{"id":"F2006B06084","name":"AD/PC-12/20 - Stick Pusher System - Replacement","slug":"ad-pc-12-20-stick-pusher-system-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114482,"registerId":"commonwealth-F2006B06084-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PC-12/20 - Stick Pusher System - Replacement","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-12/20 Stick Pusher System \\- Replacement 10/99 DM\n\nApplicability: Model PC-12 and PC-12/45 aircraft up to and including MSN180. Requirement: Replace the Stick Pusher Capstan and Servo in accordance with Pilatus Service\n\nBulletin No.22-003 dated 24 June 1999.\n\nNote: FOCA AD HB 99-406 dated 16 August 1999 refers.\n\nCompliance: Within four months of the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 25 August 1999.\n\nBackground: Due to manufacturing tolerances it has been found that the original model stick pusher system can input higher control column forces than required by design. This Directive introduces a modified Stick Pusher Capstan and Servo to ensure that control column forces stay within design limits.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive narrowly mandates the replacement of the Stick Pusher Capstan and Servo on specified PC-12/PC-12/45 serial numbers and sets a fixed compliance period. The text does not expand the class of affected aircraft, add new operational limitations, or introduce new regulatory mechanisms beyond the replacement requirement and its timing (Applicability) (Requirement) (Compliance)."},"complexity_factors":["Narrow applicability: applies only to PC-12 and PC-12/45 aeroplanes up to MSN180 (Applicability).","Single, discrete action mandated: replace two named components per a single service bulletin (Requirement).","Short, fixed compliance window (four months) creating scheduling pressure but not procedural complexity (Compliance).","Dependence on a manufacturer service bulletin for technical execution rather than multiple regulatory procedures (Requirement).","Limited ancillary instructions: only a related foreign AD is noted, no alternative compliance paths or exemptions are described (Note)."],"plain_english_summary":"This directive mandates replacement of the Stick Pusher Capstan and Servo on Pilatus PC‑12 and PC‑12/45 aeroplanes (MSN ≤ 180) per Pilatus Service Bulletin No. 22‑003, to be completed within four months of the 25 Aug 1999 effective date. \n\nOwners/operators must arrange and pay for parts, labour and downtime. The change corrects a tolerance issue that could cause excessive control‑column forces, creating short‑term demand for parts and maintenance but reducing a safety risk."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive with a single specific purpose. It has not expanded beyond its original intent of mandating a specific hardware replacement for safety reasons."},"complexity_factors":["Very short document (approximately 150 words)","Only 2 defined/model references (PC-12 and PC-12/45, MSN180)","Single, unambiguous compliance requirement with clear deadline","No nested exceptions or conditional logic","No cross-references to other legislation (only references to manufacturer service bulletin and related foreign directive for information)","Straightforward applicability criteria (serial number based)"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners and operators of certain Pilatus PC-12 aircraft to replace a safety device called the \"Stick Pusher System.\" This system is designed to automatically push the control column forward to prevent the aircraft from stalling (losing lift and falling out of the sky).\n\n**Who it affects:** Anyone who owns or operates Pilatus PC-12 or PC-12/45 aircraft with serial numbers up to and including MSN180 (roughly the first 180 aircraft built).\n\n**Why the change was needed:** The original stick pusher system was manufactured with slightly loose tolerances, meaning it could sometimes push the control column harder than intended. This could potentially make the aircraft harder to control during a critical safety intervention. The replacement parts fix this issue.\n\n**What must be done:** Replace the \"Capstan\" (a rotating cylinder that grips and moves the control column) and the \"Servo\" (the motor/mechanism that provides the pushing force) following the manufacturer's instructions in Pilatus Service Bulletin No.22-003.\n\n**When it must be done:** Within four months of 25 August 1999 (so by late December 1999).\n\n**Why it matters:** This is a flight safety issue. If the stick pusher activates during flight (which happens automatically when the aircraft is at risk of stalling) and pushes too hard, it could surprise the pilot or make recovery more difficult. The directive ensures all affected aircraft get the fix before something goes wrong."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement","history":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement/history","analysis":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement/analysis","conflicts":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement/conflicts","importantCases":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement/important-cases","documents":"/api/acts/ad-pc-12-20-stick-pusher-system-replacement/documents"}}