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.