COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Piper PA-42 (Cheyenne III) Series Aeroplanes
AD/PA-42/5 Major Structural Fatigue Limitations 4/84
Applicability: All models.
Requirement: 1. Retire the wing main spar lower caps and root fittings and the centre beam assembly from service at or before 18750 hours time in service.
2. Retire the fuselage pressurised cabin at or before 13650 pressure cycles.
Note 1: To avoid confusion, it should be noted that the lower spar cap comprises the complete spar cap assembly including the “T” section element together with the nesting angles and reinforcing strips.
Note 2: On the basis of currently available fatigue substantiating data only one spar cap replacement is permitted. This will allow a once only wing life extension for the aircraft from spar cap replacement after which the airframe in its entirety will be retired.
Effective: Forthwith.
Background: This directive formally promulgates the retirement lives for the above major structural items as determined by full scale fatigue testing.
Overview
The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B05995, address significant safety concerns regarding the structural integrity of Piper PA-42 (Cheyenne III) series aeroplanes. Enacted by the Australian Government, this regulation aims to ensure the airworthiness of these aircraft by imposing mandatory retirement limits on critical components, thereby mitigating risks associated with structural fatigue. The directive was issued by the Civil Aviation Safety Authority (CASA) and is intended to enforce a safety framework that extends the operational life of the aircraft while ensuring compliance with stringent fatigue testing standards. The overarching policy objective is to maintain the highest safety standards in civil aviation by specifying precise retirement timelines for key structural elements, thus preventing catastrophic failures due to metal fatigue.
This legislative instrument underscores the commitment of the Australian Government and CASA to uphold rigorous safety protocols, ensuring that aircraft continue to operate within their designed limits. By mandating the retirement of the wing main spar lower caps, root fittings, centre beam assembly, and the fuselage pressurised cabin at specified service hours and pressure cycles, the directive seeks to avert potential hazards that could compromise flight safety. The directive's immediate enforcement aims to provide clear and actionable guidelines for operators, thereby enhancing overall aviation safety and reliability.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, governs the airworthiness of Piper PA-42 (Cheyenne III) series aeroplanes. This regulation applies to all models of the specified aircraft, mandating structural integrity checks and retirement of critical components to ensure safety. For instance, the wing main spar lower caps and root fittings, along with the centre beam assembly, must be retired from service before reaching 18,750 hours of time in service, and the fuselage pressurised cabin must be retired before completing 13,650 pressure cycles. The directive is effective immediately and is based on the results of full-scale fatigue testing, ensuring that these aeroplanes remain airworthy and compliant with safety standards. The regulation does not specify any exclusions or exemptions but enforces strict adherence to the stipulated timelines and conditions to maintain the safety and airworthiness of the aircraft.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39, includes the Airworthiness Directives (ADs) for various aircraft, such as the Piper PA-42 (Cheyenne III) Series Aeroplanes, which are subject to AD/PA-42/5 concerning major structural fatigue limitations. This AD mandates certain retirement timelines for specific components of the aircraft to ensure safety (s. 1). Firstly, it requires the retirement of the wing main spar lower caps and root fittings, as well as the centre beam assembly, at or before 18,750 hours of time in service (s. 1(1)). Secondly, the directive specifies that the fuselage pressurised cabin must be retired at or before 13,650 pressure cycles (s. 1(2)). These requirements are intended to mitigate the risk of structural failure due to fatigue.
Under the Civil Aviation Regulations, entities governed by these ADs, such as aircraft operators and maintenance providers, must adhere to the specified retirement timelines for the mentioned components. Operators are obligated to ensure that the wing main spar lower caps and root fittings, the centre beam assembly, and the fuselage pressurised cabin are retired within the prescribed hours or cycles. This includes performing the necessary inspections and maintenance actions to comply with the AD. It is essential for these entities to maintain accurate records of the service hours and pressure cycles to facilitate timely retirements and avoid non-compliance.
Failure to comply with the provisions of the AD/PA-42/5 may result in serious safety implications and potential legal consequences. The Civil Aviation Safety Authority (CASA) enforces these regulations, and any breach of the specified retirement timelines may lead to enforcement actions. The consequences of non-compliance can include administrative penalties, grounding of the aircraft, and in severe cases, criminal charges against the responsible parties. The maximum penalties for such offences can include substantial fines and imprisonment, depending on the severity and impact of the non-compliance. It is critical for all involved parties to strictly adhere to the ADs to ensure the continued airworthiness and safety of the aircraft.