{"id":"F2006B09710","name":"AD/F27/143 - Port Elevator Torque Tube","slug":"ad-f27-143-port-elevator-torque-tube","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115881,"registerId":"commonwealth-F2006B09710-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F27/143 - Port Elevator Torque Tube","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/F27/143 Port Elevator Torque Tube 4/97\n\nApplicability: F27 Mk 100 to Mk 700 all serial numbers. Requirement:  Inspect in accordance with Fokker SB F27/55-66.\n\nNote: RLD AD 1995-007 refers.\n\n \n\nCompliance: Prior to the accumulation of 45 000 flight cycles or before 31 July 1997, whichever occurs last.\n\n \n\nThis Airworthiness Directive becomes effective on 27 March 1997.\n\n \n\nBackground: This Directive is raised following the report of cracking found on the torque tube support of the port elevator.\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, targeted safety directive addressing a specific structural defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection for elevator torque tube cracking."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 substantive requirement (inspection per specified service bulletin)","Simple applicability clause (specific aircraft series by serial number)","Single compliance condition with clear 'whichever occurs last' logic","No defined terms section, no cross-references to other legislation beyond a single note referencing a Dutch aviation authority directive (RLD AD 1995-007)","No nested exceptions or conditional logic"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to **Fokker F27 aircraft** (a type of regional turboprop plane) with serial numbers covering Marks 100 through 700.\n\n**What it requires:**\n- Aircraft operators must **inspect the port (left side) elevator torque tube** — a structural component that helps control the plane's pitch — following specific instructions in Fokker Service Bulletin F27/55-66.\n\n**When it must be done:**\n- Before the aircraft reaches **45,000 flight cycles** (roughly, one takeoff and landing), **or** before **31 July 1997**, whichever comes **later** (meaning operators have until the later of these two dates, not the earlier).\n\n**Why it matters:**\n- The directive was issued after **cracking was discovered** in the torque tube support. Left unchecked, this could compromise the aircraft's control surfaces and potentially lead to loss of control. This is a **preventive safety measure** to catch structural fatigue before it becomes dangerous.\n\n**Key point:** This is not optional. Airworthiness Directives are legally binding on aircraft operators, and non-compliance can ground an aircraft."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope appears consistent with its stated purpose in the instrument: it applies to all F27 Mk 100–700 airframes and requires inspection of the port elevator torque tube support to address a reported cracking issue (Applicability; Requirement; Background). There is no text in this instrument indicating an expansion or narrowing of scope from an earlier intent within the supplied source material; the AD cross-references RLD AD 1995-007 but does not modify the applicability or the inspection requirement stated here (Note)."},"complexity_factors":["Narrow, well-defined applicability (F27 Mk 100 to Mk 700 all serial numbers) reduces scope complexity (Applicability).","Single actionable requirement: inspect in accordance with a specific Fokker Service Bulletin, which centralises technical detail outside the AD (Requirement).","Compliance follows a simple conditional deadline (prior to 45,000 flight cycles or before 31 July 1997, whichever occurs last), creating a straightforward but time-sensitive obligation (Compliance).","Dependence on an external document (Fokker SB F27/55-66) increases operational complexity because remedial steps and detailed procedures are not included in the AD text (Requirement).","Reference to another AD (RLD AD 1995-007) requires cross-checking related directives (Note).","Limited detail in this AD about corrective action if cracking is found increases implementation uncertainty for operators and maintainers (absence of remedial detail in AD)."],"plain_english_summary":"This AD requires owners/operators of Fokker F27 Mk100–Mk700 aircraft to perform the Fokker Service Bulletin F27/55-66 inspection of the port elevator torque tube support (issued after a report of cracking) before the aeroplane reaches 45,000 flight cycles or by 31 July 1997, whichever is later. Affected operators and maintenance organisations must schedule, fund and carry out the inspection per the service bulletin."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-143-port-elevator-torque-tube","history":"/api/acts/ad-f27-143-port-elevator-torque-tube/history","analysis":"/api/acts/ad-f27-143-port-elevator-torque-tube/analysis","conflicts":"/api/acts/ad-f27-143-port-elevator-torque-tube/conflicts","importantCases":"/api/acts/ad-f27-143-port-elevator-torque-tube/important-cases","documents":"/api/acts/ad-f27-143-port-elevator-torque-tube/documents"}}