COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bell Helicopter Textron 204 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 204/31 Main Rotor Yoke 8/2000
Applicability: All Model 204B with Main Rotor hub assembly P/N 204-012-101 and yoke assembly P/N 204-011-102.
Requirement: 1. Remove the main rotor yoke from the hub assembly and inspect the yoke:
- for corrosion pits, scratches and damage in the pillow block bushing hole, in each spindle radius and yoke web section, using as a minimum, a 5X magnifying glass; and
b. for cracks, using a magnetic particle inspection method - special attention needs to be directed to the centre section web, spindles , radius and pillow block bushing holes.
Repair and refinish any corrosion or cracking indications which are within the limits specified in the current Revision of the Bell 204B Component Repair and Overhaul Manual in accordance with the Manual's instructions. Remove from service those yokes where the corrosion or cracking falls outside those limits.
2. Retire the Main Rotor yoke from service.
Note: FAA ADs 79-20-05 and 81-19-02 refer.
Compliance: For Main Rotor yokes with:
- a. 500 hours or more time in service at the effective date of this directive, before the issue of an Australian CofA; or
b. less than 500 hours time in service at the effective date of this directive, before attaining 1000 hours time in service; and
2. retire at 3600 hours time in service,
This Airworthiness Directive becomes effective on 10 August 2000.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Background: This directive is raised to prevent the development and subsequent increase in size of stress raisers which would give rise to premature failure of the main rotor yoke. It also follows the re-introduction of the AD Series after sixteen years.
Further testing of the yoke by the manufacture has determined that the 204-011-102 yoke may not safely operate beyond 3600 hours.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 6 July 2000
The above AD is notified in the Commonwealth of Australia Gazette on 12 July 2000.
Overview
The Civil Aviation Regulations 1998, enacted by the Australian Parliament, form the foundational legal framework for civil aviation in Australia, with the Civil Aviation Safety Authority (CASA) responsible for their administration. One such regulation is Part 39 - 105, which outlines the scheduling of Airworthiness Directives, including the AD/BELL 204/31 issued in August 2000. This directive was introduced to address potential safety issues with the main rotor yoke of Bell Helicopter Textron 204 Series Helicopters, specifically those with Main Rotor hub assembly P/N 204-012-101 and yoke assembly P/N 204-011-102. The primary objective of this Airworthiness Directive was to prevent the development of stress raisers that could lead to premature failure of the main rotor yoke, thereby ensuring the ongoing safety of the aircraft. The directive mandates specific actions, including inspection for corrosion and cracks, repair of identified issues within specified limits, and retirement of the yokes outside these limits or after reaching a total of 3600 hours of service.
Scope and Application
The Civil Aviation Safety Authority (CASA) has issued an Airworthiness Directive (AD) under the Civil Aviation Regulations 1998 (CAR 1998), specifically targeting all Bell Helicopter Textron 204 Series helicopters with Main Rotor hub assembly P/N 204-012-101 and yoke assembly P/N 204-011-102. The directive mandates specific inspections and maintenance actions to ensure the safety of these aircraft. The AD applies to aircraft where the main rotor yoke has accumulated 500 hours or more of service time at the directive's effective date, or before reaching 1000 hours for yokes with less than 500 hours at the effective date. Furthermore, the main rotor yoke must be retired from service once it reaches 3600 hours. The AD requires the removal and inspection of the main rotor yoke for corrosion and cracks, with specified repair or retirement based on the findings. This directive applies nationally within Australia and is enforced by CASA, ensuring compliance across all relevant jurisdictions and operators.
Key Provisions
The main operative sections of the Civil Aviation Regulations 1998, Part 39 - 105, focus on ensuring the airworthiness of specific helicopter models. This Airworthiness Directive (AD) applies to all Model 204B helicopters equipped with a Main Rotor hub assembly P/N 204-012-101 and yoke assembly P/N 204-011-102. Section 1 of the requirement mandates that the main rotor yoke be removed from the hub assembly and inspected thoroughly for corrosion pits, scratches, and damage using a 5X magnifying glass. Additionally, magnetic particle inspection must be conducted to detect any cracks, with a particular focus on the centre section web, spindles, radius, and pillow block bushing holes. If any corrosion or cracking is found within permissible limits, it must be repaired and refinished according to the Bell 204B Component Repair and Overhaul Manual. However, if the corrosion or cracking exceeds these limits, the yoke must be retired from service. Section 2 of the requirement states that the main rotor yoke should be retired at 3600 hours of service time.
The Civil Aviation Regulations 1998 impose several obligations and requirements on the parties involved. Owners and operators of Bell Helicopter Textron 204 Series helicopters must ensure that the inspections and repairs outlined in the directive are carried out. This includes removing the main rotor yoke and conducting the specified inspections within the stipulated timeframes. Any findings of corrosion or cracks must be addressed according to the manual’s instructions, and if necessary, the yoke must be removed from service. Furthermore, operators must adhere to the compliance timeline, which requires inspections and retirements to be completed before specific service hour thresholds are reached.
Failure to comply with the Airworthiness Directive may result in serious consequences. Under the Civil Aviation Regulations 1998, non-compliance with airworthiness directives is an offence that could lead to criminal or civil penalties. The maximum penalties for such offences can include substantial fines and imprisonment, depending on the severity and frequency of the non-compliance. Additionally, operating an aircraft that does not meet airworthiness standards can result in the suspension or revocation of the aircraft's Certificate of Airworthiness, which is a critical document for legal operation. These stringent measures are in place to ensure that all parties adhere to the safety standards set forth by the Civil Aviation Safety Authority.