DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0265; Project Identifier MCAI-2020-01541-R]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(AHD) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK117 C-2 and
MBB-BK117 D-2 helicopters. This proposed AD was prompted by a report of
increased control force in the collective axis. This proposed AD would
require repetitive visual inspections of the main rotor actuator (MRA),
as specified in a 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 May 24,
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-2021-0265.

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-2021-0265;
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: Katherine Venegas, Aviation Safety
Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood,
California 90712; telephone (562) 627-5353; email
katherine.venegas@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-2021-0265; Project Identifier
MCAI-2020-01541-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 Katherine Venegas,
Aviation Safety Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount
Blvd., Lakewood, California 90712; telephone (562) 627-5353; email
katherine.venegas@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, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2018-0283, dated December 20, 2018
(EASA AD 2018-0283), to correct an unsafe condition for AHD Model MBB-
BK117 C-2 and MBB-BK117 D-2 helicopters. EASA later issued EASA AD
2020-0257, dated November 17, 2020 (EASA AD 2020-0257), to supersede
EASA AD 2018-0283.

This proposed AD was prompted by a report of increased control
force in the collective axis on an AHD Model EC135 helicopter.
Subsequent inspections determined that a nut on a piston of the MRA had
cracked and separated from the piston rod. Due to design similarity,
Model MBB-BK117 C-2 and MBB-BK117 D-2 helicopters are also affected by
this unsafe condition. The FAA is proposing this AD to prevent failure
of the MRA and subsequent loss of control of the helicopter. See the
EASA AD for additional background information.

Related Service Information Under 1 CFR Part 51

EASA AD 2020-0257 describes procedures for a repetitive visual
inspection of the MRA and depending on the results, replacing the
affected parts.

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 EASA
AD 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.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified
in EASA AD 2020-0257 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 EASA 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 2020-0257
will be incorporated by reference in the FAA final rule. This proposed
AD would, therefore, require compliance with EASA AD 2020-0257 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 2020-0257 that is required for compliance with EASA AD 2020-
0257 will be available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-0265 after the FAA
final rule is published.

Differences Between This Proposed AD and the EASA AD

The EASA AD requires contacting Airbus Helicopters or replacing an
affected part, whereas this proposed AD would require performing the
corrective action in accordance with FAA-approved procedures or
removing the affected parts from service instead. The service
information referenced in the EASA AD refers to calendar time when
specifying the compliance time for the inspections, whereas this
proposed AD uses hours time-in-service. The EASA AD allows a tolerance
to the compliance times, whereas this proposed AD would not. The EASA
AD does not specify a compliance time for the reporting requirements;
this proposed AD would require performing the reporting action within
30 days after the effective date of this AD.

Interim Action

The FAA considers this proposed AD interim action. If final action
is later identified, the FAA might consider further rulemaking then.

Costs of Compliance

The FAA estimates that this AD affects 216 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates that operators may incur the following
costs in order to comply with this proposed AD.

Inspecting the nuts on the MRA pistons would take about 1 work-hour
for an estimated cost of $85 per helicopter and $18,360 for the U.S.
fleet, per inspection cycle.

Replacing the MRA would take about 7 work-hours and parts would
cost $286,554 for an estimated cost of $287,149 per helicopter.

Repairing the MRA would take up to about 8 work hours and parts
would cost about $110 for an estimated cost of up to $790 per MRA.

If required, reporting information would take about 1 work-hour for
an estimated cost of $85 per instance.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a current valid OMB control number. The control
number for the collection of information required by this proposed AD
is 2120-0056. The paperwork cost associated with this proposed AD has
been detailed in the Costs of Compliance section of this document and
includes time for reviewing instructions, as well as completing and
reviewing the collection of information. Therefore, all reporting
associated with this proposed AD is mandatory. Comments concerning the
accuracy of this burden and suggestions for reducing the burden should
be directed to Information Collection Clearance Officer, Federal
Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-
1524.

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: