{"id":"F2006B09681","name":"AD/F27/113 - RH Elevator Stn 300 Rib","slug":"ad-f27-113-rh-elevator-stn-300-rib","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115825,"registerId":"commonwealth-F2006B09681-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F27/113 - RH Elevator Stn 300 Rib","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 F27 Series Aeroplanes\n\n \n\nAD/F27/113 RH Elevator Stn 300 Rib 7/87\n\nApplicability: All models listed in the Requirement Document. Requirement: Action in accordance with Fokker SB F27/55-63.\n\nNote: RLD BLA 87-32 refers.\n\n \n\nCompliance: Prior to 31 December 1987.\n\n \n\nBackground: The manufacturer reports instances of heavy corrosion and stress corrosion cracking in the milled rib.\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 safety directive focused on a specific structural defect in a particular aircraft type. It has not expanded beyond its original purpose of addressing corrosion in the F27 elevator rib."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly referenced (the Requirement Document)","No cross-references to other legislation beyond the parent regulations","Single, unambiguous compliance requirement with clear deadline","No conditional logic or exceptions","Straightforward applicability statement covering all models in a named document"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998. It applies to **Fokker F27 series aircraft**.\n\n**What it does:**\n- Requires aircraft operators to inspect and repair the **right-hand (RH) elevator** at a specific structural point called \"Station 300 rib\"\n- The work must follow instructions in **Fokker Service Bulletin F27/55-63**\n\n**Why it matters:**\n- The manufacturer found **serious corrosion and stress corrosion cracking** in this metal rib (a structural component)\n- This cracking could weaken the aircraft's control surfaces, potentially affecting flight safety\n- The directive forces operators to fix this before the aircraft can continue flying safely\n\n**Who must comply:**\n- All operators of Fokker F27 aircraft (a Dutch-built turboprop airliner popular in regional Australia)\n- Compliance was required **before 31 December 1987**\n\n**Key terms explained:**\n- **Airworthiness Directive (AD):** A mandatory safety order from aviation regulators requiring specific repairs or inspections\n- **Service Bulletin:** Manufacturer's technical instructions for maintenance\n- **Station 300:** A specific measurement point along the aircraft structure (like a coordinate system for planes)\n- **Stress corrosion cracking:** Metal cracking caused by a combination of tension and corrosive environment"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive confines its effect to the models listed in the Requirement Document and mandates action according to the manufacturer's service bulletin with a fixed compliance date. The instrument does not expand or narrow technical scope beyond correcting the reported corrosion and cracking in the specified milled rib; it operationalises the manufacturer’s corrective guidance as a mandatory requirement without adding broader obligations."},"complexity_factors":["Narrow technical scope (single component: RH elevator station 300 milled rib). (Background; Requirement.)","Relies on an external technical document (Fokker SB F27/55-63) for detailed procedures, increasing dependency on that bulletin. (Requirement.)","Clear, single compliance deadline imposes an immediate scheduling constraint. (Compliance: \"Prior to 31 December 1987.\")","Applicability refers to another document (Requirement Document) rather than listing models directly, requiring cross-reference to determine exact affected fleet. (Applicability.)","Reference to an additional item (RLD BLA 87-32) introduces another documentary dependency. (Note.)"],"plain_english_summary":"This airworthiness directive, issued by CASA, makes Fokker’s service bulletin F27/55‑63 mandatory: affected Fokker F27 aircraft must have the right‑hand elevator station 300 milled rib inspected and corrected for reported heavy corrosion and stress‑corrosion cracking by the stated deadline (prior to 31 December 1987). It converts the manufacturer’s recommended fix into a regulatory requirement and places inspection, repair and cost responsibility on aircraft owners/operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib","history":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib/history","analysis":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib/analysis","conflicts":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib/conflicts","importantCases":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib/important-cases","documents":"/api/acts/ad-f27-113-rh-elevator-stn-300-rib/documents"}}