AD/PC-12/11 - Flap System - Alternate Flap Capability Removal

Overview

The Civil Aviation Regulations 1998, specifically within Part 39 - 105, detail the Civil Aviation Safety Authority’s (CASA) schedule of airworthiness directives, including AD/PC-12/11 for the Pilatus PC-12 Series Aeroplanes. This directive was enacted to address the problem of misuse of the alternate flap system by operating crews, which had been identified as a safety concern through investigations into accidents and operating techniques globally. The objective of the directive is to enhance safety by removing the alternate flap system from the centre console of the cockpit of the specified Pilatus PC-12 aircraft models until modifications are implemented to improve the reliability of the automatic flap system. The compliance requirement mandates that the specified changes must be carried out within 30 days of the directive's effective date of 4 November 1998.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, address the safety of aircraft operations in Australia by mandating compliance with certain directives, including those issued by the Civil Aviation Safety Authority (CASA). This particular regulation pertains to the Pilatus PC-12 series aeroplanes, specifically those with Manufacturer’s Serial Numbers (MSN) ranging from 101 to 227, inclusive, and 232. The directive requires the removal of the ALTERNATE FLAP switch from the cockpit centre console and its replacement with a blanking plate, along with the installation of a FLAP MAINT switch and the insertion of specific revisions into the Pilot’s Operating Handbook and Aircraft Maintenance Manual. Compliance with these modifications must be achieved within 30 days of the directive's effective date, which is 4 November 1998. This mandate is a response to global investigations indicating misuse of the Alternate Flaps system, aiming to enhance the reliability of the automatic flap system on these aircraft. The regulation applies to aircraft within the specified serial number range and is enforced under the jurisdiction of the Commonwealth of Australia.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate the removal of the alternate flap capability from certain Pilatus PC-12 series aeroplanes. This directive applies to models PC12 and PC12/45 with Manufacturer’s Serial Numbers (MSN) ranging from 101 to 227 inclusive, and 232 (Section 13/98 DM). The directive, effective from 4 November 1998, requires operators to remove the ALTERNATE FLAP switch from the cockpit centre console and replace it with a blanking plate as per Pilatus Service Bulletin No. 27-004 dated 15 September 1998. Additionally, a FLAP MAINT switch must be installed, and appropriate revisions must be made to the Pilot’s Operating Handbook and Aircraft Maintenance Manual, also in accordance with the same service bulletin. Operators of the affected aircraft must comply with these requirements within 30 days of the directive’s effective date. The directive aims to prevent misuse of the Alternate Flaps system, which has been identified as a potential safety risk. This requirement ensures that the cockpit layout is standardised and that pilots do not inadvertently activate the alternate flap system, which could lead to unsafe conditions during flight. Failure to comply with the AD/PC-12/11 directive can result in serious safety implications and potential regulatory penalties. The Civil Aviation Safety Authority (CASA) has the authority to enforce compliance through inspections, audits, and enforcement actions. Non-compliance could lead to the grounding of the aircraft until the required modifications are made, and could also result in fines or other penalties imposed by CASA. The specific penalties for non-compliance are not detailed in the directive but are in line with the broader regulatory framework governing aviation safety in Australia. The directive is a direct response to safety concerns raised by investigations into accidents and operating techniques worldwide. By removing the alternate flap capability, CASA aims to enhance the safety of these aircraft by eliminating a source of potential pilot error. This proactive measure underscores the importance of adhering to airworthiness directives to maintain high safety standards in the aviation industry.