{"id":"F2006B09678","name":"AD/F27/109 - Elevator Trim Tab Control Bracket Attachment","slug":"ad-f27-109-elevator-trim-tab-control-bracket-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115819,"registerId":"commonwealth-F2006B09678-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F27/109 - Elevator Trim Tab Control Bracket Attachment","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/F27/109 Elevator Trim Tab Control Bracket Attachment 9/85\n\nApplicability: All models F27 with S/Nos 10105 to 10648, 10654, 10658 to 10660, 10662 to 10667,\n\n10669 and 10672.\n\n \n\nRequirement: Action in accordance with Fokker Service Bulletin F27/55-59.\n\n \n\nNote: RLD AD 85-46 refers.\n\n \n\nCompliance: Prior to 30 November 1985.\n\n \n\nBackground:  After an occurrence of rudder trim tab flutter it was found that the rivets used in the vicinity of the tab control bracket attachment were of the incorrect type. Due to the similarity of construction of the elevator trim tab, a one time inspection is required.\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, time-bound safety directive addressing a specific technical defect in specific aircraft. It has not expanded beyond its original purpose of mandating inspection/repair of elevator trim tab rivets."},"complexity_factors":["Very short document (under 200 words)","Only one substantive requirement: comply with referenced service bulletin","Limited applicability (specific aircraft serial numbers listed)","Single compliance deadline with no conditional extensions","No defined terms section","No cross-references to other legislation beyond a note about related Dutch aviation authority directive (RLD AD 85-46)"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain **Fokker F27 aircraft** to inspect and fix a problem with the **elevator trim tab control bracket** — a component that helps control the plane's pitch (up and down movement).\n\n**The problem:**\nAfter a case of \"rudder trim tab flutter\" (dangerous, rapid vibration of a control surface), investigators discovered that **wrong rivets** had been used near the trim tab control bracket. Because the elevator trim tab is built similarly to the rudder trim tab, regulators required a one-time inspection to check for the same fault.\n\n**Who must comply:**\nOwners/operators of Fokker F27 aircraft with specific serial numbers (10105–10648, 10654, 10658–10660, 10662–10667, 10669, and 10672).\n\n**What they must do:**\nFollow the instructions in **Fokker Service Bulletin F27/55-59** — a technical document from the manufacturer detailing the inspection and any necessary repairs.\n\n**Deadline:**\nBefore 30 November 1985.\n\n**Why it matters:**\nIncorrect rivets could lead to structural failure or control surface flutter, potentially causing loss of aircraft control. This directive prevents accidents by ensuring the hardware is correct."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD sets a one-time inspection requirement for the listed F27 serial numbers and requires action ‘in accordance with’ the manufacturer's service bulletin. The directive’s scope is confined to those serial numbers and the single inspection mandate; there is no indication in the text that the AD expands or narrows an earlier stated scope beyond that one-time inspection requirement (Applicability; Requirement; Compliance)."},"complexity_factors":["Narrow applicability defined by specific serial number ranges (Applicability)","Mandated compliance relies on an external document (Fokker Service Bulletin F27/55-59) rather than containing full procedures (Requirement)","Fixed compliance deadline (Compliance)","Reference to another airworthiness directive (RLD AD 85-46) which may require cross-checking (Note)","Technical nature of the inspection (trim tab rivet type and potential flutter) requires domain-specific maintenance capability (Background)"],"plain_english_summary":"This directive mandated a one‑time inspection and any corrective work on the elevator trim tab control bracket rivet installation for specified Fokker F27 airframes, to be done per Fokker Service Bulletin F27/55‑59 and completed before 30 November 1985. It targets owners/operators of the listed serial numbers, who must obtain and pay for the inspection/repairs. Issued after incorrect rivets causing rudder‑trim flutter were found on a similar surface."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment","history":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment/history","analysis":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment/analysis","conflicts":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment/conflicts","importantCases":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment/important-cases","documents":"/api/acts/ad-f27-109-elevator-trim-tab-control-bracket-attachment/documents"}}