In March of 2007, the Chicago Aircraft Certification Office received a report of a crack found in the forward cone of a PGB shaft. The PGB shaft was installed in an RRC AE 2100D3 turboprop engine that was removed from service due to high vibration. RRC investigated and determined that a certain population of PGB shaft- and-carrier assemblies could fail due to cracks developing in the forward shaft cone. The affected population, manufactured before June 2005, could have a high stress concentration in the bottom of a certain drilled hole, due to improper surface finish. RRC issued alert service bulletins to borescope-inspect the affected population of PGB shafts for cracks. Based on the inspection results, we determined that AD action is necessary. These engines are U.S. type-certificated, but as of the effective date of this AD are only installed on military airplanes. Failure to inspect the PGB shaft forward cone for cracks could result in separation of the propeller from the airplane, which could result in injury, and damage to the airplane.
Relevant Service Information
We have reviewed and approved the technical contents of RRC Service Bulletin (SB) No. AE 2100D2-A-72-073, Revision 1, dated February 18, 2008, RRC SB No. AE 2100D3-A-72-256, Revision 1, dated February 18, 2008, and RRC SB No. AE 2100J-A-72-071, Revision 1, dated February 18, 2008. Those SBs list the affected population of PGB shaft-and-carrier assemblies by serial number (SN).
FAA's Determination and Requirements of This AD
Although no airplanes that are registered in the United States use these turboprop engines, the possibility exists that the engines could be used on airplanes that are registered in the United States in the future. The unsafe condition described previously is likely to exist or develop on other engines of the same type design. We are issuing this AD to prevent separation of the propeller from the airplane, which could result in injury,and damage to the airplane. This AD requires:
Monitoring the affected population of PGB shaft-and- carrier assemblies for vibration during flight;
Borescope-inspecting the forward cone of the PGB shaft for cracking if vibration is experienced; and
Removing the affected PGB shaft-and-carrier assembly at the next shop visit for PGB inspection or repair. Replacing the affected PGB shaft-and-carrier assembly with a shaft and carrier assembly that is eligible for installation, is terminating action for the vibration monitoring required by this AD.
You must use the service information described previously to determine SN applicability of PGB shaft-and-carrier assemblies.
FAA's Determination of the Effective Date
Since there are no domestic operators of these RRC AE 2100D2, AE 2100D2A, AE 2100D3, and AE 2100J turboprop engines as of the effective date of this AD, notice and opportunity for public comment before issuing this AD are unnecessary. A situation exists that allows the immediate adoption of this regulation.
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-2009-0082; Directorate Identifier 2008-NE-42-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, if provided, 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--AIRWORTHINESSDIRECTIVES
1. The authority citation for part 39 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 adding the following new airworthiness directive: