# Proposed AD FAA-2011-0956: Thielert Aircraft Engines GmbH (TAE) TAE 125-02-99 and TAE 125-02-114 Reciprocating Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2012-02-05
- Products: Thielert Aircraft Engines
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 18, 2011, 76 FR 64289
- Comments due: December 2, 2011
- Became: [AD 2012-02-05](https://openairdocs.org/ad/2012-02-05)
- Docket: FAA-2011-0956 (https://www.regulations.gov/docket/FAA-2011-0956, where comments are filed)
- Project: 2011-NE-23-AD
- FR document: 2011-26827
- Official PDF: https://openairdocs.org/files/sha256/6f/e8/6fe89e5bd015f586f92cb489b2749fae64ab8532403d12a704d2e2a10084c259 (from https://www.govinfo.gov/content/pkg/FR-2011-10-18/pdf/2011-26827.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/10/18/2011-26827/airworthiness-directives-thielert-aircraft-engines-gmbh-tae-tae-125-02-99-and-tae-125-02-114
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/664E84A4741E68A88625792D004873D9.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0956

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

In-flight engine shutdown incidents have been reported on aeroplanes equipped with TAE 125 engines. Preliminary investigations showed that it was mainly the result of the sensitivity of friction disk Part Number (P/N) 05-7211-K010201 against possible misalignment of gearbox and core engine during assembly.

This condition, if not corrected, could result in further cases of engine in-flight shutdown and consequent loss of control of the aeroplane.

To address this unsafe condition, Thielert Aircraft Engines GmbH has developed a new friction disk.

We are proposing this AD to prevent in-flight engine shutdown, which could result in loss of control of the airplane.

## Notices in this docket

- Oct 18, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-26827, comments due Dec 2, 2011 (https://www.federalregister.gov/documents/2011/10/18/2011-26827/airworthiness-directives-thielert-aircraft-engines-gmbh-tae-tae-125-02-99-and-tae-125-02-114)

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