COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bell Helicopter Textron 412 Series Helicopters
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 CAR 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.
AD/BELL 412/42 Main Hydraulic Servo Actuator
Rod End Lock Washer
9/2001
DM
Applicability: Model 412, 412EP and 412CF helicopters incorporating hydraulic servo actuator, part number 41000470, serial numbers with “HR’ prefix up to and including 10010.
Requirement: 1. Inspect the tab on the rod end locking washer of each hydraulic servo actuator for bending and twisting in accordance with “Accomplishment Instructions”, Paragraph 2.A of Bell Helicopter Textron, Inc Service Bulletin 412-00-105 or 412CF-00-12, as applicable.
2. Replace P/No NAS513-6 lock washer with P/No NAS513K6C locking device in accordance with “Accomplishment Instructions”, Paragraph 2.B of Bell Helicopter Textron, Inc Service Bulletin 412-00-105 or 412CF-00-12, as applicable.
Note: FAA AD 2001-08-04 refers
Compliance: 1. Within 25 flight hours after the effective date of this Airworthiness Directive.
2. Within 100 flight hours after the effective date of this Airworthiness Directive or at next actuator overhaul, whichever occurs first.
This Airworthiness Directive becomes effective on 25 July 2001.
Background: This Directive is prompted by reports of damaged main hydraulic actuator rod end lock washers which can result in rod end disengagement from the actuator and potential for loss of control of the main rotor.
James Coyne
Delegate of the Civil Aviation Safety Authority 18 July 2001
The above AD is notified in the Commonwealth of Australia Gazette on 25 July 2001.
Overview
The Civil Aviation Regulations 1998, enacted by the Australian Parliament, govern the safety and operational standards of civil aviation in Australia. This legislation aims to ensure that all civil aviation activities within Australia comply with stringent safety regulations. One specific legislative instrument under this Act is the Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) to address identified safety issues with aircraft. For instance, AD/BELL 412/42 issued in 2001 pertains to Bell Helicopter Textron 412 Series helicopters, specifically targeting a safety issue with the main hydraulic servo actuator rod end lock washer. This AD was introduced to mitigate the risk of rod end disengagement, which could potentially lead to loss of control over the main rotor, thereby ensuring continued airworthiness and safety of the affected aircraft. The directive mandates specific inspections and replacements as outlined, with the overarching policy objective being the enhancement of aviation safety through proactive maintenance and regulatory oversight.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates that this Airworthiness Directive applies to all Bell Helicopter Textron 412 Series helicopters, namely the Model 412, 412EP, and 412CF, that incorporate a hydraulic servo actuator part number 41000470 with serial numbers prefixed by "HR" up to and including 10010. This regulation is pertinent to the aircraft's operators and maintenance personnel within the jurisdiction of the Civil Aviation Safety Authority (CASA). The directive is designed to ensure the safety of the helicopters by addressing potential unsafe conditions related to the hydraulic servo actuator's rod end locking washer. The directive requires specific actions to be taken, including inspecting and replacing the rod end lock washer, in accordance with the outlined instructions from Bell Helicopter Textron, Inc Service Bulletin 412-00-105 or 412CF-00-12. The requirement to comply with this Airworthiness Directive must be fulfilled within certain flight hours after its effective date, which is 25 July 2001, as published in the Commonwealth of Australia Gazette. This directive is integral to maintaining the airworthiness of the specified helicopter models within Australia's airspace.
Key Provisions
The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 mandates specific actions to be taken concerning the Bell Helicopter Textron 412 Series Helicopters, particularly those with hydraulic servo actuators (section 1). These helicopters must undergo inspections and, if necessary, replacements of certain components to address identified safety concerns. The applicability section (section 2) specifies the model and serial numbers of the helicopters that are subject to this directive. The requirement section (section 3) outlines the actions to be taken, which include inspecting the rod end locking washer of each hydraulic servo actuator for bending and twisting, and replacing the P/No NAS513-6 lock washer with P/No NAS513K6C locking device. These actions must be carried out in accordance with the instructions provided in the Bell Helicopter Textron, Inc Service Bulletins 412-00-105 or 412CF-00-12, as applicable.
The AD imposes obligations on the operators and owners of the specified Bell Helicopter Textron 412 Series Helicopters to ensure compliance with the outlined requirements. Operators must conduct the required inspections and replacements within specified timeframes. Specifically, the inspections must be completed within 25 flight hours after the effective date of the AD, and the replacement of the lock washer must be completed within 100 flight hours after the effective date of the AD or at the next actuator overhaul, whichever comes first (section 4). Compliance with these requirements is mandatory to maintain the airworthiness of the helicopters and ensure the safety of all personnel involved.
Failure to comply with the AD can result in serious consequences. The AD explicitly states that it becomes effective on 25 July 2001 (section 5). Any helicopter operator or owner found not to be in compliance with the mandated inspections and replacements may face legal and safety repercussions. The primary motivation for issuing this AD is the reported instances of damaged main hydraulic actuator rod end lock washers, which can lead to the disengagement of the rod end from the actuator and a potential loss of control of the main rotor. This underscores the critical nature of adhering to the AD's provisions to prevent such safety hazards.