AD/B-2/25 - Tail Rotor Blade - Inspection

Overview

The Civil Aviation Regulations 1998 (Cth) were enacted to provide a comprehensive regulatory framework for civil aviation in Australia, ensuring the safety and efficiency of air travel and operations. This legislation is administered by the Civil Aviation Safety Authority (CASA) and includes specific directives to address particular safety issues. One such directive, AD/B-2/25, pertains to the Brantly B-2 Series Helicopters, focusing on the inspection of tail rotor blades. The directive was introduced to address potential safety issues associated with the tail rotor blade assembly, particularly concerning the thrust bearing shoulder relief radius and circumferential tool marks. The policy objective behind this directive is to ensure that any identified defects are rectified promptly to prevent in-flight hazards and maintain the airworthiness of the aircraft. The directive mandates immediate compliance to uphold the highest safety standards in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 – 105 under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, applies to all Brantly B-2 series helicopters with serial numbers 454 and below. This legislation mandates a thorough inspection of the tail rotor blade assembly, requiring the removal and disassembly of the tail rotor blade assembly P/N B2-111-11 from hub and thrust bearings, following the procedures outlined in the Brantly Model B2B Maintenance Manual. The inspection includes making an impression of the thrust bearing shoulder relief radius and inspecting it for a radius less than 0.020 inches using letter sealing wax or another suitable low-temperature melting material. Additionally, the inspection involves checking for sharp circumferential tool marks deeper than 0.010 inches using at least a two-power magnifying glass. Any blade found with tool marks exceeding 0.010 inches or a relief radius less than 0.020 inches must be removed from service before further flight. Conversely, blades with acceptable measurements must be reinstalled following the guidelines in the Brantly Model B2B Maintenance Manual or FAA AD 65-28-1. Compliance with these directives is required forthwith, ensuring the airworthiness and safety of the aircraft in question.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, impose certain airworthiness directives for Brantly B-2 series helicopters, identified by serial numbers 454 and below. These regulations mandate inspections on the tail rotor blade to ensure compliance with safety standards. Under section 1/66, the tail rotor blade assembly must be removed and disassembled according to the Brantly Model B2B Maintenance Manual (1.1). Once disassembled, the inspection process involves using a sealing wax or similar material to create an impression of the thrust bearing shoulder relief radius at blade station 3.06, ensuring this radius is not less than 0.020 inches (2.). Additionally, a visual inspection must be conducted using at least a two-power magnifying glass to check for any circumferential tool marks deeper than 0.010 inches (3.). If any tool marks exceed 0.010 inches or if the relief radius is found to be less than 0.020 inches, the blade must be removed from service until it meets the specified requirements (4.). If the blade meets the criteria, it can be reinstalled as per the Brantly Model B2B Maintenance Manual or FAA AD 65-28-1 (5.). The Act imposes several obligations on the operators and maintenance personnel of Brantly B-2 series helicopters. Primarily, these include the timely disassembly and inspection of the tail rotor blade assembly to ensure it meets the specified standards (1/66). Operators and maintenance personnel must be proficient in following the Brantly Model B2B Maintenance Manual and the FAA AD 65-28-1 procedures to conduct the required inspections accurately. Ensuring the relief radius and the absence of circumferential tool marks are within the specified limits is crucial. The regulations require operators to remove any non-compliant blades from service immediately and only reinstall those that meet the set standards, thereby ensuring continued compliance with airworthiness directives (4. and 5.). Failure to comply with the airworthiness directives outlined in the Civil Aviation Regulations 1998 can lead to serious consequences. While specific penalties are not detailed in the legislative instrument, non-compliance can result in grounding the aircraft, which can have significant operational and financial implications. Furthermore, continued operation of non-compliant aircraft poses significant safety risks, potentially leading to more severe legal and civil consequences. The overarching goal of these regulations is to ensure the safety and airworthiness of Brantly B-2 series helicopters, and failure to adhere to these standards can result in severe repercussions for operators and maintenance personnel.