Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B06738, address specific safety concerns related to the Sikorsky S-76 series helicopters, particularly regarding the tail gearbox forward fairing. Enacted by the Australian Parliament, this legislation aims to ensure the continued airworthiness of these aircraft by mitigating risks associated with bonding failures in the tail gearbox forward fairing. The policy objective is to prevent incidents that could lead to damage to the tail rotor blades and loss of control, thereby enhancing overall aviation safety. This directive requires operators to perform a visual inspection of the attachment angle on each tail gearbox forward fairing and take corrective action if necessary, in accordance with specified instructions. The directive became effective on 20 October 1999, and compliance must be achieved within 50 hours of the aircraft being in service post this date, with subsequent inspections occurring at intervals not exceeding 1500 hours. This legislative measure responds to reports from the Federal Aviation Administration (FAA) of bonding failures, which have resulted in both in-flight and ground incidents. The regulatory approach underscores the importance of proactive maintenance to prevent potential hazards, thereby protecting both the crew and the public.

Scope and Application

The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives under the Civil Aviation Regulations 1998 specifically addresses the safety of Sikorsky S-76 Series helicopters, targeting all Model S-76A, B, and C helicopters. This regulation applies to operators and owners of these helicopters within Australia and mandates that a visual inspection of the attachment angle on each tail gearbox forward fairing must be performed in accordance with the instructions detailed in the Sikorsky Aircraft Corporation Alert Service Bulletin (ASB) 76-55-16. If the inspection reveals a disbond area of 1.0 square inch or more, the attachment angle must be repaired or replaced before further flight. Compliance with this directive is required within 50 hours of time in service after the directive's effective date of 20 October 1999, and then at intervals not exceeding 1500 hours of time in service. This legislation ensures that any identified safety issues are promptly addressed to mitigate the risk of tail gearbox forward fairing separation, which could otherwise lead to severe consequences such as damage to the tail rotor blades and loss of helicopter control.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39, Section 105, sets forth specific requirements for the airworthiness of certain aircraft, including the Sikorsky S-76 Series Helicopters. The most notable provision in this context is the Airworthiness Directive (AD/S76/62) concerning the tail gearbox forward fairing to pylon attachment angle. This directive applies to all Model S-76A, B, and C helicopters and was issued on 20 October 1999. According to Section 12/99DM, the requirement is that an operator must perform a visual inspection of the attachment angle on each tail gearbox forward fairing. This inspection must be conducted in accordance with the Accomplishment Instructions detailed in paragraph A of Sikorsky Aircraft Corporation Alert Service Bulletin (ASB) 76-55-16, dated May 12, 1999. The directive imposes a clear obligation on the operator to ensure the airworthiness of the helicopter by identifying and addressing any disbond areas that equal or exceed 1.0 square inch. If such a disbond area is found during the inspection, the attachment angle must be repaired or replaced with a serviceable one, following the Accomplishment Instructions in paragraph B of ASB 76-55-16. This corrective action must be completed before further flight. The inspection is required within 50 hours of time in service after the directive's effective date of 20 October 1999, or if the initial inspection has already been performed. Subsequent inspections must occur at intervals not exceeding 1500 hours of time in service. Failure to comply with this Airworthiness Directive could have significant legal and safety repercussions. The Federal Aviation Administration (FAA) AD 99-19-30 Amdt 39-11317 references the importance of this directive, indicating that non-compliance could result in severe consequences. While the specific penalties or legal consequences for non-compliance are not detailed in the provided text, the general implications include potential grounding of the aircraft, fines, and other regulatory actions that could affect the operator's licence and reputation. Given the safety-critical nature of the directive, the Civil Aviation Safety Authority (CASA) takes non-compliance very seriously, underscoring the importance of adhering to the outlined requirements.