{"id":"F2006B09644","name":"AD/F100/42 - Landing Gear Locking Mechanism","slug":"ad-f100-42-landing-gear-locking-mechanism","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54460,"registerId":"commonwealth-F2006B09644-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/F100/42 Landing Gear Locking Mechanis","sectionType":"part","heading":"AD/F100/42 Landing Gear Locking Mechanism 6/2000","content":"# AD/F100/42 Landing Gear Locking Mechanism 6/2000\n\nApplicability: Model F28 Mk 100 series aircraft.\n\nRequirement: Inspect the main landing gear downlock actuator in accordance with the Accomplishment Instructions in Fokker Service Bulletin SBF100-32-094 Revision 1.\n\nNote: RLD AD 94-163(A) refers.\n\nCompliance: Unless previously carried out, within 6 calendar months from the effective date of this Airworthiness Directive.\n\nThis Airworthiness Directive becomes effective on 15 June 2000.\n\nBackground: The manufacturer has advised that a Fokker 100 experienced a main undercarriage collapse during landing. Subsequent investigation confirmed that no undercarriage component had failed but extreme inward side-load conditions during the landing caused the lock toggle link to be pulled out of the overcentre position resulting in a main gear collapse.\n\n![Signature of Eugene Paul Holzapfel, Delegate of the Civil Aviation Safety Authority.](image.003.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 2 May 2000\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 17 May 2000.","sortOrder":1}],"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 AD maintains its original narrow scope — addressing a specific mechanical failure mode in a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined applicability criterion (specific aircraft model)","Single, clear requirement with reference to external technical standard (Service Bulletin)","Simple compliance deadline (6 months from effective date)","No nested exceptions, conditional logic, or cross-references to other legislation beyond a single note referencing a related Dutch aviation directive","Straightforward background explaining the safety rationale"],"plain_english_summary":"This AD mandates that owners/operators of Fokker 100 (F28 Mk 100 series) aircraft inspect the main landing gear downlock actuator per Fokker Service Bulletin SBF100-32-094 Revision 1, following a gear-collapse incident caused by the locking mechanism being pulled out of position.  \n\nIt is a legal requirement for affected aircraft to complete the inspection within six months of 15 June 2000 (by 15 December 2000) unless already done."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Scope remains focused on inspecting the main landing-gear downlock actuator for Model F28 Mk 100 aircraft as specified in the Applicability and Requirement. The AD prescribes a time-bound inspection (Compliance) following the manufacturer's instructions; it does not expand applicability beyond the stated model or add continuing operational restrictions."},"complexity_factors":["Narrow applicability — only Model F28 Mk 100 aircraft are targeted (Applicability).","Specified technical action — inspection of the main landing-gear downlock actuator per manufacturer Service Bulletin SBF100-32-094 Rev 1 (Requirement).","Fixed compliance window — inspections must be done within 6 calendar months from the AD effective date (Compliance).","Regulatory authority — issued by CASA delegate under subregulation 39.1(1) of CAR 1998, creating binding obligation (first paragraph).","Root-cause description is mechanical and situational — extreme inward side-loads pulling the lock-toggle link out of overcentre, not a component fracture (Background).","Dependence on external document — effectiveness depends on access to and following the referenced Fokker Service Bulletin (Requirement).","Cross-reference to prior directive — RLD AD 94-163(A) is noted and may affect related compliance histories (Note).","Operational burden — inspections may require maintenance facility time and possible rectification if defects are found (implied by Requirement and Service Bulletin)."],"plain_english_summary":"This Airworthiness Directive requires operators of Fokker F28 Mk 100 aircraft to inspect the main landing-gear downlock actuator following Fokker Service Bulletin SBF100-32-094 Revision 1, within six calendar months of the effective date (15 June 2000). CASA issued the AD under subregulation 39.1(1) after an incident where extreme inward side‑loads pulled the lock-toggle link out of the overcentre position, risking main-gear collapse."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-42-landing-gear-locking-mechanism","history":"/api/acts/ad-f100-42-landing-gear-locking-mechanism/history","analysis":"/api/acts/ad-f100-42-landing-gear-locking-mechanism/analysis","conflicts":"/api/acts/ad-f100-42-landing-gear-locking-mechanism/conflicts","importantCases":"/api/acts/ad-f100-42-landing-gear-locking-mechanism/important-cases","documents":"/api/acts/ad-f100-42-landing-gear-locking-mechanism/documents"}}