AD/BELL 206/90 Amdt 6 - Tail Rotor Blade Tip Block

Overview

The Civil Aviation Regulations 1998, as amended, serve as the foundational framework for ensuring the safety and efficiency of civil aviation operations within Australia. One pertinent legislative instrument under this act is the Civil Aviation Safety Authority Schedule of Airworthiness Directives, specifically pertaining to Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters, identified by the legislative instrument number F2006B04540. This instrument was enacted to address the safety concerns associated with specific models of these helicopters, ensuring that they meet necessary safety standards to prevent accidents and maintain operational reliability. The policy objective of these regulations is to enhance the safety of civil aviation by mandating specific maintenance and inspection protocols, thereby mitigating risks associated with the identified models. The Civil Aviation (Safety) Regulations 1998 are administered by the Civil Aviation Safety Authority (CASA) under the authority granted by the Australian Parliament. The specific directive concerning the Bell and Agusta Bell 206 series helicopters was introduced to address issues related to the tail rotor blade tip blocks, particularly focusing on the prevention of structural separations and ensuring the integrity of the rivets in the tip block area. By enforcing these detailed inspection and maintenance requirements, CASA aims to uphold the highest safety standards in civil aviation, thereby protecting both the public and the aviation industry from potential hazards.

Scope and Application

The Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives under the Civil Aviation Regulations 1998 governs the maintenance and operational standards for various aircraft in Australia. Specifically, AD/BELL 206/90 Amendment 6 pertains to all models of Bell 206 and Agusta Bell 206 Series helicopters equipped with certain Tail Rotor Blades. The directive applies to Bell 206A, 206B, 206BIII, 206L, 206L-1, 206L-3, and Agusta Bell AB.206A, AB.206B, and AB.206B-1 helicopters fitted with Tail Rotor Blades of specified part numbers and serial numbers. The directive mandates a thorough cleaning and inspection of the tip block area to identify any working, corroded, or missing rivet heads, and to check for voids or separations between the shell and the tip block. If any separations are suspected, a 0.0015 inch feeler gauge should be used to confirm the presence of gaps. The coin tap test is deemed invalid for this inspection. The directive also requires the replacement of existing rivets in the tip block area with specific rivets as described in the manufacturer’s service bulletins. Compliance involves daily inspections starting from 20 February 1984, with the installation of new rivets mandated by 1 January 1986, followed by periodic inspections every 100 hours of flight time. This directive extends its regulatory reach across all helicopters fitting the specified criteria, ensuring uniform safety standards are maintained within the aviation industry.

Key Provisions

The Civil Aviation Regulations 1998, specifically PART 39 - 105, under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, addresses the airworthiness of Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters, with a focus on the tail rotor blade tip block (AD/BELL 206/90Amdt 6). The directive applies to all models Bell 206A, 206B, 206BIII, 206L, 206L-1, 206L-3, and Agusta Bell AB.206A, AB.206B and AB.206B-1 that are fitted with specific Tail Rotor Blades P/N 206-016-201-001, 206-016-201-103, and 206-016-201-107, with serial numbers as detailed in the requirement section (sections 1-3). The directive sets out specific requirements for the inspection and maintenance of the tail rotor blade tip block. Firstly, operators must thoroughly clean the tip block area and visually inspect it for any working, corroded, or missing rivet heads, as well as evidence of voids or separations between the shell and the tip block (section 1). Any suspected voids or separations not listed as acceptable in the manufacturer's service documents must be confirmed using a 0.0015 inch feeler gauge inserted between the shell and the tip block (section 2). It is important to note that the coin tap test method is not considered valid for this inspection (Note 1), and separation may exist without being visually obvious (Note 2). Additionally, operators must replace the existing five rivets in the tip block area with rivets P/N CSR903B4-14 as described in Bell Alerts SB’s 206-85-28 Rev B and 206L-85-34 Rev B (section 3). Compliance with the directive involves inspecting the tip block area at each daily inspection following 20 February 1984. If any void or separation is suspected, it must be confirmed before further flight (section 1). For aircraft maintained under ANO 100.5.1, this inspection must be recorded as maintenance required on the maintenance release. Pilots in command can perform this inspection on a daily basis without needing certification, but in other cases, certification by a licensed aircraft maintenance engineer is required (Note). The installation of new rivets must be completed by 1 January 1986 (section 2). After compliance, operators must repeat the inspections at intervals not exceeding 100 hours of time in service (section 3). Failure to comply with the airworthiness directive may result in serious safety hazards and potential legal consequences. Non-compliance with CASA directives can lead to enforcement actions, including fines, penalties, and potential grounding of the aircraft. Under the Civil Aviation Act 1988, operators found in breach of an airworthiness directive may face maximum penalties as prescribed in the regulations, which can include substantial financial penalties and imprisonment. Additionally, the operator may face civil liability for any damages or injuries resulting from non-compliance with the airworthiness directive.