{"id":"F2006B09508","name":"AD/EMB-120/20 - Flight Data Recorder Coupler Screws","slug":"ad-emb-120-20-flight-data-recorder-coupler-screws","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54067,"registerId":"commonwealth-F2006B09508-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/EMB-120/20 - Flight Data Recorder Coupler Screws","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nEmbraer EMB-120 (Brasilia) Series Aeroplanes\n\nAD/EMB-120/20 Flight Data Recorder Coupler Screws 12/97\n\nApplicability: EMBRAER EMB 120 aircraft S/N. 120003, 120004, 120006 to 120308 inclusive,\n\n120310, 120312, 120314, 120316 to 120322 inclusive and 120325.\n\nRequirement: Verify alignment between the flight data recorder potentiometers and the flight control mechanism shafts and lock the flexible coupler screws by applying Loctite adhesive to its threads in accordance with EMBRAER Service Bulletin Nr. 120-31- 0038.\n\nNote: Brazilian AD 97-08-01-EMBRAER Amdt 39-793 refers.\n\nCompliance: Unless previously accomplished within the next 400 hours time in service.\n\nThis airworthiness directive becomes effective on 6 November 1997.\n\nBackground: The Brazilian DCA has found the occurrence of erroneous flight control displacement records in the flight data recorder caused by looseness of the flexible coupler screws.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating a safety fix for flight data recorder coupler screws."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly used (\"time in service\")","Single, straightforward mechanical requirement with clear reference to manufacturer service bulletin","Simple applicability list using serial numbers","No nested exceptions or conditional logic — one compliance deadline with single exemption (\"unless previously accomplished\")","No cross-references to other legislation beyond a single note about the corresponding Brazilian AD"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety fix for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain Embraer EMB-120 \"Brasilia\" aircraft to check and fix a mechanical problem with the **flight data recorder** (the \"black box\" that records flight information). Specifically, they must:\n- Check that the sensors (potentiometers) that record control movements are properly aligned with the actual flight control shafts\n- Lock the flexible coupler screws in place using Loctite adhesive (thread-locking glue)\n\n**Who it affects:**\nOwners and operators of specific Embraer EMB-120 aircraft with serial numbers listed in the directive (roughly 300+ aircraft, excluding some specific serial numbers like 120005, 120309, 120311, etc.).\n\n**Why it matters:**\nLoose screws in the flight data recorder coupling were causing **false recordings** of flight control movements. This means the black box data could show the wrong information about what the pilots were actually doing with the controls — a serious safety issue for accident investigations and flight monitoring.\n\n**When it must be done:**\nWithin the next 400 hours of flight time (unless already fixed).\n\n**The bottom line:**\nThis is a targeted safety order from the Civil Aviation Safety Authority (CASA) implementing a Brazilian safety finding. It prevents unreliable flight data recordings by ensuring mechanical connections stay tight."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The text sets a corrective maintenance requirement for a defined set of aircraft to address looseness of flexible coupler screws that produced erroneous flight data recorder records. The AD’s stated mechanics (inspect alignment and apply Loctite per the Embraer Service Bulletin) and its applicability are explicit in the instrument. Nothing in the provided text indicates a change from the AD’s original, stated intent to remedy that specific fault mode (Requirement, Applicability, Background)."},"complexity_factors":["Narrow, serial-numbered applicability requiring operators to check a concrete set of aircraft (Applicability).","Requires execution in accordance with an external manufacturer Service Bulletin (Requirement) — dependence on an external technical document.","Physical maintenance action (alignment verification and adhesive application) that requires qualified personnel and creates a short-term operational scheduling impact (Requirement, Compliance).","Fixed compliance window (400 hours time in service) that operators must schedule into maintenance cycles (Compliance).","Cross-reference to a foreign authority action (Brazilian AD) which adds an international regulatory linkage (Note, Background)."],"plain_english_summary":"This AD requires owners/operators of the specified Embraer EMB‑120 serial-numbered aircraft to inspect FDR potentiometer-to-control‑shaft alignment and secure flexible coupler screws with thread‑locking adhesive per Embraer Service Bulletin 120‑31‑0038, to be done within 400 hours TIS. \n\nIt targets the listed aircraft because loose coupler screws were causing erroneous flight‑data‑recorder control records; compliance and associated costs fall to the aircraft owners/operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws","history":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws/history","analysis":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws/analysis","conflicts":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws/conflicts","importantCases":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws/important-cases","documents":"/api/acts/ad-emb-120-20-flight-data-recorder-coupler-screws/documents"}}