COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
DHC-6 (Twin Otter) Series Aeroplanes
AD/DHC-6/64 Elevator Pushrod Ball Ends 7/90
Applicability: All models.
Requirement: Remove the pushrods (P/N C6CF 1466-1 or C6CF 1141-1) from the aircraft. Remove the rod ends from both ends of the pushrod and inspect for corrosion, damage, freedom of rotation and cracks, in accordance with Transport Canada Emergency AD CF-90-10.
Compliance: Within the next 25 hours time in service or five days, whichever occurs first, after 14 May 1990, unless accomplished within the previous 21 days.
Background: Fatigue failure of an elevator pushrod ball end has occurred in service. It is suspected that the cause may have been related to seizure of the ball and/or bending or misalignment.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, is an essential piece of legislation governing all aspects of civil aviation within Australia. One particular section of interest is Part 39, which addresses the issuance of Airworthiness Directives aimed at ensuring the safety and airworthiness of aircraft. The directive AD/DHC-6/64 pertains specifically to De Havilland Canada DHC-6 (Twin Otter) Series aeroplanes, focusing on the elevator pushrod ball ends. This directive was introduced to address the problem of fatigue failure of the elevator pushrod ball ends, a safety concern that could potentially lead to severe operational hazards. The policy objective is to mandate the inspection and replacement of these components to prevent in-service failures and ensure the continued safety of air travel.
The Civil Aviation Safety Authority, under the authority granted by the Civil Aviation Act 1988, issues these directives to mitigate risks identified through operational experience and engineering analysis. The directive mandates that all DHC-6 series aircraft must have their pushrods inspected for corrosion, damage, freedom of rotation, and cracks within a specified timeframe after a certain date, unless an inspection has already been performed within the preceding 21 days. This proactive approach underscores the commitment to maintaining high safety standards within the aviation industry.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105, which pertains to Civil Aviation Safety Authority Schedule of Airworthiness Directives for DHC-6 (Twin Otter) Series Aeroplanes, sets out mandatory requirements for the maintenance and safety of aircraft within Australian airspace. This legislation applies to all models of DHC-6 Twin Otter aircraft and mandates that the pushrods (P/N C6CF 1466-1 or C6CF 1141-1) be removed from the aircraft and their rod ends inspected for corrosion, damage, freedom of rotation, and cracks, following the procedures outlined in Transport Canada Emergency AD CF-90-10. Compliance with these directives is required within 25 hours time in service or five days, whichever occurs first, following 14 May 1990, unless the inspection was already completed within the previous 21 days. This directive is critical as it addresses the issue of fatigue failure of the elevator pushrod ball ends, which has occurred in service and may be related to seizure of the ball and/or bending or misalignment.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39, Section 105, includes a schedule of airworthiness directives concerning various aircraft, including the DHC-6 (Twin Otter) Series Aeroplanes. One such directive, AD/DHC-6/64, pertains to the elevator pushrod ball ends of these aircraft (Section 105). This directive mandates that the pushrods, specifically P/N C6CF 1466-1 or C6CF 1141-1, be removed from the aircraft and their rod ends inspected for corrosion, damage, freedom of rotation, and cracks in accordance with the guidelines set by Transport Canada Emergency AD CF-90-10. The directive applies to all models of the DHC-6 series (Section 105).
To comply with this directive, the pushrods must be removed and inspected within 25 hours of time in service or within five days, whichever comes first, after 14 May 1990, unless the inspection has been completed within the previous 21 days (Section 105). This ensures that the aircraft remain safe to operate by identifying and addressing any issues with the elevator pushrod ball ends. The directive's background indicates that fatigue failure of an elevator pushrod ball end has occurred in service, potentially due to seizure of the ball and/or bending or misalignment (Section 105).
The obligations imposed by this airworthiness directive are clear and specific. Operators of DHC-6 series aeroplanes must ensure that the pushrods are removed and inspected for the aforementioned issues within the specified timeframes. This is a critical safety measure to prevent any potential failures that could compromise the integrity of the aircraft during flight. Operators must maintain detailed records of compliance to demonstrate adherence to these safety standards.
Breaching the requirements of this directive can lead to serious consequences. While the specific penalties are not detailed in the text provided, non-compliance with airworthiness directives can generally result in enforcement actions by the Civil Aviation Safety Authority (CASA). This may include fines, suspension of the aircraft's operating certificate, or other regulatory actions. Such penalties underscore the importance of adhering to the directive to maintain the highest safety standards in aviation.