DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0453; Project Identifier MCAI-2021-00377-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 supersede Airworthiness Directive (AD)
2021-04-15, which applies to all Airbus Helicopters Model AS355E,
AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters; and certain
Model AS350B3 helicopters. AD 2021-04-15 requires repetitive visual
inspections of the right-hand side of the vertical fin spar for
discrepancies (cracking), and corrective action if necessary. Since the
FAA issued AD 2021-04-15, the FAA has determined that additional
actions are required to address the unsafe condition. This proposed AD
would retain the requirements of AD 2021-04-15, and would require
repetitive cleaning and repetitive detailed inspections for cracking of
the vertical fin spar and vertical fin upper attachments, and
corrective action if necessary, as specified in a European Union
Aviation Safety Agency (EASA) AD, which is proposed for incorporation
by reference (IBR). This proposed AD would also expand the
applicability to include additional Model AS350B3 helicopters. 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 23,
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; telephone +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-
0453.

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-2021-0453;
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: Kathleen Arrigotti, Program Manager,
Large Aircraft Section, International Validation Branch, Compliance &
Airworthiness Division, FAA, 2200 South 216th St., Des Moines, WA
98198; telephone and fax 206-231-3218; email
kathleen.arrigotti@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-2021-0453; Project Identifier
MCAI-2021-00377-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
Kathleen Arrigotti, Program Manager, Large Aircraft Section,
International Validation Branch, Compliance & Airworthiness Division,
FAA, 2200 South 216th St., Des Moines, WA 98198; telephone and fax 206-
231-3218; email kathleen.arrigotti@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 2021-04-15, Amendment 39-21437 (86 FR 13165,
March 8, 2021) (AD 2021-04-15), which applies to all Airbus Helicopters
Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters;
and certain Model AS350B3 helicopters.

AD 2021-04-15 requires repetitive visual inspections of the right-hand
side of the vertical fin spar for cracking, and corrective action if
necessary. The FAA issued AD 2021-04-15 to address cracking in the spar
of the upper part of the vertical fin and fractures in the front
attachment screws. This condition could lead to in-flight separation of
the upper part of the vertical fin, resulting in loss of control of the
helicopter.

Actions Since AD 2021-04-15 Was Issued

The preamble to AD 2021-04-15 explains that the FAA was considering
further rulemaking to address the actions specified in paragraph (2) of
EASA AD 2020-0186, dated August 20, 2020. The FAA has now determined
that further rulemaking is indeed necessary, and this proposed AD
follows from that determination. This proposed AD would require
additional actions and would expand the applicability to include
additional Airbus Helicopters Model AS350B3 helicopters (i.e., Model
AS350B3 helicopters modified through Eurocopter AS350 Service Bulletin
55.00.14 in service). Eurocopter AS350 Service Bulletin 55.00.14 was
optional terminating action in EASA AD 2020-0186. However, helicopters
modified by Eurocopter AS350 Service Bulletin 55.00.14 are affected by
fatigue cracking and must be inspected. A terminating action is not
included in this proposed AD.

The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2021-0099, dated April 9, 2021 (EASA
AD 2021-0099) (also referred to as the Mandatory Continuing
Airworthiness Information, or the MCAI), to correct an unsafe condition
for all Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2,
AS355N, and AS355NP helicopters; and all Model AS350B3 helicopters
except those that have that embodied Airbus Helicopters Modification
073148 in production. EASA stated that recent analysis identified that
AS350B3 helicopters modified through Eurocopter AS350 Service Bulletin
55.00.14 (any revision) in service might also be affected by the
identified unsafe condition.

This proposed AD was prompted by a determination that additional
actions are required to address the unsafe condition and additional
helicopters are affected by the identified unsafe condition. This
proposed AD was also prompted by a report that, during an unscheduled
post-flight inspection of the tail cone area of an Airbus Helicopters
Model AS355NP helicopter, a crack was found in the spar of the upper
part of the vertical fin and fractures were found in the two front
attachment screws. Airbus Helicopters Model AS350B3 helicopters have a
similar vertical fin configuration and are subject to comparable load
levels as the affected Model AS355NP helicopter, therefore, this model
may be subject to the same unsafe condition revealed on the Model
AS355NP helicopter. The FAA is proposing this AD to address cracking in
the spar of the upper part of the vertical fin and fractures in the
front attachment screws. This condition could lead to in-flight
separation of the upper part of the vertical fin, resulting in loss of
control of the helicopter. See the MCAI for additional background
information.

Related Service Information Under 1 CFR Part 51

EASA AD 2021-0099 specifies procedures for repetitive visual
inspections of the right-hand side of the vertical fin spar for
cracking; repetitive cleaning and repetitive detailed inspections for
cracking of the vertical fin spar and vertical fin upper attachments;
and corrective action. The corrective action includes repair.

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

These products have been approved by the aviation authority of
another country, and are 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 these
same type designs.

Explanation of Retained Requirements

Although this proposed AD does not explicitly restate the
requirements of AD 2021-04-15, this proposed AD would retain all of the
requirements of AD 2021-04-15. Those requirements are referenced in
EASA AD 2021-0099, 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 2021-0099 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 (CAAs) to use this process. As a result, EASA AD 2021-0099
will be incorporated by reference in the FAA final rule. This proposed
AD would, therefore, require compliance with EASA AD 2021-0099 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 2021-0099 that is required for compliance with EASA AD 2021-
0099 will be available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0453 after the FAA
final rule is published.

Costs of Compliance

The FAA estimates that this proposed AD affects 650 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 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:

Estimated Costs of On-Condition Actions

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) 2021-04-15, Amendment 39-21437
(86 FR 13165, March 8, 2021); and

b. Adding the following new AD: