AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Pilatus PC-12 Series Aeroplanes
AD/PC-12/41 Generator Control Unit 6/2004
Applicability: All PC-12 and PC-12/45 airplanes, Manufacturer Serial Numbers (MSN) 101 through 507 with the second battery factory option and which do not have Generator Control Unit (GCU) part number (P/N) 988.21.15.103 installed.
Requirement: 1. Remove GCU P/N 988.21.15.102 and install GCU P/N 988.21.15.103 in accordance with the Accomplishment Instructions of Pilatus PC-12 Service Bulletin (SB) No. 24-022 dated 13 June 2003.
Note 1: The following Service Bulletins should be accomplished before or at the same time as PC-12 SB No. 24-022, as applicable:
PC-12 SB 24-010 Revision 1 dated 06 October 2003.
- When an Electrosystems generator P/N 978.87.24.121 is installed.
PC-12 SB 24-019 Revision 1 dated 06 June 2003.
- When an Electrodelta voltage regulator P/N 988.21.15.101 is installed. (This SB changes the P/N of the GCU to 988.21.15.103.)
2. GCUs with P/N 988.21.15.102 may not be installed as a replacement part on any aeroplane with the second battery factory option installed.
Note 2: FOCA (Switzerland) AD HB-2004-101 refers.
Compliance: For Requirement 1 - At the next 100 hour or annual inspection, but no later than 90 days after the effective date of this Directive.
For Requirement 2 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 10 June 2004.
Background: The Swiss Federal Office for Civil Aviation (FOCA) has received reports of incidents on PC-12 series aeroplanes with the second battery installation where the 2nd battery was discharged due to loss of the 2nd generator output, without any failure being indicated.
Pilatus PC-12 Series Aeroplanes
AD/PC-12/41 (continued)
Investigation revealed that the GCU lets the 2nd battery energise the number 2 generator relay until the power from the battery is insufficient to hold the relay closed. This condition, if not corrected, could result in failure of the second generator not being detected whilst the 2nd battery is discharging.
This Directive requires the replacement of the GCU to correct the anomaly.
James Coyne
Delegate of the Civil Aviation Safety Authority 27 April 2004
The above AD is notified in the Commonwealth of Australia Gazette on 19 May 2004.
Overview
The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive (AD) for Pilatus PC-12 Series Aeroplanes, AD/PC-12/41, in 2004. This directive was introduced to address safety concerns identified by the Swiss Federal Office for Civil Aviation (FOCA) regarding incidents of the second battery discharging in PC-12 aeroplanes with a second battery factory option. The directive aims to ensure that the unsafe condition, where the second generator output is lost without any failure being indicated, is corrected to prevent potential failures of the second generator. The AD mandates the replacement of the Generator Control Unit (GCU) and outlines specific compliance instructions to be followed by aircraft operators. The directive became effective on 10 June 2004, with compliance required at the next 100-hour or annual inspection, but no later than 90 days after the directive's effective date.
Scope and Application
The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) applies specifically to Pilatus PC-12 and PC-12/45 aeroplanes with manufacturer serial numbers (MSN) ranging from 101 through 507, provided they have the second battery factory option and do not have the Generator Control Unit (GCU) part number (P/N) 988.21.15.103 installed. The directive mandates the removal of GCU P/N 988.21.15.102 and the installation of GCU P/N 988.21.15.103 in accordance with the instructions set out in Pilatus PC-12 Service Bulletin No. 24-022 dated 13 June 2003, with specific references to other service bulletins to be completed as necessary. Additionally, GCUs with P/N 988.21.15.102 are prohibited from being installed as a replacement part on any aeroplane with the second battery factory option installed. Compliance with the directive is required at the next 100-hour or annual inspection, but no later than 90 days after the effective date of the directive, which is 10 June 2004. This AD, issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998, is applicable across the Commonwealth of Australia.
Key Provisions
The Airworthiness Directive (AD) applies to all Pilatus PC-12 and PC-12/45 aeroplanes with the second battery factory option installed, specifically those with Manufacturer Serial Numbers (MSN) ranging from 101 to 507, and those that do not have the Generator Control Unit (GCU) part number (P/N) 988.21.15.103 installed (Applicability). The main requirement of this AD is the removal of the GCU P/N 988.21.15.102 and installation of the GCU P/N 988.21.15.103 in accordance with the Accomplishment Instructions of Pilatus PC-12 Service Bulletin (SB) No. 24-022 dated 13 June 2003 (Requirement 1). Additionally, GCUs with P/N 988.21.15.102 must not be installed as a replacement part on any aeroplane with the second battery factory option installed (Requirement 2).
Entities governed by this AD must comply with the specified requirements to ensure the safety of the aircraft. Specifically, the directive mandates that the specified GCU replacement must be carried out at the next 100-hour or annual inspection, but no later than 90 days after the effective date of the directive. This compliance timeframe ensures that the safety issue is addressed in a timely manner (Compliance).
Failure to comply with the AD can result in civil or criminal consequences. While the AD does not explicitly outline specific penalties or consequences, non-compliance with ADs generally may lead to aircraft being deemed unairworthy, which can result in fines or other enforcement actions. The AD became effective on 10 June 2004, and any non-compliance after this date may be subject to scrutiny and potential penalties.