[Federal Register Volume 77, Number 23 (Friday, February 3, 2012)]
[Notices]
[Pages 5514-5516]
[FR Doc No: 2012-2442]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2009-0927; FRL-9626-8]

Mandatory Reporting of Greenhouse Gases: Notice of Preliminary
Determinations Regarding Requests To Use Provisional Global Warming
Potentials Under the Fluorinated Gas Production Category of the
Greenhouse Gas Reporting Rule

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of data availability and request for comment.

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SUMMARY: The EPA is announcing and explaining to the public its
preliminary determinations regarding requests to use provisional global
warming potentials for eight fluorinated greenhouse gases submitted by
DuPont de Nemours, Inc. and Honeywell International for purposes of
certain calculations in the Fluorinated Gas Production portion of the
Mandatory Greenhouse Gas Reporting Rule. EPA's preliminary
determination is that the requests for seven of the eight fluorinated
GHGs meet the requirements of the rule.

DATES: Comments must be received on or before February 21, 2012.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2009-0927, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov:
Follow the online instructions for submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: EPA Docket Center, Attention Docket OAR-2009-0927,
Mail code: 2822T, 1200 Pennsylvania Avenue NW., Washington, DC 20460.
     Hand Delivery: EPA Docket Center, Public Reading Room,
Room 3334, EPA West Building, Attention Docket EPA-HQ-OAR-2009-0927,
1301 Constitution Avenue NW., Washington, DC 20004. Such deliveries are
only accepted during the Docket's normal hours of operation, and
special arrangements should be made for deliveries of boxed
information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2009-0927. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through http://www.regulations.gov. The http://www.regulations.gov. Web site is an
``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an email comment directly to EPA without
going through http://www.regulations.gov your email address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at EPA's Docket Center,
Public Reading Room, EPA West Building, Room 3334, 1301 Constitution
Avenue NW., Washington, DC 20004. This Docket Facility is open from
8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal
holidays. The Docket telephone number for the Public Reading Room is
(202) 566-1744 and the telephone number for the Air Docket is (202)
566-1742.

FOR FURTHER INFORMATION CONTACT: Deborah Ottinger, Climate Change
Division, Office of Atmospheric Programs (MC-6207J), Environmental
Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460;
telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; email
address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this notice apply to me?

    This notice applies to five facilities considered to be fluorinated
gas production facilities under subpart L (Fluorinated Gas Production)
of the Mandatory Greenhouse Gas Reporting rule (40 CFR part 98). These
facilities are Honeywell International's Buffalo Research Laboratory
and DuPont's Fayetteville, North Carolina; Deepwater, New Jersey;
Washington Works, West Virginia; and Eldorado, Arkansas facilities.
This notice may also be of interest to members of the public with
knowledge of or interest in the estimation of global warming
potentials.

B. What is this notice about?

    This notice announces and explains to the public EPA's preliminary
determinations regarding the provisional global warming potentials
(GWPs) for eight fluorinated greenhouse gases (GHGs) submitted by E.
DuPont de Nemours, Inc. (DuPont) and Honeywell International
(Honeywell) for the purposes of the calculations in 40 CFR 98.123(c)(1)
(a provision of subpart L of the Mandatory Greenhouse Gas Reporting
rule). EPA's preliminary determination is that the requests for seven
of the eight fluorinated GHGs meet the requirements of the rule. As
discussed further below, the calculations in 40 CFR 98.123(c)(1) are
used to determine whether a facility must use stack testing to
establish an emission factor for a continuous process vent. For
continuous process vents that are calculated to emit less than 10,000
metric tons carbon-dioxide equivalent (mtCO2e) annually,
facilities have the option to use engineering calculations rather than
stack testing to establish an emission factor.

C. What information is EPA making available for review and comment?

    EPA is making available for review and comment provisional GWPs for
fluorinated GHGs submitted by Dupont and Honeywell for the purposes of
the calculations in 40 CFR 98.123(c)(1). EPA is also making available
to the public the underlying materials in the submitted requests that
were used to estimate the provisional GWPs, and EPA's analysis of those
materials.

D. Where can I get more information?

    All of the information can be obtained through the Docket and at
http://www.regulations.gov (see ADDRESSES section above for docket
contact information).

E. Submitting Confidential Business Information (CBI).

    Do not submit information you are claiming as CBI to EPA through
http://www.regulations.gov or email. Clearly mark the part of the
information that you claim to be CBI. Information so marked will not be
disclosed except in accordance with procedures set forth in 40 CFR part
2. For CBI information in a disk or CD-ROM that you mail to EPA, mark
the outside of the disk or CD-ROM as CBI and then identify
electronically within the disk or CD-ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for
inclusion in the public docket.

II. Background

    Under 40 CFR 98.123(c)(1), fluorinated gas producers that wish to
use 40 CFR 98.123(c) (the Emission Factor Method or Emission
Calculation Factor Method) to estimate emissions from a continuous
process must make a preliminary estimate of the annual carbon dioxide
equivalent (CO2e) emissions of fluorinated GHGs from each
process vent. They are required to do so using the engineering
calculations or assessments specified in the rule. If the preliminary
estimate indicates that a vent emits 10,000 mtCO2e or more
annually, facilities must use stack testing to establish an emission
factor for that vent. If the preliminary estimate indicates that a vent
emits less than 10,000 mtCO2e annually, facilities may use
engineering calculations or assessments to establish an emission
calculation factor.
    Under 40 CFR 98.123(c)(1)(v), to convert the fluorinated GHG
emissions to CO2e, fluorinated gas producers must use
Equation A-1 of 40 CFR 98.2. For fluorinated GHGs whose GWPs are not
listed in Table A-1 to subpart A of part 98, producers must use a
default GWP of 2,000 unless they submit a request to use other GWPs for
those fluorinated GHGs in that process under 40 CFR 98.123(c)(1)(vi),
and EPA approves that request.
    Under 40 CFR 98.123(c)(1)(vi), fluorinated gas producers may submit
a request to use a GWP other than 2,000 for fluorinated GHGs whose GWPs
are not listed in Table A-1 to subpart A if their process vent emits
one or more fluorinated GHGs (1) whose GWPs are not listed in Table A-1
to subpart A, (2) that are emitted in quantities that, with a default
GWP of 2,000, result in total calculated annual emissions equal to or
greater than 10,000 metric tons CO2e for the vent, and (3)
that they believe have GWPs that would result in total calculated
annual emissions less than 10,000 metric tons CO2e.
    Under 40 CFR 98.123(c)(1)(vi)(B), EPA reviews each request to
determine whether it is complete, substantiates each of the provisional
GWPs, and demonstrates that the process vents are calculated to emit
less than 10,000 metric tons CO2e of fluorinated GHGs only
when the proposed provisional GWPs, not the default GWP of 2,000, are
used for the fluorinated GHGs for which the provisional GWPs are
requested. If EPA makes a preliminary determination that each of these
criteria is met, EPA publishes a notice for public comment including
the determination and the data and analysis submitted by the producers
under 40 CFR 98.123(c)(1)(vi)(A)(1) through (3).
    Under 40 CFR 98.123(c)(1)(vi)(A)(1) through (3), fluorinated gas
producers must include the following information in the request for
each fluorinated GHG that does not have a GWP listed in Table A-1 to
subpart A of part 98 and that constitutes more than one percent by mass
of the stream emitted from the vent:
    (1) The identity of the fluorinated GHG, including its chemical
formula and, if available, CAS number.
    (2) The estimated GWP of the fluorinated GHG.
    (3) The data and analysis that supports the estimate of the GWP of
the fluorinated GHG, including:
    (i) Data and analysis related to the low-pressure gas phase
infrared absorption spectrum of the fluorinated GHG.
    (ii) Data and analysis related to the estimated atmospheric
lifetime of the fluorinated GHG (reaction mechanisms and rates,
including for example, photolysis and reaction with atmospheric
components such as hydroxyl radicals (OH), ozone (O3),
carbon monoxide (CO), and water).
    (iii) The radiative transfer analysis that integrates the lifetime
and infrared absorption spectrum data to calculate the GWP.
    (iv) Any published or unpublished studies of the GWP of the gas.

A. Requests to Use Provisional GWPs

    On February 25, 2011, Honeywell requested to use provisional GWPs
for two fluorinated GHGs for the purposes of the calculations in
paragraph (c)(1) of 40 CFR 98.123. Honeywell requested to use
provisional (i.e., lower) GWPs for two commercial chemicals produced at
their Buffalo Research Laboratory: HFC-1234ze and HFC-1234yf. Honeywell
included published scientific papers and other information to fulfill
the requirements under paragraphs (c)(1)(vi)(A)(1) through (3) of 40
CFR 98.123.
    On February 28, 2011, DuPont requested to use provisional GWPs for
six fluorinated GHGs for the purposes of calculations in 40 CFR
98.123(c)(1). DuPont requested to use provisional (i.e., lower) GWPs
for six chemicals at DuPont plant sites subject to subpart L:
hexafluoropropylene (HFP), perfluoromethyl vinyl ether (PMVE),
tetrafluoroethylene (TFE), 3,3,3-trifluoropropene (TFP), vinyl fluoride
(VF), and vinylidine fluoride (VF2). For each chemical, DuPont included
peer-reviewed scientific data and other information to fulfill the
requirements under paragraphs (c)(1)(vi)(A)(1) through (3).

B. Preliminary Determinations and Their Rationale

    In accordance with 40 CFR 98.123(c)(1)(vi)(B), EPA reviewed the
requests from both Honeywell and DuPont to determine whether each was
complete, substantiated each of the provisional GWPs, and demonstrated
that the process vents were calculated to emit less than 10,000 metric
tons CO2e of fluorinated GHGs only when the proposed
provisional GWPs, not the default GWP of 2,000, were used for the
fluorinated GHGs for which the provisional GWPs were requested.
    EPA made a preliminary determination that each of these criteria
was met for the requests submitted by both Honeywell and DuPont, with
one exception. The exception was for HFC-1234yf, which was emitted in
quantities that, with a default GWP of 2,000, resulted in total
calculated annual emissions of less than 10,000 mtCO2e.
Because the calculated emissions did not meet the threshold criterion,
EPA is not evaluating the provisional GWP for HFC-1234yf in this
action. EPA notes, however, that the provisional GWP submitted by
Honeywell is the same as the GWP recognized in other EPA final actions
(e.g., March 29, 2011; 76 FR 17488). EPA will consider this information
in future updates to Table A-1 of 40 CFR part 98.
    The remainder of this section includes a summary of the
determination and the data and analysis submitted by the producers
under 40 CFR 98.123(c)(1)(vi)(A)(1) through (3).
    EPA's preliminary determination included review of the submitted
information by a leading subject matter expert on GWP estimation who
was also a co-developer of the GWP concept. EPA concluded that the
methods overall

were likely to overestimate GWPs (maybe by an order of magnitude or
more) rather than underestimate them. Because 40 CFR 98.123(c)(1)
allows the use of engineering calculations only when estimated
emissions fall below 10,000 metric tons CO2e, an
overestimated GWP is considered acceptable by EPA in the context of 40
CFR 98.123(c)(1). Therefore, the conclusion of EPA's review was that
the background information was adequate and that it justified the use
of the alternative GWPs in the context of 40 CFR 98.123(c)(1)(vi).
    The overestimation of the GWPs submitted by both Honeywell and
DuPont results from the fact that the commonly-used estimation
techniques employed in the analyses cited by both companies use
simplifying assumptions that are not fully applicable to compounds that
are short-lived in the atmosphere--defined here as any compound with an
atmospheric lifetime less than 1 year. (All of the compounds for which
provisional GWPs were requested are short-lived based on this
definition.) Essentially, the estimation techniques assume that the
compounds are well-mixed in the atmosphere, but short-lived compounds
do not last long enough to become well mixed (i.e., spread evenly over
all longitudes, latitudes, and altitudes). Instead, their
concentrations decrease rapidly with distance from their emission
point, particularly with changing latitude and altitude.
    The assumption that the compounds are well mixed affects the
estimates of both of the primary components of GWPs: Atmospheric
lifetime and radiative forcing. In the analyses cited by the companies,
atmospheric lifetimes are estimated either by assuming that the short-
lived compound is exposed to the global average concentration of
hydroxyl radicals (OH) or by deriving the lifetime of the short-lived
(i.e., not well mixed) compound from the known lifetime of a long-lived
(i.e., well mixed) reference compound based on the compounds'
respective reaction rates with OH. Both approaches are likely to
overestimate the lifetime (and therefore the GWP) of the short-lived
compound because they essentially assume that the concentration of the
short-lived compound remains constant with altitude. This overestimates
the share of the short-lived compound that resides higher in the
atmosphere, where lower OH concentrations, temperatures, and pressures
slow reaction rates and lengthen lifetimes. Radiative forcing is also
estimated based on the assumption that the concentration of the short-
lived compound remains constant with altitude. This assumption is
likely to overestimate the radiative forcing (and therefore the GWP) of
short-lived compounds because, again, it overestimates the share of the
short-lived compound that resides higher in the atmosphere. GHGs higher
in the atmosphere (i.e., near the tropopause) are responsible for more
radiative forcing than the same GHGs lower in the atmosphere. (As
discussed in the Supporting Analysis, this is related to the fact that
temperatures near the tropopause are lower than those at the surface.)
Together, these assumptions may result in overestimates of the GWP by a
factor of ten or more. The rationale for EPA's preliminary
determination is discussed in more detail in the Supporting Analysis,
which is available in the docket.
    The provisional GWPs are shown in Table 1.

     Table 1--Provisional Global Warming Potentials for Fluorinated
 Greenhouse Gases for Which EPA Has Made Preliminary Determinations That
All Approval Criteria Have Been Met for the Purposes of the Calculations
                      in 98.123(c)(1) of Subpart L
------------------------------------------------------------------------
         Fluorinated GHG                CAS No.         Provisional GWP
------------------------------------------------------------------------
HFC-1234ze.......................         29118-24-9                6
Hexafluoropropylene (HFP)........           116-15-4                0.25
Perfluoromethyl vinyl ether                1187-93-5                3
 (PMVE)..........................
Tetrafluoroethylene (TFE)........           116-14-3                0.02
Trifluoro propene (TFP)..........           677-21-4                3
Vinyl fluoride (VF)..............            75-02-5                0.7
Vinylidine fluoride (VF2)........            75-38-7                0.9
------------------------------------------------------------------------

    EPA will review public comment on this notice prior to taking final
action on its preliminary determinations. The final determinations will
be placed in the docket for this action.

    Dated: January 27, 2012.
Sarah Dunham,
Director, Office of Atmospheric Programs.
[FR Doc. 2012-2442 Filed 2-2-12; 8:45 am]
BILLING CODE 6560-50-P


[Federal Register Volume 86, Number 198 (Monday, October 18, 2021)]
[Rules and Regulations]
[Pages 57574-57577]
[FR Doc No: 2021-22468]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0579; Project Identifier MCAI-2020-00267-R;
Amendment 39-21748; AD 2021-20-10]
RIN 2120-AA64

Airworthiness Directives; Leonardo S.p.a. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Leonardo S.p.a. Model AB139 and AW139 helicopters. This AD was
prompted by a report of several occurrences of a cracked main gearbox
(MGB) spherical bearing lock nut (lock nut). This AD requires removing
from service a certain part-numbered MGB lock nut that is installed on
certain part-numbered MGBs and replacing it with newly designed MGB
lock nut. This AD also prohibits installing any MGB with the affected
MGB lock nut and prohibits installing any affected MGB lock nut on any
helicopter. The FAA is issuing this AD to address the unsafe condition
on these products.

DATES: This AD is effective November 22, 2021.
    The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of November 22,
2021.

ADDRESSES: For service information identified in this final rule,
contact Leonardo S.p.A. Helicopters, Emanuele Bufano, Head of
Airworthiness, Viale G.Agusta 520, 21017 C.Costa di Samarate (Va)
Italy; telephone +39-0331-225074; fax +39-0331-229046; or at https://customerportal.leonardocompany.com/en-US/.
    You may view the referenced service information at the FAA, Office
of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room
6N-321, Fort Worth, TX 76177. For information on the availability of
this material at the FAA, call<PHONE_NUMBER>. Service information that
is incorporated by reference is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0579.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0579; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, the
European Union Aviation Safety Agency (EASA) AD, any comments received,
and other information. The street address for Docket Operations is U.S.
Department of Transportation, Docket Operations, M-30, West Building
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC
20590.

FOR FURTHER INFORMATION CONTACT: Rao Edupuganti, Aerospace Engineer,
Dynamic Systems Section, Technical Innovation Policy Branch, Policy &
Innovation Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177;
telephone<PHONE_NUMBER>; email [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Leonardo S.p.a. Model
AB139 and AW139 helicopters, without MGB lock nut part number (P/N)
3G6320A09152 installed and with MGB P/N 3G6320A00131, 3G6320A00132,
3G6320A00133, 3G6320A00134, 3G6320A00135, 3G6320A00136, 3G6320A22031,
4G6320A00132, or 4G6320A00133 installed; or MGB P/N 3G320A00133 with
serial number (S/N) M23, or MGB P/N 3G6320A00134, with S/N M6, N76,
N92, P124, P129, P131, P162, P184, Q230, Q243, Q249, R272, V21, V39,
V96, V163, V211, V241, V272, V281, V384, V386, or V622 installed; or
MGB P/N 3G6320A00136 with S/N AW1, AW2, AW3, AW5, or AW10 installed.
The NPRM published in the Federal Register on July 26, 2021 (86 FR
39984). In the NPRM, the FAA proposed to require within 100 hours time
in service (TIS) or during the next scheduled MGB overhaul, whichever
occurs first after the effective date of this AD, removing a certain
part-numbered MGB lock nut from service and replacing it with a
different part-numbered MGB lock nut. The NPRM also proposed to
prohibit installing an MGB having an affected MGB lock nut and also
prohibit installing an affected MGB lock nut on any helicopter as of
the effective date of the NPRM.
    The NPRM was prompted a series of EASA ADs beginning with EASA AD
2019-0036, dated February 15, 2019 (EASA AD 2019-0036), issued by EASA,
which is the Technical Agent for the Member States of the European
Union, to correct an unsafe condition for all serial-numbered Leonardo
S.p.a. Helicopters (formerly Finmeccanica S.p.A, AgustaWestland S.p.A.,
Agusta S.p.A.; and AgustaWestland Philadelphia Corporation, formerly
Agusta Aerospace Corporation) Model AB139 and AW139 helicopters. EASA
advised that an occurrence was reported of a cracked MGB lock nut P/N
3G6310A09151, which is used to keep the planetary gears in position.
EASA AD 2019-0036 required replacing each MGB lock nut with an
airworthy MGB lock nut. EASA advised this condition, if not detected
and corrected, could lead to failure of the MGB planetary gears,
resulting in loss of control of the helicopter.
    After EASA issued EASA AD 2019-0036, an additional occurrence was
reported of a cracked MGB lock nut P/N 3G6320A09151. Accordingly, EASA
superseded EASA AD 2019-0036 with EASA AD 2019-0174, dated July 18,
2019 (EASA AD 2019-0174), which retained the requirements of EASA AD
2019-0036 but reduced the compliance times. After EASA issued EASA AD
2019-0174, Leonardo Helicopters issued Alert Service Bulletin No. 139-
609, dated December 18, 2019 to provide instructions for replacing the
affected MGB lock nut with MGB lock nut P/N 3G6320A09152, which has a
redesigned flange reducing the stress at the bearing nut locations
where cracks were detected.
    Accordingly, EASA then issued EASA AD 2020-0011, dated January 29,
2020, and corrected January 30, 2020 (EASA AD 2020-0011), which
superseded EASA AD 2019-0174, and partially retained the requirements
of EASA AD 2019-0174. EASA AD 2020-0011 revised the compliance times in
EASA AD 2019-0174, required replacing each affected MGB lock nut with a
newly designed MGB lock nut, and prohibited installing an affected MGB
on any helicopter. After EASA issued EASA AD 2020-0011, EASA identified
certain MGB part numbers that were inadvertently categorized
incorrectly and therefore listed in the wrong group of helicopters.
Accordingly, EASA issued EASA AD 2020-0011R1, dated November 20, 2020
(EASA AD 2020-011R1), thereby revising EASA AD 2020-0011. EASA AD 2020-
0011R1 retains the requirements of EASA AD 2020-0011 and corrects
Appendix 1 of EASA AD 2020-0011.
    After EASA issued EASA AD 2020-0011R1, Leonardo Helicopters issued
Alert Service Bulletin No. 139-609, Revision A, dated April 13, 2021
(ASB 139-609 Rev A), which identifies an additional part-numbered MGB,
which is also affected by the unsafe condition. Accordingly, EASA
superseded EASA AD 2020-0011R1 with EASA AD 2021-0121, dated May 4,
2021 (EASA AD 2021-0121). EASA AD 2021-0121 adds an additional part-
numbered MGB with a certain S/N to the list of affected parts. EASA AD
2021-0121 retains the requirements of EASA AD 2020-0011R1, and corrects
Table 1 and Appendix 1 of EASA AD 2020-0011R1.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of
the costs.

Conclusion

    These helicopters have been approved by EASA and are approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Union, EASA has notified the FAA about the
unsafe condition described in its AD. The FAA reviewed the relevant
data and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed ASB 139-609 Rev A, which specifies procedures for
replacing an affected MGB lock nut with

the new MGB lock nut, within certain compliance times for certain part-
numbered MGBs with certain serial numbers.
    This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in the ADDRESSES section.

Other Related Service Information

    The FAA also reviewed Leonardo Helicopters ASB No. 139-567,
Revision B, dated October 18, 2019, which provides additional
information for replacing the MGB lock nut.

Differences Between This AD and EASA AD 2021-0121

    EASA AD 2021-0121 requires a compliance time based on number of
landings, whereas this AD requires a compliance time based on hours
TIS. The service information referenced in EASA AD 2021-0121 requires
submitting certain information and parts to Leonardo, whereas this AD
does not. EASA AD 2021-0121 applies to all serial-numbered Model AB139
and AW139 helicopters, whereas this AD only applies to Model AB139 and
AW139 helicopters without certain part-numbered MGB lock nuts installed
and with certain part-numbered MGBs installed.

Costs of Compliance

    The FAA estimates that this AD affects 130 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
this AD.
    Replacing each affected MGB lock nut with a newly designed MGB lock
nut takes about 190 work-hours (during next MGB overhaul) and parts
cost about $7,600 for an estimated cost of $23,750 per replacement.

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.
    The FAA is 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) Will not affect intrastate aviation in Alaska, 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.

List of Subjects in 14 CFR Part 39

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

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:

2021-20-10 Leonardo S.p.a.: Amendment 39-21748; Docket No. FAA-2021-
0579; Project Identifier MCAI-2020-00267.

(a) Effective Date

    This airworthiness directive (AD) is effective November 22,
2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Leonardo S.p.a. Model AB139 and AW139
helicopters, certificated in any category, without main gearbox
(MGB) spherical bearing lock nut (lock nut) part number (P/N)
3G6320A09152 installed and with:
    (1) MGB P/N 3G6320A00131, 3G6320A00132, 3G6320A00133,
3G6320A00134, 3G6320A00135, 3G6320A00136, 3G6320A22031,
4G6320A00132, or 4G6320A00133 installed, or
    (2) MGB P/N 3G320A00133 with serial number (S/N) M23, or MGB P/N
3G6320A00134, with S/N M6, N76, N92, P124, P129, P131, P162, P184,
Q230, Q243, Q249, R272, V21, V39, V96, V163, V211, V241, V272, V281,
V384, V386, or V622 installed, or
    (3) MGB P/N 3G6320A00136 with S/N AW1, AW2, AW3, AW5, or AW10
installed.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 6320, Main Rotor
Gearbox.

(e) Unsafe Condition

    This AD was prompted by a cracked MGB lock nut. The FAA is
issuing this AD to replace an affected MGB lock nut with a new MGB
lock nut. The unsafe condition, if not addressed, could result in
failure of the MGB planetary gears, resulting in loss of control of
the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Required Actions

    (1) Within 100 hours time-in-service, or during the next
scheduled MGB overhaul, whichever occurs first after the effective
date of this AD, remove each MGB lock nut P/N 3G6320A09151 from
service and replace with MGB lock nut P/N 3G6320A09152 in accordance
with Annex A, steps 1 through 17, of Leonardo Helicopters Alert
Service Bulletin No. 139-609, Revision A, dated April 13, 2021,
except you are not required to send parts to Leonardo Helicopters.
    Note to paragraph (g)(1): Leonardo Helicopters service
information refers to an MGB lock nut as a ring nut.
    (2) As of the effective date of this AD, do not install any MGB
having MGB lock nut P/N 3G630A09151 on any helicopter, and do not
install any MGB lock nut P/N 3G630A09151 on any helicopter.

(h) Special Flight Permits

    Special flight permits are prohibited.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation Branch, FAA, has the
authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the manager of the International Validation Branch, send
it to the attention of the person identified in paragraph (j)(1) of
this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.

(j) Related Information

    (1) For more information about this AD, contact Rao Edupuganti,
Aerospace Engineer, Dynamic Systems Section, Technical Innovation
Policy Branch, Policy & Innovation Division, FAA, 10101 Hillwood
Pkwy., Fort Worth, TX 76177; telephone<PHONE_NUMBER>; email
[email protected].
    (2) The subject of this AD is addressed in European Union
Aviation Safety Agency (EASA) AD 2021-0121, dated May 4, 2021. You
may view the EASA AD at https://www.regulations.gov in Docket No.
FAA-2021-0579.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the
incorporation by reference of the service information listed in this
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
    (i) Leonardo Helicopters Alert Service Bulletin No. 139-609,
Revision A, dated April 13, 2021.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact
Leonardo S.p.A. Helicopters, Emanuele Bufano, Head of Airworthiness,
Viale G. Agusta 520, 21017 C. Costa di Samarate (Va) Italy;
telephone +39-0331-225074; fax +39-0331-229046; or at https://customerportal.leonardocompany.com/en-US/.
    (4) You may view this service information at the FAA, Office of
the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room
6N-321, Fort Worth, TX 76177. For information on the availability of
this material at the FAA, call<PHONE_NUMBER>.
    (5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on September 16, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-22468 Filed 10-15-21; 8:45 am]
BILLING CODE 4910-13-P