COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters
AD/HU 369/79 Tail Rotor Transmission Output Shaft Duplex Bearings
13/89
Applicability: All model 369D, 369E and 369F/FF series helicopters with P/N 369D25400 tail rotor assemblies installed.
Requirement: Action in accordance with McDonnell Douglas S.I.N No DN-161, EN-51 or FN-38, as applicable.
Compliance: At the next periodic inspection for issue of a Maintenance Release or by 30 June 1990, whichever occurs first.
Background: Duplex bearings fitted to the tail rotor gearbox output shaft may have been manufactured with excessive tolerances. To confirm the bearing tolerance is within limits a one time inspection for excessive play in the output shaft, is required.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes Airworthiness Directives (AD) issued by the Civil Aviation Safety Authority to ensure the safety and airworthiness of aircraft. One such AD is AD/HU 369/79, which addresses the tail rotor transmission output shaft duplex bearings in McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters. This directive was enacted to address the potential issue of excessive tolerances in the duplex bearings, which could compromise the safety of the aircraft. The directive mandates that all model 369D, 369E, and 369F/FF series helicopters with specific tail rotor assemblies must undergo a one-time inspection to ensure the bearing tolerance is within the required limits. Compliance with this directive must be achieved by the next periodic inspection for a Maintenance Release or by 30 June 1990, whichever comes first.
The Civil Aviation Safety Authority, as the enforcing body under the Civil Aviation Act 1988, issues these directives to mitigate any identified safety risks in aircraft operation. The policy objective behind AD/HU 369/79 is to ensure that the specified helicopters are safe to operate by rectifying any potential manufacturing defects in the tail rotor gearbox output shaft duplex bearings. This proactive measure aims to prevent any in-flight failures that could arise from the identified issue, thereby maintaining the highest standards of aviation safety.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, governs the safety requirements for certain types of helicopters. This legislation applies to all model 369D, 369E, and 369F/FF series helicopters equipped with P/N 369D25400 tail rotor assemblies. The directive mandates that these helicopters undergo an inspection to ensure the tail rotor transmission output shaft duplex bearings meet specified tolerances. Compliance with this directive is required at the next periodic inspection for the issuance of a Maintenance Release or by 30 June 1990, whichever comes first. This requirement stems from concerns that the duplex bearings may have been manufactured with excessive tolerances, which could compromise the helicopter’s safety. The regulation ensures that the issue is addressed through specific actions outlined in McDonnell Douglas S.I.N No DN-161, EN-51, or FN-38, as applicable.
Key Provisions
The main operative sections of the Civil Aviation Regulations 1998, Part 39, particularly AD/HU 369/79, concern the airworthiness directives (ADs) for the McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters, specifically addressing issues with tail rotor transmission output shaft duplex bearings (section 13/89). This AD applies to all model 369D, 369E, and 369F/FF series helicopters equipped with P/N 369D25400 tail rotor assemblies. The requirement is to perform an action in accordance with McDonnell Douglas Service Instructions (S.I.) No DN-161, EN-51, or FN-38, as applicable. Compliance must be achieved at the next periodic inspection for the issuance of a Maintenance Release or by 30 June 1990, whichever is earlier.
The obligations imposed by this AD necessitate that operators of the specified helicopter models ensure their tail rotor transmission output shaft duplex bearings meet the required tolerances. This involves conducting a one-time inspection to confirm that the output shaft does not exhibit excessive play, which could result from manufacturing tolerances that are outside acceptable limits. Operators must follow the specific service instructions provided by McDonnell Douglas to address any identified issues, which may include replacing or adjusting the bearings.
Failure to comply with the AD/HU 369/79 may lead to serious safety concerns, as the improper functioning of the tail rotor transmission can compromise the helicopter's stability and control during flight. While the Civil Aviation Regulations do not explicitly state penalties for non-compliance in this specific AD, general non-compliance with airworthiness directives can result in severe consequences, including the potential for grounding the aircraft, civil penalties, and criminal charges if the non-compliance leads to an accident or incident. Operators must, therefore, take the directive seriously to avoid any potential legal and safety repercussions.