{"id":"F2006B07416","name":"AD/THIELERT/2 - Detachment of HP Fuel Pump Mounting Bolts","slug":"ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49660,"registerId":"commonwealth-F2006B07416-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/THIELERT/2 - Detachment of HP Fuel Pump Mounting Bolts","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)  \n\nThielert Piston Engines\n\nAD/THIELERT/2 Detachment of HP Fuel Pump Mounting Bolts\n\n  \n1/2005\n\nDM\n\nApplicability: All Thielert TAE125-01 Model Engines equipped with High Pressure (HP) Fuel Pumps:\n\na. Part Numbers (P/N) 02-7310-04005R3 and 02-7310-04005R4 with S/N’s listed on page 3 of the manufacturer’s Service Bulletin (SB) No. TAE 125- 0009 R1 dated 29 October 2004; and\n\nb. P/N 02-7310-04005R2; and\n\nc. All High Pressure Pumps with a P/N beginning with “A”.\n\nRequirement: 1. For HP Pumps P/N 02-7310-04005R3 and P/N 02-7310-04005R4 with S/Ns listed on page 3 of SB TAE 125-0009 R1, secure the pump mounting bolts with Loctite 243 Blue, medium strength Threadlocker as per provisions of the SB.\n\n    2. Replace all HP Fuel Pumps P/N 02-7310-04005R2.\n\n    3. Replace all HP Fuel Pumps with a P/N beginning with “A”.\n\nNote: German LBA Airworthiness Directive D-2004-473 dated 14 November 2004 as approved by EASA reference No 2004-10850 dated 04 November 2004 refers.\n\nCompliance: Unless previously accomplished, within the next 20 flight hours or within the next 30 calendar days after the effectivity date of this Directive, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 24 November 2004.\n\nBackground: Mounting bolts of HP Fuel Pumps have been found detached due to insufficient locking of the affected bolts. In one case a significant fuel leakage at the fuel pump occurred shortly before take-off of the aircraft.\n\nLoosening of fuel pump mounting bolts can result in fuel leakage, engine fire and / or loss of engine power because of the fuel starvation.\n\nThielert Piston Engines\n\nAD/THIELERT/2 (continued)\n\nThe actions specified in this Airworthiness Directive are intended to correct the identified unsafe condition.\n\n![Signature of James Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 17 November 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 24 November 2004.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in specific Thielert engine fuel pumps. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single-issue safety directive with straightforward applicability criteria based on part/serial numbers","Only three distinct requirement categories with clear, non-nested conditions","Minimal cross-referencing (only to manufacturer Service Bulletin TAE 125-0009 R1 and German LBA directive for context)","Simple compliance timeframe (20 hours OR 30 days, whichever first)","No defined terms section or interpretation provisions","Short, self-contained document (approximately 1 page of substantive content)"],"plain_english_summary":"This AD requires operators of Thielert TAE125-01 engines to secure or replace certain high‑pressure fuel pumps to prevent mounting-bolt loosening that can cause fuel leaks, engine fire, or sudden failure. Affected pumps include specific R3/R4 serials (apply Loctite per manufacturer), all R2 pumps (replace), and all pumps with an “A” prefix (replace). Compliance is mandated within 20 flight hours or 30 days from 24 November 2004."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The Directive targets a specific set of HP fuel pumps and engines identified by part and serial numbers and adopts corrective actions in the manufacturer Service Bulletin and referenced foreign ADs. There is no express expansion beyond those identified pumps or engines in this text."},"complexity_factors":["Narrow technical scope: applies only to Thielert TAE125-01 engines with specified HP pump part‑numbers and listed serial numbers (Applicability).","Action choices: two different corrective paths (apply Loctite to particular P/Ns or replace pumps for other P/N ranges) increasing procedural variation (Requirement).","Short compliance window: 20 flight hours or 30 days creates logistical pressure for inspections and repairs (Compliance).","Cross-references: requires checking manufacturer Service Bulletin TAE 125-0009 R1 and references German LBA/EASA ADs for serial numbers and procedures (Requirement/Note).","Maintenance standard: work is safety‑critical and will likely require qualified technicians and certified parts, adding administrative and labour burden (Background/Requirement).","Supply risk: replacement of pumps (certain P/Ns) may create parts-sourcing and downtime issues for operators (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires operators of aircraft fitted with Thielert TAE125-01 engines and specified high‑pressure (HP) fuel pumps to either secure pump mounting bolts with Loctite 243 threadlocker or replace affected pumps. Compliance must occur within 20 flight hours or 30 days. CASA states the steps address detached pump bolts that have caused fuel leakage and risk of fire or engine power loss."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts","history":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts/history","analysis":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts/analysis","conflicts":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts/conflicts","importantCases":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts/important-cases","documents":"/api/acts/ad-thielert-2-detachment-of-hp-fuel-pump-mounting-bolts/documents"}}