AD/AC/4 - Main Landing Gear Upper Retaining Pins - Replacement

Overview

The Civil Aviation Regulations 1998, as amended, form a critical part of Australia's regulatory framework for ensuring the safety and efficiency of civil aviation within the country. One notable addition to these regulations is the 1998 Airworthiness Directive concerning the Twin Commander series aeroplanes manufactured by Gulfstream, Rockwell, and Aerocommander. This legislative instrument was introduced to address the specific safety concerns identified with the main landing gear upper NK retaining pins on certain models. The Australian Government, through its enactment by the Parliament, aimed to ensure that these safety directives were promptly and effectively implemented to mitigate potential risks to flight safety. The policy objective underpinning this directive was to maintain the highest possible safety standards in the civil aviation sector by addressing design and manufacturing deficiencies in critical aircraft components. By mandating the immediate replacement of the retaining pins, the directive sought to prevent any potential mechanical failure that could compromise the structural integrity of the landing gear, thereby ensuring the continued airworthiness of the specified aircraft models. This proactive approach underscores the commitment of the Australian Government to safeguard the safety of both passengers and crew within the national airspace.

Scope and Application

The Civil Aviation Safety Authority (CASA) has issued an Airworthiness Directive under the Civil Aviation Regulations 1998, specifically targeting the Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600, and 700) series aeroplanes. This regulation applies to certain models within this series, namely the 560A, 560E, and 680, with serial numbers ranging from 231 to 559. The directive mandates the replacement of the main landing gear upper NK retaining pins to ensure compliance with safety standards. Compliance is required forthwith, meaning that the specified action must be undertaken immediately. The regulation extends its jurisdictional reach across the Commonwealth of Australia, ensuring that all relevant aircraft operators and maintenance providers within the country adhere to these safety directives. The directive does not provide specific exclusions, exemptions, or thresholds beyond the specified models and serial numbers, but may be subject to further clarification or extension through subordinate instruments issued by CASA.

Key Provisions

The main operative sections of this Civil Aviation Safety Authority (CASA) regulation (AD/AC/4) pertain to the replacement of the NK retaining pins in the main landing gear upper structure of certain Twin Commander aeroplanes. Specifically, section 39-105 addresses the applicability of the directive, which covers models 560A, 560E, and 680 with serial numbers ranging from 231 to 559. Compliance with this directive is mandated immediately, as stated in section 39-105.1, and it can be achieved by referencing either Aero Commander Service Bulletin No. 43 or Federal Aviation Administration AD 57-15-1. Under this regulation, the primary obligations for the parties governed include ensuring that the specified models of Twin Commander aeroplanes undergo a thorough inspection and replacement of the NK retaining pins in their main landing gear upper structure. The requirement is that this action must be completed without delay, ensuring the safety and airworthiness of the aircraft in question. Compliance documentation can be derived from either Aero Commander SB No. 43 or FAA AD 57-15-1, which both provide the necessary technical specifications and procedures for the replacement. In the event of non-compliance with the directive outlined in section 39-105, there are potential civil and criminal consequences. While specific penalties are not detailed within the regulation itself, failure to comply with CASA directives can lead to severe penalties under the Civil Aviation Act 1988. This includes potential fines, enforcement actions, and possible grounding of the aircraft until compliance is achieved. The consequences can be substantial, reflecting the importance of adhering to safety directives to ensure the continued safety and operational integrity of the affected aircraft.