cth) were enacted to regulate civil aviation activities in Australia and ensure safety standards are met across the industry. One specific legislative instrument under these regulations, F2006B04656, addresses the issue of fuel cell interconnect tube damage in Bell Helicopter Textron 412 Series Helicopters. This directive was introduced to mitigate potential risks associated with the cargo suspension assembly causing damage to the fuel interconnect tube during slung load operations. The Civil Aviation Safety Authority (CASA) established this directive to ensure compliance with safety standards, following a service bulletin issued by the manufacturer, Bell Helicopter Textron. The policy objective is to enhance aviation safety by preventing potential fuel leaks and ensuring the structural integrity of the aircraft’s fuel system.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Bell Helicopter Textron 412 series helicopters, including models 412 and 412 NB within the specified serial number range. This directive aims to address potential damage to the fuel cell interconnect tube caused by the cargo suspension assembly during slung load operations. Compliance with the directive involves adhering to the requirements outlined in Bell Alert Service Bulletin No 412-88-40, the latest revision. The directive mandates daily inspections for leakage in aircraft fitted with a particular cargo suspension assembly part number. If leakage is detected, the tube must be replaced before further flight. If no leakage is evident, the tube must be replaced at the next maintenance release inspection or by a specified deadline. For aircraft that have never had the cargo suspension assembly fitted or for those having it installed for the first time, specific timelines are provided for replacing the interconnect tube. Additionally, the directive requires that two rubber fuel hoses be inspected for correct clamping during the tube installation. This regulation ensures the safety and airworthiness of the specified helicopter models by mitigating risks associated with the fuel system.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, outline the requirements for airworthiness directives related to the Bell Helicopter Textron 412 Series Helicopters. One such directive, AD/BELL 412/21, concerns the fuel cell interconnect tube. This directive applies to all Bell 412 or 412 NB helicopters within a specific serial number range as detailed in the Requirement Document (section 5/89DM). The directive mandates actions in accordance with Bell Alert Service Bulletin No 412-88-40, with the latest revision being applicable. Under the directive, specific actions must be taken depending on the aircraft's history with the cargo suspension assembly. For aircraft that are fitted or were previously fitted with the P/N 204-072-915-103 external cargo suspension assembly, the fuel cell interconnect tube must be inspected daily for any leakage. If leakage is detected, the tube must be replaced before the aircraft can fly again. If no leakage is found, the tube must be replaced either at the next maintenance release inspection or by 30 April 1989, whichever comes first (section 1). For aircraft that have never had the cargo suspension assembly fitted, the tube must be replaced at the next maintenance release inspection or by 31 July 1989, whichever occurs first (section 2). Additionally, for aircraft having the cargo suspension assembly installed for the first time, it is mandatory to ensure that the interconnect tube P/N 412-061-673-101 is fitted during the installation of the cargo suspension assembly (section 3). The directive imposes clear obligations on the parties governed by it. Operators and owners of affected helicopters must adhere to the inspection and replacement requirements outlined in the airworthiness directive. They must ensure that the fuel cell interconnect tube is inspected or replaced according to the specified timelines and conditions. Failure to comply with these requirements can lead to serious safety risks, including potential fuel system failures during flight. Failure to comply with the airworthiness directive can result in significant consequences. Under the Civil Aviation Regulations, non-compliance may be considered an offence. Such an offence could lead to enforcement actions by the Civil Aviation Safety Authority (CASA). The penalties for non-compliance can be severe, including potential civil penalties and criminal charges. The specific penalties depend on the severity of the breach and may include substantial fines. The regulations do not explicitly state maximum penalties within the directive itself, but non-compliance with CASA directives is generally treated seriously, with potential penalties reflecting the gravity of the breach.