DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0143; Product Identifier 2019-SW-024-AD]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters Deutschland GmbH
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Airbus Helicopters Deutschland GmbH Model BO-105A, BO-105C,
BO-105S, and BO-105LS A-3 helicopters. This proposed AD was prompted by
the FAA's determination that aging of the elastomeric material in a
tension torsion strap (TT-strap) could affect the structural
characteristics of the TT-strap. This proposed AD would require
replacement of certain TT-straps with serviceable parts and
implementation of a new storage life limit for TT-straps, as specified
in a European Aviation Safety Agency (now 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 April 26, 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 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-2021-0143.

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-
0143; 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: Blaine Williams, Aviation Safety
Engineer, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood,
CA 90712-4137; telephone 562-627-5371; email blaine.willaims@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-2021-0143; Product Identifier
2019-SW-024-AD" 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
Blaine Williams, Aviation Safety Engineer, Los Angeles ACO Branch, 3960
Paramount Boulevard, Lakewood, CA 90712-4137; telephone 562-627-5371;
email blaine.willaims@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.

Discussion

The EASA (now European Union Aviation Safety Agency), which is the
Technical Agent for the Member States of the European Union, has issued
EASA AD 2019-0024, dated February 4, 2019 (EASA AD 2019-0024) (also
referred to as the Mandatory Continuing Airworthiness Information, or
the MCAI), to correct an unsafe condition for certain Airbus
Helicopters Deutschland GmbH Model BO-105A, BO-105C, BO-105D, BO-105S,
and BO-105LS A-3 helicopters. Model BO-105D helicopters are not
certificated by the FAA and are not included on the U.S. type
certificate data sheet; this proposed AD therefore does not include
those helicopters in the applicability.

This proposed AD was prompted by the FAA's determination that aging
of the elastomeric material in a TT-strap could affect the structural
characteristics of the TT-strap. The FAA is proposing this AD to
address aging of the elastomeric material in a TT-strap, which could
lead to premature failure of a TT-strap, resulting in loss of control
of the helicopter. See the MCAI for additional background information.

Relationship Between This Proposed AD and AD 2016-25-14

This proposed AD would not supersede AD 2016-25-14, Amendment 39-
18740 (81 FR 94944, December 27, 2016) (AD 2016-25-14). This proposed
AD would require replacement of certain TT-straps with serviceable
parts. Accomplishment of the proposed replacement would then terminate
all of the requirements of AD 2016-25-14 for Model BO-105LS A-3
helicopters only.

Related Service Information Under 1 CFR Part 51

EASA AD 2019-0024 describes procedures for replacing certain TT-
straps with serviceable parts and requires a storage life limit for TT-
straps.

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.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified
in EASA AD 2019-0024, 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 MCAI."

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 2019-0024
will be incorporated by reference in the FAA final rule. This proposed
AD would, therefore, require compliance with EASA AD 2019-0024 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 2019-0024 that is required for compliance with EASA AD 2019-
0024 will be available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0143 after the FAA
final rule is published.

Differences Between This Proposed AD and the MCAI

Although EASA AD 2019-0024 does not specify a life limit for the
Lord TT-Straps part number (P/N) J17322-1 and P/N 117-14111, this
proposed AD does specify a life limit for those parts.

Where EASA AD 2019-0024 specifies that installation of a Lord TT-
Strap is allowed provided the first flight of that helicopter after
that installation is accomplished before the storage life of that Lord
TT-Strap exceeds 5 years, for this proposed AD, the installation of a
Lord TT-Strap is allowed provided the first flight of that helicopter
after that installation is accomplished before 5 years since the TT-
strap's date of manufacture.

Where EASA AD 2019-0024 defines "serviceable part" as a Lord TT-
Strap having a storage life not exceeding 5 years, for this proposed
AD, a serviceable part is Lord TT-straps P/N J17322-1 and P/N 117-14111
having less than 5 years since that TT-strap's date of manufacture.

Where EASA AD 2019-0024 specifies that the "cure date" of a TT-
Strap can be determined using the information provided in the
applicable service information specified in EASA AD 2019-0024, or
contacting Airbus Helicopters for applicable instructions, for this
proposed AD, the option of contacting Airbus Helicopters is not
required.

Costs of Compliance

The FAA estimates that this proposed AD affects 61 helicopters of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

Estimated Costs for Required Actions

According to the manufacturer, some or all of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected operators. The FAA does not control warranty
coverage for affected operators. As a result, the FAA has included all
known costs in the cost estimate.

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) 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 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: