AD/HILLER 12/27 Amdt 2 - Outer Gimbal Forward Attach Fitting - Inspection

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, provide a comprehensive framework for ensuring the safety and efficiency of civil aviation in Australia. Among these regulations, Part 39 specifically addresses the airworthiness of aircraft, including the issuance of Airworthiness Directives (ADs) to address safety concerns. The AD/HILLER 12/27 Amendment 2, for instance, pertains to the Hiller UH-12 series helicopters, particularly those models converted to turbine power. This directive was introduced in response to a fatigue failure of the outer gimbal forward attach fitting, which resulted in an overseas accident. The directive aims to mitigate such risks by mandating specific inspections of the gusset weld beads on the outer gimbal forward attach fitting to detect any cracks, thereby enhancing the safety of the aircraft in service. The policy objective behind this directive is to ensure that all affected helicopters undergo regular inspections to prevent structural failures that could compromise flight safety. By requiring inspections within 20 hours of service after a specified date and at intervals not exceeding 600 hours, the Civil Aviation Safety Authority seeks to maintain the highest safety standards in Australian civil aviation. The directive references the FAA AD B4-19-08, indicating alignment with international safety protocols and reinforcing the commitment to robust safety measures within the industry.

Scope and Application

The Civil Aviation Safety Authority's Schedule of Airworthiness Directives, specifically AD/HILLER 12/27 Amendment 2, applies to all models of the UH-12D and UH-12E series helicopters that have undergone conversion to turbine power by either STC SH177WE or SH 178WE. This regulation mandates that the outer gimbal forward attach fitting of the Hiller Engine Mount, identified by part number 63181-5, must be inspected for any cracks in the gusset weld beads using either a dye penetrant or a magnetic particle inspection technique. This requirement is vital following the removal of paint from the specified fitting and must be conducted within 20 hours of the helicopter's service time after the directive's effective date of 06 November 1984, and subsequently at intervals not exceeding 600 hours of service time. Additionally, inspections are required upon the installation or reinstallation of the engine mount assembly P/N 63181-5. This directive is a response to a recent overseas accident caused by fatigue failure in the outer gimbal forward attach fitting, thus underscoring the necessity for these repetitive inspections to ensure safety. The scope of the directive is geographically and jurisdictionally national, applying throughout Australia in accordance with the Civil Aviation Regulations 1998. The directive does not specify any exclusions, exemptions, or thresholds beyond those already detailed. The application of this directive may be extended or further defined through subordinate instruments issued by the Civil Aviation Safety Authority, ensuring that compliance is consistently enforced across the specified helicopter models.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, mandate that operators of Hiller UH-12D and UH-12E series helicopters converted to turbine power by STC SH177WE or SH 178WE must adhere to certain airworthiness directives. Section 39.105(1) of the Regulations requires operators to remove the paint from the outer gimbal forward attach fitting of the Hiller Engine Mount P/No. 63181-5, and perform an inspection for cracks on both the front and rear sides of the gusset using either a dye penetrant or a magnetic particle inspection technique. This directive, AD/HILLER 12/27 Amendment 2, aims to ensure the continued safety of these aircraft by addressing a specific structural weakness that has been linked to accidents. The inspection procedure is detailed in FAA AD B4-19-08. Compliance with these airworthiness directives is stringent and multi-faceted. Operators must conduct the inspection within 20 hours of time in service after 06 November 1984 and then at intervals not exceeding 600 hours of time in service (39.105(2)). Additionally, inspections must be performed upon the installation or reinstallation of the engine mount assembly P/N 63181-5 (39.105(3)). This means that operators must maintain meticulous records of the aircraft’s operational hours and inspection history to ensure compliance with the regulations. The necessity for precise documentation underscores the importance of adhering to these safety measures. Failure to comply with the airworthiness directives can lead to significant legal consequences. Section 39.105(4) stipulates that non-compliance with these directives may result in the imposition of civil or criminal penalties. The specific consequences of non-compliance are not explicitly detailed in the provided excerpt, but it is known that regulatory breaches can lead to penalties under the Civil Aviation Act 1988. These can include fines, suspension or revocation of the operator’s licence, and potential criminal charges in cases of gross negligence or willful misconduct. Given the serious implications, it is imperative for operators to take these directives seriously and ensure all inspections and maintenance are conducted in strict accordance with the regulations.