COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bell Helicopter Textron 47 (All Variants) Series Helicopters
AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BELL 47/92 Amdt 4 and issues the following 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 47/92
Amdt 5
Applicability: All models.
Main Rotor Blade Grips 2/2001 TX
Requirement: 1. Inspect the internal threaded portion of each main rotor blade grip barrel using eddy current procedure DOA/NDI/EC6. Copies of this procedure are available from the Authority.
2. Retire the main rotor blade grips from service before exceeding 5000 hours time in service.
Note: Grip assemblies part number 47-120-252-5 are not approved for use in Australia.
Compliance: Unless the initial inspection is already accomplished, at the threshold of 600 hours component time since new or within 25 hours time in service after 21 December 2000, whichever occurs later. Repeat thereafter at intervals not to exceed 600 hours component time in service until retired in accordance with Requirement 2.
Note: Compliance with the requirements of this Directive permits operation beyond the retirement life stipulated in the manufacturer’s documentation.
This amendment becomes effective on 21 December 2000.
Background: Numerous fatigue cracks in the internal threads of the main rotor blade grips have been detected in-service by the specified eddy current procedure, which would not be detectable by dye penetrant methods. To control this risk of failure, the previously substantiated 5,000 hour retirement life was reintroduced.
The previous issue of this Directive and Transport Canada AD CF-1988-08 required eddy current inspections at the same initial inspection threshold, with the TC AD 300 hour repeat interval being the only difference. FAA AD 86-06-08 R1 required a fluorescent dye penetrant inspection method, a 1,200 hour threshold and a 300 hour repeat interval.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
A new FAA AD, 2000-18-51, requires a liquid penetrant or eddy current inspection at significantly reduced inspection intervals and establishes a 1,200 hour retirement life. The changes were prompted by the results of an accident investigation and a field survey; findings not supported by Bell.
Amendment 5 retains the inspection method and the repetitive inspection interval, but changes the initial inspection threshold. This change is in response to Transport Canada AD CF-1988-08 R1 which was prompted by three cases of cracks being found before the initial inspection threshold. The Authority has received several MDRs of cracked blade grips that were found before the initial 1200 hour inspection threshold.
Amendment 4 of this Airworthiness Directive became effective on 12 October 1985. Amendment 3 of this Airworthiness Directive became effective on 30 June 1985.
The original issue of this Airworthiness Directive became effective on 2 July 1985.
William Ronald Smith
Delegate of the Civil Aviation Safety Authority 19 December 2000
The above AD is notified in the Commonwealth of Australia Gazette on 21 December 2000.
Overview
The Civil Aviation Regulations 1998, which were enacted by the Parliament of the Commonwealth of Australia, provide a framework for ensuring the safety of civil aviation in Australia. These regulations are overseen by the Civil Aviation Safety Authority (CASA), which has the responsibility to issue airworthiness directives to address safety issues as they arise. In response to incidents where fatigue cracks in the internal threads of the main rotor blade grips of Bell Helicopter Textron 47 (All Variants) Series Helicopters were detected, CASA issued Airworthiness Directive AD/BELL 47/92 Amdt 5. This amendment aimed to rectify the unsafe condition by requiring inspections using an eddy current procedure and setting a retirement limit for the main rotor blade grips. The policy objective behind this directive is to enhance aviation safety by ensuring that these helicopters are maintained in a condition that precludes the occurrence of such defects, thus preventing potential accidents and ensuring the reliability of air travel.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to Bell Helicopter Textron 47 (All Variants) Series Helicopters. This legislation mandates actions to ensure the airworthiness of these helicopters, focusing on the internal threaded portion of each main rotor blade grip and their service life. The AD/BELL 47/92 Amdt 5 requires an inspection of the main rotor blade grips using an eddy current procedure, with these inspections occurring at the threshold of 600 hours of component time since new or within 25 hours of time in service after 21 December 2000, whichever is later, and repeating at intervals not exceeding 600 hours of component time in service. The main rotor blade grips must be retired from service before they exceed 5000 hours of time in service. This AD applies nationally across Australia, overseen by the Civil Aviation Safety Authority, and does not specify exclusions or exemptions beyond the outlined inspection and retirement requirements. The AD extends its application through subordinate instruments to ensure compliance with the safety directives set forth.
Key Provisions
The Civil Aviation Regulations 1998 (CAR 1998) Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives includes a specific Airworthiness Directive (AD) for Bell Helicopter Textron 47 (All Variants) Series Helicopters, identified as AD/BELL 47/92 Amdt 5. This AD pertains to the main rotor blade grips and mandates specific actions to ensure the safe operation of these helicopters. Firstly, under the requirement section (1), the AD stipulates that the internal threaded portion of each main rotor blade grip barrel must be inspected using the eddy current procedure DOA/NDI/EC6. This inspection is necessary to detect any fatigue cracks, which could otherwise go unnoticed using traditional dye penetrant methods. Secondly, the AD requires the retirement of main rotor blade grips from service once they exceed 5000 hours of time in service. Additionally, it notes that grip assemblies part number 47-120-252-5 are not approved for use in Australia.
In terms of obligations and requirements, operators and owners of Bell Helicopter Textron 47 series helicopters must ensure that the specified inspections are carried out at the prescribed intervals. Specifically, the initial inspection must be conducted at the threshold of 600 hours of component time since new or within 25 hours of time in service after 21 December 2000, whichever is later. Subsequent inspections must occur at intervals not exceeding 600 hours of component time in service until the blade grips are retired. Compliance with these inspection requirements allows operators to extend the operational life beyond what is stipulated in the manufacturer’s documentation.
Failure to comply with the requirements outlined in the AD can result in significant consequences. Under the CAR 1998, non-compliance with Airworthiness Directives is an offence, and penalties can include fines and imprisonment. The specific penalties are not detailed within the AD itself but are governed by the broader provisions of the CAR 1998. Operators found in breach of these regulations could face substantial financial penalties and potential criminal charges, which underscore the importance of adhering to the AD’s stipulations.