Discussion
On August 17, 2011, we issued Emergency AD 2011-18-51, for all Honeywell International Inc. TPE331 model turboprop engines with a PMA replacement Dixie Aerospace, LLC main shaft bearing, P/N 3108098-1WD, installed. That AD requires inspection of the airplane records to determine if a Dixie Aerospace, LLC main shaft bearing, part number (P/ N) 3108098-1WD, is installed in the engine, and if installed, removal of that bearing from service, before further flight. That emergency AD resulted from an excessive failure rate of PMA main shaft bearings, P/N 3108098-1WD, manufactured by Dixie Aerospace, LLC. That emergency AD was not published in the Federal Register, but was sent to all known U.S. owners and operators of these engines. This AD requires the same actions. We are issuing this AD to prevent engine main rotor seizure resulting in engine damage, shutdown, and damage to the airplane.
Under 14 CFR 39.1, the Engine & Propeller Directorate is only authorized to issue airworthiness directives that apply to aircraft engines, propellers, or appliances (hereinafter referred to in this AD as ``products'') when an unsafe condition exists in a product; and that unsafe condition is likely to exist or develop in other products of the same type design. Therefore, although the unsafe condition is caused by the failure of certain PMA parts manufactured by Dixie Aerospace, LLC, for the product affected, we must include the type certificate (TC) holder's legal name in the subject line of the AD. For this AD, the TC holder is Honeywell International Inc.
Actions Since AD 2011-18-51 Was Issued
We are revising Emergency AD 2011-18-51 with this final rule because we determined the need to list the affected bearings by serial number (S/N) in the AD for clarification.
FAA's Determination
We are issuing this AD because we evaluated all relevant information and determined the unsafe condition described previously islikely to exist or develop in other products of the same type design.
AD Requirements
This AD requires an inspection of records to determine if certain S/N Dixie Aerospace, LLC main shaft bearings, P/N 3108098-1WD, are installed in Honeywell International Inc. TPE331 model turboprop engines. Within 10 operating hours, affected bearings must be removed from service.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because the bearing failure mechanism is severe and sudden. Therefore, we find that notice and opportunity for prior public comment 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 we did notprovide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2011-0935 and Directorate Identifier 2011-NE-28- AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
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 we receive about this AD.
Costs of Compliance
We estimate that this AD will require 1,000 engines installed on airplanes of U.S. registry to have their records inspected, and the inspection will take about 0.5 hour per engine. We also estimate that one engine will require the affected main shaft bearing to be removed from service. We also estimate that it will take about 24 work-hours per engine to remove the bearing from service and that the average labor rate is $85 per work-hour. A replacement bearing will cost about $5,750. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $50,290.
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
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.
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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 DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.