{"id":"F2006B09609","name":"AD/F100/1 - Flight Controls - Horizontal Stabiliser Dual Actuator - Periodic Inspection","slug":"ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54361,"registerId":"commonwealth-F2006B09609-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F100/1 - Flight Controls - Horizontal Stabiliser Dual Actuator - Periodic Inspection","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/F100/1 Flight Controls \\- Horizontal Stabiliser\n\nDual Actuator \\- Periodic Inspection\n\n  \n1/99\n\nApplicability: F28 Mk100 aircraft serial numbers 11244 to 11356 (incl) which do not have modified Horizontal Stabiliser Dual Hydraulic Control Actuators in accordance with Fokker Service Bulletin F100-27-032 dated 20 September 1991.\n\nRequirement: 1. Perform an initial inspection in accordance with Fokker Service Bulletin F100-27- 029 dated 29 January 1991.\n\n2. Repeat the inspection at 1. Above.\n\nNote: RLD Airworthiness Directive 91-015 Issue 2 dated 18 October 1991 refers.\n\nCompliance: 1. Aircraft which have accumulated more than 2000 flight hours or 12 months time in service at the effective date of this Directive shall be inspected within the next 400 flight hours or two months time in service.\n\n2. Every 2000 flight hours or twelve months time in service.\n\nThis Airworthiness Directive becomes effective on 28 January 1999.\n\nBackground: A number of operators reported faults with the horizontal stabiliser system which were attributed to water ingress into the dual actuator servo valve manifold end cap. This directive introduces an inspection to check for such contamination pending modification of the system. Modification of the system in accordance with manufacturer’s instructions cancels this requirement.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive (AD) — a targeted safety instrument with narrow, specific applicability. It addresses exactly one technical issue (water ingress in a specific actuator) for a defined aircraft subset. No scope creep is evident; the instrument remains tightly focused on its original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear manufacturer reference","Only 2 defined applicability criteria (serial number range and modification status)","Simple compliance timeline with two straightforward thresholds (flight hours OR calendar time)","No nested exceptions or conditional logic — only one cancellation condition (modification per specified service bulletin)","Short document (under 300 words) with single purpose"],"plain_english_summary":"This safety order requires operators of certain Fokker F100s (serials 11244–11356) that haven’t received the 1991 actuator modification to inspect the dual hydraulic actuator for the horizontal stabiliser for water contamination. Water ingress has caused valve faults, so until the manufacturer issues a permanent fix, regular inspections are mandated (initial then recurring at specified intervals) to ensure flight safety. Upgrading the actuator per the manufacturer’s service bulletin removes the inspection requirement."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies only to specified Fokker F100 serial numbers that lack the manufacturer modification and requires temporary, periodic inspections pending that modification. It does not expand applicability beyond those aircraft or impose other new maintenance actions; the requirement is cancellable upon completion of the prescribed modification (Applicability; Requirement; Background)."},"complexity_factors":["Narrow, aircraft-specific applicability limited to serial numbers 11244–11356 (Applicability).","Relies on external manufacturer service bulletins for inspection procedures and for cancelling the requirement (Requirement; Background).","Two-part compliance timing: an initial-window trigger for aircraft >2000 flight hours or 12 months, then repeating intervals every 2000 flight hours or 12 months (Compliance).","Technical inspection targets water ingress in a hydraulic servo valve manifold end cap — requires maintenance expertise and access to detailed SB procedures (Requirement; Background).","Short follow-up window for overdue aircraft (inspect within 400 flight hours or two months) increases operational scheduling pressure (Compliance).","Cancellation mechanism depends on operators completing a modification per manufacturer instructions, creating a trade-off between recurring inspection costs and one-off modification expense (Background; Requirement).","Cross-reference to earlier RLD Airworthiness Directive may create coordination or record-checking obligations (Note).","Clear effective date fixes regulator discretion on timing but leaves inspection scope and acceptability to SB compliance and maintenance judgement (Effective date; Requirement)."],"plain_english_summary":"Requires operators of specified Fokker F100 aircraft (serials 11244–11356) that have not had a particular actuator modification to carry out an initial and recurring inspection of the horizontal stabiliser dual hydraulic actuator for water contamination. Operators pay for and perform the inspections; the Civil Aviation Safety Authority set the compliance timing from 28 January 1999; installing the manufacturer’s modification cancels the inspection obligation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection","history":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection/history","analysis":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection/analysis","conflicts":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection/conflicts","importantCases":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection/important-cases","documents":"/api/acts/ad-f100-1-flight-controls-horizontal-stabiliser-dual-actuator-periodic-inspection/documents"}}