{"id":"F2007L00640","name":"AD/750XL/9 - S-Tec X 55 Autopilot System - Disconnect","slug":"ad-750xl-9-s-tec-x-55-autopilot-system-disconnect","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":64119,"registerId":"commonwealth-F2007L00640-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Pacific Aerospace 750XL Series Aeroplane","sectionType":"division","heading":"Pacific Aerospace 750XL Series Aeroplanes","content":"### Pacific Aerospace 750XL Series Aeroplanes\n\n| AD/750XL/9 | S-Tec X 55 Autopilot System – Disconnect | 5/2007 TX |\n| ---------- | ---------------------------------------- | --------- |\n\n| Applicability: | Model PAC 750XL aircraft, S/Ns 125, 126 and 127.                                                                                                                                                   |\n| -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Disconnect the autopilot and install a placard. Pacific Aerospace Limited 750XL Alert Service Bulletin PACASB/XL/001 dated 16 February 2007 refers.DO NOT USENote: CAA(NZ) AD DAC/750XL/12 refers. |\n| Compliance:    | Before further flight after 12 March 2007.                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 12 March 2007.                                                                                                                                   |\n| Background:    | To prevent failure of the Autopilot System Computer resulting in the possibility of an out of trim condition, which may lead to loss of aircraft control.                                          |\n\n![](image.002.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n9 March 2007","sortOrder":0},{"sectionNumber":"AD/750XL/9","sectionType":"part","heading":"AD/750XL/9","content":"## AD/750XL/9","sortOrder":1},{"sectionNumber":"S-Tec X 55 Autopilot System — Disconnect","sectionType":"part","heading":"S-Tec X 55 Autopilot System — Disconnect","content":"## S-Tec X 55 Autopilot System – Disconnect","sortOrder":2},{"sectionNumber":"5/2007 TX","sectionType":"part","heading":"5/2007 TX","content":"## 5/2007 TX","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1502},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original targeted scope addressing a specific autopilot defect on three identified aircraft. No expansion of scope or mission creep is evident."},"complexity_factors":["Extremely narrow applicability (only three specific aircraft serial numbers)","Single, unambiguous compliance requirement (disconnect and placard)","External reference to manufacturer's Alert Service Bulletin for technical procedures","Cross-reference to corresponding New Zealand aviation safety directive"],"plain_english_summary":"**What this does:** This safety order (called an Airworthiness Directive) targets three specific Pacific Aerospace 750XL aircraft—serial numbers 125, 126, and 127. It requires operators to disconnect the S-Tec X 55 autopilot system and install a warning placard before flying again after 12 March 2007.\n\n**Why it matters:** The autopilot computer has a fault that could fail in flight. If it fails, the aircraft might become dangerously unbalanced (\"out of trim\"), potentially making the plane uncontrollable.\n\n**What needs to happen:**\n- **Disconnect** the autopilot system\n- **Install** a placard (basically a warning sticker) in the cockpit\n- **Check** the manufacturer's Alert Service Bulletin PACASB/XL/001 for technical details\n- **Comply** before the aircraft next flies after the deadline\n\nThe directive aligns with a similar safety notice issued in New Zealand (CAA(NZ) AD DAC/750XL/12)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect","history":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect/history","analysis":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect/analysis","conflicts":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect/conflicts","importantCases":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect/important-cases","documents":"/api/acts/ad-750xl-9-s-tec-x-55-autopilot-system-disconnect/documents"}}