[Federal Register Volume 86, Number 140 (Monday, July 26, 2021)]
[Proposed Rules]
[Pages 39984-39986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-15722]


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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]
RIN 2120-AA64


Airworthiness Directives; Leonardo S.p.a. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Leonardo S.p.a. (Leonardo) Model AB139 and AW139 
helicopters. This proposed AD was prompted by a report of several 
occurrences of a cracked main gearbox (MGB) spherical bearing lock nut 
(lock nut). This proposed AD would require 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 
proposed AD would also would prohibit installing any MGB with the 
affected MGB lock nut and would prohibit installing any affected MGB 
lock nut on any helicopter. The FAA is proposing this AD to address the 
unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by September 
9, 2021.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     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 20590-0001.
     Hand Delivery: Deliver to the Mail address between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, 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 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 (817) 
222-5110.

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 NPRM, the European 
Union Aviation Safety Agency (EASA) AD, any comments received, and 
other information. The street address for Docket Operations is listed 
above.

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 (817) 222-5110; email rao.edupuganti@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2021-0579; Project Identifier 
MCAI-2020-00267-R'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
http://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI

[[Page 39985]]

as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Rao 
Edupuganti, Aerospace Engineer, Dynamic Systems Section, Technical 
Innovation Policy Branch, Policy & Innovation Division, FAA, 10101 
Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email 
rao.edupuganti@faa.gov. Any commentary that the FAA receives which is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Background

    EASA, which is the Technical Agent for the Member States of the 
European Union, issued EASA AD 2019-0036, dated February 15, 2019 (EASA 
AD 2019-0036), 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 advises that an occurrence was reported of a 
cracked MGB lock nut part number (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 (ASB) 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 
that certain MGB part numbers 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), 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 
ASB 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.

FAA's Determination

    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 is proposing this AD 
after evaluating all known relevant information and determining that an 
unsafe condition is likely to exist or develop on other helicopters of 
the same type designs.

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.

Proposed AD Requirements

    This proposed AD would 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 new part-numbered MGB 
lock nut. This proposed AD would 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 proposed AD.

Differences Between This Proposed AD and the EASA AD

    EASA AD 2021-0121 requires a compliance time based on number of 
landings, whereas this proposed AD would require 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 proposed AD would not. EASA AD 2021-0121 applies to all 
serial-numbered Model AB139 and AW139 helicopters, whereas this 
proposed AD would only apply 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, if adopted as proposed, would 
affect 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 proposed AD.
    Replacing each affected MGB lock nut with a newly designed MGB lock 
nut would take about 190 work-hours (during next MGB overhaul) and 
parts would 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

[[Page 39986]]

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.

Regulatory Findings

    The FAA 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. Would not affect intrastate aviation in Alaska, and
    3. Would 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 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

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:

Leonardo S.p.a.: Docket No. FAA-2021-0579; Project Identifier MCAI-
2020-00267-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by September 9, 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 (ASB 
139-609, Rev A), 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: 9-AVS-AIR-730-AMOC@faa.gov.
    (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 (817) 222-5110; email 
rao.edupuganti@faa.gov.
    (2) 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/. You may view this 
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 (817) 222-5110.
    (3) 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 on the internet at https://www.regulations.gov 
in Docket No. FAA-2021-0579.

    Issued on July 20, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-15722 Filed 7-23-21; 8:45 am]
BILLING CODE 4910-13-P


