DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0829; Project Identifier MCAI-2021-00189-R]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2021-04-21, which applies to certain Airbus Helicopters Model EC120B
helicopters. AD 2021-04-21 requires an inspection of the attachment
bolts of the main rotor (MR) hub scissors assembly for discrepancies
and repair if necessary; part marking of the attachment bolts of the MR
hub scissors assembly; and repetitive inspections of the part marking
of the attachment bolts, and repair if necessary. Since the FAA issued
AD 2021-04-21, the FAA has determined that additional part marking of
the washer, scissor branch, and mast ring of the corresponding nut
side, and repetitive inspections of the additional part markings are
necessary. This proposed AD would continue to require the actions in AD
2021-04-21; and also would require part marking of the washer, scissor
branch, and mast ring of the corresponding nut side, and repetitive
inspections of the additional part markings and repair if necessary; as
specified in a European Union Aviation Safety Agency (EASA) AD, which
is proposed for incorporation by reference (IBR). 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 November 8,
2021.

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 https://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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For material that is proposed for IBR in this AD, contact the EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999
000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu. You may
find this IBR material on the EASA website at https://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 in the AD docket on the internet at https:
//www.regulations.gov by searching for and locating Docket No. FAA-2021-
0829.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2021-0829;
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. Comments will be
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Hal Jensen, Aerospace Engineer,
Operational Safety Branch, Compliance & Airworthiness Division, FAA,
950 L'Enfant Plaza N SW, Washington, DC 20024; phone: (202) 267-9167;
email: hal.jensen@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-2021-0829; Project Identifier
MCAI-2021-00189-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
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this proposal.

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 Hal
Jensen, Aerospace Engineer, Operational Safety Branch, Compliance &
Airworthiness Division, FAA, 950 L'Enfant Plaza N SW, Washington, DC
20024; phone: (202) 267-9167; email: hal.jensen@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

The FAA issued AD 2021-04-21, Amendment 39-21443 (86 FR 17278,
April 2, 2021) (AD 2021-04-21), which applies to certain Airbus
Helicopters Model EC120B helicopters. AD 2021-04-21 requires an
inspection of the attachment bolts of the MR hub scissors
assembly for discrepancies and repair if necessary; part marking of the
attachment bolts of the MR hub scissors assembly; and repetitive
inspections of the part marking of the attachment bolts, and repair if
necessary. The FAA issued AD 2021-04-21 to address broken and bent
attachment bolts of the MR hub scissors assembly, which could lead to
detachment of a MR hub scissors attachment bolt, possibly resulting in
complete loss of control of the helicopter.

Actions Since AD 2021-04-21 Was Issued

Since the FAA issued AD 2021-04-21, the FAA has determined that
additional part marking of the washer, scissor branch, and mast ring of
the corresponding nut side, and repetitive inspections of the
additional part markings are necessary to detect rotation of the
attachment bolts of the MR hub scissors assembly.

The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2021-0046, dated February 12, 2021
(EASA AD 2021-0046) (also referred to as the Mandatory Continuing
Airworthiness Information, or the MCAI), to correct an unsafe condition
for all Airbus Helicopters Model EC120B helicopters. Although EASA AD
2021-0046 applies to all Model EC120B helicopters, this proposed AD
would apply to helicopters with an affected part installed instead.

This proposed AD was prompted by a report of broken and bent
attachment bolts of the MR hub scissors assembly and a determination
that additional part markings of the washer, scissor branch, and mast
ring of the corresponding nut side, and repetitive inspections of the
additional part markings are necessary. The FAA is proposing this AD to
address broken and bent attachment bolts of the MR hub scissors
assembly, which could lead to detachment of a MR hub scissors
attachment bolt, possibly resulting in complete loss of control of the
helicopter. See the MCAI for additional background information.

Related Service Information Under 1 CFR Part 51

EASA AD 2021-0046 specifies procedures for an inspection of the
attachment bolts of the MR hub scissors assembly for discrepancies
(discrepancies include corrosion, fretting, wear, cracking, bolt play,
and bolt tightening torque) and repair if necessary; part marking of
the washer, scissor branch, and mast ring of the attachment bolts and
corresponding nut side of the MR hub scissors assembly; and repetitive
inspections, after part marking, for discrepancies, and repair if
necessary. The inspections of the attachment bolts of the MR hub
assembly include checking the play and torque of the scissors
attachment bolts and making sure that there are no hard spots in the
scissors link hinge.
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.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the bilateral agreement with the State of Design Authority, the FAA
has been notified of the unsafe condition described in the MCAI
referenced above. The FAA is proposing this AD after evaluating all the
relevant information and determining the unsafe condition described
previously is likely to exist or develop in other products of the same
type design.

Explanation of Retained Requirements

Although this proposed AD does not explicitly restate the
requirements of AD 2021-04-21, this proposed AD would retain all of the
requirements of AD 2021-04-21. Those requirements are referenced in
EASA AD 2021-0046, which, in turn, is referenced in paragraph (g) of
this proposed AD.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified
in EASA AD 2021-0046 described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this AD.

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA initially worked with Airbus and EASA to develop a
process to use certain EASA ADs as the primary source of information
for compliance with requirements for corresponding FAA ADs. The FAA has
since coordinated with other manufacturers and civil aviation
authorities to use this process. As a result, EASA AD 2021-0046 will be
incorporated by reference in the FAA final rule. This proposed AD
would, therefore, require compliance with EASA AD 2021-0046 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 the EASA AD 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 the EASA AD. Service information specified
in EASA AD 2021-0046 that is required for compliance with EASA AD 2021-
0046 will be available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0829 after the FAA
final rule is published.

Costs of Compliance

The FAA estimates that this proposed AD affects 89 helicopters of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

Estimated Costs for Required Actions

The FAA estimates that it would take about 1 hour per product to
comply with the proposed reporting requirement in this proposed AD. The
average labor rate is $85 per hour. Based on these figures, the FAA
estimates the cost of reporting on U.S. operators to be $7,565, or $85
per product.

The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of any
required actions. The FAA has no way of determining the number of
helicopters that might need these on-condition actions:

On-Condition Costs

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 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 control
number for the collection of information required by this proposed AD
is 2120-0056. The paperwork cost associated with this proposed AD has
been detailed in the Costs of Compliance section of this document and
includes time for reviewing instructions, as well as completing and
reviewing the collection of information. Therefore, all reporting
associated with this proposed AD is mandatory. Comments concerning the
accuracy of this burden and suggestions for reducing the burden should
be directed to Information Collection Clearance Officer, Federal
Aviation Administration, 10101 Hillwood Pkwy., 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:

a. Removing Airworthiness Directive (AD) 2021-04-21, Amendment 39-21443
(86 FR 17278, April 2, 2021); and

b. Adding the following new AD: