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 369/93 Main Transmission Gear Replacement 11/97
Applicability: All Model 369D, E, F, FF, 500N, AH-6 and MH-6 helicopters with main rotor transmission part number (P/N) 369D25100 installed.
Requirement: 1. Determine if the installed transmission output drive gear, P/N 369D25127-11, has a serial number (S/N) in the range S/N 005570-0646 thru S/N 005570-0765 or S/N 005570-0876 thru' S/N 005570-0998. This may be achieved by inspection of records, contact with the manufacturer or by direct inspection through the open liquid level plug port (MDHS Service Information Notice DN-189/EN82/FN- 69/NN-009 dated Jan 10, 1997 refers).
2. If the gear proves to be one of the affected S/N listed above, the gear is to be replaced with an airworthy gear with a S/N other than those listed at 1. above in accordance with the compliance summary below.
Note: FAA AD 97-15 -08 amendment 39-10081 refers.
Compliance: 1. Within the next 10 hours time in service after the effective date of this directive identify the gear serial number.
2. Gears identified in requirement 1 above are to be replaced as follows:
- For helicopters equipped with a cargo hook assembly, with a separate, permanently maintained log of actual hours time in service (TIS) of external load operation, remove and replace the gear within the next 25 hours TIS for external load operations, or within 400 hours TIS for non-external load operations, whichever comes first.
b. For helicopters equipped with a cargo hook assembly with no separate, permanently maintained log of actual external load operation, remove and replace the gear within the next 25 hours TIS after the effective date of this directive. Owners/operators may elect to begin maintaining a separate permanent log of external load operations from the effective date of this directive and then comply with the requirements of 2(a) of this AD.
c. For helicopters without cargo hook assemblies, remove and replace the gear within the next 400 hours TIS after the effective date of this directive.
3. There are no follow on inspections or maintenance requirements once the gear has been replaced as required above.
Background: Several reports of spalled or fractured gear teeth of the output transmission drive of the affected aircraft have lead to the generation of this Directive to identify and replace certain gear serial numbers. The defect was traced to a quality control problem within the gear manufacturing process and the affected batches have been traced.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Overview
The Civil Aviation Regulations 1998, under Part 39 - 105, incorporates the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, which aim to ensure the ongoing airworthiness of aircraft by addressing safety issues as they arise. One such directive, AD/HU 369/93, pertains specifically to the replacement of the main transmission gear in certain McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters. This directive was enacted in response to reports of spalled or fractured gear teeth in the affected aircraft, traced back to a quality control issue during the manufacturing process. The policy objective of this legislation is to mitigate safety risks by mandating the replacement of specific serial numbers of the transmission output drive gear, thereby preventing potential in-flight failures and ensuring the continued safety of these aircraft.
The directive applies to all Model 369D, E, F, FF, 500N, AH-6, and MH-6 helicopters equipped with the main rotor transmission part number 369D25100. It requires operators to identify whether the installed transmission output drive gear falls within specified serial number ranges and, if so, to replace it with an airworthy gear bearing a different serial number. The replacement timeline varies depending on the helicopter's equipment configuration, with specific requirements for helicopters with and without cargo hook assemblies. This proactive measure is intended to address the identified defect comprehensively and ensure compliance with aviation safety standards.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105 issued by the Civil Aviation Safety Authority, mandates that all operators of Model 369D, E, F, FF, 500N, AH-6 and MH-6 helicopters equipped with a main rotor transmission part number 369D25100 must comply with Airworthiness Directive AD/HU 369/93 concerning the replacement of the main transmission output drive gear. This requirement applies irrespective of the location of the helicopter's operation within Australia, thereby enforcing a national standard for the maintenance and safety of these aircraft. The directive necessitates an inspection to determine if the transmission output drive gear, identified by part number 369D25127-11, falls within a specified serial number range. If the gear's serial number matches those listed in the directive, it must be replaced with an airworthy gear bearing a different serial number. Compliance with the directive involves replacing the affected gear within specified timeframes based on the helicopter's operational history and equipment, ensuring that safety standards are maintained throughout the Australian civil aviation industry. The directive is comprehensive and leaves no room for exclusions or exemptions, thus providing a clear and mandatory framework for all affected helicopter operators.
Key Provisions
The Civil Aviation Regulations 1998, specifically under Part 39 - 105, contain a Schedule of Airworthiness Directives that govern the maintenance and operation of aircraft. One such directive, AD/HU 369/93, pertains to McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters, focusing on the replacement of the main transmission gear (section 1). This directive applies to all Model 369D, E, F, FF, 500N, AH-6, and MH-6 helicopters with the main rotor transmission part number (P/N) 369D25100 installed (section 1).
The main operative sections of this directive require operators to determine if the installed transmission output drive gear, P/N 369D25127-11, has a serial number (S/N) within the specified range (S/N 005570-0646 thru S/N 005570-0765 or S/N 005570-0876 thru S/N 005570-0998) (section 1.1). This can be done by inspecting records, contacting the manufacturer, or by direct inspection through the open liquid level plug port (section 1.1). If the gear falls within the affected serial number range, it must be replaced with an airworthy gear that has a different serial number (section 1.2). The replacement must be carried out within specific timeframes depending on whether the helicopter is equipped with a cargo hook assembly and if a separate, permanent log of external load operations is maintained (section 2). For helicopters with a cargo hook assembly and a maintained log, the gear must be replaced within 25 hours of external load operations or within 400 hours of non-external load operations, whichever comes first (section 2.a). For those without a maintained log, the replacement must occur within 25 hours after the directive's effective date (section 2.b). For helicopters without a cargo hook assembly, the replacement must occur within 400 hours after the directive's effective date (section 2.c).
The Act imposes several obligations on helicopter operators and owners. They must ensure that the required inspections and replacements are carried out within the specified timeframes. Operators must maintain accurate records and, if they have a cargo hook assembly, keep a separate log of external load operations. Failure to comply with these requirements may result in civil or criminal consequences. Specifically, non-compliance with airworthiness directives can lead to significant penalties under the Civil Aviation Act 1988. The maximum penalty for contravening these regulations includes fines of up to $275,000 for individuals and $1.375 million for corporations, along with potential imprisonment terms. Additionally, the Civil Aviation Safety Authority (CASA) can take enforcement actions, including grounding the aircraft, until compliance is achieved. These stringent measures underscore the importance of adhering to the directives to ensure the continued airworthiness and safety of the aircraft.