DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2670; Project Identifier MCAI-2024-00736-R;
Amendment 39-22916; AD 2024-25-51]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters Deutschland GmbH
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Airbus Helicopters Deutschland GmbH Model MBB-BK 117 C-2 helicopters.
The FAA previously sent this AD as an emergency AD to all known U.S.
owners and operators of these helicopters. This AD was prompted by a
report of vibrations of the yaw axis during a hover taxi. This AD
requires repetitively inspecting the bolted joint between the cardan-
pivot joint assembly and the tail rotor actuator piston rod and,
depending on the results, taking corrective action. This AD also
prohibits installing certain tail rotor actuators unless its
requirements are met. These actions are specified in a European Union
Aviation Safety Agency (EASA) AD, which is incorporated by reference.
The FAA is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective January 17, 2025. Emergency AD 2024-25-51,
issued on December 12, 2024, which contains the requirements of this
amendment, was effective with actual notice.

The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 17,
2025.
The FAA must receive comments on this AD by February 18, 2025.

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 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.

AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-2670; 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 final rule, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.

Material Incorporated by Reference:

For EASA material identified in this AD, contact EASA,
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999
000; email: ADs@easa.europa.eu; website: easa.europa.eu. You may find
this material on the EASA website at ad.easa.europa.eu.

You may view this material at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Parkway, 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 at
regulations.gov under Docket No. FAA-2024-2670.

FOR FURTHER INFORMATION CONTACT: Tara Lucas, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (206)
231-3189; email: Tara.Lucas@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments to an address listed under
the ADDRESSES section. Include "Docket No. FAA-2024-2670; Project
Identifier MCAI-2024-00736-R" at the beginning of your comments. The
most helpful comments reference a specific portion of the final rule,
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 final rule 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
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Tara
Lucas, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY
11590; phone: (206) 231-3189; email: Tara.Lucas@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 Emergency AD 2024-25-51, dated December 12, 2024
(the emergency AD), to address an unsafe condition on Airbus
Helicopters Deutschland GmbH Model MBB-BK 117 C-2 helicopters. The FAA
sent the emergency AD to all known U.S. owners and operators of these
helicopters. For helicopters having tail rotor actuator part number (P/
N) B673M40A1002 (manufacturer P/N 5038A0000-01) installed, the
emergency AD requires repetitively inspecting the bolted joint between
the cardan-pivot joint assembly and the tail rotor actuator piston rod
and, depending on the results, taking corrective action. The emergency
AD also prohibits installing this part-numbered tail rotor actuator on
any helicopter unless it is new, or the inspection is done.

The emergency AD was prompted by Emergency AD 2024-0237-E, dated
December 9, 2024 (EASA Emergency AD 2024-0237-E) (also referred to as
the MCAI), issued by EASA, which is the Technical Agent for the Member
States of the European Union, to correct an unsafe condition on all
Airbus Helicopters Deutschland GmbH Model MBB-BK117 C-2 helicopters.
The MCAI states a bolt on the tail rotor actuator that connects the
cardan-pivot joint assembly with the tail rotor actuator piston rod was
found worn and broken during a subsequent inspection. EASA considers
the MCAI an interim action.

The FAA is issuing this AD to detect a worn tail rotor actuator
bolt. This condition, if not addressed, could result in failure of a
tail rotor actuator bolt, loss of tail rotor control, and subsequent
loss of control of the helicopter.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-2670.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed EASA Emergency AD 2024-0237-E, which requires, for
helicopters having tail rotor actuator P/N B673M40A1002 (manufacturer
P/N 5038A0000-01) installed, repetitively inspecting the bolted joint
between the cardan-pivot joint assembly and the tail rotor actuator
piston rod. Depending on the results, EASA Emergency AD 2024-0237-E
requires contacting AH [Airbus Helicopters] to obtain applicable repair
instructions and accomplishing those instructions within the compliance
time specified within. EASA Emergency AD 2024-0237-E also prohibits
installing this part-numbered tail rotor actuator on any helicopter
unless its requirements are met.

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

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 this State of Design Authority, it
has notified the FAA of the unsafe condition described in the MCAI
described above. The FAA is issuing this AD after determining that the
unsafe condition described previously is likely to exist or develop on
other products of the same type design.

AD Requirements

This AD requires accomplishing the actions specified in EASA
Emergency AD 2024-0237-E described previously, 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 developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result,
EASA Emergency AD 2024-0237-E is incorporated by reference in this AD.
This AD requires compliance with EASA Emergency AD 2024-0237-E in its
entirety through that incorporation, except for any differences
identified as exceptions in the regulatory text of this AD. Using
common terms that are the same as the heading of a particular section
in EASA Emergency AD 2024-0237-E 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 EASA Emergency AD
2024-0237-E. Material required by EASA Emergency AD 2024-0237-E for
compliance will be available at regulations.gov under Docket No. FAA-
2024-2670 after this AD is published.

Interim Action

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

Justification for Immediate Adoption and Determination of the Effective Date

Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for "good cause," finds that
those procedures are "impracticable, unnecessary, or contrary to the
public interest." Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.

An unsafe condition exists that required the immediate adoption of
the emergency AD to all known U.S. owners and operators of these
helicopters. The FAA found that the risk to the flying public justified
waiving notice and comment prior to adoption of this rule because a
tail rotor actuator is part of an assembly that is critical to the
control of a helicopter. Failure of this part could result in an
emergency condition on these helicopters, which primarily conduct air
ambulance and military operations. Additionally, the FAA has no
information pertaining to the extent of wear in the tail rotor actuator
bolts that may currently exist in helicopters or how quickly the
condition may propagate to failure, therefore, the initial actions
required by this AD must be accomplished before next flight. These
conditions still exist, therefore, notice and opportunity for prior
public comment are impracticable and contrary to the public interest
pursuant to 5 U.S.C. 553(b).

In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and comment.

Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without notice
and comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 156 helicopters of U.S. registry.

The FAA estimates the following costs to comply with this AD:

Estimated Costs of Required Actions

Corrective actions that may be required depending on the results of
an inspection could vary from helicopter to helicopter. The FAA has no
data to determine the costs to accomplish these corrective actions. The
FAA estimates the following costs to do any necessary replacement that
may be done.

On-Condition Costs

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

This AD will not have federalism implications under Executive Order
13132. This AD will 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 that this AD:

(1) Is not a "significant regulatory action" under Executive Order 12866, and

(2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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: