AD/PC-12/20 - Stick Pusher System - Replacement

Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B06084, encompass various regulatory measures to ensure the safety and airworthiness of aircraft within Australian airspace. Specifically, Part 39 addresses the safety standards and compliance directives for aircraft operations, and the 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives outlines specific safety mandates for different aircraft models. One such directive, AD/PC-12/20, pertains to the Pilatus PC-12 series aeroplanes and mandates the replacement of the Stick Pusher Capstan and Servo to mitigate issues arising from manufacturing tolerances that cause higher-than-designed control column forces. The directive was introduced to ensure that the control column forces remain within safe operational limits, thereby addressing a critical safety concern identified with the original design of the stick pusher system in these aircraft. The objective of this directive is to maintain the highest safety standards in civil aviation, as mandated by the Civil Aviation Safety Authority under the legislative framework provided by the Civil Aviation Regulations 1998.

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 105 under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, mandates the replacement of the Stick Pusher Capstan and Servo in Pilatus PC-12 Series Aeroplanes, including models PC-12 and PC-12/45, up to and including manufacturing serial number (MSN) 180. This requirement is outlined in AD/PC-12/20 and necessitates compliance within four months from the directive's effective date, which is 25 August 1999. The directive aligns with Pilatus Service Bulletin No.22-003 dated 24 June 1999 and is referenced by FOCA AD HB 99-406 dated 16 August 1999. The directive aims to address a manufacturing issue where the original stick pusher system can exert higher control column forces than designed, thus ensuring that all control forces remain within the specified design limits. The application of this directive is strictly jurisdictional within the Commonwealth of Australia and applies to all relevant aircraft registered under CASA regulations.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, specify that for Pilatus PC-12 Series aeroplanes, including models PC-12 and PC-12/45 up to and including MSN 180, the Stick Pusher Capstan and Servo must be replaced (section 39-105). This replacement is mandated to comply with Pilatus Service Bulletin No. 22-003 dated 24 June 1999. This directive is also referenced in FOCA AD HB 99-406 dated 16 August 1999. The directive became effective on 25 August 1999, and compliance must be achieved within four months of this date. The obligations imposed by this directive require the aircraft operators to ensure that the modifications to the Stick Pusher Capstan and Servo are carried out as specified in the Pilatus Service Bulletin No. 22-003. Operators must also ensure that the modifications are completed before the four-month compliance period expires. This involves not only the physical replacement of the components but also ensuring that the replacement parts meet the design specifications and have been approved by the relevant authorities. Failure to comply with the Airworthiness Directive AD/PC-12/20 could result in serious consequences. If an aircraft is found to be non-compliant, it may be grounded until the required modifications are completed. In addition, operators who fail to adhere to the mandated timeline and specifications may face regulatory action, including fines or other penalties as stipulated under the Civil Aviation Act 1988. While specific penalties are not detailed in the directive itself, the overarching legislation provides for significant financial penalties and potential criminal charges for non-compliance with safety directives.