DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0293; Product Identifier 2017-SW-052-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 Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model
EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and
EC135T3 helicopters. This proposed AD would require modification of the
tail rotor (T/R) control installation, a functional test, and
corrective actions as necessary. This proposed AD is prompted by cases
of insufficient clearance between a certain T/R control bearing
connection and the helicopter structure, which were detected on the
production line. The FAA is proposing this AD to address an unsafe
condition on these products.

DATES: The FAA must receive comments on this proposed AD by June 1,
2021.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: 202-493-2251.

Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.

Hand Delivery: Deliver to the "Mail" address 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 the referenced service information at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321,
Fort Worth, TX 76177.

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-2019-0293;
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 European Aviation Safety Agency (EASA) AD, any comments
received, and other information. The street address for Docket
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: David Hatfield, Aviation Safety
Engineer, Aircraft Systems Section, Technical Innovation Policy Branch,
FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-
5110; email david.hatfield@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-2019-0293; Product Identifier
2017-SW-052-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 NPRM.

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 David Hatfield, Aviation Safety Engineer, Aircraft Systems
Section, Technical Innovation Policy Branch, FAA, 10101 Hill wood
Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email
david.hatfield@faa.gov. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Background

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2017-0147, dated August 10, 2017
(EASA AD 2017-0147), to correct an unsafe condition for Airbus
Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1,
EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and
EC635T3 helicopters. EASA advises that several cases of insufficient
clearance between a certain T/R bearing connection and the helicopter
structure were detected during inspections of helicopters on the
production line. EASA states that this condition, if not corrected and
in the case of an unglued bearing, could lead to blockage of the pedal
controlling the T/R thrust and loss of the T/R control. EASA further
advises that this could result in a forced landing with damage to the
helicopter and injury to the occupants.

Accordingly, EASA AD 2017-0147 requires modifying the T/R control
installation by adding a Teflon washer, which reduces the degree of
freedom in case of a drifting bearing at the affected connection. EASA
AD 2017-0147 also requires a functional test for clearance, and
depending on the results, either accomplishing additional corrective
actions or contacting Airbus Helicopters for instructions.

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 issuing this NPRM
after determining that an unsafe condition described previously is
likely to exist or develop on other helicopters of the same type
designs.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Airbus Helicopters Alert Service Bulletin EC135-
67A-031, Revision 0, dated March 30, 2017 (ASB EC135-67A-031), for
Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1,
EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and
EC635T3 helicopters. For serial numbers (S/N) up to 1254 inclusive,
except S/N 1235, this service information specifies retrofitting a
Teflon washer on the T/R controls, performing a functional test of the
modified T/R control installation to inspect for clearance, and making
any necessary adjustments. This service information advises that S/N
1255 and up will have the Teflon washer installed in production.

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.

Proposed AD Requirements in This NPRM

This proposed AD would apply to Model EC135P1, EC135P2, EC135P2+,
EC135P3, EC135T1, EC125T2+, and EC135T3 helicopters with a S/N up to
1254 inclusive (except for S/N 1235) and would require modifying the T/
R control within 360 hours time-in-service (TIS) by installing a Teflon
washer and performing a functional test in accordance with specified
portions of ASB EC135-67A-031. Based on the results of the functional
test, this proposed AD would require making repairs in accordance with
FAA-approved procedures.

Differences Between This Proposed AD and the EASA AD

The EASA AD sets compliance times at 12 months, while this proposed
AD would require compliance within 360 hours TIS. The EASA AD applies
to Airbus Helicopters Model 635 T1, 635 T2+, 635 T3, 635 P2+, 635 P3
helicopters, and this proposed AD would not because those models do not
have an FAA type certificate. The EASA AD requires contacting Airbus
Helicopters for approved repair procedures, while this proposed AD
would require a repair using FAA-approved procedures. The EASA AD
requires revising the "aircraft maintenance program," whereas this AD
does not because not all U.S. operators are required to have a
maintenance program.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 331 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 proposed AD.

Modifying the T/R control installation and conducting a functional
test would take about 3 work-hours and parts would cost about $25 for
an estimated cost of $280 per helicopter and $92,680 for the U.S.
fleet.

If required, adjusting the clearance would take about 1 work-hour
for an estimated cost of $85 per helicopter.

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, 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: