AD/BELL 47/31 - Lateral Cyclic Torque Tube Safety Washers

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, serve as a comprehensive regulatory framework governing all aspects of civil aviation within Australia. Specifically, Part 39 - 105 of these regulations establishes a Schedule of Airworthiness Directives aimed at ensuring the safety and airworthiness of aircraft. The directive AD/BELL 47/31 focuses on Bell Helicopter Textron 47 (All Variants) Series Helicopters, mandating the fitting of steel safety washers to the lateral cyclic torque tubes to prevent any potential interference with the bearings. The objective of this directive is to enhance safety by eliminating the risk of mechanical failure due to bearing interference, ensuring the aircraft remains compliant with stringent safety standards. Compliance with this directive is required forthwith, underscoring the urgency and importance placed on maintaining the airworthiness of these helicopters.

Scope and Application

The Civil Aviation Regulations 1998, under Part 39 - 105, pertain specifically to ensuring the airworthiness of aircraft through safety directives issued by the Civil Aviation Safety Authority (CASA). This legislative instrument applies to all variants of Bell Helicopter Textron 47 series helicopters, mandating the incorporation of specific safety measures to ensure operational safety and compliance with national aviation standards. The directive AD/BELL 47/31 requires the fitting of steel safety washers to each end of the lateral cyclic torque tube, ensuring these washers do not interfere with the ball bearings in any control position. Compliance with this directive is mandatory and must be achieved without delay, underscoring the importance of maintaining the structural integrity and safety of these aircraft. The scope of this directive extends to all models within the specified helicopter series, ensuring a uniform approach to safety across the fleet. The directive's jurisdictional reach is national, as it is issued under the authority of the Commonwealth of Australia. There are no stated exclusions or exemptions, and compliance thresholds are set forth clearly in the directive. The application of this safety measure is further extended or may be detailed through subordinate instruments, ensuring that all necessary steps are clearly defined and adhered to by operators and maintenance personnel.

Key Provisions

The Civil Aviation Regulations 1998, specifically within Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, address safety measures for the Bell Helicopter Textron 47 (all variants) series helicopters. One such directive, AD/BELL 47/31, pertains to the lateral cyclic torque tubes and mandates specific safety washers to ensure operational integrity (section 11/61). This directive applies universally to all models of the mentioned helicopter series. The directive requires the installation of steel safety washers at each end of the lateral cyclic torque tube, on the outer side of the ball bearing. The washers must have an outside diameter of approximately 1 1/2 inches and be designed to avoid any interference with the bearings in all control positions. The shape of the washers should be such as to prevent any possible interference, and a suitable design is illustrated in Figure 1, which is referenced within the directive. Compliance with these requirements is mandatory and must be achieved immediately. Entities governed by this directive, such as helicopter operators and maintenance providers, must ensure that the specified safety washers are fitted correctly and that the nuts are removed, washers installed, nuts replaced, torqued to between 100-110 inch pounds, and secured with split pins. Failure to adhere to these provisions could compromise the airworthiness of the aircraft, leading to serious safety implications. Failure to comply with the requirements set forth in AD/BELL 47/31 may result in significant consequences. Although the specific penalties are not detailed within this directive, non-compliance with Civil Aviation Regulations can generally result in both civil and criminal penalties. Civil penalties may include fines and the potential grounding of the affected aircraft until compliance is achieved. Criminal penalties might also apply, depending on the severity of the breach and its impact on aviation safety. It is crucial for all parties to strictly adhere to these safety measures to avoid these adverse outcomes.