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[Federal Register Volume 77, Number 172 (Wednesday, September 5, 2012)]
[Rules and Regulations]
[Pages 54353-54354]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-21262]

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Rules and Regulations
                                                Federal Register
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Federal Register / Vol. 77, No. 172 / Wednesday, September 5, 2012 / 
Rules and Regulations

[[Page 54353]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0354; Directorate Identifier 2010-SW-104-AD; 
Amendment 39-17165; AD 2012-17-02]
RIN 2120-AA64

Airworthiness Directives; Eurocopter France Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting 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 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 
AD will require replacing the main rotor mast nut with an airworthy 
main rotor mast nut to prevent this scenario.

DATES: This AD is effective October 10, 2012.

ADDRESSES: 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 the referenced 
service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 
76137.

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 AD, any incorporated-by-reference 
service information, the economic evaluation, any comments received, 
and other information. The street address for the Docket Operations 
Office (phone: 800-647-5527) is U.S. Department of Transportation, 
Docket Operations Office, M-30, West Building Ground Floor, Room W12-
140, 1200 New Jersey Avenue SE., Washington, DC 20590.

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:

Discussion

    On April 4, 2012, at 77 FR 20319, 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 all Eurocopter France 
(EC) Model SA-365N, SA-365N1, SA-366G1, AS-365N2, AS 365 N3, EC 155B, 
and EC155B1 helicopters. That NPRM proposed to require replacing the 
main rotor mast nut with an airworthy main rotor mast nut to prevent 
failure of the main rotor mast and subsequent 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, has issued EASA 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD, but we did not receive any comments on the NPRM.

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

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 October 27, 2010. The ASBs contain procedures

[[Page 54354]]

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.

Costs of Compliance

    We estimate that this AD affects 30 helicopters of U.S. registry. 
We estimate that replacing the mast nut with an airworthy mast nut will 
require 32 work-hours, at an average labor cost of $85 per work-hour. 
Parts will 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 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.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2012-17-02 Eurocopter France Helicopters: Amendment 39-17165; 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, certificated in any category.

(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) Effective Date

    This AD becomes effective October 10, 2012.

(d) 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.

 (e) 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.

(f) Alternative Methods of Compliance (AMOCs)

    (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 14 CFR part 119 operating 
certificate or under 14 CFR 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.

 (g) 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 October 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 a copy 
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.

(h) Subject

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

    Issued in Fort Worth, Texas, on August 16, 2012.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2012-21262 Filed 9-4-12; 8:45 am]
BILLING CODE 4910-13-P
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