DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0095; Project Identifier MCAI-2020-01658-R;
Amendment 39-21439; AD 2021-04-17]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2,
AS350D, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This
AD was prompted by two reports of debonding of the tail rotor (T/R)
blade leading edge protection shields. This AD requires repetitively
inspecting certain T/R blades and depending on the inspection results,
replacing the T/R blade, as specified in a European Union Aviation
Safety Agency (EASA) AD, which is incorporated by reference (IBR). This
AD also prohibits installing certain T/R blades. The FAA is issuing
this AD to address the unsafe condition on these products.

DATES: This AD becomes effective March 23, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 23,
2021.
The FAA must receive comments on this AD by April 22, 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 IBR material in this AD, contact the EASA, Konrad-Adenauer-Ufer
3, 50668 Cologne, Germany; telephone +49 221 8999 000; email
ADs@easa.europa.eu; internet www.easa.europa.eu. You may find this
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-2021-0095.

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-
0095; 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 AD, 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: Kristi Bradley, Aviation Safety
Engineer, General Aviation & Rotorcraft Section, International
Validation Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177;
telephone (817) 222-5110; email kristin.bradley@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2020-0224R1, dated November 11, 2020
(EASA AD 2020-0224R1), to correct an unsafe condition for all Airbus
Helicopters Model AS 350 B, AS 350 BA, AS 350 BB, AS 350 B1, AS350 B2,
AS 350 D, AS 355 E, AS 355 F, AS 355 F1, AS 355 F2, and AS 355 N
helicopters. EASA AD 2020-0224R1 revises EASA AD 2020-0224-E, dated
October 16, 2020, to expand the list of serviceable parts (post-mod
075580).
This AD was prompted by two reports of large debonding of the T/R
blade leading edge protection shields. According to EASA, the design
and assembly procedure of the affected part (pre-mod 075580) is such
that rapid debonding can occur if humidity/liquid water reaches the
bonding surface between the leading edge and blade spar. The FAA is
issuing this AD to prevent failure of the T/R blade, which could result
in loss of tail rotor control and subsequent loss of control of the
helicopter. See the EASA AD for additional background information.

Related IBR Material Under 1 CFR Part 51

EASA AD 2020-0224R1 specifies repetitively visually inspecting each
T/R blade leading edge protection shield and repetitively tap
inspecting each T/R blade leading edge. EASA AD 2020-0224R1 also
prohibits the installation of an affected part and specifies a longer-
term modification to replace each affected part with a serviceable
part. EASA AD 2020-0224R1 states that replacing all affected parts with
serviceable parts on a helicopter constitutes terminating action for
the repetitive visual and tap inspections.
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

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 these same type designs.

Requirements of This AD

This AD requires accomplishing the actions specified in EASA AD
2020-0224R1, described previously, as incorporated by reference, except
for any differences identified as exceptions in the regulatory text of
this AD and except as discussed under ``Differences Between this AD and
the EASA AD.'' Additionally, the owner/operator (pilot) may perform the
required visual checks but must enter compliance with the applicable
paragraph of this AD in the helicopter maintenance records in
accordance with 14 CFR 43.9(a)(1) through (4) and 91.417(a)(2)(v). A
pilot may perform these checks because they only involve visually
checking affected T/R blade leading edge protection shields and bonding
strips. This action can be performed equally well by a pilot or a
mechanic. This check is an exception to the FAA's standard maintenance
regulations.

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 (CAAs) to use this process. As a result, EASA AD 2020-
0224R1 will be incorporated by reference in the FAA final rule. This AD
would, therefore, require compliance with EASA AD 2020-0224R1 in its
entirety, through that incorporation, except for any differences
identified as exceptions in the regulatory text of this 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
2020-0224R1 that is required for compliance with EASA AD 2020-0224R1 is
available on the internet at https://www.regulations.gov by searching
for and locating Docket No. FAA-2021-0095.

Differences Between This AD and the EASA AD

The EASA AD applies to all Model AS 350 B, AS 350 BA, AS 350 BB, AS
350 B1, AS350 B2, AS 350 D, AS 355 E, AS 355 F, AS 355 F1, AS 355 F2,
and AS 355 N helicopters, whereas this AD applies to Model AS350B,
AS350BA, AS350B1, AS350B2, AS350D, AS355E, AS355F, AS355F1, AS355F2,
and AS355N helicopters with certain part-numbered T/R blades installed
instead. This AD does not apply to Model AS 350 BB because this model
is not FAA type-certificated. The EASA AD requires visually inspecting
each T/R blade leading edge protection shield. This AD requires
visually checking each T/R blade leading edge protection shield and
bonding strip instead and allows a pilot to accomplish these visual
checks. The EASA AD requires a longer-term modification of replacing
each affected part with a serviceable part, whereas this AD does not.
The FAA plans to publish a notice of proposed rulemaking to give the
public an opportunity to comment on this longer-term requirement.

FAA's Justification and Determination of the Effective Date

Section 553(b)(3)(B) of the Administrative Procedure Act (5 U.S.C.)
authorizes agencies to dispense with notice and comment procedures for
rules when the agency, for ``good cause'' finds that those procedures
are ``impracticable, unnecessary, or contrary to the public interest.''
Under this section, an agency, upon finding good cause, may issue a
final rule without seeking comment prior to the rulemaking.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies waiving notice and comment prior to adoption of this rule
because the visual repetitive checks must be done before each flight
and the initial instance of the repetitive tap inspections must be done
within 30 hours time-in-service, a time period of up to about 1.5
months based on the average flight-hour utilization rate of these
helicopters. Accordingly, the compliance time for the required actions
is shorter than the time necessary for the public to comment and for
publication of the final rule. Therefore, notice and opportunity for
prior public comment are impracticable and contrary to public interest
pursuant to 5 U.S.C. 553(b)(3)(B). In addition, for the reasons stated
above, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d)
for making this amendment effective in less than 30 days.

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this AD. Send your comments to an address listed under
ADDRESSES. Include ``Docket No. FAA-2021-0095; Project Identifier MCAI-
2020-01658-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the AD, 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
AD 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 AD.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Kristi
Bradley, Aviation Safety Engineer, General Aviation & Rotorcraft
Section, International Validation Branch, FAA, 10101 Hillwood Pkwy.,
Fort Worth, TX 76177; telephone (817) 222-5110; email
kristin.bradley@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.

Regulatory Flexibility Act (RFA)

The requirements of the RFA do not apply when an agency finds good
cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and
comment. Because the FAA has determined that it has good cause to adopt
this rule without notice and comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 450 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.
Visually checking the T/R blades takes about 0.25 work-hour for an
estimated cost of $21 per helicopter and $9,450 for the U.S. fleet, per
inspection cycle. Tap inspecting the T/R blades takes about 0.5 work-
hour for an estimated cost of $43 per helicopter and $19,350 for the
U.S. fleet, per inspection cycle. Replacing a T/R blade takes about 12
work-hours and parts cost about $10,000 for an estimated cost of
$11,020 per T/R blade.

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 AD would not have federalism
implications under Executive Order 13132. This 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 regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866, and
(2) Will not affect intrastate aviation in Alaska.

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

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: