{"id":"F2005L00819","name":"AD/THIELERT/1 Amdt 2 - Engine Failure Due to Electrical System Failure","slug":"ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":113132,"registerId":"commonwealth-F2005L00819-current","compilationNumber":null,"startDate":"2026-04-03","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/1 Amdt 2 | Engine Failure Due to ElectricalSystem Failure | 5/2005 DM |\n| -------------------- | ---------------------------------------------- | --------- |\n\n| Applicability: | All TAE125-01 aircraft engines. |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement: | 1. Modify the electrical power supply system by accomplishing one of the following three modifications in accordance with relevant aircraft manufacturer or supplemental type certificate holder documentation (Thielert Aircraft Engine GmbH Service Bulletin TM TAE 125-008 Revision 2 dated 4 February 2005 also refers): |\n| | a. Replace alternator part number (P/N) 02-7150-55002R2 with alternator P/N 02-7150-55002R3. |\n| | b. For Existing Installations - Replace alternator P/N 02-7150-55002R2 with alternator and alternator regulator sets as follows: |\n| | (i) Diamond aircraft - P/N 02-7150-55008R1 (Alternator Set 14V DAI with ALTREG FF). |\n| | (ii) All other - P/N 02-7150-55016R1 (Alternator Set 14Vwith ALTREG FFL). |\n| | c. Install a stabilising capacitor. |\n| | Note 1: Replacements of alternators on Diamond aircraft in accordance with previous issues of this Directive before the effective date of this Directive are considered acceptable for compliance with this Directive. |\n| | 2. Check the actual capacity of the aircraft battery in accordance with Gill Aircraft Battery Service Manual (Gill Document Number Q01-1120) Chapter 7.7 - Continued Airworthiness Determination for Gill Aircraft Batteries. |\n| | 3. For new installations the following Alternator Sets must be used: |\n| | a. Diamond aircraft - P/N 02-7150-55800R1 (Alternator Set 14V DAI with ALTREG). |\n| | b. All other - P/N 02-7150-55018R1 (Alternator Set 14Vwith ALTREG). |\n\n| | Note 2: LBA AD D-2004-457R2 (EASA approval 2005-1968) refers. |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirement 1 - At the next 300 hourly inspection, but no later than 30 April 2005. |\n| | For Requirement 2 - At each 100 hourly inspection until Requirement 1 is accomplished. |\n| | For Requirement 3 - As of the effective date of this Directive. |\n| | This Amendment becomes effective on 6 April 2005. |\n| Background: | The German Luftfhart-Bundesamt advised that during tests of the electrical system conducted by the engine manufacturer it was found that in case of a failure of the battery line, of the battery relay or of the battery the engine may fail. It was established that the reason for this failure was an electrical malfunction of the alternator. |\n| | The actions specified in the original issue of this Directive were intended to prevent an in-flight engine failure in case of a failure of the electrical aircraft power supply, which could result in an emergency landing or loss of power of the aircraft. |\n| | Amendment 1, whilst reflecting the requirements of the original issue, extended the compliance time and introduced a repetitive battery capacity check until modifications were accomplished. The amendment also introduced minor formatting changes. |\n| | This Amendment introduces a revised P/N for replacement alternator sets in existing installations (except for Diamond aircraft) and added requirements for new installations. |\n| | The original issue of this Directive became effective on 23 December 2004. |\n| | Amendment 1 became effective on 19 January 2005. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n31 March 2005","sortOrder":0},{"sectionNumber":"AD/THIELERT/1 Amdt 2","sectionType":"part","heading":"AD/THIELERT/1 Amdt 2","content":"## AD/THIELERT/1 Amdt 2","sortOrder":1},{"sectionNumber":"Engine Failure Due to ElectricalSystem F","sectionType":"part","heading":"Engine Failure Due to ElectricalSystem Failure","content":"## Engine Failure Due to Electrical \nSystem Failure","sortOrder":2},{"sectionNumber":"5/2005 DM","sectionType":"part","heading":"5/2005 DM","content":"## 5/2005 DM","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":3,"scope_assessment":{"changed":true,"description":"The original directive (December 2004) required electrical system modifications only. Amendment 1 (January 2005) added repetitive battery capacity checks as an interim measure. This Amendment 2 (March 2005) further expanded scope by: (1) introducing revised part numbers for replacement alternator sets, (2) adding entirely new requirements for new installations (not just modifications to existing engines), and (3) creating aircraft-type-specific requirements (Diamond vs others). The directive has evolved from a simple 'replace the alternator' order to a comprehensive regime covering existing fleet modifications, interim safety measures, and new installation standards."},"complexity_factors":["Multiple compliance pathways (3 options for existing installations, 2 for new installations)","Specific part number references (8 distinct P/Ns referenced)","Different requirements for Diamond aircraft vs all other aircraft","Staggered compliance deadlines (300-hour inspection vs hard date of 30 April 2005)","Interim requirement (battery checks every 100 hours) that ceases upon completion of main requirement","Cross-reference to German aviation authority (LBA) and EASA approval","Grandfathering clause (Note 1 allowing previous replacements to count as compliance)"],"plain_english_summary":"This CASA Airworthiness Directive mandates fixes for Thielert TAE125-01 engines after tests showed certain battery/relay failures can cause alternator faults and in-flight engine shutdowns. Operators must, by the next 300‑hour inspection (or by 30 Apr 2005), carry out one of three approved electrical modifications (alternator replacement or stabilising capacitor); until then, battery capacity checks are required every 100 flight hours. New engine installations must use specified alternator sets from the AD effective 6 Apr 2005."},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"Compared with the original Directive the amendment revises replacement alternator part‑numbers for existing installations (except Diamond aircraft) and adds mandatory alternator sets for new installations; it also preserves the interim battery‑check regime introduced earlier (Background; Requirement 1; Requirement 3; Requirement 2)."},"complexity_factors":["Multiple compliance options for the same safety objective (three alternative modifications) (Requirement 1)","Different part‑numbers and alternator sets specified for Diamond vs all other installations and for existing vs new installations (Requirement 1; Requirement 3)","Interim repetitive inspection obligation (battery capacity check every 100 hours) until modification is completed (Requirement 2; Compliance)","Hard compliance deadline tied to inspection intervals (next 300‑hour inspection or by a calendar date) creating scheduling constraints (Compliance)","Dependence on external technical documents and service bulletins for implementation details (Thielert Service Bulletin TM TAE 125-008 Rev 2; Gill Aircraft Battery Service Manual) (Requirement 1; Requirement 2)","Notes and grandfathering (prior replacements on Diamond aircraft accepted) introduce variability in who must act (Note 1)","Technical specificity (exact alternator/alternator regulator part numbers) increases procurement and maintenance complexity (Requirement 1; Requirement 3)"],"plain_english_summary":"This Airworthiness Directive forces owners/operators of aircraft with TAE125-01 engines to change the electrical power supply: either replace the alternator with specified part numbers or install a stabilising capacitor, and to perform repeated battery-capacity checks until the modification is done (Requirements 1–3; Compliance). Costs and execution are borne by aircraft owners/operators, with the modification required at the next 300‑hour inspection or by 30 April 2005 and interim 100‑hour battery checks until compliance (Compliance; Requirement 2)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure","history":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure/history","analysis":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure/analysis","conflicts":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure/conflicts","importantCases":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure/important-cases","documents":"/api/acts/ad-thielert-1-amdt-2-engine-failure-due-to-electrical-system-failure/documents"}}