DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1297; Project Identifier MCAI-2022-00736-R]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Airbus Helicopters Model EC225LP helicopters. This proposed AD
was prompted by a report of water in the oil of a main gearbox (MGB).
This AD requires replacing certain main rotor (M/R) mast upper stops
assembly screws. This proposed AD would also require inspecting certain
M/R mast cover plates and accomplishing MGB oil analyses and, depending on the
results, replacing the M/R mast cover plate, accomplishing an
additional inspection, or replacing the MGB. This proposed AD would
also prohibit installing certain M/R mast upper stops assembly screws,
M/R masts with an affected M/R mast upper stops assembly screw
installed, or used M/R mast cover plates on any helicopter. Lastly,
this proposed AD would prohibit installing affected M/R masts unless
the inspections are done. These actions are specified in a European
Union Aviation Safety Agency (EASA) AD, which is proposed for
incorporation by reference. 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 July 1,
2024.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to 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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1297; 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, any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For EASA material, contact EASA, Konrad-Adenauer-Ufer 3,
50668 Cologne, Germany; telephone +49 221 8999 000; email
ADs@easa.europa.eu; internet easa.europa.eu. You may find the EASA
material on the EASA website at ad.easa.europa.eu.
You may view this material 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. It is also available at
regulations.gov under Docket No. FAA-2024-1297.
Other Related Service Information: For Airbus Helicopters service
information identified in this NPRM, contact Airbus Helicopters, 2701
North Forum Drive, Grand Prairie, TX 75052; phone (972) 641-0000 or
(800) 232-0323; fax (972) 641-3775; or at airbus.com/en/products-services/helicopters/hcare-services/airbusworld. You may also view this
service information at the FAA contact information under Material
Incorporated by Reference above.

FOR FURTHER INFORMATION CONTACT: Dan McCully, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone (404)
474-5548; email william.mccully@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-2024-1297; Project Identifier
MCAI-2022-00736-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
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 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 Dan
McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone (404) 474-5548; email
william.mccully@faa.gov. Any commentary that the FAA receives that 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, has issued EASA AD 2022-0104, dated June 9, 2022 (EASA
AD 2022-0104), to correct an unsafe condition on Airbus Helicopters
Model EC 225 LP helicopters.
This proposed AD was prompted by a report of water in the oil of an
MGB, due to an incorrect installation of the upper M/R mast cover
plate. According to Airbus Helicopters, a detailed inspection of the
MGB showed corrosion on the M/R mast and inside the MGB. The upper M/R
mast cover plate was deformed. Also, according to Airbus Helicopters, a
different M/R mast had damaged upper stop screws installed, also due to
an incorrect installation. The FAA is issuing this proposed AD to
prevent water in the MGB oil. The unsafe condition, if not addressed,
could result in corrosion of the M/R mast and inside the MGB,
degradation of the MGB, degradation of the upper stops assembly,
failure of a critical part, and subsequent loss of control of the
helicopter.
You may examine EASA AD 2022-0104 in the AD docket at
regulations.gov under Docket No. FAA-2024-1297.

Related Service Information Under 1 CFR Part 51

EASA AD 2022-0104 requires replacing each M/R mast upper stops
assembly screw, except those marked with ``BC'' on the screw head. For
certain helicopters, EASA AD 2022-0104 requires inspecting a certain
part-numbered M/R mast cover plate and depending on the results,
replacing the cover plate and accomplishing an additional inspection.
For those same certain helicopters, EASA AD 2022-0104 also requires
accomplishing MGB oil analyses and, depending on the results,
accomplishing an additional inspection. Depending on the results of the
additional inspection following the M/R mast cover plate inspection or
MGB oil analyses, EASA AD 2022-0104 requires replacing the MGB. As an
option, EASA AD 2022-0104 allows replacing the MGB as an acceptable
alternative method to comply with the required MGB oil sample analyses.
Lastly, EASA AD 2022-0104 prohibits installing M/R mast upper stops
assembly screws--except those marked
with ``BC'' on the screw head, M/R masts with an affected M/R mast
upper stops assembly screw installed, and used M/R mast cover plates on
any helicopter. EASA AD 2022-0104 also prohibits installing an affected
M/R mast unless its required inspections are done.
This material 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 Airbus Helicopters No. EC225-62A016, Revision
1, dated February 28, 2023. This service information specifies
procedures for inspecting the M/R mast upper stops assembly screws to
determine if they're marked with ``BC'' on the screw head and depending
on the results, replacing those screws one by one. This service
information also specifies procedures for checking the flatness of the
M/R mast cover plate and, depending on the results, removing and
discarding that cover plate, installing a flat cover plate, draining
the MGB, writing to Airbus Helicopters to do a detailed MGB inspection,
and removing the M/R mast. Depending on the detailed MGB inspection
results, this service information specifies filling the MGB with oil
and installing the M/R mast; or replacing the MGB with an airworthy
MGB, sending the removed MGB to an approved D-level center for repair,
and installing the M/R mast.
This service information also specifies procedures for collecting
an MGB oil sample and sending the sample to an Airbus Helicopters
approved laboratory for water content analysis. Depending on the
analysis results, this service information specifies draining the MGB,
writing to Airbus Helicopters to do a detailed MGB inspection, and
removing the M/R mast. Depending on the detailed MGB inspection
results, this service information specifies filling the MGB with oil
and installing the M/R mast; or replacing the MGB with an airworthy
MGB, sending the removed MGB to an approved D-level center for repair,
and installing the M/R mast.

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
the unsafe condition described previously is likely to exist or develop
on other helicopters of the same type design.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified
in EASA AD 2022-0104, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this proposed AD and except as discussed under
``Differences Between this Proposed AD and the EASA AD.''

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result, the
FAA proposes to incorporate EASA AD 2022-0104 by reference in the FAA
final rule. This proposed AD would, therefore, require compliance with
EASA AD 2022-0104 in its entirety through that incorporation, except
for any differences identified as exceptions in the regulatory text of
this proposed AD. Using common terms that are the same as the heading
of a particular section in EASA AD 2022-0104 does not mean that
operators need comply only with that section. For example, where the AD
requirement refers to ``all required actions and compliance times,''
compliance with this AD requirement is not limited to the section
titled ``Required Action(s) and Compliance Time(s)'' in EASA AD 2022-
0104. Service information referenced in EASA AD 2022-0104 for
compliance will be available at regulations.gov under Docket No. FAA-
2024-1297 after the FAA final rule is published.

Differences Between This Proposed AD and the EASA AD

For certain helicopters, EASA AD 2022-0104 specifies sending oil
samples to an Airbus Helicopters approved laboratory for an analysis of
the water content, whereas this proposed AD would require sending the
main gearbox oil sample for water content analysis. Additionally, for
those helicopters, EASA AD 2022-0104 specifies taking and analyzing the
second MGB oil sample within 110 FH or 3 months after the initial oil
sample, whereas this proposed AD would require collecting the second
main gearbox oil sample and sending it for water content analysis
within 110 hours time-in-service or 3 months after accomplishing the
initial instance of those actions, whichever occurs later. Depending on
the results of the cover plate inspection or an oil sample analysis,
EASA AD 2022-0104 specifies contacting Airbus Helicopters to request to
accomplish a detailed inspection, which shall be accomplished by
authorized Airbus Helicopters staff and the Airbus Helicopters
qualified staff identify any discrepancies, whereas this proposed AD
would require a detailed inspection, which must define what is
considered a discrepancy and be done in accordance with a method
approved by the FAA, EASA, or Airbus Helicopters' EASA Design
Organization Approval.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 32 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 the M/R mast upper stops assembly screws (up to 10
screws) would take up to approximately 0.5 work-hour and parts would
cost up to approximately $250 (for 10 screws) for an estimated cost of
up to $293 per helicopter and $9,376 for the U.S. fleet.
For certain helicopters, inspecting the M/R mast cover plate would
take approximately 0.5 work-hour for an estimated cost of $43 per
helicopter and up to $1,376 for the U.S. fleet. Collecting an MGB oil
sample and sending the MGB oil sample for water content analysis, which
is considered a reporting requirement in this proposed AD, would take
approximately 1.5 work-hours (0.5 work-hour for collecting and 1 work-
hour for sending) for an estimated cost of $128 per helicopter and up
to $4,096 for the U.S. fleet, per instance.
If required, replacing the M/R mast cover plate would take
approximately 2 work-hours and parts would cost approximately $276 for
an estimated cost of $446 per helicopter. The detailed inspection that
may be needed could vary significantly from helicopter to helicopter.
The FAA has no data to determine the costs to accomplish the detailed
inspection or the number of helicopters that may need it. Replacing an
MGB would take approximately 40 work-hours and parts would cost
approximately $998,595 (overhauled) for an estimated cost of $1,001,995
per helicopter.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a current valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to take
approximately 1.5 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.

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 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 above, 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

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. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: