Overview

The Civil Aviation Safety Authority (CASA) introduced the Airworthiness Directive (AD) under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998 to address a potential safety risk identified in the Pilatus PC-12 Series Aeroplanes. Specifically, the AD aims to mitigate the risk of failure of the main landing gear shock absorber attachment bolts, which could result in landing gear collapse. This risk was found to be associated with hydrogen embrittlement caused by improper cadmium plating of the high strength steel part. The directive applies to all Model PC-12 and PC-12/45 aircraft with Manufacturer Serial Numbers 101 through 482. CASA issued the AD to ensure that the required inspections and replacements of the bolts are conducted within specified timeframes to maintain airworthiness and passenger safety.

Scope and Application

This Airworthiness Directive applies specifically to all Pilatus PC-12 and PC-12/45 series aircraft, encompassing Manufacturer Serial Numbers 101 through 482. The directive is issued under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998 by a delegate of the Civil Aviation Safety Authority (CASA) and mandates that certain actions be taken to rectify an identified unsafe condition related to the main landing gear shock absorber attachment bolts. The directive applies within the Commonwealth of Australia and requires the inspection of the left and right main landing gear assemblies, part numbers 532.10.12.049 and 532.10.12.050, to determine if their serial numbers start with the letters AM. If both main landing gear assembly serial numbers do not start with the letter AM, no further action is required. However, if either serial number starts with AM, the main landing gear shock absorber attachment bolts must be replaced with new bolts in accordance with Pilatus Aircraft Service Bulletin 32-015. Compliance with this directive must occur within 100 hours of the aircraft being in service or within 30 days of the directive's effective date of 19 November 2003, whichever is earlier, and before further flight. This AD does not apply to any main landing gear assemblies whose serial numbers do not start with AM and no action is required for these.

Key Provisions

This Airworthiness Directive (AD), issued under the authority of the Civil Aviation Safety Authority (CASA), specifies certain requirements for Pilatus PC-12 series aeroplanes, specifically those with manufacturer serial numbers between 101 and 482 (section 1). The directive applies to all Model PC-12 and PC-12/45 aircraft within the specified serial number range (section 1). The requirement outlined in the AD mandates that the left and right main landing gear assemblies be inspected to ascertain if their serial numbers begin with the letters "AM" (section 2). Pilatus Aircraft Service Bulletin (SB) 32-015 provides further details on this inspection. If neither of the main landing gear assembly serial numbers starts with "AM," no further action is necessary (section 2). However, if any of the serial numbers start with "AM," the main landing gear(s) shock absorber attachment bolts must be replaced with new bolts in accordance with SB 32-015 (section 2). Additionally, any spare main landing gear assembly with a serial number beginning with "AM" must not be installed unless the attachment bolts part number 532.10.12.110 have also been replaced with new bolts in accordance with SB 32-015 (section 2). The compliance section stipulates that the required action must be taken within 100 hours of the aircraft being in service or within 30 days after 19 November 2003, whichever is sooner, and before further flight (section 3). The AD imposes specific obligations on the owners and operators of the affected Pilatus PC-12 series aeroplanes. They are required to inspect the main landing gear assemblies to determine if their serial numbers start with the letters "AM" and, if so, replace the shock absorber attachment bolts with new bolts in accordance with SB 32-015 (section 2). This requirement is designed to mitigate the risk of bolt failure due to hydrogen embrittlement, which could lead to a catastrophic landing gear collapse. Compliance with the AD must be achieved within the specified timeframe and before further flight, ensuring that the aircraft is safe to operate (section 3). Any spare main landing gear assemblies with serial numbers starting with "AM" must not be installed unless the specified bolts have been replaced (section 2). Failure to comply with the AD may result in severe consequences. The AD explicitly states that the aircraft must not be flown until the required actions have been completed (section 3). Non-compliance could potentially result in unsafe conditions that could endanger the flight, leading to possible civil or criminal penalties. While the specific penalties are not detailed in the AD, it is important to note that CASA takes non-compliance seriously, and the consequences could include fines, legal action, or further regulatory measures against the non-compliant party. The safety of the aircraft and its occupants is paramount, and adherence to the AD is critical to avoid any adverse outcomes.