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 May 15, 2012, we issued Emergency AD 2012-10-51 for the ECD Model EC135 series helicopters to detect a crack on the MRH shaft flange. Emergency AD 2012-10-51 required a pilot check of the lower MRH shaft flange for a crack or deformed blade attachment bolt safety pins before the first flight of each day, inspecting the upper and lower MRH shaft flanges for a crack within 5 hours time-in-service (TIS), and replacing the MRH shaft if there is a crack.
After we issued Emergency AD 2012-10-51, the European Aviation Safety
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Agency (EASA), which is the Technical Agent for the Member States of the European Union, issued EASA AD No. 2012-0085-E, dated May 17, 2012 (2012-0085-E), which superseded EASA AD No. 2012-0041R1, dated March 15, 2012 (2012-0041R1), to correct an unsafe condition for the ECD Model EC 135 serieshelicopters. EASA advises that since issuing 2012- 0041R1, further cracks have been detected on two other helicopters during the pre-flight checks. These are the same two cracks that prompted our Emergency AD. However, EASA also states that identification of deformed safety pins may not be sufficient to detect a crack on the MRH shaft flange. ECD is investigating the cause of the cracks and has developed new inspection procedures with further corrective actions. Therefore, we issued superseding Emergency AD 2012- 10-53 on May 18, 2012, to detect a crack on the MRH shaft flange, which if not corrected could result in failure of the MRH and subsequent loss of control of the helicopter.
When we issued superseding Emergency AD 2012-10-53, we included additional part-numbered MRH shafts that should have been included in EAD 2012-10-51, changed the daily checks to recurring checks at intervals not to exceed 6 hours TIS, added a 10 hour-TIS recurring inspection on MRH shafts with 400 or more hours TIS, and removed the check of the blade attachment bolt safety pins for deformation.
This is the Federal Register publication of Emergency AD 2012-10-53 as Amendment 39-17254; AD 2012-10-53. There are no differences in the regulatory language or requirements between this AD and that Emergency AD as it was previously sent to all known owners and operators of these helicopters.
FAA's Determination
These helicopters have been approved by the aviation authority of Germany and are approved for operation in the United States. Pursuant to our bilateral agreement with Germany, 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
Eurocopter has issued Emergency Alert Service Bulletin EC135-62A- 029, Revision 2, dated May 17, 2012 (EC135-62A-029), which describes procedures for conducting a repetitive check of the visible area of the upper and lower MRH shaft flanges and a repetitive inspection of the area of the blade bolts lower MRH shaft flange.
AD Requirements
This AD supersedes Emergency AD 2012-10-51 and requires the following:
Before further flight, and thereafter at intervals not to exceed 6 hours TIS, checking the lower MRH shaft flange and the visible area of the upper MRH shaft flange for a crack. An owner/operator (pilot) may perform this required visual check and must enter compliance with the applicable paragraph of this AD into the helicopter maintenance records in accordance with 14 CFR 43.9(a)(1)-(4) and 91.417(a)(2)(v). A pilot may perform this check because it involves only looking at the visible area of the MRH shaft flanges and can be performed equally well by a pilot or a mechanic. This check is an exception to our standard maintenance regulations.
For an MRH shaft with 400 or more hours TIS, within 10 hours TIS, and thereafter at intervals not to exceed 10 hours TIS, removing the rotor-hub cap; inspecting the upper and lower hub-shaft flanges for a crack; removing the blade attachment bolt safety pins, nut, and washer; and inspecting the lower hub-shaft flange bolt attachment areas for a crack.
If there is a crack, replacing the MRH shaft.
Differences Between This AD and the EASA AD
The EASA AD identifies ECD Alert Service Bulletin EC135-62A-029, Revision 1, dated May 16, 2012. This AD references Revision 2. The EASA AD requires you to report the findings and sending any cracked MRH to ECD, and this AD does not. The EASA AD requires the initial check within 3 days, while this AD requires the check before further flight.
Interim Action
We consider this AD to be an interim action. Eurocopter is currently developing a modification that will address the unsafe condition identified in thisAD. Once this modification is developed, approved, and available, we might consider additional rulemaking.
Costs of Compliance
We estimate that this AD will affect 244 helicopters of U.S. Registry. We estimate inspecting the MRH shaft flanges will require 2.5 hours at an average labor rate of $85 per work-hour, for a total cost per helicopter of $212 and a total cost to U.S. operators of $51,850 per inspection cycle. Replacing an MRH shaft will require about 8 hours at an average labor rate of $85 per work-hour, and required parts will cost $55,715, for a total cost per helicopter of $56,395.
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 before further flight.
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 impracticable 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 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, I certify that this AD:
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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.