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 369/99 Four-Bladed Tail Rotor Fork 8/99
DM
Applicability: Model 369D and E helicopters, with four-bladed tail rotor fork assemblies, part numbers 369D21701-21, installed.
Requirement: Inspect in accordance with MD Helicopters Inc. Service Bulletin 369D-198 or 369E- 092, as applicable.
Note: FAA Priority Letter AD 99-13-09 refers.
Compliance: Unless the initial inspection is already accomplished, before further flight after
30 June 1999; and if affected, thereafter at intervals not to exceed 50 hours time in service.
If no ridges are found on the initial inspection, raise an MDR quoting this directive, and include action under para 1E of the requirement document if necessary.
This Airworthiness Directive becomes effective on 30 June 1999.
Background: The FAA received reports from the manufacturer of the discovery of a discrepant part.
During the manufacturing process, an unknown number of certain four-bladed tail rotor fork assemblies were incorrectly machined in critical areas after the shot-peening process. The two ridges on each of the arms of the fork assemblies were incorrectly machined off. This condition, if not corrected, could result in failure which could cause loss of a tail rotor blade and subsequent loss of control of the helicopter.
Overview
The Civil Aviation Regulations 1998, amended through the Legislative instrument F2006B10763, introduced specific Airworthiness Directives to address safety concerns in civil aviation. This legislative instrument, enacted by the Commonwealth of Australia, aims to ensure that certain helicopters meet stringent safety standards to prevent potential catastrophic failures. The policy objective is to safeguard the integrity of helicopter operations by mandating regular inspections and maintenance of critical components, specifically targeting the four-bladed tail rotor fork assemblies of McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters. The directive, effective from 30 June 1999, requires inspections in line with specified service bulletins and sets out compliance timelines to ensure that any defects are identified and rectified before further flight, thereby maintaining airworthiness and enhancing overall aviation safety.
Scope and Application
The Civil Aviation Safety Authority's Schedule of Airworthiness Directives, specifically AD/HU 369/99, applies to McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters, particularly models 369D and E, that are equipped with four-bladed tail rotor fork assemblies bearing part numbers 369D21701-21. This directive mandates inspections to ensure compliance with MD Helicopters Inc. Service Bulletins 369D-198 or 369E-092, as relevant, to identify and rectify any discrepancies in the machining of the tail rotor fork assemblies. Non-compliance could lead to severe consequences, including the loss of a tail rotor blade and subsequent loss of control. The directive became effective on 30 June 1999, with inspections required before further flight after this date and, if necessary, at intervals not exceeding 50 hours of service. If no ridges are detected during the initial inspection, an MDR should be filed, quoting this directive and including any necessary actions under paragraph 1E of the requirement document. This legislative instrument operates under the jurisdiction of the Commonwealth of Australia and its application is not limited by geographic boundaries, extending nationally to all operators of the specified helicopter models.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, include an Airworthiness Directive (AD) for McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters, identified as AD/HU 369/99. This directive pertains to the four-bladed tail rotor fork, with part numbers 369D21701-21, installed on model 369D and E helicopters. The directive mandates that these helicopters be inspected in accordance with MD Helicopters Inc. Service Bulletins 369D-198 or 369E-092, as applicable. A notable reference is the FAA Priority Letter AD 99-13-09. The directive applies to helicopters that have not yet undergone an initial inspection or are scheduled for flight after 30 June 1999. If no ridges are detected during the initial inspection, an MDR (Maintenance Deviation Report) should be filed quoting this directive, and any necessary actions should be taken as outlined in paragraph 1E of the requirement document.
Operators and owners of the affected helicopters must ensure that these inspections are conducted by authorised personnel following the specified procedures. Compliance with these inspection requirements is essential to ensure the airworthiness of the helicopters. The directive became effective on 30 June 1999, and operators must adhere to the stipulated intervals for subsequent inspections, which should not exceed 50 hours of time in service. This directive was issued due to the discovery of a manufacturing defect, where certain four-bladed tail rotor fork assemblies had two ridges on each arm incorrectly machined off after the shot-peening process. If left uncorrected, this condition could lead to a failure resulting in the loss of a tail rotor blade and potentially loss of control of the helicopter.
Failure to comply with this Airworthiness Directive could result in serious safety hazards. Operators who do not adhere to the inspection requirements and subsequent actions may face regulatory scrutiny, potential grounding of the aircraft, and other enforcement actions by the Civil Aviation Safety Authority (CASA). The consequences of non-compliance can include fines, operational restrictions, and legal action under the Civil Aviation Act 1988 and associated regulations. The maximum penalties for non-compliance with airworthiness directives can be substantial, reflecting the critical importance of adhering to these safety measures.