AD/PC-12/15 - Flap Actuator - Life Limitation

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, were enacted to ensure the safety and airworthiness of aircraft operating within Australia. One of the amendments to this regulation, AD/PC-12/15, addresses a critical safety concern regarding the flap actuators of Pilatus PC-12 series aeroplanes. This directive was introduced to mitigate risks associated with the premature wear of certain flap actuators, which were found to be produced with modified gears that could lead to operational failures. The problem arose from a shortage of standard flap actuators, prompting the need for a limited life policy for these specific units. The directive was issued by the Civil Aviation Safety Authority and became effective on 22 April 1999, aiming to ensure that these potentially faulty actuators are inspected, replaced, or removed from service by 30 September 1999 to maintain the safety and reliability of the aircraft.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to airworthiness directives issued by the Civil Aviation Safety Authority (CASA). In this instance, AD/PC-12/15 applies to the Pilatus PC-12 Series Aeroplanes, particularly models PC12 and PC12/45. The regulation requires operators of these aircraft to inspect and identify the serial numbers of installed flap screw actuators, record their in-service hours and landings, and modify their maintenance programmes accordingly. Furthermore, operators must replace any limited service life flap screw actuators identified by their yellow bodies and specific serial numbers. This requirement applies at the next scheduled inspection or when specific conditions related to wear or usage thresholds are met. The directive becomes effective on 22 April 1999 and mandates full compliance by 30 September 1999. The regulation is geographically applicable within the Commonwealth of Australia, imposing obligations on aircraft operators and maintenance personnel within this jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39, establish the authority and requirements for ensuring the airworthiness of aircraft in Australia. Specifically, Section 39-105 pertains to the Australian Civil Aviation Safety Authority's (CASA) schedule of airworthiness directives, which are legally binding instructions issued by CASA to ensure the safe operation of aircraft. The directive AD/PC-12/15 focuses on the Pilatus PC-12 Series aeroplanes, mandating a life limitation on flap actuators. Section 4/99 of this directive applies to the Model PC12 and PC12/45 aircraft and sets out the requirements to ensure these aircraft remain airworthy. First, the directive requires a one-time inspection to determine the serial number of the installed flap screw actuators (section 1a). This inspection must be carried out in accordance with Para 3A of Pilatus PC-12 Service Bulletin No. 27-007 dated 26 January 1999. Second, all limited service life flap screw actuators, identified by their yellow bodies and specific serial numbers, must be recorded in the aircraft log book, and their in-service hours and landings must be logged (section 1b). Additionally, the system of maintenance must be updated to reflect that these items are of limited life and require a separate inspection and replacement programme. The details of this programme are specified in the Aircraft Maintenance Manual Temporary Revisions 04-03 and 27-10 dated 15 January 1999. Finally, the directive mandates the replacement of the limited life flap screw actuators. Compliance with this directive is mandatory and must occur at the next scheduled flap screw actuator inspection or check (backlash check) or prior to the fitment of a new item (section 1). Compliance is also required whenever one of the following conditions occurs: the flap system backlash limits exceed those given in the Aircraft Maintenance Manual, the life-limited flap screw actuators have accumulated a total of 500 hours or 650 landings, whichever occurs first, or no later than 30 September 1999 (section 2). Failure to comply with this directive can result in severe penalties. Under Section 91 of the Civil Aviation Act 1988, non-compliance can lead to significant civil penalties, including fines up to a maximum of $275,700 for individuals and $1.38 million for corporations, depending on the severity of the breach. Additionally, criminal penalties may apply, including imprisonment for up to two years for individuals and five years for corporations. These penalties underscore the importance of adhering to CASA's airworthiness directives to ensure the safety of all passengers and crew on board the affected aircraft.