[Federal Register Volume 90, Number 44 (Friday, March 7, 2025)]
[Rules and Regulations]
[Pages 11473-11475]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-03698]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2147; Project Identifier MCAI-2022-01515-R; 
Amendment 39-22967; AD 2025-04-09]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Airbus Helicopters Model EC 155B, EC155B1, SA-365N, SA-365N1, AS-365N2, 
and AS 365 N3 helicopters. This AD prompted by an engine compartment 
fire where the upper stiffener of the central firewall in the engine 
compartment was found damaged. This AD requires replacing the aluminum 
central firewall stiffener with a titanium central firewall stiffener 
and prohibits installing an aluminum central firewall stiffener. 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 April 11, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 11, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-2147; 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 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    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: [email protected]; 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. The EASA material is also 
available at regulations.gov under Docket No. FAA-2024-2147.

FOR FURTHER INFORMATION CONTACT: Hye Yoon Jang, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (206) 231-3758; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Airbus Helicopters 
Model EC 155B, EC155B1, SA-365N, SA-365N1, AS-365N2, and AS 365 N3 
helicopters. The NPRM published in the Federal Register on September 
30, 2024 (89 FR 79483). The NPRM was prompted by AD 2022-0231, dated 
November 28, 2022, issued by EASA, which is the Technical Agent for the 
Member States of the European Union (EASA AD 2022-0231) (also referred 
to as the MCAI). The MCAI states that an engine fire occurred where the 
upper stiffener of the central firewall, made of aluminum, in the 
engine compartment was found damaged. The FAA is proposing this AD to 
address failure of a central firewall stiffener made of aluminum, 
possibly due to its inability to withstand high temperatures of an 
engine fire and subsequently not seal the engine compartment properly. 
In the event of an engine fire, the unsafe condition, if not addressed, 
could result in fire propagating from one engine compartment to the 
other and subsequent loss of control of the helicopter.
    In the NPRM, the FAA proposed to require replacing aluminum central 
firewall stiffeners with titanium central firewall stiffeners and 
prohibit installing an aluminum central firewall stiffener, as 
specified in EASA AD 2022-0231. The FAA is issuing this AD to address 
the unsafe condition on these products.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2024-2147.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    These products have been approved by the aviation authority of 
another

[[Page 11474]]

country and are 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 
referenced above. The FAA reviewed the relevant data and determined 
that air safety requires adopting this AD as proposed. Accordingly, the 
FAA is issuing this AD to address the unsafe condition on these 
products. Except for minor editorial changes, this AD is adopted as 
proposed in the NPRM.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed EASA AD 2022-0231, which requires replacing 
aluminum central firewall stiffeners with titanium central firewall 
stiffeners and prohibits installing an aluminum central firewall 
stiffener on any helicopter.
    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.

Costs of Compliance

    The FAA estimates that this AD affects 35 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 to comply with this AD.
    Replacing the aluminum central firewall stiffener with a titanium 
central firewall stiffener takes 7 work-hours and parts cost $1,737 to 
$2,801 depending on the part number for an estimated cost of $2,332 to 
$3,396 per helicopter and $81,620 to $118,860 for the U.S. fleet.

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,
    (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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(f), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2025-04-09 Airbus Helicopters: Amendment 39-22967; Docket No. FAA-
2024-2147; Project Identifier MCAI-2022-01515-R.

(a) Effective Date

    This airworthiness directive (AD) is effective April 11, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Model EC 155B, EC155B1, 
SA-365N, SA-365N1, AS-365N2, and AS 365 N3 helicopters, certificated 
in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5412, Nacelle/Pylon, 
Bulkhead/Firewall.

(e) Unsafe Condition

    This AD was prompted by an engine compartment fire where the 
upper stiffener of the central firewall, made of aluminum, in the 
engine compartment was found damaged. The FAA is issuing this AD to 
address failure of a central firewall stiffener made of aluminum, 
possibly due to its inability to withstand high temperatures of an 
engine fire and subsequently not seal the engine compartment 
properly. In the event of an engine fire, the unsafe condition, if 
not addressed, could result in fire propagating from one engine 
compartment to the other and subsequent loss of control of the 
helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Requirements

    Except as specified in paragraphs (h) and (i) of this AD: Comply 
with all required actions and compliance times specified in, and in 
accordance with, European Union Aviation Safety Agency (EASA) AD 
2022-0231, dated November 28, 2022 (EASA AD 2022-0231).

(h) Exceptions to EASA AD 2022-0231

    (1) Where EASA AD 2022-0231 refers to its effective date, this 
AD requires using the effective date of this AD.
    (2) Where EASA AD 2022-0231 refers to flight hours, this AD 
requires using hours time-in-service.
    (3) Where the material referenced in EASA AD 2022-0231 specifies 
discarding certain parts, this AD requires removing those parts from 
service.
    (4) Where the material referenced in EASA AD 2022-0231 states 
``If the bracket (f) is in unsatisfactory condition (DETAIL D),'' 
this AD requires replacing that text with ``Inspect the bracket (f) 
(DETAIL D) for airworthy condition; for the purpose of this AD, an 
unairworthy condition may be indicated by corrosion, a crack, or 
wear. If the bracket (f) is in an unairworthy condition.''
    (5) Where the material referenced in EASA AD 2022-0231 states to 
``Do a check of the cover strip (g) and the fireproof seal (h) to 
replace if necessary (SECTION B-B),'' this AD requires replacing 
that text with ``Inspect the cover strip (g) and the fireproof seal 
(h) for airworthy condition. If the cover strip (g) or the fireproof 
seal (h) is in an unairworthy condition, remove each unairworthy 
part from service and replace it with a new (zero total hours time-
in-service) part (SECTION B-B).''
    (6) This AD does not adopt the ``Remarks'' section of EASA AD 
2022-0231.

(i) No Reporting Requirement

    Although the material referenced in EASA AD 2022-0231 specifies 
to submit certain information to the manufacturer, this AD does not 
require that action.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation Branch, FAA, has the 
authority to approve

[[Page 11475]]

AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
International Validation Branch, send it to the attention of the 
person identified in paragraph (k) of this AD. Information may be 
emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local Flight Standards District Office/certificate holding 
district office.

(k) Related Information

    For more information about this AD, contact Hye Yoon Jang, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (206) 231-3758; email: 
[email protected].

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2022-0231, 
dated November 28, 2022.
    (ii) [Reserved]
    (3) For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 
000; email: [email protected]; website: easa.europa.eu. You may 
find the EASA material on the EASA website at ad.easa.europa.eu.
    (4) 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.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on February 18, 2025.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-03698 Filed 3-6-25; 8:45 am]
BILLING CODE 4910-13-P