{"id":"F2006B06077","name":"AD/PC-12/14 - No. 2 Generator Cut-Out Relay","slug":"ad-pc-12-14-no-2-generator-cut-out-relay","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114475,"registerId":"commonwealth-F2006B06077-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-12/14 - No. 2 Generator Cut-Out Relay","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nPilatus PC-12 Series Aeroplanes\n\nAD/PC-12/14 No. 2 Generator Cut-Out Relay 2/99\n\nApplicability: Model PC-12 and PC-12/45 aeroplanes with Manufactures Serial Numbers 101 to 180 inclusive.\n\nRequirement: If not previously accomplished, install a cut-out relay in the second generator electrical circuit in accordance with Pilatus Aircraft Ltd PC-12 Service Bulletin 24- 009 dated 23 September 1998.\n\nNote: FOCA Switzerland AD HB 98-537 refers.\n\nCompliance: Prior to 30 April 1999.\n\nThis Airworthiness Directive becomes effective on 25 February 1999.\n\nBackground: FOCA has reported occurrences of over-voltage where the over-voltage protection of the second generator was found not to automatically disconnect the second generator from the electrical system. This Directive requires the installation of a cut-out relay, controlled by the voltage control unit, which ensures that the second generator is isolated automatically should a faulty condition occur.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a specific Airworthiness Directive (AD) with a narrow, well-defined scope targeting a known safety defect in specific aircraft. It has not expanded beyond its original purpose of mandating a specific safety modification."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined applicability criteria (model type and serial number range)","Single, unambiguous compliance requirement with reference to external technical document (Service Bulletin 24-009)","No nested conditions, exceptions, or cross-references to other legislation","Straightforward deadline structure (single fixed date)","Minimal legal terminology - primarily technical aviation terms"],"plain_english_summary":"This is a **safety order for specific Pilatus PC-12 aircraft**.\n\n**What it does:**\nIt requires owners or operators of certain PC-12 aeroplanes (serial numbers 101 to 180) to install an electrical safety device called a \"cut-out relay\" in the second generator circuit. This device acts like a circuit breaker that automatically disconnects the second generator if it develops a fault that causes dangerous over-voltage (too much electrical power).\n\n**Who it affects:**\n- Owners and operators of Pilatus PC-12 and PC-12/45 aircraft with serial numbers 101 through 180\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\nSwiss aviation authorities (FOCA) found cases where the existing over-voltage protection failed to automatically disconnect faulty second generators. Without this fix, a generator fault could damage the aircraft's electrical systems or create safety hazards. The directive mandates a specific repair using Pilatus Service Bulletin 24-009.\n\n**Key deadlines:**\n- The fix must be done before 30 April 1999\n- The order took effect on 25 February 1999"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive's text confines the requirement to installing a cut-out relay on the second generator circuit for specific PC-12 serial-numbered aircraft to address reported failures of the second generator's over-voltage protection. The instrument’s stated mechanics and stated rationale are aligned in the text; there is no indication within the document that the scope has been broadened or otherwise changed from that stated purpose."},"complexity_factors":["Limited and precise applicability (Model PC-12 and PC-12/45, serial numbers 101–180) reduces scope complexity. (Applicability)","Technical installation required: fitting an electrical cut-out relay into a generator circuit requires qualified maintenance and adherence to the manufacturer’s service bulletin. (Requirement)","Regulatory bindingness and deadline: the AD is mandatory under the Civil Aviation Regulations and sets a firm compliance date (prior to 30 April 1999). (Header; Compliance)","Mandatory reliance on a specific manufacturer service bulletin (Pilatus SB 24-009) channels the method of compliance and may constrain choice of procedure and parts. (Requirement)","Operational coordination: aircraft downtime, parts availability and scheduling with maintenance organisations create practical implementation complexity despite the AD’s short textual length. (Requirement; Compliance)"],"plain_english_summary":"What the directive does (mechanics)\n\n- Requires installation of a cut-out relay in the second-generator electrical circuit on specified Pilatus PC-12 aeroplanes. The installation must follow Pilatus Aircraft Ltd Service Bulletin 24-009 dated 23 September 1998. (Requirement)\n- Applies only to Model PC-12 and PC-12/45 aeroplanes with manufacturer serial numbers 101 to 180 inclusive. (Applicability)\n- Must be completed before 30 April 1999; the directive became effective on 25 February 1999. (Compliance / Effective date)\n\nOfficial reason given\n\n- The Swiss aviation authority (FOCA) reported occurrences of over-voltage where the existing over-voltage protection on the second generator did not automatically disconnect that generator from the electrical system. The directive’s stated purpose is to ensure the second generator will be isolated automatically if a fault occurs, by means of the installed cut-out relay. (Background / Note)\n\nWho must act, who pays, and who decides\n\n- Owners/operators of the affected aeroplanes must install the cut-out relay to comply. The Requirement references the manufacturer’s service bulletin as the mandated method of compliance, so work must follow that document. (Applicability; Requirement)\n- The Civil Aviation Safety Authority issued the Airworthiness Directive under the Civil Aviation Regulations 1998 (Part 39–105). Compliance is therefore a regulatory obligation rather than voluntary. (Header; Schedule of Airworthiness Directives)\n- The directive does not specify financial assistance; therefore the text implies that operators bear the direct costs (parts, labour, aircraft downtime) of carrying out the installation. (Requirement; Compliance)\n\nIncentives, trade‑offs and implementation mechanics\n\n- Incentives: complying operators avoid the regulated risk of operating with a generator that may not disconnect automatically during an over-voltage event, as identified by FOCA. (Background)\n- Trade‑offs and opportunity costs: operators must take affected aircraft out of service for the retrofit, incur parts and labour costs, and follow the manufacturer’s installation procedure. The directive prescribes the manufacturer’s service bulletin as the means of compliance, which channels the technical solution through Pilatus’s specified procedure. (Requirement)\n- Implementation risk and compliance burden: correct installation depends on following the Pilatus service bulletin; errors or delays in obtaining parts, qualified maintenance, or documentation could prolong aircraft downtime or leave the aircraft non‑compliant until the work is done. The AD sets a firm compliance date (prior to 30 April 1999), which creates a time pressure for scheduling the work. (Requirement; Compliance)\n\nEffects on private choice and service providers\n\n- Affected operators must choose when and where to have the work performed; the AD’s cross-reference to the manufacturer’s service bulletin means the procedure and parts are defined by Pilatus, which may influence which maintenance providers and parts suppliers are used. (Requirement)\n- The AD is limited in scope to serial numbers 101–180; only these aircraft are required to change behaviour (have the relay installed). Other owners/operators are not affected by this directive. (Applicability)\n\nScope and administrative context\n\n- The AD references a corresponding Swiss AD (FOCA HB 98-537), indicating that the requirement responds to an international safety report and that national authorities are aligning on the corrective measure. (Note)\n\nSource references: Applicability; Requirement; Compliance; Background; Note; header identifying Civil Aviation Regulations 1998, Part 39–105."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay","history":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay/history","analysis":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay/analysis","conflicts":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay/conflicts","importantCases":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay/important-cases","documents":"/api/acts/ad-pc-12-14-no-2-generator-cut-out-relay/documents"}}