{"id":"F2009L01483","name":"AD/F50/100 - Flap Mechanical Drive","slug":"ad-f50-100-flap-mechanical-drive","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":78068,"registerId":"commonwealth-F2009L01483-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker F50 (F27 Mk 50) Series Aeroplanes","sectionType":"division","heading":"Fokker F50 (F27 Mk 50) Series Aeroplanes","content":"### Fokker F50 (F27 Mk 50) Series Aeroplanes\n\n| AD/F50/100 | Flap Mechanical Drive | 5/2009 |\n| ---------- | --------------------- | ------ |\n\n| Applicability: | Model F27 Mark 050, Mark 0502 and Mark 0604 aircraft, all serial numbers, if in a post-SBF50-27-030 configuration.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Action in accordance with the requirements of EASA AD 2009-0047.Note: Fokker Services SBF50-27-043 original issue, or later EASA approved revision, refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Compliance:    | As specified in the requirement document, with a revised effective date of7 May 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n|                | This Airworthiness Directive becomes effective on 7 May 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| Background:    | Extensive damage was found on a Fokker 50 left hand inner flap and nacelle during a walk-around check. The damage had been caused by a broken fork of the inner flap outboard driveshaft; and resulted in asymmetric flap extension, and interference between the flap and nacelle. A metallurgical investigation revealed that the fork end failed in a fatigue mode, and most probably caused by the “cyclic load” as a result of regularly reaching the mechanical end stop position. This condition, if not corrected, could lead to further cases of asymmetric flap extension, possibly resulting in loss of control of the aircraft. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n17 March 2009","sortOrder":0},{"sectionNumber":"AD/F50/100","sectionType":"part","heading":"AD/F50/100","content":"## AD/F50/100","sortOrder":1},{"sectionNumber":"Flap Mechanical Drive","sectionType":"part","heading":"Flap Mechanical Drive","content":"## Flap Mechanical Drive","sortOrder":2},{"sectionNumber":"5/2009","sectionType":"part","heading":"5/2009","content":"## 5/2009","sortOrder":3}],"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, targeted airworthiness directive addressing a specific mechanical defect in a specific aircraft type. The scope remains precisely limited to the flap drive system fatigue issue identified in the background."},"complexity_factors":["Very short document (under 300 words)","Only 1 defined term implicitly referenced (SBF50-27-030 configuration)","Single requirement: comply with external EASA directive","No nested conditions or exceptions — straightforward applicability test (specific models + specific configuration)","No cross-references to other Australian legislation","Clear, single compliance date"],"plain_english_summary":"This AD mandates inspections and corrective action on the flap mechanical drive system for certain Fokker F27 Mark 050/0502/0604 (Fokker F50) aircraft that were previously modified per SBF50-27-030. It responds to a broken driveshaft fork that led to asymmetric flap extension and serious damage, requiring operators to follow EASA AD 2009-0047 and Fokker SBF50-27-043 to prevent loss of control."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The instrument applies to specified F27 Mark models in a post‑SBF50‑27‑030 configuration and delegates corrective steps to EASA AD 2009‑0047. The text does not indicate a change to a prior scope or expansion beyond that stated applicability."},"complexity_factors":["Dependence on external mandatory documents: EASA AD 2009-0047 and Fokker Services SBF50-27-043 (Requirement/Note).","Conditional applicability: applies only to aircraft in a post‑SBF50‑27‑030 configuration (Applicability).","Safety-critical technical cause (fatigue failure of flap outboard driveshaft fork) requiring physical inspection/repair (Background).","Mandatory compliance date and legal force set by CASA (Compliance).","Limited prescriptive detail in the AD itself — implementers must obtain and follow the referenced EASA/Fokker documents (Requirement)."],"plain_english_summary":"Requires operators of Fokker F27 Mark 050, 0502 and 0604 aircraft in a post‑SBF50‑27‑030 configuration to carry out the actions set out in EASA AD 2009‑0047 (Requirement). The AD responds to fatigue failure of a flap outboard driveshaft fork that caused asymmetric flap extension (Background). Compliance is mandatory from 7 May 2009, so operators bear inspection and repair costs; CASA issued the directive (Applicability/Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-100-flap-mechanical-drive","history":"/api/acts/ad-f50-100-flap-mechanical-drive/history","analysis":"/api/acts/ad-f50-100-flap-mechanical-drive/analysis","conflicts":"/api/acts/ad-f50-100-flap-mechanical-drive/conflicts","importantCases":"/api/acts/ad-f50-100-flap-mechanical-drive/important-cases","documents":"/api/acts/ad-f50-100-flap-mechanical-drive/documents"}}