DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0239; Product Identifier 2018-SW-073-AD]
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 adopt a new airworthiness directive (AD)
for all Airbus Helicopters Model EC120B helicopters. This proposed AD
was prompted by a report that a changed manufacturing process for the
tail rotor blades (TRB) was implemented, affecting the structural
characteristics of the blades and generating a new part number for
these blades. This proposed AD would require re-identifying each
affected TRB having a certain part number and serial number and
establishing a life limit for the new part numbers. This AD also
prohibits installation of any affected TRB identified with the old part
number on any helicopter. 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 27,
2020.

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 service information identified in this NPRM, contact Airbus
Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone
972-641-0000 or 800-232-0323; fax 972-641-3775; or at https://www.airbus.
com/helicopters/services/technical-support.html. You may view this service
information 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.

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-2020-0239;
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, the Mandatory Continuing Airworthiness Information (MCAI),
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, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5485;
email Kristin.Bradley@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 the ADDRESSES section. Include "Docket No. FAA-2020-0239;
Product Identifier 2018-SW-073-AD" at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this NPRM. The FAA will
consider all comments received by the closing date and may amend this
NPRM because of those comments.

The FAA will post all comments received, without change, to https://www.
regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact received about this NPRM.

Discussion

The European Union Aviation Safety Agency (previously European
Aviation Safety Agency) (EASA), which is the Technical Agent for the
Member States of the European Union, has issued EASA AD 2018-0183,
dated August 28, 2018 (referred to after this as "the MCAI"), to
correct an unsafe condition for all Airbus EC120 B helicopters. EASA
advises that a changed manufacturing process for TRBs was implemented,
affecting the structural characteristic of the TRBs and generating a
new part number for these blades. Because this is a newly established
part number, no service life limit currently exists for this part. This
EASA AD identifies a service life limit for the new TRB part numbers,
which, if not required, might result in TRBs exceeding their service
life limit. This condition, if not corrected, could lead to loss of the
TRB and subsequent loss of control of the helicopter. The EASA AD also
prohibits installation of any affected TRB identified with the old part
number on any helicopter and prohibits rework, repair, or modification
of any affected part.

You may examine the MCAI in the AD docket on the internet at
https://www.regulations.gov by searching for and locating Docket No.
FAA-2020-0239.

Related Service Information Under 1 CFR Part 51

Airbus Helicopters has issued Alert Service Bulletin EC120-04A008,
dated July 18, 2018 ("ASB EC120-04A008"). This service information
describes procedures for re-identifying a TRB with P/N C642A0300103 for
certain serial numbers as specified in ASB EC120-04A008.

This service information 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

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

Proposed Requirements of This NPRM

This proposed AD would require re-identifying each affected TRB
with a new part number, establishing a life limit for the new TRB part
number, and prohibiting installation of any affected TRB having the old
part number.

Costs of Compliance

The FAA estimates that this proposed AD affects 94 helicopters of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

Estimated Costs for Required Actions *

* The FAA has received no definitive data that would enable providing cost estimates
for the additional applicable maintenance instructions specified in this proposed AD.
** The FAA has received no definitive data on the parts cost.

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 (AD):