
[Federal Register Volume 77, Number 65 (Wednesday, April 4, 2012)]
[Proposed Rules]
[Pages 20319-20321]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-8056]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0354; Directorate Identifier 2010-SW-104-AD]
RIN 2120-AA64


Airworthiness Directives; Eurocopter France Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
Eurocopter France (EC) Model SA-365N, SA-365N1, SA-366G1, AS-365N2, AS 
365 N3, EC 155B, and EC155B1 helicopters. This proposed AD was prompted 
by the discovery of a cracked main rotor mast nut. This condition, if 
not corrected, could lead to complete failure of the mast nut, 
resulting in failure of the rotor mast and loss of control of the 
helicopter. This proposed AD would require replacing the main rotor 
mast nut with an airworthy main rotor mast nut. We are proposing this 
AD to prevent failure of the main rotor mast and subsequent loss of 
control of the helicopter.

DATES: We must receive comments on this proposed AD by June 4, 2012.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    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 proposed AD, the 
economic evaluation, any

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comments received, and other information. The street address for the 
Docket Operations Office (telephone 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.
    For service information identified in this proposed AD, contact 
American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 
75052, telephone (972) 641-0000 or (800) 232-0323, fax (972) 641-3775, 
or at http://www.eurocopter.com/techpub. You may review a copy of the 
referenced service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.

FOR FURTHER INFORMATION CONTACT: Gary Roach, Aviation Safety Engineer, 
Regulations and Policy Group, Rotorcraft Directorate, FAA, 2601 Meacham 
Blvd., Fort Worth, TX 76137; telephone (817) 222-5110; email 
gary.b.roach@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    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 might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, 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 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 proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Union, has issued AD No.: 
2006-0368R1, dated December 2, 2010, and corrected December 8, 2010 (AD 
2006-0368R1), to correct an unsafe condition for the EC Model SA 365 N, 
SA 365 N1, AS 365 N2, AS 365 N3, SA 366 G1, EC 155 B, and EC 155 B1 
helicopters. EASA advises that a cracked (partially failed) main rotor 
mast nut was discovered during a complete overhaul of a main rotor 
mast. The start of the crack was related to circular scoring found in 
the nut threads. EASA states that this condition, if not corrected, 
``could lead to complete failure of the mast nut, possibly resulting in 
failure of the rotor mast and consequent loss of control of the 
helicopter.'' To address this unsafe condition, EASA issued Emergency 
AD 2006-0368-E, dated December 6, 2006 (AD 2006-0368-E), to require 
repetitive inspections of the mast nut, and replacement of the nut if 
cracked. Since issuance of AD 2006-0368-E, EC has developed 
modification (MOD) 0762C42 to improve the strength of the mast nut by 
changing its material. Replacing mast nut part number (P/N) 360A31-
1020-20 with mast nut P/N 365A31-2060-20 or 365A31-2060-21 (as 
applicable to helicopter type) ``constitutes an optional terminating 
action'' for the repetitive inspection requirements. For this reason, 
EASA issued AD 2006-0368R1 ``to inform which helicopters remain subject 
to inspections and replacement requirements'' of the AD.

FAA's Determination

    We are proposing this AD because we evaluated all known relevant 
information and determined that an unsafe condition exists and is 
likely to exist or develop on other products of these same type 
designs.

Related Service Information

    We reviewed EC Alert Service Bulletin (ASB) No. 62.00.23, Revision 
1, for Model SA-365N, SA-365N1, AS-365N2, and AS 365 N3 helicopters; EC 
ASB 62.12, Revision 1, for Model SA-366G1 helicopters; and EC ASB 
62A014, Revision 1, for Model EC 155B and EC155B1 helicopters, all 
dated Oct 27, 2010. The ASBs contain procedures for repetitively 
inspecting the mast nut for a crack or failure. The ASBs remove any 
helicopter with MOD 0762C42 incorporated from the applicability of the 
ASB. EASA classified this ASB as mandatory and issued AD 2006-0368R1 to 
ensure the continued airworthiness of these helicopters.

Proposed AD Requirements

    This proposed AD would require, for EC Model SA-365N, SA-365N1, 
SA366G1, AS-365N2, AS 365 N3, EC 155B, and EC155B1 helicopters, 
certificated in any category, with a mast nut P/N 360A31-1020-20 
installed:
     For EC Models SA-365N, SA-365N1, AS-365N2, and AS 365 N3, 
prior to accumulating 1,650 hours time-in-service (TIS) or within the 
next 50 hours TIS, whichever occurs later, remove mast nut P/N 360A31-
1020-20 and replace with an airworthy mast nut of a different P/N.
     For EC Model SA-366G1, prior to accumulating 990 hours TIS 
or within the next 30 hours TIS, whichever occurs later, remove mast 
nut P/N 360A31-1020-20 and replace with an airworthy mast nut of a 
different P/N.
     For EC Models EC 155B and EC155B1, prior to accumulating 
660 hours TIS or within the next 50 hours TIS, whichever occurs later, 
remove mast nut P/N 360A31-1020-20 and replace with an airworthy mast 
nut of a different P/N.

Differences Between This Proposed AD and the EASA AD

    The EASA AD allows for either inspecting the mast nut at regular 
intervals or replacing the mast nut, while the proposed AD requires 
replacing the mast nut. The EASA AD uses flight hours of the main rotor 
mast assembly, while the proposed AD uses TIS of the helicopter.

Costs of Compliance

    We estimate that this proposed AD affects 30 helicopters of U.S. 
registry. We estimate that replacing the mast nut with an airworthy 
mast nut would require 32 work-hours, at an average labor cost of $85 
per work-hour. Parts would cost about $3,100. Based on these costs, we 
estimate a total cost per helicopter of $5,820, and a total cost for 
the U.S. operator fleet of $174,600.

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.

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Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
    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);
    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 proposed 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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 (AD):

Eurocopter France: Docket No. FAA-2012-0354; Directorate Identifier 
2010-SW-104-AD.

 (a) Applicability

    This AD applies to Eurocopter France (EC) Model SA-365N, SA-
365N1, SA-366G1, AS-365N2, AS 365 N3, EC 155B, and EC155B1 
helicopters with a mast nut, part number (P/N) 360A31-1020-20, 
installed.

(b) Unsafe Condition

    This AD describes the unsafe condition as a cracked main rotor 
mast nut. This condition could result in failure of the rotor mast 
and subsequent loss of control of the helicopter.

(c) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(d) Required Actions

    (1) For EC Models SA-365N, SA-365N1, AS-365N2, and AS 365 N3, 
prior to accumulating 1,650 hours time-in-service (TIS) or within 
the next 50 hours TIS, whichever occurs later, remove mast nut P/N 
360A31-1020-20 and replace with an airworthy mast nut that has a P/N 
other than P/N 360A31-1020-20.
    (2) For EC Model SA-366G1, prior to accumulating 990 hours TIS 
or within the next 30 hours TIS, whichever occurs later, remove mast 
nut P/N 360A31-1020-20 and replace with an airworthy mast nut that 
has a P/N other than P/N 360A31-1020-20.
    (3) For EC Models EC 155B and EC155B1, prior to accumulating 660 
hours TIS or within the next 50 hours TIS, whichever occurs later, 
remove mast nut P/N 360A31-1020-20 and replace with an airworthy 
mast nut that has a P/N other than P/N 360A31-1020-20.

(e) Alternative Methods of Compliance (AMOC)

    (1) The Manager, Safety Management Group, FAA, may approve AMOCs 
for this AD. Send your proposal to: Gary Roach, Aviation Safety 
Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA, 
2601 Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5110; 
email gary.b.roach@faa.gov.
    (2) For operations conducted under a Part 119 operating 
certificate or under Part 91, Subpart K, we suggest that you notify 
your principal inspector, or lacking a principal inspector, the 
manager of the local flight standards district office or certificate 
holding district office before operating any aircraft complying with 
this AD through an AMOC.

(f) Additional Information

    (1) Eurocopter Alert Service Bulletin No. 62.00.23, No. 62.12, 
and No. 62A014, which are not incorporated by reference, contain 
additional information about the subject of this AD. All of the 
service bulletins are Revision 1 and all are dated Oct 27, 2010. For 
service information identified in this AD, contact American 
Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 
75052, telephone (972) 641-0000 or (800) 232-0323, fax (972) 641-
3775, or at http://www.eurocopter.com/techpub. You may review copies 
of the service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.
    (2) The subject of this AD is addressed in in European Aviation 
Safety Agency AD No.: 2006-0368R1, dated December 2, 2010, and 
corrected December 8, 2010.

(g) Subject

    Joint Aircraft Service Component (JASC) Code: 6300, main rotor 
drive system.

    Issued in Fort Worth, Texas, on March 26, 2012.
Scott A. Horn,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2012-8056 Filed 4-3-12; 8:45 am]
BILLING CODE 4910-13-P


