AD/BELL 205/52 - Tail Rotor Trunnion Bearing Housing

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, were enacted to establish and enforce standards and directives to ensure the safety of civil aviation. The regulations address various technical and operational aspects of aircraft to mitigate risks and ensure public safety. One such directive, AD/BELL 205/52, pertains to Bell Helicopter Textron 205 Series helicopters, focusing on the tail rotor trunnion bearing housing. This directive was introduced to address a critical safety concern where a trunnion bearing housing end web was found below specified dimensions, which had the potential to cause excessive tail rotor vibration and loss of control. The Australian Government, through the Civil Aviation Safety Authority, established this directive to mandate specific actions to prevent such failures, ensuring the continued safety of the aircraft and its occupants. Compliance with this directive is mandatory for all model 205A and 205A-1 helicopters equipped with kit P/N 212-704-129-101, with stringent timelines provided for inspections and corrective actions as outlined in Bell Alert Service Bulletin No. 205-86-24, Revision A.

Scope and Application

The Civil Aviation Safety Authority’s Schedule of Airworthiness Directives under the Civil Aviation Regulations 1998 applies specifically to all model 205A and 205A-1 Bell Helicopter Textron 205 Series Helicopters fitted with kit P/N 212-704-129-101. The directive is designed to address a critical safety concern where the trunnion bearing housing end web has been found below the specified dimensions, which, if not rectified, can lead to excessive tail rotor vibration and potentially result in a loss of control. The directive mandates compliance with Bell Alert Service Bulletin No. 205-86-24, Revision A, requiring actions to be taken within specified timeframes: within 25 hours of time in service or seven days from 6 August 1986, and thereafter at intervals not exceeding 25 hours of time in service or seven days until the requirement is met. Additionally, the directive necessitates compliance within 150 hours of time in service or 60 days from 31 July 1986. The scope of this regulation is limited to the mentioned helicopter models and components and applies across the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, include detailed directives for the airworthiness of Bell Helicopter Textron 205 Series Helicopters, particularly the AD/BELL 205/52 concerning the tail rotor trunnion bearing housing. These provisions are outlined in the schedule of airworthiness directives, which mandate specific actions to ensure the safe operation of these aircraft. The directive applies to all model 205A and 205A-1 helicopters equipped with kit P/N 212-704-129-101, as referenced in SI 212-68. The main requirement is to take action in accordance with Bell Alert Service Bulletin No. 205-86-24, Revision A. Compliance with these directives is critical and involves two main phases. Part I of the requirement document stipulates that action must be taken within 25 hours of time in service or seven days, whichever occurs first, after 6 August 1986. This initial compliance must then be followed by regular inspections at intervals not exceeding 25 hours of time in service or seven days, whichever occurs first, until Part II is complied with. Part II requires compliance within 150 hours of time in service or 60 days after 31 July 1986. The obligations imposed by these regulations are clear and stringent. Operators of the affected helicopters must ensure that the necessary inspections and maintenance actions are carried out as specified. This includes adherence to the schedule and specific technical requirements outlined in the Bell Alert Service Bulletin No. 205-86-24, Revision A. Failure to comply with these directives can have serious safety implications, as the background information indicates that failure of the tail rotor trunnion bearing housing can lead to excessive tail rotor vibration and loss of control, potentially resulting in catastrophic outcomes. Failure to comply with these airworthiness directives can result in severe consequences. The regulations do not explicitly detail specific offences or penalties within the provided text; however, non-compliance with airworthiness directives under the Civil Aviation Regulations 1998 can generally lead to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions may include fines, operational restrictions, or even the grounding of the aircraft. The precise penalties are not specified in the excerpt but can be severe, reflecting the critical nature of maintaining airworthiness in aviation safety.