AD/DH114/29 Amdt 1 - Main Undercarriage - Main and Damper Jack Bolts - Inspection and Modification

Overview

The Civil Aviation Regulations 1998, specifically in Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, contains amendments concerning the Heron Series Aeroplanes, as detailed in AD/DH114/29. This legislation was enacted to address issues related to the structural integrity of the main undercarriage in certain aircraft models, particularly focusing on the NK jack bolts that attach the damper and main components. The enactment was overseen by the Civil Aviation Safety Authority, with the policy objective of enhancing aviation safety by preventing mechanical failure through regular inspection and necessary modifications. This legislative instrument ensures that the aircraft are maintained in a safe operational condition, reducing the risk of in-flight failure that could potentially lead to catastrophic outcomes. The amendment requires all Series 2 aircraft to undergo a specified inspection process for the attachment bolts of the damper jack and the main jack. For aircraft fitted with certain bolt numbers, the directive mandates the removal and inspection for fatigue cracking, using a magnetic particle method, and the incorporation of specific modifications. Compliance with these directives is stringent, with different timeframes for inspections and modifications based on the aircraft's service history and bolt specifications. This ensures that maintenance is conducted in a timely manner, maintaining the airworthiness of the aircraft and aligning with the overarching goal of safeguarding public safety in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, as amended, establish the legal framework for ensuring the safety of civil aviation in Australia, overseen by the Civil Aviation Safety Authority (CASA). Specifically, Part 39 - 105 pertains to airworthiness directives for various aircraft, including the Heron Series Aeroplanes. The directive AD/DH114/29 Amendment 1 focuses on the inspection and modification of the NK Jack Bolts in the main undercarriage of Series 2 aircraft. This directive applies to all Series 2 Heron aircraft, mandating detailed inspection procedures for specific bolts to detect fatigue cracking. The directive applies to aircraft equipped with particular attachment bolt part numbers and requires inspections to be conducted using a magnetic particle method. Compliance with these inspections and modifications is critical and must occur within specified time intervals after certain service hours and dates. This regulation underscores the importance of maintaining airworthiness standards to ensure the safety and reliability of civil aviation operations within Australian airspace.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 – 105, addresses the airworthiness directives for the DH114 (Heron) series aeroplanes, with a focus on the main undercarriage, including the main and damper NK jack bolts. Section AD/DH114/29 outlines the requirements for the inspection and modification of these components to ensure safety. For aircraft fitted with specific attachment bolts (P/No. 14-2U.299), it is required to remove and inspect the bolts for fatigue cracking around the centre grease hole using a magnetic particle method (s. 1(a)). Additionally, for these aircraft, Modification No. 1536 must be incorporated (s. 1(b)). For aircraft fitted with different attachment bolts (P/No. 14-2U.631), the inspection process involves removing the bolts and checking for cracks using the same magnetic particle method (s. 2). The regulations impose several obligations on the parties involved. Aircraft operators must ensure that the specified inspections are carried out within the stipulated timeframes. For aircraft inspected under the previous directive, inspections must be completed within 300 hours of service from the last inspection (s. 1(a)). For other aircraft, the inspection must occur within 150 hours of service after 31 May 1972 and subsequently at intervals not exceeding 300 hours (s. 1(a)). All inspections must be completed before 31 December 1972. For aircraft with the specified modifications, inspections should occur within 2400 hours after the incorporation of the modification and thereafter at intervals not exceeding 2400 hours (s. 2). Breach of these requirements can lead to serious consequences. Non-compliance with the airworthiness directives can result in the aircraft being deemed unsafe to operate, potentially leading to grounding of the aircraft. While the specific penalties are not detailed in the provided text, under the broader Civil Aviation Act 1988, penalties for non-compliance with airworthiness regulations can include substantial fines and imprisonment. The exact penalties would be determined based on the severity and frequency of the breaches, as well as any harm resulting from non-compliance.