AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters
AD/HU 369/115 Fuselage Station 75 Control Support Bracket Assembly
1/2005
DM
Applicability: Model 600N helicopters, serial numbers with a prefix of “RN” and numbers 025, 029, 032, 034 through 038, 040, 041, 045, 048, or 067; or, any Model 600N helicopter with a yaw stability augmentation system (YSAS) installed, and with a control support bracket assembly, part number 369N2608-11, installed.
Requirement: 1. Replace the fuselage Station 75 control support bracket assembly, part number 369N2608-11, with a serviceable control support bracket assembly, part number 600N2608-1.
Helicopter serial numbers and revised finite life (time in service) list:
RN025 2556 hrs, RN029 2377 hrs, RN032 2498 hrs, RN034 2456 hrs, RN035
2243 hrs, RN036 2652 hrs, RN037 2544 hrs, RN038 2531 hrs, RN040 2562
hrs, RN041 2763 hrs, RN045 2015 hrs, RN048 2125 hrs, and RN067 1600 hrs.
2. For helicopters with a YSAS installed that are not listed in above serial number and revised finite life list, replace the control support bracket assembly part number 369N2608-11 with a serviceable control support bracket assembly, part number 600N2608-1.
For helicopters with no YSAS installed, but with a control support bracket assembly part number 369N2608-11 installed, replace the control support bracket assembly part number 600N2608-1, before installation of a YSAS.
This Directive revises the Limitations section of the applicable maintenance manual by reducing the life limit of the control support bracket assembly, part number 369N2608-11, to the life limits stated in the above serial number and revised finite life list or to 1,600 hours time in service, whichever occurs first.
Note 1: MD Helicopters, Inc. Service Bulletin No. SB600N-040, dated 18 September 2003, refers.
Note 2: FAA AD 2004-22-12 Amdt 39-13840 refers.
McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters
AD/HU 369/115 (continued)
Compliance: 1. Before 1 December 2005 or upon accumulating the time listed in the serial number and revised finite life list in the Requirement part of this Directive; whichever occurs first.
2. Before 1 December 2005 or upon accumulating 1,600 hours time in service since installation of the YSAS, whichever occurs first.
This Airworthiness Directive becomes effective on 8 December 2004.
Background: This Directive is prompted by information received from the manufacturer indicating that the fatigue life of the control support bracket is shorter than the original analysis indicated. The actions required by this Directive are intended to prevent failure of the control support bracket and subsequent loss of control of the helicopter.
David Villiers
Delegate of the Civil Aviation Safety Authority 2 December 2004
The above AD is notified in the Commonwealth of Australia Gazette on 8 December 2004.
Overview
The Civil Aviation Safety Authority (CASA) issued Airworthiness Directive AD/HU 369/115 on 2 December 2004 under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998. This directive addresses an identified safety concern regarding the fatigue life of the control support bracket assembly in certain McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters. Specifically, the directive mandates the replacement of the control support bracket assembly part number 369N2608-11 with a serviceable control support bracket assembly part number 600N2608-1 to prevent potential failure and subsequent loss of control of the helicopter. The policy objective is to enhance the safety of air travel by ensuring the longevity and reliability of critical components in helicopters, thereby mitigating risks associated with structural failures.
Scope and Application
This Airworthiness Directive applies specifically to the McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters, particularly to the Model 600N helicopters that match certain serial numbers with a prefix of “RN” or have a yaw stability augmentation system (YSAS) installed, and a control support bracket assembly part number 369N2608-11. The directive is issued by the delegate of the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 (CASR 1998). Its objective is to address an identified unsafe condition by mandating specific actions to ensure the airworthiness of these helicopters. Compliance with the directive is mandatory and must be achieved within the specified timelines, either by a certain date or after a particular number of flight hours, depending on the helicopter’s configuration and history. The directive applies across the entire Commonwealth of Australia and was published in the Commonwealth of Australia Gazette on 8 December 2004.
Key Provisions
The Airworthiness Directive (AD) specified in the legislative instrument F2006B10674 mandates certain actions for the specified McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters. The AD applies to Model 600N helicopters with specific serial numbers, or any Model 600N helicopter with a yaw stability augmentation system (YSAS) installed and a control support bracket assembly part number 369N2608-11. The directive requires the replacement of the existing control support bracket assembly with a serviceable one, part number 600N2608-1, under specified circumstances (sections 1-2). For helicopters with YSAS installed but not listed by serial number, the replacement must still be completed. For helicopters without YSAS but with the control support bracket assembly part number 369N2608-11, the replacement must occur before the installation of a YSAS.
The AD imposes clear obligations on the parties governed by it. Owners or operators of the affected helicopters must comply with the replacement requirements outlined in the directive. This includes ensuring that the replacement of the control support bracket assembly is carried out in accordance with the instructions provided and within the specified timeframes (section 1). The directive also revises the limitations section of the applicable maintenance manual, reducing the life limit of the control support bracket assembly to the specified life limits or 1,600 hours time in service, whichever occurs first.
Failure to comply with the AD can result in severe consequences. The directive is a legal requirement issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998. Non-compliance could potentially lead to the grounding of the affected aircraft, which could result in significant operational disruptions and financial losses. Additionally, failure to adhere to the AD could compromise the safety of the aircraft, leading to potential accidents or incidents that could endanger lives and property. The directive becomes effective on 8 December 2004, and compliance is mandatory by 1 December 2005 or upon accumulating the specified time in service, whichever occurs first.