Overview

The Airworthiness Directive issued under the Civil Aviation Act 1988 (Cth) aims to address safety concerns related to broken damper shafts in specific Gulfstream aircraft models. Enacted in 2004 by the Civil Aviation Safety Authority (CASA) as a legislative instrument, the directive targets the Gulfstream Model G-1159, G-1159A, G-1159B, and G-IV series aeroplanes. The primary objective of this directive is to ensure the detection and correction of potentially hazardous conditions arising from broken damper shafts, which could lead to loss of control over the aircraft. The directive mandates a series of inspections and necessary actions to mitigate these risks, thereby enhancing the overall safety and airworthiness of the specified aircraft models.

Scope and Application

The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) applies specifically to Gulfstream Model G-1159, G-1159A, G-1159B, and G-IV series aeroplanes. The directive mandates certain actions to address an identified unsafe condition concerning broken damper shafts in aileron and elevator actuators, which could lead to a loss of control over these flight surfaces. The requirements set out in the directive must be adhered to by operators and owners of these specified aircraft models. The directive's jurisdictional reach is national, applicable across the Commonwealth of Australia, ensuring that all relevant aircraft within these categories must comply with the stipulated safety measures. The directive does not provide explicit exclusions or exemptions, meaning it applies broadly to all aircraft within the specified series regardless of their specific operational use or ownership status. Compliance with the directive is mandatory, with specific timelines for inspections and actions, and it may be extended or further detailed through subordinate instruments or additional CASA communications.

Key Provisions

The Airworthiness Directive (AD) issued under subregulation 39.1 (1) of CASR 1998 pertains to the Gulfstream (Grumman) G1159 and G-IV series aeroplanes, specifically those models G-1159, G-1159A, G-1159B, and G-IV. The directive mandates specific actions to address the identified safety issue of broken damper shafts within the aileron and elevator actuator assemblies (section 1). The primary requirement involves conducting a one-time general visual inspection of the left and right aileron and elevator actuators to ascertain the part number (P/N) and serial number (S/N) of each actuator, following the guidelines outlined in the applicable alert customer bulletin (section 1(1)). This visual inspection should be thorough and conducted from within touching distance, potentially using mirrors, under suitable lighting conditions, and may necessitate the removal or opening of access panels or doors (section 1(1)). A detailed inspection is required for any actuator identified during this process, particularly those listed in the applicable alert customer bulletin or those with missing or unreadable P/N and/or S/N, to detect a broken damper shaft (section 1(2)). The detailed inspection should be intensive, potentially involving supplementary lighting, inspection aids, and surface cleaning (section 1(2)). If no broken damper shaft is found during this inspection, the inspection should be repeated (section 1(2)(a)). However, if any broken damper shaft is detected, the actuator must be replaced in accordance with the applicable alert customer bulletin (section 1(2)(b)). The AD imposes several obligations on the parties involved. Primarily, it mandates that a one-time general visual inspection of the aileron and elevator actuators be carried out to identify the part number and serial number of each actuator (section 1(1)). Following this initial inspection, a detailed inspection is required for specific actuators identified in the applicable alert customer bulletin or those with missing or unreadable part number or serial number (section 1(2)). If a broken damper shaft is detected during the detailed inspection, the actuator must be replaced (section 1(2)(b)). Additionally, the AD specifies that no aileron or elevator actuator listed in the applicable alert customer bulletin should be installed unless it has been inspected according to the detailed inspection requirements (section 1(3)). The AD also outlines ongoing inspection intervals, stipulating that a repeat detailed inspection must be performed at intervals not exceeding 500 flight hours or 12 months from the last detailed inspection (section 2(a)). Moreover, any replacement actuator must undergo a detailed inspection before fitment (section 1(2)(b)). Failure to comply with the requirements of this Airworthiness Directive can result in serious consequences. The AD mandates that the specified inspections and actions be undertaken within 50 flight hours after the effective date of the directive and before further flight (section 3(1) and (2)). Additionally, the ongoing repeat inspection must occur at intervals not exceeding 500 flight hours or 12 months, whichever occurs first, from the last detailed inspection (section 2(a)). Non-compliance with these requirements could lead to unsafe conditions, such as the locking of an aileron or elevator actuator, resulting in a loss of control and reduced controllability of the aeroplane. While the AD does not explicitly state penalties for non-compliance, the potential for significant safety risks underscores the importance of adhering to these mandates.