Discussion
On March 14, 2013, at 78 FR 16200, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to include an AD that would apply to Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, and AS355F2 helicopters with an autopilot installed; Model AS350B3 helicopters with an autopilot or modification 073252 installed; and Model AS355N and AS355NP helicopters with an autopilot or modification 071908 installed. The NPRM proposed to require inspecting the tail rotor control stop screws to determine if they are correctly aligned and adjusting the screws if they are misaligned. The proposed requirements were intended to detect a loose nut or a misaligned stop screw, which, if not corrected, could limit yaw authority, and consequently, result in a loss of helicopter control.
The NPRM was prompted by AD No. 2011-0164, dated August 31, 2011, issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued AD No. 2011-0164 to correct an unsafe condition for Eurocopter Model AS350B, AS350BA, AS350BB, AS350B1, AS350B2, AS350B3, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with either an autopilot or certain modifications installed. EASA advises that during take-off with a sling load, the pilot of a Model AS350B3 helicopter reached one of the yaw stops before its usual position. The inspection that followed revealed that a tail rotor control stop nut was loose and that the corresponding tail rotor control stop screw was ``out of adjustment.'' EASA states that this condition, if not detected and corrected, ``can lead to the loss of adjustment of the affected stop and consequently limit yaw authority, possibly resulting in loss of control of the helicopter.''
Comments
After our NPRM (78 FR 16200, March 14, 2013), was published, we received comments from one commenter.
Request
The commenter suggested that an AD is unnecessary because operators should have already tightened the screw.
We disagree that an AD is not needed. More than one tightening of a screw is necessary to correct this unsafe condition. This AD also requires monitoring the stop screws through repetitive inspections to determine whether a screw has become loose. Without these inspections, if a screw becomes loose and is not corrected, yaw authority could be limited, resulting in loss of helicopter control.
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, reviewed the relevant information, considered the comment received, and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.
Differences Between this AD and the EASA AD
The EASA AD requires contacting Eurocopter under certain conditions. This does AD not. The EASA AD applies to Eurocopter Model AS350BB helicopters. This AD does not because Model AS350BB does not have an FAA type certificate. However, this AD applies to Eurocopter Model AS350C and AS350D1 helicopters because they have an FAA type certificate and because they have similar tail rotor stop screw assemblies as the other applicable helicopter models. The EASA AD does not apply to the Model AS350C and AS350D1 helicopters.
Interim Action
We consider this AD to be an interim action because Eurocopter is developing a modification to address the unsafe condition identified in this AD. After this modification is developed, approved, and available, we might consider additional rulemaking.
Related Service Information
Eurocopter has issued Alert Service Bulletin (ASB) No. AS350- 05.00.64 for Model AS350B, BA, BB, B1, B2, B3, and D civil helicopters and Model AS350L1 military helicopters, and ASB No. AS355-05.00.59 for Model AS355E, F, F1, F2, N, and NP civil helicopters, both Revision 0 and both dated August 30, 2011. The ASBs specify inspecting the locking of the stop screws and, if warranted, adjusting the stops, marking the screw/nut assembly with a red line of paint, and periodically inspecting the paint line's alignment on the screw/nut assembly.
Costs of Compliance
We estimate that this AD will affect 911 helicopters of U.S. Registry and that labor costs average $85 per work-hour.
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Based on these estimates, we expect the following costs:
Inspecting the locking of the stop screws takes about a 0.4 work-hour for a labor cost of about $34 per helicopter and $30,974 for the U.S. fleet. No parts are needed.
Adjusting the stop screws, if needed, requires about a 0.2 work-hour for a labor cost of $17. No parts are needed.
Painting the line requires a 0.1 work-hour for a labor cost of about $9 per helicopter and $8,199 for the U.S. fleet. No parts are needed.
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 helicopters 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.
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 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.