AD/BELL 47/100 - Stabiliser Bar Damper Link Assembly

Overview

The Civil Aviation Regulations 1998, under Part 39 – 105, issued by the Civil Aviation Safety Authority, address the critical issue of ensuring the airworthiness of aircraft operating within Australia. Specifically, Airworthiness Directive AD/BELL 47/100 targets the Bell Helicopter Textron 47 series, requiring the removal, modification, and reinstallation of stabiliser bar damper link assemblies to prevent potential failure and loss of control. This directive was enacted to rectify a safety concern identified by the Federal Aviation Administration, which reported incidents where damper link bushings loosened, leading to separation from the stabiliser bar or hydraulic damper. The objective is to ensure the continued safety and operational reliability of these helicopters by mandating timely compliance with the specified modifications.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, mandate that certain Bell Helicopter Textron 47 (all variants) series helicopters must comply with specific airworthiness directives. This regulation applies to all aircraft operators and owners of the listed helicopter models, which include the 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters. The directive requires the removal of the stabiliser bar damper link assemblies from the helicopter, the installation of a safety washer kit (part number CA-047-96-022-1), and the reinstallation of the stabiliser bar damper link assemblies according to the Accomplishment Instructions in Bell Helicopter Textron, Inc. Alert Service Bulletin 47-96-22, dated 16 August 1996. Compliance with this directive is mandatory unless the requirement has already been fulfilled, and it must occur within 100 hours of time in service after 16 July 1998 or before 16 November 1998, whichever comes first. The directive becomes effective on 16 July 1998. The regulation is applicable across the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority, ensuring that all relevant entities and industries adhere to the specified safety standards to mitigate risks associated with the failure of the damper link assembly.

Key Provisions

The Civil Aviation Regulations 1998 (Cth) under Part 39, specifically Section 105, contains airworthiness directives that govern the maintenance and operational standards of various aircraft, including the Bell Helicopter Textron 47 series. This particular directive, AD/BELL 47/100, pertains to the stabiliser bar damper link assembly of the Bell Helicopter Textron 47 (all variants) series helicopters. The directive mandates the removal of the stabiliser bar damper link assemblies from the helicopter, the installation of a safety washer kit (part number CA-047-96-022-1), and the reinstallation of the assemblies in accordance with the Accomplishment Instructions outlined in Bell Helicopter Textron, Inc. Alert Service Bulletin 47-96-22, dated 16 August 1996. This directive applies to all variants of the Bell 47 helicopters, including the 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K models. Compliance with AD/BELL 47/100 is mandatory for all operators of the specified helicopter models. The directive requires that the necessary modifications be completed within 100 hours of time in service after 16 July 1998, or before 16 November 1998, whichever occurs first. Failure to comply with this directive can result in serious safety hazards, as the directive was issued in response to reports of incidents where the bushings of the damper link assemblies loosened and exited the damper link rod ends, leading to the damper link separating from the stabiliser bar or the hydraulic damper. Such failures could result in degraded control response and potentially loss of control of the helicopter. Under the Civil Aviation Regulations 1998, violations of airworthiness directives can lead to significant consequences. Operators who fail to comply with these directives can be subject to enforcement actions, including fines and potential criminal charges. The specific penalties are determined based on the severity of the violation and the circumstances surrounding the breach. In cases where non-compliance leads to an accident or serious incident, the penalties can be severe, including substantial fines and imprisonment for individuals responsible for the oversight. Additionally, the Civil Aviation Safety Authority has the authority to take actions such as grounding the aircraft, imposing operational restrictions, or revoking the aircraft's airworthiness certificate, which can have significant operational and financial implications for the operator.