[Federal Register Volume 87, Number 247 (Tuesday, December 27, 2022)]
[Rules and Regulations]
[Pages 79232-79235]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-28090]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0465; Project Identifier AD-2022-00330-R; 
Amendment 39-22288; AD 2022-27-03]
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 superseding Airworthiness Directive (AD) 2021-20-10 
for certain Leonardo S.p.a. Model AB139 and AW139 helicopters. AD 2021-
20-10 required removing from service a certain part-numbered main 
gearbox (MGB) spherical bearing lock nut (lock nut) that is installed 
on certain part-numbered MGBs and replacing it with a newly designed 
MGB lock nut. AD 2021-20-10 also prohibited installing any MGB with the 
affected MGB lock nut and prohibited installing any affected MGB lock 
nut on any helicopter. Since the FAA issued AD 2021-20-10, it was 
discovered that a part number (P/N) was incorrectly listed and that the 
applicability needed to be clarified. This AD retains the requirements 
of AD 2021-20-10 and clarifies the applicability. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective January 31, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 22, 
2021 (86 FR 57574, October 18, 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 
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. Service information that is incorporated by reference is also 
available at regulations.gov by searching for and locating Docket No. 
FAA-2022-0465.

Examining the AD Docket

    You may examine the AD docket at regulations.govby searching for 
and locating Docket No. FAA-2022-0465; 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, any comments 
received, and other information. The 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: Kristi Bradley, Program Manager, COS 
Program Management Section, Operational Safety Branch, Compliance & 
Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 
76177; telephone (817) 222-5110; email [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2021-20-10, Amendment 39-21748 (86 FR 
57574, October 18, 2021) (AD 2021-20-10). AD 2021-20-10 applied to 
Leonardo S.p.a. Model AB139 and AW139 helicopters, without MGB lock nut 
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 installed, 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.
    AD 2021-20-10 required, within 100 hours time-in-service (TIS), or 
during the next scheduled MGB overhaul, whichever occurs first after 
the effective

[[Page 79233]]

date of the AD, removing a certain part-numbered MGB lock nut from 
service and replacing it with a different part-numbered MGB lock nut. 
AD 2021-20-10 also prohibited installing an MGB having an affected MGB 
lock nut on any helicopter and also prohibited installing an affected 
MGB lock nut on any helicopter as of the effective date of the AD.
    AD 2021-20-10 was prompted by 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 retained the requirements of EASA AD 2020-0011 and corrected 
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, 
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.
    Accordingly, EASA AD 2021-0121 requires replacing each affected MGB 
lock nut with a newly designed MGB lock nut, and prohibits installing 
an affected MGB on any helicopter.
    The NPRM published in the Federal Register on April 20, 2022 (87 FR 
23477). The NPRM was prompted by the discovery that MGB P/N 
3G6320A00133 was incorrectly listed as MGB P/N 3G320A00133 in both the 
preamble and applicability paragraph of AD 2021-20-10. Also, the FAA 
determined that all MGBs, regardless of S/N, are affected by the unsafe 
condition. Therefore, the NPRM proposed to remove any reference to S/Ns 
in the applicability. In addition, the NPRM included the total U.S. 
fleet costs, which were inadvertently excluded in AD 2021-20-10. In the 
NPRM, the FAA also proposed to retain all of the requirements of AD 
2021-20-10.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from three commenters. The commenters 
were Leonardo Helicopters, Bristow Group, and Chevron Aviation. All 
commenters requested a change to the compliance time and two made a 
statement concerning who can perform the service task. The following 
presents the comments received on the NPRM and the FAA's response to 
each comment.

Requests To Change the Compliance Time To Upgrade the MGB Lock Nuts

    All commenters referred to an FAA-approved global Alternative 
Method of Compliance (AMOC) to AD 2021-20-10 and two commenters 
requested that the FAA change the proposed AD's compliance time to 
align with the global AMOC. The other commenter specifically requested 
that the compliance time approved in the global AMOC of 28,000 landings 
or during the next scheduled MGB overhaul be incorporated into the 
compliance time of the proposed AD.
    The FAA agrees; however, instead of revising the Required Actions 
paragraph, the FAA has revised the AMOC paragraph by allowing the AMOC 
previously approved for AD 2021-20-10 as an approved AMOC for the 
corresponding requirements in paragraph (g) of this AD.

Required Actions

    Two commenters noted that replacing the lock nut can only be 
performed by Leonardo at the overhaul level, but requested no change to 
the required actions of the proposed AD; the FAA, therefore, made no 
changes in this regard.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting the AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, 
including correcting a part number in paragraph (g)(2) of the required 
actions, and any other changes described previously, this AD is adopted 
as proposed in the NPRM. None of the changes will increase the economic 
burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Leonardo Helicopters Alert Service Bulletin No. 
139-609, Revision A, dated April 13, 2021, which the Director of the 
Federal Register approved for incorporation by reference as of November 
22, 2021 (86 FR 57574, October 18, 2021).
    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 Alert Service Bulletin 
No. 139-567, Revision B, dated October 18, 2019, which provides 
additional

[[Page 79234]]

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 applies to all Model AB139 and 
AW139 helicopters, regardless of S/N, with a certain part-numbered MGB 
lock nut and MGB 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 helicopter and 
$3,087,500 for the U.S. fleet.

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 products identified in this rulemaking action.

Regulatory Findings

    The FAA has determined that 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:
0
a. Removing Airworthiness Directive 2021-20-10, Amendment 39-21748 (86 
FR 57574, October 18, 2021); and
0
b. Adding the following new airworthiness directive:

2022-27-03 Leonardo S.p.a.: Amendment 39-22288; Docket No. FAA-2022-
0465; Project Identifier AD-2022-00330-R.

(a) Effective Date

    This airworthiness directive (AD) is effective January 31, 2023.

(b) Affected ADs

    This AD replaces AD 2021-20-10, Amendment 39-21748 (86 FR 57574, 
October 18, 2021) (AD 2021-20-10).

(c) Applicability

    This AD applies to Leonardo S.p.a. Model AB139 and AW139 
helicopters, certificated in any category, with a main rotor gearbox 
(MGB) part number (P/N) 3G6320A00131, 3G6320A00132, 3G6320A00133, 
3G6320A00134, 3G6320A00135, 3G6320A00136, 3G6320A22031, 
4G6320A00132, or 4G6320A00133, and MGB spherical bearing lock nut 
(lock nut) P/N 3G6320A09151 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 November 22, 
2021 (the effective date of AD 2021-20-10), 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 1 to paragraph (g)(1): Leonardo Helicopters service 
information refers to an MGB lock nut as a ring nut.
    (2) As of November 22, 2021 (the effective date of AD 2021-20-
10), do not install any MGB having MGB lock nut P/N 3G6320A09151 on 
any helicopter, and do not install any MGB lock nut P/N 3G6320A09151 
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)(2) 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.
    (3) AMOCs approved previously for AD 2021-20-10 are approved as 
AMOCs for the corresponding requirements in paragraph (g) of this 
AD.

(j) Related Information

    (1) Refer to EASA AD 2021-0121, dated May 4, 2021, for related 
information. This EASA AD may be found in the AD docket at 
regulations.gov under Docket No. FAA-2022-0465.
    (2) For more information about this AD, contact Kristi Bradley, 
Program Manager, COS Program Management Section, Operational Safety 
Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood 
Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email 
[email protected].

[[Page 79235]]

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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.
    (3) The following service information was approved for IBR on 
November 22, 2021 (86 FR 57574, October 18, 2021).
    (i) Leonardo Helicopters Alert Service Bulletin No. 139-609, 
Revision A, dated April 13, 2021.
    (ii) [Reserved]
    (4) 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 
customerportal.leonardocompany.com/en-US/.
    (5) You may view this service information at 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.
    (6) 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: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on December 20, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-28090 Filed 12-23-22; 8:45 am]
BILLING CODE 4910-13-P


