{"id":"F2007L03962","name":"AD/THIELERT/6 - Engine Oil System - Catchtank (Sump) Filter Adapter","slug":"ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70659,"registerId":"commonwealth-F2007L03962-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Thielert Piston Engines","sectionType":"division","heading":"Thielert Piston Engines","content":"### Thielert Piston Engines\n\n| AD/THIELERT/6 | Engine Oil System - Catchtank (Sump)Filter Adapter | 11/2007 |\n| ------------- | -------------------------------------------------- | ------- |\n\n| Applicability: | Thielert Aircraft Engines TAE125-01 engines all serial numbers (s/n), up to and including s/n 02-01-1018.Note 1: These engines are known to be installed on, but not limited to, Cessna 172 and (Reims-built) F172 series (EASA STC Nr. EASA.A.S.01527); Piper PA-28 series (EASA STC Nr. EASA.A.S.01632), APEX (Robin) DR 400 series (EASA STC Nr. EASA.A.S.01380); and Diamond DA40 and DA42 series aircraft.                                                                                                                                                                                                                                                                                                                                                    |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Modify the engine oil system in accordance with Thielert Aircraft Engines TM/SB TAE 125-0016, initial issue dated 19 September 2006 or Revision 1 dated15 June 2007.Note 2: EASA AD 2007-0232 dated 23 August 2007 refers.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Compliance:    | Within the next 50 flight hours after the effective date of this directive, but not later than 30 November 2007, whichever occurs first after the effective date of this AD.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n|                | This Airworthiness Directive becomes effective on 25 October 2007.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n| Background:    | An in-flight engine shutdown incident was reported on an aircraft equipped with a TAE125-01 engine. This was found to be mainly the result of a blockage of the scavenge oil gear pump due to a broken axial bearing of the turbocharger. The broken parts were sucked into the oil pump and caused a seizure. With the pump inoperative, the oil separator overfilled, causing the engine oil to escape via the breather vent line. This caused a loss of oil that resulted in the engine overheating and subsequent shutdown. Thielert, the engine TC holder, has developed a filter adaptor for the Oil Catchtank (Sump) that is designed to prevent foreign objects from entering into the scavenge pump, minimising the chance of such an incident recurring. |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n13 September 2007","sortOrder":0},{"sectionNumber":"AD/THIELERT/6","sectionType":"part","heading":"AD/THIELERT/6","content":"## AD/THIELERT/6","sortOrder":1},{"sectionNumber":"Engine Oil System - Catchtank (Sump)Filt","sectionType":"part","heading":"Engine Oil System - Catchtank (Sump)Filter Adapter","content":"## Engine Oil System - Catchtank (Sump)  \nFilter Adapter","sortOrder":2},{"sectionNumber":"11/2007","sectionType":"part","heading":"11/2007","content":"## 11/2007","sortOrder":3}],"analysis":{"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with a narrow, well-defined scope addressing a specific safety defect in a particular engine model. The scope remains tightly focused on the original safety purpose."},"complexity_factors":["Single, specific technical requirement with clear reference to manufacturer service bulletin","Only one defined applicability criterion (engine serial number range)","Simple compliance deadline structure (flight hours OR calendar date, whichever first)","No nested exceptions, conditional logic, or cross-references to other legislation","Background narrative explains the safety rationale in plain language","Total length is approximately 300 words of substantive content"],"plain_english_summary":"This AD requires owners/operators of Thielert TAE125-01 engines (serials up to 02-01-1018) to install a filter adapter on the oil catchtank to stop metal debris reaching the oil pump. It applies to aircraft like Cessna 172, Piper PA-28, Diamond DA40/DA42 and Robin DR400 using these engines.\n\nThe measure prevents in‑flight shutdowns after turbocharger bearing failure. Work must follow Thielert TM/SB TAE 125-0016 within 50 flight hours or by 30 Nov 2007."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive stays within the original, stated safety purpose: prevent foreign objects entering the scavenge oil pump (and the specific failure chain that led to an in‑flight shutdown). It does not broaden to other engine types, other serial ranges, nor to unrelated maintenance requirements. The scope is narrowly limited to the stated engine model/serials and the single corrective modification."},"complexity_factors":["Single, narrowly framed required action (fit filter adapter) with one service bulletin referenced (Thielert TM/SB TAE 125-0016)","Limited applicability clause: one engine model and serial number range (TAE125-01, up to s/n 02-01-1018)","Single compliance window: 50 flight hours or a specific calendar cut‑off (30 Nov 2007)","Short document length with no layered exceptions or alternate compliance methods","Reference to an external EASA AD and the manufacturer service bulletin introduces a dependency on external documents for technical detail"],"plain_english_summary":"**What this directive does (mechanical change)\n\n- Requires fitting a filter adapter to the engine oil catchtank (sump) on certain Thielert TAE125-01 piston engines.\n- The modification must be done exactly as set out in Thielert Service Bulletin / Technical Manual TAE 125-0016 (initial issue 19 Sept 2006 or Revision 1 dated 15 June 2007). (Requirement)\n\nWho it applies to\n\n- Owners and operators of aircraft fitted with Thielert Aircraft Engines TAE125-01 engines with serial numbers up to and including 02-01-1018. (Applicability)\n- Those engines are installed under various Supplemental Type Certificates (STCs) on types such as Cessna 172/F172, Piper PA-28, Robin DR 400 and Diamond DA40/DA42, so affected aircraft include those STC installations. (Applicability)\n\nWhen it must be done\n\n- The modification must be completed within the next 50 flight hours after the directive becomes effective, or by 30 November 2007, whichever comes first. The directive became effective 25 October 2007. (Compliance)\n\nWhy the change was ordered (stated reason)\n\n- Regulators say an in‑flight engine shutdown occurred because broken turbocharger bearing parts were drawn into the scavenge oil pump, seized the pump, caused oil routing and loss, and led to engine overheating and shutdown. The filter adapter is intended to stop foreign debris from entering the scavenge pump and so reduce the chance of the same failure recurring. (Background)\n\nPractical effects, costs and incentives\n\n- Who pays: aircraft owners/operators pay for the parts and labour to install the filter adapter and any associated downtime. (Requirement / Compliance)\n- Who decides: a certificated maintenance organisation or authorised mechanic must carry out the modification to the manufacturer’s service instructions; the regulator enforces compliance. (Requirement)\n- Behaviour change: operators must schedule the modification within a short compliance window (50 flight hours or by the calendar date), which may force immediate maintenance slots or short‑term grounding. After installation, operators will likely inspect the adapter/filter as part of regular oil‑system checks.\n- Concentrated vs diffuse costs: costs are concentrated on individual owners/operators of the specified engines; the safety benefit is distributed across those operators and any airspace users affected by engine reliability. The manufacturer (Thielert) supplies the adaptor (the AD references the Thielert service instruction), so there is a commercial relationship for parts and instructions.\n- Trade‑offs and implementation risks: the measure reduces a specific mechanical failure mode but imposes immediate out‑of‑service time and part/labour expense. Potential implementation risks include short‑term part availability, scheduling pressure on maintenance facilities, and correct installation to the service instructions. (Background / Requirement)\n- Substitution effects: operators may prioritise the modification over other non‑urgent work; they cannot lawfully defer it past the compliance deadline without regulatory approval. (Compliance)\n\nNet description of mechanism and limits\n\n- The AD is a targeted, single‑action safety mandate: install a debris filter adapter on the oil catchtank to prevent foreign material entering the scavenge pump. It applies only to TAE125‑01 engines up to the stated serial number and relies on the manufacturer’s technical document for the exact installation steps. (Applicability / Requirement)\n\nSources cited in this directive: Applicability, Requirement, Compliance and Background sections of the AD.**"}},"importantCases":[],"_links":{"self":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter","history":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter/history","analysis":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter/analysis","conflicts":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter/conflicts","importantCases":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter/important-cases","documents":"/api/acts/ad-thielert-6-engine-oil-system-catchtank-sump-filter-adapter/documents"}}