
[Federal Register: June 28, 2010 (Volume 75, Number 123)]
[Proposed Rules]               
[Page 36581-36583]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28jn10-18]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0610; Directorate Identifier 2009-SW-47-AD]
RIN 2120-AA64

 
Airworthiness Directives; Eurocopter France Model EC 155B, 
EC155B1, SA-360C, SA-365C, SA-365C1, SA-365C2, SA-365N, SA-365N1, AS-
365N2, AS 365 N3, and SA-366G1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes superseding an existing airworthiness 
directive (AD) for the specified Eurocopter France (Eurocopter) 
helicopters. That AD requires repetitively inspecting the main gearbox 
(MGB) planet gear carrier for a crack and replacing any MGB that has a 
cracked planet gear carrier before further flight. This action would 
require the same inspections required by the existing AD but would 
shorten the initial inspection interval. This proposal is prompted by 
the discovery of another crack in a MGB planet gear carrier and 
additional analysis that indicates that the initial inspection interval 
must be shortened. The actions specified by the proposed AD are 
intended to detect a crack in the web of the planet gear carrier, which 
could lead to a MGB seizure and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before August 27, 2010.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
     You may get the service information identified in this 
proposed AD from American Eurocopter Corporation, 2701 Forum Drive, 
Grand Prairie, TX 75053-

[[Page 36582]]

4005, telephone (800) 232-0323, fax (972) 641-3710, or at http://
www.eurocopter.com.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Gary Roach, Aviation Safety Engineer, 
Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 
76137, telephone (817) 222-5130, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the caption ADDRESSES. Include ``Docket No. FAA-2010-0610; 
Directorate Identifier 2009-SW-47-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed rulemaking. Using the 
search function of the docket Web site, you can find and read the 
comments to any of our dockets, including the name of the individual 
who sent or signed the comment. You may review the DOT's complete 
Privacy Act Statement in the Federal Register published on April 11, 
2000 (65 FR 19477-78).

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The street address for the Docket Operations office 
(telephone (800) 647-5527) is in the ADDRESSES section of this AD. 
Comments will be available in the AD docket shortly after receipt.

Discussion

    On February 1, 2005, we issued AD 2005-03-09, Amendment 39-13965 
(70 FR 7382, February 14, 2005), to require the following:
     For a MGB that has less than 250 hours time-in-service 
(TIS) since new or last overhaul, borescope inspecting or visually 
inspecting the web of the planet gear carrier for a crack. The 
inspections must be done on or before the MGB reaches 265 hours TIS and 
then at intervals not to exceed 50 hours TIS.
     For a MGB that has 250 or more hours TIS since new or 
since last overhaul, borescope inspecting or visually inspecting the 
web of the planet gear carrier for a crack. The inspections must be 
done within 15 hours TIS and then at intervals not to exceed 50 hours 
TIS.
     For any MGB that has a cracked planet gear carrier, 
replacing the MGB with an airworthy MGB before further flight.
    That action was prompted by the discovery of cracks in the main 
gearbox during overhaul. The requirements of that AD are intended to 
detect a crack in the web of the planet gear carrier, which could lead 
to a MGB seizure and subsequent loss of control of the helicopter.
    Since the issuance of AD 2005-03-09, an additional crack has been 
found in the MGB planet gear carrier of a Eurocopter Model EC 155 
helicopter. That crack was caused by a progressive fatigue failure 
caused by scoring in the blend radius between the pin and the web. An 
additional analysis indicates that the initial inspection must be 
shortened. Therefore, this proposed AD would shorten the initial 
inspection from 265 hours TIS to 35 hours TIS. The recurring 50 hour-
TIS inspections would remain the same.
    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for France, has issued EASA Emergency Airworthiness Directive No. 
2007-0288-E, dated November 15, 2007. EASA states that cracks were 
discovered in the web of the MGB planet gear carrier. The two affected 
MGB units had been removed for overhaul/repair, subsequent to the 
detection of metal chips at the magnetic plugs. Investigation of the 
first case showed a failure of the head of a screw that secures the sun 
gear bearing. The screw head was caught by the planet gear/fixed ring 
gear/sun gear drive train. The second case was discovered by the 
manufacturer and did not seem to be associated with any other failure. 
You may obtain further information by examining the MCAI and any 
related service information in the AD docket.

Related Service Information

    Eurocopter France has issued the following Emergency Alert Service 
Bulletins:
     No. 05A007, Revision 2, for the Model EC155 helicopters;
     No. 05.00.48, Revision 3, for the Model AS365 helicopters;
     No. 05.26, Revision 2, for the Model SA360 and SA365 
helicopters; and
     No. 05.33, Revision 2, for the SA366 helicopters.
    Each Emergency Alert Service Bulletin (EASB) at the stated revision 
level is dated November 16, 2009 and describes the discovery of a 
progressive fatigue failure of the planet gear carrier. The EASBs 
specify inspecting the MGB planet gear carrier for a crack and removing 
the MGB and contacting the manufacturer before the next flight if a 
crack is found.

FAA's Evaluation and Unsafe Condition Determination

    These products 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, their technical 
representative, has notified us of the unsafe condition described in 
the MCAI AD. We are proposing 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 products of these same type 
designs. This proposed AD would require inspecting the MGB planet gear 
carrier for a crack and replacing the MGB before further flight if a 
crack is found. The actions would be required to be accomplished by 
following specified portions of the EASBs described previously.

Differences Between This Proposed AD and the EASA AD

    The MCAI references the service information rather than stating 
compliance times as we have done in this proposed AD. Unlike the EASBs, 
we have structured our compliance times based on a 250-hour TIS 
threshold. Also, the proposed AD does not require you to report cracks 
in the planet gear carrier to the manufacturer.

Costs of Compliance

    We estimate that this AD will affect 145 helicopters of U.S. 
registry. We also estimate that it would take about 1 work-hour per 
helicopter for each borescope inspection and 12 work-hours for each 
visual inspection. Replacing the MGB, if necessary, would take about 16 
work-hours. The average labor rate is $85 per work-hour. Required parts 
would cost about $66,780 per MGB. Based on these figures, we estimate 
the cost of this AD on U.S. operators would be $3,486,760, assuming 
that a borescope inspection would be done on the entire fleet 12 times 
a year, that no

[[Page 36583]]

visual inspections would be done, and that 49 MGBs would be replaced.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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 above, I certify that the 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); and
    3. 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. See the AD docket to examine the economic 
evaluation.

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety, 
Incorporation by reference.

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. Section 39.13 is amended by removing Amendment 39-13965 (70 FR 
7382, February 14, 2005), and adding the following new AD:

Eurocopter France: Docket No. FAA-2010-0610; Directorate Identifier 
2009-SW-47-AD. Supersedes AD 2005-03-09; Docket No. FAA-2005-20294; 
Directorate Identifier 2004-SW-39-AD.

Applicability

    Model EC 155B, EC155B1, SA-360C, SA-365C, SA-365C1, SA-365C2, 
SA-365N, SA-365N1, AS-365N2, AS 365 N3, and SA-366G1 helicopters, 
certificated in any category.

Compliance

    Required as indicated.

------------------------------------------------------------------------
   For a main gearbox (MGB) that has:                Inspect:
------------------------------------------------------------------------
(1) Less than 250 hours time-in-service  On or before the MGB reaches 35
 (TIS) since new or last overhaul.        hours TIS, unless accomplished
                                          previously, and thereafter at
                                          intervals not to exceed 50
                                          hours TIS.
(2) 250 or more hours TIS since new or   Within 15 hours TIS, unless
 last overhaul.                           accomplished previously, and
                                          thereafter at intervals not to
                                          exceed 50 hours TIS.
------------------------------------------------------------------------

    To detect a crack in the web of the planet gear carrier, which 
could lead to a MGB seizure and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) Either borescope inspect the web of the MGB planet gear 
carrier for a crack in accordance with the Operational Procedure, 
paragraphs 2.B.2. through 2.B.2.a.1, of Eurocopter Emergency Alert 
Service Bulletin (EASB) No. 05A007, Revision 2; No. 05.00.48, 
Revision 3; No. 05.26, Revision 2; or No. 05.33, Revision 2; as 
applicable to your model helicopter, or visually inspect the MGB 
planet gear carrier in accordance with the Operational Procedure, 
paragraphs 2.B.3. through paragraph 2.B.3.a.1, of the EASB 
applicable to your model helicopter. Each EASB at the stated 
revision level is dated November 16, 2009.
    (b) If a crack is found in the planet gear carrier, replace the 
MGB with an airworthy MGB before further flight.
    (c) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Manager, Safety Management Group, FAA, ATTN: Gary Roach, 
Aviation Safety Engineer, Rotorcraft Directorate, FAA, 2601 Meacham 
Blvd., Fort Worth, Texas 76137, telephone (817) 222-5130, fax (817) 
222-5961, for information about previously approved alternative 
methods of compliance.
    (d) The Joint Aircraft System/Component (JASC) Code is 6320: 
Main Rotor Gearbox.


    Note: The subject of this AD is addressed in European Aviation 
Safety Agency AD No. 2007-0288-E, dated November 15, 2007.


    Issued in Fort Worth, Texas, on June 16, 2010.
Gwendolynne O'Connell,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-15370 Filed 6-25-10; 8:45 am]
BILLING CODE 4910-13-P

