{"id":"F2006B09777","name":"AD/F28/41 - Wing Flap Mechanical Actuators - Modification","slug":"ad-f28-41-wing-flap-mechanical-actuators-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54686,"registerId":"commonwealth-F2006B09777-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/41 - Wing Flap Mechanical Actuators - Modification","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Fokker F28 Series Aeroplanes\n\n \n\nAD/F28/41 Wing Flap Mechanical Actuators - Modification 6/79\n\nApplicability: All models with S/Nos. 11003 to 11162, 11991 and 11992. Document:  1. Fokker SB No. F28/27-136; or\n\n2. Menasco SB No. SB27-78; or 3. RLD AD BLA 79-34-27.\n\nCompliance: As detailed in the requirement document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD text sets a specific, limited scope: modification of wing flap mechanical actuators on Fokker F28 aeroplanes with the listed serial numbers and requires compliance with one of three named technical documents. The instrument itself contains no language indicating a change in that stated scope from an earlier or original intent; it confines action to the enumerated aircraft and cross‑references the requirement documents (Applicability; Document; Compliance)."},"complexity_factors":["Narrow, clearly enumerated applicability by serial number reduces scope ambiguity (Applicability).","Mandates technical work but does not include the technical steps in the AD itself, instead cross‑references three external documents (Document), which raises operational dependency on those documents.","No compliance timeframe, cost, or penalty information included in the AD text increases administrative follow‑up required by operators (Compliance).","Technical nature of work (mechanical actuator modification) requires qualified maintenance resources and parts, adding practical complexity despite clear applicability.","Multiple alternative referenced documents can introduce variation in implementation if their instructions differ (Document)."],"plain_english_summary":"This AD mandates a modification of wing‑flap mechanical actuators on Fokker F28 airframes (S/N 11003–11162, 11991, 11992), making compliance compulsory under Part 39. Affected operators and maintenance organisations must perform the modification using one of three specified service bulletins/ADs; operators bear the cost and scheduling and must consult those documents for the technical steps and compliance timing."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical component on a specific aircraft type. It has not expanded beyond its original purpose of mandating a safety modification to wing flap actuators on Fokker F28 aircraft."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 3 defined/referenced documents (the service bulletins and foreign AD)","Simple applicability clause using serial number ranges","No nested conditional logic or exceptions","No cross-references to other legislation beyond the enabling regulations (Civil Aviation Regulations 1998, Part 39)","Single compliance requirement with no alternative compliance methods or phased implementation","No interpretation section or defined terms"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific **Fokker F28 series aircraft** to modify the **wing flap mechanical actuators** (the machinery that moves the wing flaps — the movable surfaces on the back of the wings that help control lift and speed during takeoff and landing).\n\n**Who it affects:** Anyone who owns or operates Fokker F28 aircraft with **serial numbers 11003 to 11162, plus serial numbers 11991 and 11992**.\n\n**What must be done:** Operators must follow the instructions in one of three referenced documents:\n- Fokker Service Bulletin F28/27-136, **or**\n- Menasco Service Bulletin SB27-78, **or** \n- RLD (Dutch aviation authority) AD BLA 79-34-27\n\n**Why it matters:** Wing flaps are critical for safe flight operations. This directive addresses a known safety issue with the mechanical actuators that drive these flaps, ensuring the aircraft remains airworthy and safe to fly. Non-compliance means the aircraft cannot legally operate in Australian airspace.\n\n**Key point:** The directive itself doesn't contain the detailed technical instructions — it simply mandates that operators must follow the specific service bulletins or foreign airworthiness directive listed above."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification","history":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification/history","analysis":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification/analysis","conflicts":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification/conflicts","importantCases":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification/important-cases","documents":"/api/acts/ad-f28-41-wing-flap-mechanical-actuators-modification/documents"}}