On April 9, 2007, the FAA issued AD 2005-13- 25R1, Amendment 39-15028 (72 FR 19110, April 17, 2007). That AD requires initial and repetitive inspections, cleaning, lubrication, and checks for proper operation of the HMU acceleration controller axle on engines that incorporate modification TU 62A, unless the engine incorporates modification TU 132. That AD was the result of several reports of the HMU acceleration controller axle sticking. The stuck acceleration controller axle resulted in engine overspeed and commanded and uncommanded in-flight engine shutdowns. That condition, if not corrected, could result in loss of control of engine fuel flow in manual control mode or mixed control mode, which can lead to engine overspeed, and in-flight engine shutdown resulting in a forced autorotation landing or accident.
Actions Since AD 2005-13-25R1 Was Issued
Since we issued AD 2005-13-25R1, the European Aviation Safety Authority (EASA), which is the airworthiness agent for the Member States of the European Union, has informed us that the manufacturer, Turbom ca S.A., has reported additional occurrences of stuck controller axles in the metering valve body. Some of these occurrences occurred on engines that incorporated modification TU 132. Turbom ca S.A. introduced modification TU 149 to eliminate the cause of the unsafe condition on the ARRIEL 2B turboshaft engines. This AD requires inspecting and lubricating the P3 cover and HMU acceleration control axle on HMUs that are not modified to TU 149. It also approves incorporating modification TU 149 to eliminate the cause of the unsafe condition and the repetitive inspections required by this AD. We are issuing this AD to prevent loss of control of engine fuel flow in the manual or mixed control modes, which can lead to engine overspeed, and in-flight engine shutdown resulting in a forced autorotation landing or accident.
Relevant Service Information
Turbom ca has issued Mandatory Service Bulletin A292 73 2814, Version D, dated October 16, 2009, that describes procedures for inspecting, lubricating, and checking for proper operation of the HMU acceleration controller axle. EASA classified this service bulletin as mandatory and issued AD 2009-0246, dated November 10, 2009, in order to assure the airworthiness of these ARRIEL 2B turboshaft engines in the European Union.
Bilateral Airworthiness Agreement
This engine model is manufactured in France, and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under that agreement, EASA has kept us informed of the situation described above. We have examined EASA's findings, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
FAA's Determination and Requirements of This AD
The unsafe condition described previously is likely to exist or develop on other Turbom ca S.A. ARRIEL 2B turboshaft engines of the same type design. We are issuing this AD to prevent loss of control of engine fuel flow in the manual control mode or mixed control mode, which can lead to engine overspeed, and in-flight engine shutdown resulting in a forced autorotation landing or accident. This AD requires initial and repetitive inspections, cleaning, lubrication, and checks for proper operation of the HMU acceleration controller axle. You must use the service information described previously to perform the actions required by this AD.
FAA's Determination of the Effective Date
Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to send us any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include ``AD Docket No. FAA-2005-21624; Directorate Identifier 2005-NE-17-AD'' in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it.
We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).
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 (telephone (800) 647-5527) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
Authority for This Rulemaking
Title 49 of the 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 because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Regulatory Findings
We have 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 that 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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by removing Amendment 39-15028 (72 FR 19110, April 17, 2007), and by adding a new airworthiness directive, Amendment 39-16439, to read as follows: