[4910-13-P] 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2012-0885; Directorate Identifier 2012-NE-18-AD; Amendment 

39-17307; AD 2012-26-12] 

RIN 2120-AA64 

Airworthiness Directives; Thielert Aircraft Engines GmbH Reciprocating Engines. 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new airworthiness directive (AD) for all Thielert 

Aircraft Engines GmbH (TAE) TAE 125-02-99 and TAE 125-02-114 reciprocating 

engines. This AD requires inspection of the oil filler plug vent hole at the next scheduled 

maintenance or within 110 flight hours after the effective date of this AD. If chips are 

found to be blocking the vent hole, additional corrective action is required before next 

flight. This AD was prompted by an in-flight shutdown of an airplane equipped with a 

TAE 125-02-99 engine. We are issuing this AD to prevent engine in-flight shutdown or 

power loss, possibly resulting in reduced control of the airplane. 

DATES: This AD becomes effective [Insert date 35 days after date of publication in the 

FEDERAL REGISTER]. The Director of the Federal Register approved the incorporation 

by reference of certain publications listed in this AD as of [Insert date 35 days after date 

of publication in the FEDERAL REGISTER]. 
ADDRESSES: The Docket Operations office is located at Docket Management Facility, 

U.S. Department ofTransportation, 1200 New Jersey Avenue SE., West Building Ground 

Floor, Room W12-140, Washington, DC 20590-0001. 

FOR FURTHER INFORMATION CONTACT: Frederick Zink, Aerospace Engineer, 

Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; e-mail: frederick.zink@faa.gov; telephone: 781-

238-7779; fax: 781-238-7199. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to 

include an AD that would apply to the specified products. That NPRM was published in 

the Federal Register on August 31 , 2012 (77 FR 53154). That NPRM proposed to correct 

an unsafe condition for the specified products. The MCAI states: 

An engine in-flight shutdown has been reported on an aeroplane 

equipped with a TAE 125-02-99 engine. The results ofthe 

investigation showed that this was due to blockage of the gearbox 

oil filling plug vent hole, which caused pressurisation in the 

gearbox, resulting in oil leakage and a slipping clutch. This 

condition, if not corrected, could result in further cases of engine 

in-flight shutdown and consequent loss of control of the aeroplane. 

Further investigation revealed that the blockage to the oil cap vent was the result of a 

residual chip from machining the oil cap vent hole. The chip is from the manufacturing 

process and did not fall offthe oil plug. This is not the result of material in the oil system 

causing the blockage. You may obtain further information including the affected gearbox 

serial number list by examining the MCAI in the AD docket. 

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Comments 

We gave the public the opportunity to participate in developing this AD. We 

received no comments on the NPRM. 

Conclusion 

We reviewed the available data and determined that air safety and the public 

interest require adopting the AD as proposed. 

Costs of Compliance 

We estimate that this AD will affect about 45 engines installed on airplanes of 

U.S. registry. We also estimate that it will take about 2.5 hours per product to comply 

with this proposed AD. The average labor rate is $85 per hour. Required parts will cost 

about $30 per engine. Based on these figures, we estimate the cost of the AD to U.S. 

operators to be $10,913. 

Authority for This Rulemaking 

Title 49 ofthe United States Code specifies the FAA's authority to issue rules on 

aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. 

"Subtitle VII: Aviation Programs," describes in more detail the scope of the Agency's 

authority. 

We are issuing this rulemaking under the authority described in "Subtitle VII, 

Part A, Subpart III, Section 44701: General requirements." Under that section, Congress 

charges the FAA with promoting safe flight of civil aircraft in air commerce by 

prescribing regulations for practices, methods, and procedures the Administrator finds 

necessary for safety in air commerce. This regulation is within the scope of that authority 

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because it addresses an unsafe condition that is likely to exist or develop on products 

identified in this rulemaking action. 

Regulatory Findings 

We determined that this AD will not have federalism implications under 

Executive Order 13132. This AD will not have a substantial direct effect on the States, on 

the relationship between the national government and the States, or on the distribution of 

power and responsibilities among the various levels of government. 

For the reasons discussed above, I certify this AD: 

1. Is not a "significant regulatory action" under Executive Order 12866; 

2. Is not a "significant rule" under the DOT Regulatory Policies and Procedures 

( 44 FR 11034, February 26, 1979); and 

3. Will not have a significant economic impact, positive or negative, on a 

substantial number of small entities under the criteria of the Regulatory Flexibility Act. 

We prepared a regulatory evaluation of the estimated costs to comply with this 

AD and placed it in the AD docket. 

Examining the AD Docket 

You may examine the AD docket on the Internet at http://www.regulations. gov; 

or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. The AD docket contains this AD, the regulatory 

evaluation, any comments received, and other information. The street address for the 

Docket Operations office (phone: (800) 647-5527) is provided in the ADDRESSES 

section. Comments will be available in the AD docket shortly after receipt. 

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List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. 

Adoption of the Amendment 

Accordingly, under the authority delegated to me by the Administrator, the FAA 

amends 14 CFR part 39 as follows: 

PART 39 -AIRWORTHINESS DIRECTIVES 

1. The authority citation for part 39 continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113,44701. 

§ 39.13 [Amended] 

2. The FAA amends§ 39.13 by adding the following new AD: 

2012-26-12 Thielert Aircraft Engines GmbH: Amendment 39-17307; Docket No. 

F AA-2012-0885 ; Directorate Identifier 2012-NE-18-AD. 

(a) Effective Date 

This airworthiness directive (AD) becomes effective [Insert date 35 days after 

date of publication in the FEDERAL REGISTER]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Thielert Aircraft Engines (T AE) T AE 125-02-99 and T AE 

125-02-114 reciprocating engines. 

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(d) Reason 

This AD was prompted by an in-flight shutdown of an airplane equipped with a 

TAE 125-02-99 engine. We are issuing this AD to prevent engine in-flight shutdown or 

power loss, possibly resulting in reduced control of the airplane. 

(e) Actions and Compliance 

Unless already done, within 110 flight hours after the effective date of this AD, or 

at the next scheduled maintenance, whichever occurs first, do the following. 

(1) Remove the oil filler plug and check for chips blocking the vent hole in 

accordance with TAE Service Bulletin (SB) TM TAE 125-1015 Pl , Initial Issue, dated 

April 27, 2012. 

(2) If chips are found during the inspection in paragraph ( e )(1) of this AD, 

disassemble the gearbox and check the radial shaft sealing rings (at the clutch and the 

propeller shaft) for leakage. If leakage is noted, replace the gearbox before the next flight. 

(f) Installation Prohibition 

After the effective date of this AD, do not install a gearbox with a SIN listed in 

T AE SB TM T AE 125-1015 P 1, Initial Issue, dated April 27, 2012, into any engine 

unless the oil filler plug has passed the inspection required by paragraph (e)( 1) of this 

AD. 

(g) Alternative Methods of Compliance (AMOCs) 

The Manager, Engine Certification Office, FAA, may approve AMOCs for this 

AD. Use the procedures found in 14 CFR 39.19. 

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(h) Related Information 

(1) For more information about this AD, contact Frederick Zink, Aerospace 

Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; e-mail: frederick.zink@faa.gov; 

telephone (781) 238-7779; fax (781) 238-7199. 

(2) Refer to MCAI Airworthiness Directive No. 2012-0112, dated June 22, 2012, 

and T AE SB TM T AE 125-1015 P 1, Initial Issue, dated April 27, 2012 for related 

information. 

(i) Material Incorporated by Reference 

(1) The Director of the Federal Register approved the incorporation by reference 

(IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 51. 

(2) You must use this service information as applicable to do the actions required 

by this AD, unless the AD specifies otherwise. 

(i) Thielert Aircraft Engines GmbH (T AE) Service Bulletin TM T AE 125-1015 

P1 , Initial Issue, dated April27, 2012. 

(ii) Reserved. 

(3) For TAE service information identified in this AD, contact Thielert Aircraft 

Engines GmbH, Platanenstrasse 14 D-09350, Lichtenstein, Germany, telephone: +49-

37204-696-0; fax: +49-37204-696-2912; e-mail: info@centurion-engines.com. 

( 4) You may view this service information at FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability ofthis material at the FAA, call 781-238-7125. 

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( 5) You may view this service information at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibrlocations.html. 

Issued in Burlington, Massachusetts, on December 27, 2012. 

Colleen M. D' Alessandro, 

Assistant Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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