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
75053-4005, 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
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 Pro-
cedures (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 devel-
op 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: