{"id":"F2006B09633","name":"AD/F100/31 - Flight Augmentation Computer Replacement","slug":"ad-f100-31-flight-augmentation-computer-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54429,"registerId":"commonwealth-F2006B09633-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F100/31 - Flight Augmentation Computer 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)  \nFokker F100 (F28 Mk 100) Series Aeroplanes\n\nAD/F100/31 Flight Augmentation Computer Replacement 4/99\n\nApplicability: Model F.28 Mk.0100 aeroplanes serial numbers 11244 through 11348 inclusive.\n\nRequirement: 1\\. Unless previously accomplished replace all Collins Flight Augmentation Computer (FAC) units, part number (P/N) 622-7478-321, with modified units P/N 622-7478- 401 Mod.11 in accordance with Fokker Service Bulletin (SB) F100-22-026 dated 1 July 1991.\n\n2. Replace all Collins FAC units, P/N 622-7478-401, with modified units P/N 622-7478-401 Mod.11 in accordance with Fokker SB F100-22-032 dated\n\n2 September 1991.\n\nNote: Netherlands AD 1991-057/4 refers.\n\nCompliance: 1. Prior to 22 December 1999.\n\n2. Prior to 22 December 1999.\n\nThis Airworthiness Directive becomes effective on 22 April 1999.\n\nBackground: The modified computers provide improved fault isolation to allow cross comparison of more signals than previously possible. Problems with stabiliser trim systems during ground testing and nuisance yaw-damper faults during take off have been solved by the incorporation of an additional modification.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound airworthiness directive with a narrow technical scope. It addresses a specific hardware defect in a defined aircraft fleet and does not represent scope creep from any broader regulatory scheme."},"complexity_factors":["Very short document (under 300 words)","Only 2 defined part numbers referenced","Single applicability criterion (serial number range)","Two straightforward compliance requirements with identical deadlines","No cross-references to other legislation beyond a single note about a Netherlands AD","No conditional logic or exceptions","Clear, unambiguous operative language ('replace all... in accordance with')"],"plain_english_summary":"The Civil Aviation Safety Authority requires owners/operators of about 105 Fokker F100 jets (S/N 11244–11348) to replace outdated Collins Flight Augmentation Computers with a modified FAC (622‑7478‑401 Mod.11) by 22 December 1999. The upgrade fixes false yaw‑damper alarms at takeoff and stabiliser‑trim ground‑test faults by improving fault detection and isolation, enhancing flight safety."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive enforces a manufacturer-specified retrofit for a defined fleet subset and a fixed deadline; it does not broaden applicability beyond the listed serial numbers or add new regulatory powers. It implements the service bulletin modifications as mandatory rather than voluntary, but does not change the technical scope of the original manufacturer modification (Applicability; Requirement; Compliance)."},"complexity_factors":["Technical specificity: requires replacement of particular avionics parts (FAC) with exact part numbers (Requirement 1–2).","Applicability limited by serial number range, so operators must check aircraft identity (Applicability).","Dependence on manufacturer service bulletins for procedural detail (Fokker SB F100-22-026 and F100-22-032 referenced in Requirement).","Dual-path requirement: different existing P/Ns trigger replacement steps (Requirement 1 vs 2).","Fixed compliance deadline imposes scheduling and maintenance-planning costs on operators (Compliance: prior to 22 December 1999).","Operational disruption and procurement risk: sourcing modified units and installing them may affect aircraft availability (implicit in retrofit requirement).","Regulatory enforcement: CASA directive creates legal obligation to comply (Header and Compliance).","Cross-reference to foreign AD (Netherlands AD 1991-057/4) may require operators to reconcile multiple directives (Note)."],"plain_english_summary":"Mandates replacement of specified Collins Flight Augmentation Computer (FAC) units with modified units P/N 622-7478-401 Mod.11 on Fokker F.28 Mk.0100 aeroplanes (serials 11244–11348) in line with Fokker service bulletins. Aircraft operators must complete the retrofit by 22 December 1999; the Civil Aviation Safety Authority enforces compliance. The stated technical purpose is improved fault isolation to address stabiliser trim and yaw-damper faults (Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement","history":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement/history","analysis":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement/analysis","conflicts":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement/conflicts","importantCases":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement/important-cases","documents":"/api/acts/ad-f100-31-flight-augmentation-computer-replacement/documents"}}