AD/DH114/17 - Landing Gear Actuator Piston - Inspection and Replacement

Overview

The Civil Aviation Regulations 1998, under the authority of the Civil Aviation Safety Authority (CASA), were enacted to ensure the safety of civil aviation in Australia. These regulations were introduced to address the need for stringent safety measures and compliance with international standards. The policy objective is to maintain a high level of safety in the operation of civil aircraft, including addressing specific technical and operational issues that may affect airworthiness. One such specific regulation is AD/DH114/17, which pertains to the inspection and replacement of landing gear actuator pistons for DH114 (Heron) Series Aeroplanes. This directive applies to all models equipped with certain Dunlop actuators and mandates that the pistons be inspected for signs of cracking and replaced if necessary, with specific intervals for these actions to ensure ongoing safety and compliance. The legislation requires that the pistons be inspected after a set number of landings, with the inspection interval being not more than 200 landings after a specified date, and the replacement of any cracked pistons occurring either when a crack is detected or after a set number of landings. This regulation underscores the commitment to proactive safety measures and the necessity for regular maintenance checks to prevent potential failures that could compromise the aircraft's safety. The objective is to ensure that all aircraft meet the required safety standards and that any identified issues are addressed promptly and effectively.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all Heron Series Aeroplanes that are fitted with Dunlop actuators P/N AC 11130 and have pistons P/N AHO 19742 installed. The regulation mandates actions concerning the landing gear actuator piston, including its inspection and potential replacement. The geographical reach of this regulation is national, as it is a Commonwealth-regulated document. This legislation does not explicitly state any exclusions or exemptions, but it does provide specific instructions for compliance. The regulation is enforced through the Civil Aviation Safety Authority (CASA) and may be extended or restricted through subordinate instruments. For paragraph 1, compliance requires inspecting the piston crown for signs of cracking at intervals not exceeding 200 landings after 15 June 1966. For paragraph 2, the requirement is to remove from service any Dunlop piston part number AHO 19742 whenever a cracked piston crown is detected or at intervals not exceeding 5000 landings, whichever occurs first. The requirements are superseded for Heron Model No. 1161.

Key Provisions

The key operative sections of this legislation, specifically the Civil Aviation Regulations 1998 (CAR) Part 39 - 105 concerning the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives (AD) for the DH114 (Heron) Series Aeroplanes, provide detailed instructions for maintaining the safety and airworthiness of the aircraft. Section 39.105 AD/DH114/17 addresses the inspection and replacement of the landing gear actuator piston (sections 1 and 2). Section 1 mandates the removal and inspection of the piston crown for signs of cracking, while Section 2 requires the removal from service of Dunlop pistons part number AHO 19742. The applicability of these directives is limited to models equipped with Dunlop actuators part number AC 11130 and specific pistons. The obligations imposed on the parties governed by these provisions include conducting inspections at specified intervals and removing and replacing parts as directed. Specifically, operators of DH114 (Heron) Series Aeroplanes must ensure that the pistons are inspected for cracking at intervals not exceeding 200 landings after 15 June 1966 (Section 1). Additionally, if a cracked piston crown is detected, or at intervals not exceeding 5000 landings, whichever comes first, the specified Dunlop pistons must be removed from service (Section 2). The legislation also notes that the requirements are nullified for Heron Mod. No. 1161. Failure to comply with these airworthiness directives can result in significant civil and criminal consequences. Although specific penalties are not detailed within the text, non-compliance with CASA directives can generally lead to enforcement actions by CASA, which may include fines, suspension or revocation of airworthiness certificates, and potential criminal charges for those responsible. The severity of these penalties reflects the critical nature of adhering to airworthiness directives to ensure the safety of all those involved in aviation operations.