AD/BELL 212/55 Amdt 1 - Main Rotor - Pillow Block Attachment Bolts

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, address safety concerns by issuing Airworthiness Directives (ADs) to ensure the safe operation of aircraft within Australia. This legislative instrument was enacted to fill a critical gap in maintaining aircraft safety standards, particularly in response to safety concerns identified by the Civil Aviation Safety Authority (CASA). The authority of CASA to issue these directives is derived from its role as the delegated body responsible for enforcing aviation safety regulations. The overarching policy objective of these directives is to mandate specific actions that correct identified unsafe conditions, thereby enhancing the overall safety of civil aviation within Australia. The particular AD discussed in this legislative instrument pertains to the Bell Helicopter Textron 212 series helicopters, focusing on the prevention of main rotor pillow block attachment bolt fatigue cracks, which could lead to the separation of the main rotor assembly. This AD revokes a previous directive and replaces it with new requirements to address reported cases of fatigue cracks. The directive applies to all models with main rotor yokes P/N 204-011-102-(all dash numbers) installed, with the compliance period and actions detailed in the directive. The intent of this AD is to mitigate the risk of in-flight failures by ensuring the bolts are properly maintained and torqued according to specified instructions, as detailed in Bell Helicopter Textron Alert Service Bulletin 212-90-62 Revision A.

Scope and Application

This Airworthiness Directive issued under the Civil Aviation Regulations 1998 pertains specifically to Bell Helicopter Textron 212 Series Helicopters that have main rotor yokes P/N 204-011-102 with all dash numbers installed. The directive revokes the previous AD/BELL 212/55 and mandates corrective action to address the issue of main rotor pillow block attachment bolt fatigue cracks. This requirement is to be performed in accordance with Bell Helicopter Textron Alert Service Bulletin 212-90-62 Revision A, with an exception for aircraft that incorporate stainless steel main rotor yokes, which are excluded from this directive. The directive is effective from 10 August 2000, as detailed in the compliance section of the requirement document. The purpose of this AD is to prevent the failure of the pillow block attachment bolts and the potential separation of the main rotor assembly. This directive applies nationally within the Commonwealth of Australia and extends to all relevant helicopters operated by entities within the Australian jurisdiction, unless specifically exempted.

Key Provisions

The Civil Aviation Regulations 1998 (CAR 1998) under Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, specifically addresses the airworthiness of Bell Helicopter Textron 212 Series Helicopters. This directive, AD/BELL 212/55 Amendment 1, pertains to all models equipped with main rotor yokes P/N 204-011-102 (all dash numbers) installed. The directive mandates actions to address reported cases of main rotor pillow block attachment bolt fatigue cracks, aiming to prevent failure of these bolts and the consequent separation of the main rotor assembly. The action required is detailed in Bell Helicopter Textron Alert Service Bulletin 212-90-62 Revision A, with the exception of aircraft that incorporate stainless steel main rotor yokes, which are excluded from this directive. The directive was issued by Bernard Malcom Hole, a delegate of the Civil Aviation Safety Authority, and became effective on 10 August 2000. The obligations imposed by this directive are clear and specific. Operators of Bell Helicopter Textron 212 Series Helicopters must adhere to the instructions outlined in Bell Helicopter Textron Alert Service Bulletin 212-90-62 Revision A, which includes detailed procedures for the inspection and maintenance of main rotor pillow block attachment bolts. This requirement is mandatory for all applicable aircraft, ensuring that they meet the safety standards set forth to prevent structural failure. The directive specifies that the action must be taken in accordance with the provided instructions and within the timeframe outlined in the compliance section. Failure to comply with the provisions of this Airworthiness Directive can result in serious safety risks. The primary consequence of non-compliance is the potential for main rotor pillow block attachment bolt fatigue cracks to lead to catastrophic failure of the main rotor assembly during flight, which could result in the loss of the aircraft and all on board. The Civil Aviation Safety Authority, which issues such directives, enforces these regulations strictly. Non-compliance with airworthiness directives can lead to enforcement actions, including the grounding of non-compliant aircraft, fines, and other regulatory penalties. The specific penalties for non-compliance are not detailed in the directive itself but can include both civil and criminal consequences depending on the severity and intent of the breach.