AD/PA-42/19 - Main Landing Gear Upper Strut and Oleo Tube Plug

Overview

The Civil Aviation Regulations 1998, specifically PART 39 - 105, encompasses a series of Airworthiness Directives aimed at ensuring the safe operation of aircraft within Australian airspace. One such directive, AD/PA 42/19, pertains to the Piper PA-42 (Cheyenne III) Series Aeroplanes and addresses issues with the main landing gear upper strut and oleo tube plug. This directive was introduced to address the problem of potential cracks in the main landing gear upper strut housings, which, if left uncorrected, could lead to a loss of landing gear integrity, posing a significant safety risk. The enactment of this directive by the Civil Aviation Safety Authority is intended to ensure compliance with Piper's Mandatory Service Bulletins No 912 and No 929, which outline necessary actions to maintain the airworthiness of the specified aircraft models. The directive mandates actions to be taken at specific intervals to prevent the propagation of cracks in the main landing gear upper strut housings. Compliance with these requirements is essential to meet certification standards for severe loading and to ensure the ongoing airworthiness of the affected aircraft. The policy objective of this directive is to enhance aviation safety by mandating timely inspections and repairs, thereby mitigating the risk of in-flight failures due to structural weaknesses in the landing gear components.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to airworthiness directives issued by the Civil Aviation Safety Authority (CASA) and applies to Piper PA-42 (Cheyenne III) Series Aeroplanes, particularly those with serial numbers 42-5527001 and above that have their main landing gear upper strut housings exceeding 450 hours of service time. This legislation mandates compliance with Piper's Mandatory Service Bulletins (SB) No 912 and No 929. SB 912 is critical for meeting certification requirements associated with severe loading of main landing gear struts, while SB 929 is essential for detecting potential cracks in the main landing gear upper strut housings, which, if left unaddressed, could result in a loss of landing gear integrity. Compliance with these service bulletins is necessary to ensure the continued airworthiness of the specified aircraft models. The regulations stipulate that action must be taken either before the aircraft accumulates 100 hours of service time after 22 March 1990 or at the next scheduled inspection for the issue of a Maintenance Release after that date, whichever is later. For SB 929, the action must also be performed at intervals not exceeding 100 hours of service time.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 105, include specific Airworthiness Directives (AD) for certain aircraft models to ensure safety and compliance with civil aviation standards. One such directive, AD/PA 42/19, pertains to the Piper PA-42 (Cheyenne III) series aeroplanes, specifically those with Serial Numbers 42-5527001 and above. This AD focuses on the main landing gear upper strut and oleo tube plug, aiming to prevent potential issues that could compromise the integrity of the landing gear (Section 3/90). Under this directive, the primary requirements are to follow two specific Piper Mandatory Service Bulletins (SB). Firstly, SB No 912 must be followed to address the severe loading of the main landing gear struts, which is critical to maintaining the structural integrity of the aircraft during landings (Section 1). Secondly, SB No 929 must be implemented to detect potential cracks in the main landing gear upper strut housings, a crucial measure to prevent the propagation of such cracks which could lead to catastrophic failure during operation (Section 2). The directive notes that new replacement housings will require compliance with these actions only upon accumulating 450 hours of time in service. To ensure compliance with these directives, the actions outlined in SB 912 must be completed unless already performed, before the aircraft exceeds 100 hours of time in service after 22 March 1990, or at the next scheduled inspection for the issue of a Maintenance Release after that date, whichever comes later (Section Requirement 1). SB 929 actions must also be completed before the aircraft exceeds 100 hours of time in service after 22 March 1990, or at the next scheduled inspection for the issue of a Maintenance Release after that date, and thereafter at intervals not exceeding 100 hours of time in service (Section Requirement 2). These provisions underscore the importance of timely and regular inspections and maintenance to ensure continued airworthiness. Failure to comply with these airworthiness directives can lead to significant consequences. The Civil Aviation Regulations 1998 impose obligations on aircraft operators to ensure that all maintenance and inspections are performed in accordance with the specified directives. Non-compliance with these requirements may result in enforcement actions, which can include fines, penalties, or even the grounding of the aircraft. The exact penalties for non-compliance are not specified in the legislative instrument but typically include fines that can reach significant amounts under civil aviation law, reflecting the high stakes involved in ensuring the safety and reliability of aircraft operations.