AD/BELL 47/72 Amdt 2 - Main Rotor Hub Core P/N 47-120-117-1

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the safety standards for aircraft operations in Australia. Enacted by the Parliament of the Commonwealth of Australia, the regulations are administered by the Civil Aviation Safety Authority (CASA). This legislative instrument, F2006B04698, pertains to the Bell Helicopter Textron 47 (All Variants) Series Helicopters, providing an Airworthiness Directive (AD) to ensure the ongoing safety and airworthiness of these aircraft. The policy objective is to mitigate the risk of in-service failure through regular inspection and compliance with safety directives, as evidenced by the requirement to inspect the Main Rotor Hub Core P/N 47-120-117-1 irrespective of any dimensional exclusions. The AD mandates that inspections be carried out at each issue of a new Maintenance Release for cores that have accumulated 1200 hours of total time-in-service or where the total time in service is unknown, thereby addressing a previously identified issue of undetected cracks in the hub core.

Scope and Application

The Civil Aviation Regulations 1998, under the authority of the Civil Aviation Safety Authority (CASA), include specific directives for the maintenance and inspection of certain aircraft components, with a particular focus on safety. Part 39 - 105 of the Civil Aviation Regulations 1998 mandates the inspection of the main rotor hub core P/N 47-120-117-1 for all Bell Helicopter Textron 47 (All Variants) series helicopters, irrespective of dimensional exclusions that might otherwise exempt them from regular visual inspections. This requirement applies to all model 47 series helicopters equipped with the specified hub core and necessitates inspection at each issuance of a new Maintenance Release. The directive is particularly stringent for cores that have accumulated more than 1200 hours of total time-in-service or for which the total time in service is unknown. The rationale behind this directive stems from a documented instance of a crack in the web of a hub core that was exempted from routine inspections by dimensional criteria. The amendment to these regulations aims to harmonise the inspection intervals with those outlined in the Maintenance Release, thereby ensuring consistent and thorough oversight of critical components to maintain airworthiness standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, contain critical provisions concerning the maintenance and inspection of Bell Helicopter Textron 47 (all variants) series helicopters. The pertinent section here is AD/BELL 47/72 Amendment 2, which deals with the Main Rotor Hub Core P/N 47-120-117-1 dated 3/87. According to section 39-105, the directive applies to all model 47 series helicopters equipped with the specified hub core. The main requirement is that these helicopters must be inspected in accordance with Part II of Bell SB 47-04-1-73-2, irrespective of the dimensional exclusion criteria outlined in Part I of the same document. This inspection must occur at each issue of a new Maintenance Release, particularly for cores that have surpassed 1200 hours of total time in service or for which the total time in service is unknown. The obligations imposed by this directive are stringent and aim to ensure the safety and airworthiness of the specified helicopters. Operators and maintenance personnel must adhere to the inspection protocols outlined in Part II of Bell SB 47-04-1-73-2. This means that any time a new Maintenance Release is issued, a thorough inspection must be conducted on the rotor hub core, focusing on any signs of wear, damage, or potential failure points. For cores that have exceeded 1200 hours in service or have unknown service hours, these inspections are mandatory, reflecting the importance of maintaining stringent oversight on components that are critical to flight safety. Failure to comply with these requirements can result in serious legal and safety consequences. Under the Civil Aviation Regulations 1998, non-compliance with Airworthiness Directives can lead to substantial penalties. While the specific penalties are not detailed in the text provided, general regulations under the Civil Aviation Act 1988 can impose fines and imprisonment for breaches of safety regulations. Moreover, any failure to comply with these directives could result in the grounding of the aircraft until the required inspections and necessary repairs are completed, potentially leading to significant operational disruptions and financial losses for operators. Ensuring adherence to these directives is therefore not only a legal obligation but also a critical safety measure to prevent accidents and maintain the highest standards of aviation safety.