{"id":"F2006B09824","name":"AD/F28/9 - Flap Vane Drive Mechanism - Inspection","slug":"ad-f28-9-flap-vane-drive-mechanism-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54778,"registerId":"commonwealth-F2006B09824-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/9 - Flap Vane Drive Mechanism - Inspection","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/F28/9 Flap Vane Drive Mechanism - Inspection NK\n\nApplicability: All models S/Nos. 11003 to 11026 and 11991. Document:  Fokker SB F28/27-41.\n\nCompliance: Before 31 March 1971.\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\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused on one specific mechanical inspection. It has not expanded beyond its original purpose of ensuring the flap vane drive mechanism safety on specific Fokker F28 aircraft."},"complexity_factors":["Extremely short document — only a few lines of substantive content","No defined terms section — uses plain technical language","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1988","Simple conditional structure: applicability criteria → required action → deadline","Single compliance requirement with no exceptions or alternative methods of compliance stated"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1988.\n\n**What it does:**\n- Requires owners and operators of specific Fokker F28 series aircraft to inspect the **flap vane drive mechanism** (a component that helps control the aircraft's flaps — the movable surfaces on the wings that help with takeoff and landing).\n\n**Who it affects:**\n- Owners and operators of Fokker F28 aircraft with **serial numbers 11003 to 11026 and 11991**.\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety instructions. If you don't comply, you can't legally fly the aircraft. This particular directive was issued to address a potential safety defect in the flap system that could affect flight safety.\n\n**Key details:**\n- **Compliance deadline:** Before 31 March 1971 (this is a historical directive — long past its deadline).\n- **Reference document:** Fokker Service Bulletin F28/27-41 (the manufacturer's technical instructions for the inspection).\n- **Marking \"NK\":** Likely indicates the directive was issued by the Netherlands aviation authority (as Fokker is a Dutch manufacturer) and adopted by Australia."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The supplied text sets a single, specific requirement: inspect the flap vane drive mechanism on the listed Fokker F28 serial numbers according to Fokker SB F28/27-41, with completion required before 31 March 1971. The document as supplied does not indicate any change to that scope."},"complexity_factors":["Narrow applicability: applies only to a small, specific list of serial numbers (Applicability)","Single required action: a one-off inspection rather than an ongoing or recurrent mandate (Compliance)","Fixed deadline: a single compliance date imposes scheduling pressure (Compliance)","External technical dependence: the AD requires following a referenced manufacturer service bulletin (Fokker SB F28/27-41), which operators must obtain and follow (Document)","Potential follow-on complexity: inspection may reveal faults requiring repairs, spare parts, and additional maintenance time (implied by inspection outcome)"],"plain_english_summary":"What this instrument does\n\n- This airworthiness directive (AD) requires an inspection of the flap vane drive mechanism on a small, specific set of Fokker F28 aeroplanes. (See \"Applicability\" below.)\n- The inspection must be carried out in accordance with the referenced Fokker document: Fokker Service Bulletin F28/27-41. (See \"Document\" below.)\n- The inspection had to be completed before 31 March 1971. (See \"Compliance\" below.)\n\nWho this affects\n\n- Owners and operators of the identified Fokker F28 aircraft: all serial numbers 11003 to 11026 and serial number 11991 (Applicability). They are the parties who must arrange for the inspection and any follow-up work.\n- The Civil Aviation Safety Authority (CASA) is the issuing authority under the Civil Aviation Regulations 1998, Part 39 (header). The AD sets a mandatory compliance requirement for the named aircraft.\n\nHow it works mechanically\n\n- The AD directs operators to perform an inspection of the flap vane drive mechanism, using the procedures and instructions contained in Fokker SB F28/27-41 (Document). The AD itself does not set the technical steps; it requires adherence to the referenced service bulletin.\n- The compliance obligation is a one-time action to be completed before the specified deadline (Compliance).\n\nWho pays and who decides\n\n- The operator/owner of each affected aircraft is responsible for commissioning the inspection and bearing the direct costs (labour, access to the referenced service bulletin, and any repairs or parts discovered as necessary by the inspection). The AD makes the inspection an operational/maintenance requirement for those aircraft (Applicability, Document, Compliance).\n- The Civil Aviation Safety Authority is the issuing regulator. The AD prescribes what must be done and by when; the technical how-to is delegated to the referenced Fokker service bulletin (header, Document).\n\nPractical trade-offs, incentives and implementation considerations\n\n- Compliance burden: Operators must schedule maintenance time, obtain or reference the Fokker SB F28/27-41, perform the inspection, and record compliance. If defects are found, additional maintenance, parts and downtime will be required. The AD does not detail remedial actions; those will be governed by the service bulletin and normal maintenance practice (Document).\n- Information-dependence: The AD relies on the external manufacturer document for procedure. Operators must obtain and follow Fokker SB F28/27-41 to meet the AD.\n- Timing constraint: The AD imposes a firm deadline (before 31 March 1971). That creates an operational scheduling requirement and potential opportunity cost from taking aircraft out of service to meet the inspection deadline (Compliance).\n- Decision scope and discretion: The AD prescribes the inspection requirement and references the service bulletin for technical detail. There is limited discretion for operators about whether to inspect (the AD requires it); discretion remains in how to schedule and carry out the work within accepted maintenance regulations and the service bulletin’s instructions (Applicability, Document).\n- Downstream costs: If the inspection identifies defects, operators will face repair costs and possible increased downtime. The AD itself does not allocate funding or compensation for those costs.\n\nWhat the AD implies about benefits and risks\n\n- The stated action (inspection of flap vane drive mechanism) implies an intent to identify potential defects in that part of the aircraft. The AD text does not state explicit findings or incidents prompting the AD; it only prescribes the inspection. Assessing whether the inspection delivers net safety benefits versus its costs depends on the prevalence and severity of any defects found, which is not stated in the AD itself.\n\nSource citations (from the instrument provided)\n\n- Applicability: \"All models S/Nos. 11003 to 11026 and 11991.\" (Applicability)\n- Document: \"Fokker SB F28/27-41.\" (Document)\n- Compliance: \"Before 31 March 1971.\" (Compliance)\n- Issuing authority context: Commonwealth of Australia (Civil Aviation Regulations 1998), Part 39 - 105 Civil Aviation Safety Authority (header)\n"}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection","history":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection/history","analysis":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection/analysis","conflicts":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection/conflicts","importantCases":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection/important-cases","documents":"/api/acts/ad-f28-9-flap-vane-drive-mechanism-inspection/documents"}}