AD/R22/38 Amdt 1 - Tail Rotor Gearbox Output Shaft Key

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, Civil Aviation Safety Authority Schedule of Airworthiness Directives, addresses the safety concerns associated with Robinson R22 Series Helicopters. This legislation was enacted to respond to reports of tail rotor gearboxes assembled without the necessary key, which could prevent the output gear from rotating on the output shaft. Such issues can lead to serious safety hazards, including forced landings and damage to the helicopter. The regulations were introduced to ensure the safety of all R22 helicopters fitted with tail rotor gearboxes overhauled or manufactured by Robinson Helicopter Company prior to 8 June 1992. The objective is to mandate the installation of alignment dots, inspection for misalignment, and verification of the existence of both input and output shaft keys to ensure the integrity of the tail rotor gearbox. This was enacted by the Australian Parliament to safeguard aviation safety and prevent potential accidents resulting from mechanical failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate that the Airworthiness Directive AD/R22/38 applies to all Robinson R22 series helicopters fitted with a tail rotor gearbox that was overhauled or manufactured by Robinson Helicopter Company prior to 8 June 1992. This legislative instrument, administered by the Civil Aviation Safety Authority (CASA), ensures compliance with safety standards concerning the tail rotor gearbox output shaft key. The directive is designed to mitigate risks associated with the gearbox assembly, particularly the absence of a key that prevents the output gear from rotating on the output shaft, as evidenced by prior incidents where such failures led to severe consequences. Compliance with the directive includes the installation of alignment dots, inspection for misalignment, and verification of the presence of both input and output shaft keys. Exemptions apply to certain gearbox serial numbers listed in FAA AD 95-23-05, which can be accessed through CASA offices. The directive's requirements must be met before further flight, during daily preflight checks, and within 100 hours of service or during the next annual inspection, whichever comes first.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 – 105, mandate certain airworthiness directives for the Robinson R22 series helicopters, specifically addressing the tail rotor gearbox output shaft key as per AD/R22/38 Amendment 1. This directive applies to all R22 helicopters equipped with a tail rotor gearbox that was either overhauled or manufactured by Robinson Helicopter Company before 8 June 1992 (section 2). Notably, FAA AD 95-23-05 provides a list of gearbox serial numbers exempt from these requirements, and copies of this document can be obtained from CASA Airworthiness District Offices. These regulations require the installation of alignment dots in accordance with FAA AD 95-23-05, paragraph (a), unless this has already been completed as per the original AD/R22/38 (section 1). Additionally, the alignment dots must be inspected for any signs of misalignment in line with the technical requirements of paragraph (b) of the same FAA AD. It is also essential to verify the presence of both the input and output shaft keys as per paragraph (c) of FAA AD 95-23-05, which concludes the daily preflight checks outlined in Requirement 2. The directive is intended to address reports of gearboxes assembled without the necessary key, which could lead to significant operational hazards. Entities and individuals governed by these regulations are required to adhere to several obligations. First, they must ensure that the alignment dots are installed correctly unless this has been previously accomplished in line with the original AD/R22/38. Second, they must inspect the alignment dots for any misalignment, following the technical requirements specified. Third, they must verify the presence of the input and output shaft keys as part of their compliance protocol. These actions must be carried out before further flight if not previously completed, at the start of each flight day, and within 100 hours of time in service following the directive's effective date or at the next annual inspection, whichever comes first. Failure to comply with these directives can result in significant consequences. The Civil Aviation Safety Authority (CASA) may take enforcement actions against non-compliant entities or individuals, which could include fines, suspension of airworthiness certificates, or other regulatory penalties. The severity of these penalties can vary based on the nature and extent of the non-compliance, but the regulations are clear in their intent to ensure the safety and airworthiness of the aircraft involved.