AD/BELL 206/128 - Main Rotor Blade and Trim Tab

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, form a crucial part of the regulatory framework for civil aviation in the country. Specifically, Part 39 - 105 pertains to airworthiness directives, which are legally enforceable rules regarding the design, production, maintenance, and operation of aircraft. One such directive, AD/BELL 206/128, targets Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series helicopters. This directive was introduced to address the safety concern of cracks in the main rotor blades, which could lead to catastrophic failure. The objective is to ensure that timely inspection and necessary repairs are conducted to prevent such failures and maintain the safety of the aircraft and its occupants. The directive applies to all Bell 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters equipped with certain main rotor blades and having specific serial numbers. It mandates a visual inspection for cracks in the inboard trim tab and other areas of the main rotor blade, requiring the use of a magnifying glass and proper polishing techniques. The requirement is for these inspections and any necessary rework to be completed within 50 hours of the aircraft being in service from 2 February 1995. This directive aims to mitigate the risk of rotor blade failure by ensuring that any detected cracks are appropriately addressed, thereby maintaining the airworthiness of the affected helicopters.

Scope and Application

The Civil Aviation Regulations 1998, under the Civil Aviation Safety Authority and specifically within PART 39 - 105, mandate specific airworthiness directives for certain Bell Helicopter Textron Canada (BHTC) and Agusta Bell 206 Series helicopters. This legislation applies to all Bell 206A, 206B, 206L, 206L-1, 206L-3 and 206L-4 helicopters equipped with particular main rotor blade part numbers and having serial numbers beginning with the prefix "A". However, it is pertinent to note that blades with specific serial numbers listed in Bell Alert Service Bulletins 206-93-77 or 206L-93-92 are exempt from this directive. The geographic reach of this legislation is nationwide, as it is a Commonwealth regulation. Compliance with this directive involves a thorough visual inspection for cracks in specific areas of the rotor blades, using a 10X magnifying glass and polishing out any marks as per Bell Alert Service Bulletins. Blades with inboard trim tab cracks may return to service after reworking, while those with cracks elsewhere must be removed from service. The directive mandates that these inspections and necessary reworks be completed within 50 hours from 2 February 1995. This legislative instrument underscores the importance of regular inspection and maintenance to prevent potential rotor blade failure and consequent loss of the helicopter.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the airworthiness directives for certain Bell Helicopter Textron Canada (BHTC) and Agusta Bell 206 series helicopters. The regulation in question is AD/BELL 206/128, which pertains to the main rotor blade and trim tab of these helicopters (section 1). The directive applies to Bell 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters equipped with specific main rotor blade part numbers and serial numbers beginning with the prefix “A” (section 2). However, it excludes blades listed in certain Bell Alert Service Bulletins, specifically 206-93-77 and 206L-93-92 (section 2). Under this directive, operators must visually inspect the inboard trim tab and the upper and lower surfaces of the main rotor blade in the area of the inboard trim tab for any signs of cracking (section 1). The inspection must be performed using a 10X magnifying glass and any grinding or sanding marks should be polished out in accordance with the relevant Bell Alert Service Bulletins (section 1). The regulation allows blades with cracks in the inboard trim tab to return to service after reworking as specified in the Service Bulletins. However, blades exhibiting cracks at other locations must be removed from service (section 1). Failure to comply with the directive can result in significant safety risks. The Federal Aviation Administration's AD 94-15-07 serves as a reference, indicating the seriousness of the directive (section 1). Operators must ensure that inspections and any necessary rework are completed within 50 hours of the helicopter being in service from 2 February 1995 (section 3). Non-compliance with these requirements could lead to the grounding of affected helicopters, thereby posing a risk to the safety of the aircraft and its occupants. In terms of penalties, the Civil Aviation Regulations do not explicitly detail specific penalties for non-compliance with this directive. However, failure to adhere to airworthiness directives generally can result in severe consequences. These may include the grounding of the aircraft, financial penalties, and potential legal action against the operator or individual responsible for compliance. In extreme cases, criminal charges could be brought against individuals who knowingly allow an aircraft to operate in a non-airworthy condition. The exact penalties would depend on the specific circumstances and the discretion of the Civil Aviation Safety Authority (CASA) in enforcing the regulations.