Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments prior to it becoming effective. However, we invite you to participate in this rulemaking by submitting written comments, data, or views. We also invite comments relating to the economic, environmental, energy, or federalism impacts that resulted from adopting this AD. The most helpful comments reference a specific portion of the AD, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit them only one time. We will file in the docket all comments that we receive, as well as a report summarizing each substantive public contact with FAA personnel concerning this rulemaking duringthe comment period. We will consider all the comments we receive and may conduct additional rulemaking based on those comments.
Discussion
On September 14, 2012, we issued AD 2012-19-09, Amendment 39-17204 (77 FR 58925, September 25, 2012), for Eurocopter Model EC 155B, EC155B1, SA-365N1, AS-365N2 and AS 365 N3 helicopters with a 10-bladed TRH, part number (P/N) 365A33351100, 365A33351101, or 365A33351102, installed. That AD requires visually inspecting the TRH for a crack and removing the TRH if a crack exists. The AD was prompted by reports of cracks on two TRHs. Those actions are intended to prevent the tail rotor from jamming, which could lead to reduced or loss of control of the helicopter.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, issued EASA AD No. 2011-0144, dated July 26, 2011, to correct an unsafe condition for Eurocopter Model EC 155B, EC155B1, SA-365N1, AS-365N2 and AS 365 N3 helicopters, based on reports of 2 cases of cracked TRHs. Pending further investigation, EASA AD 2011-0144 required repetitive inspections of 10-bladed TRHs every 55 flight hours. EASA considered the actions in its AD to be interim measures and expected further AD actions.
Actions Since Existing AD Was Issued
Since we issued AD 2012-19-09, Amendment 39-17204 (77 FR 58925, September 25, 2012), Eurocopter determined that helicopters with 11- bladed TRHs must also be inspected for cracks. Based on this further analysis by Eurocopter, EASA determined that the inspections must also be applied to AS 365 N2 helicopters with an 11-bladed TRH. Therefore, EASA issued superseding EASA AD 2012-0227, dated October 29, 2012, to extend the applicability to include the 11-bladed TRHs.
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FAA's Determination
These helicopters have been approved by the aviation authority of France and are approved for operation in the United States. Pursuant to our bilateral agreement with France, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs.
Related Service Information
Following the report of cracks found on the TRH of a Model AS-365 helicopter, Eurocopter issued Alert Service Bulletin (ASB) No. EC 155- 05A021, Revision 0, dated April 11, 2011, for Model EC 155B and EC155B1 helicopters and ASB No. AS365-05.00.60, Revision 0, dated April 11, 2011, for Model SA-365N1, AS-365N2, AS 365 N3, and some military helicopters. After a second report of TRH cracks, the ASBs were revised, dated July 20, 2011, to mandate and reduce the repetitive inspection interval from 110 flight hours to 55 flight hours.
On October 9, 2012, Eurocopter again revised ASB No. AS365-05.00.60 by issuing Revision 2 to extend the applicability to 11-bladed TRHs in Model AS 365 N3 helicopters.
The ASBs call for visually inspecting the TRH for a crack and, if a crack is found, removing the TRH. EASA classified these ASBs as mandatory and issued superseding AD No. 2012-0227 to ensure the continued airworthiness of these helicopters.
AD Requirements
This AD requires visually inspecting the TRH for a crack within 55 hours time in service (TIS) and, if a crack exists, removing the TRH from service. This inspection must be repeated at intervals not to exceed 55 hours TIS.
Interim Action
We consider this AD to be an interim action because Eurocopter is still investigating the cause of TRH cracks. If a final action is later identified, we might consider additional rulemaking.
Costs of Compliance
We estimate that this AD will affect 44 helicopters of U.S. Registry and that labor costs will average $85 a work-hour. We expect that it will take 1 work-hour to visually inspect the TRH for a crack, and that helicopters will average 5 inspections per year. Thus, we estimate a total annual cost of $425 per helicopter, and $18,700 for the U.S. operator fleet.
FAA's Justification and Determination of the Effective Date
Providing an opportunity for public comments prior to adopting these AD requirements would delay implementing the safety actions needed to correct this known unsafe condition. Therefore, we find that the risk to the flying public justifies waiving notice and comment prior to the adoption of this rule, because the required corrective actions must be accomplished within 55 hours TIS, a very short time period based on the average utilization rate of the highest usage helicopter model.
Since an unsafe condition exists that requires the immediate adoption of this AD, we determined that notice and opportunity for public comment before issuing this AD are impractical and contrary to the public interest and that good cause exists for making this amendment effective in less than 30 days.
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 determined that this AD will not have federalism implications underExecutive 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, 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 to the extent that it justifies making a regulatory distinction; 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.
We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.