FAA就空客直升机AS350/AS355/EC130系列主桨伺服控制螺栓扭矩问题发布拟议适航指令，全美980架受影响、合规成本仅约35万美元

[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-11814; Project Identifier MCAI-2026-00715-R]
RIN 2120-AA64
Airworthiness Directives; Airbus 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 all
Airbus Helicopters Model AS350B3, AS355F, AS355F1, AS355F2, AS355N, AS355NP,
EC130B4, and EC130T2 helicopters. This proposed AD was prompted by a report of the
loss of the tightening torque between the upper ball bearing end and a main rotor (MR)
servo-control. This proposed AD would require an inspection of the nut tightening torque
of the upper ball bearing end of all the MR servo-controls and, depending on the results,
corrective actions. The proposed AD would also require reporting the inspection results.
The FAA is proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by [INSERT DATE 45 DAYS
AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
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. FAA2026-11814; 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.
Material Incorporated by Reference:
• For European Union Aviation Safety Agency (EASA) material identified in this
proposed 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 view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For
information on the availability of this material at the FAA, call (817) 222-5110.
FOR FURTHER INFORMATION CONTACT: Aryanna Sanchez, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (520)
990-9321; email: aryanna.t.sanchez@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 using a method listed under ADDRESSES. Include
“Docket No. FAA-2026-11814; Project Identifier MCAI-2026-00715-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 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 Aryanna Sanchez,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590.
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 2026-0132, dated July 8, 2026 (EASA AD 2026-0132)
(also referred to as the MCAI), to correct an unsafe condition on all Airbus Helicopters
Model AS 350 B3, AS 355 F, AS 355 F1, AS 355 F2, AS 355 N, AS 355 NP,
EC 130 B4, and EC 130 T2 helicopters. The MCAI states a report was received of the
loss of the tightening torque between the upper ball bearing end and an MR servo-

control. The MCAI also states further investigations determined that the presence of paint
or protection on the nut retainer (lock-washer) is the root cause for this loss of tightening
torque, and that this deficiency may occur on any of the three (forward, left, and right)
MR servo-controls installed on a helicopter.
The FAA is issuing this proposed AD to inspect the nut tightening torque of the
upper ball bearing end of all the MR servo-controls and, if necessary, accomplish
corrective actions. The unsafe condition, if not addressed, could result in the
disconnection of the upper ball bearing end from the MR servo-control and loss of
control of a helicopter.
You may examine the MCAI in the AD docket at regulations.gov under Docket
No. FAA-2026-11814.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2026-0132, which specifies procedures for a onetime inspection and thereafter, after each removal and installation of an MR servocontrol, inspection of the nut tightening torque of the upper ball bearing end of the
forward, left, and right MR servo-controls, having a part number (P/N) and manufacturer
P/N as identified in Appendix 1 of the MCAI, and the associated nut retainer (lockwasher) having manufacturer P/N 360A27-2121-20 or 365A27-8193-20. Depending on
the results, the MCAI specifies procedures for re-inspecting the nut tightening torque and
accomplishing corrective actions, including inspecting the threads of the MR servocontrol and, if necessary, cleaning them; replacing the ball bearing end; replacing the MR
servo-control; or contacting AH [Airbus Helicopters] for approved instructions. EASA
AD 2026-0132 also requires reporting of all inspection results.
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
These products have been approved by the civil aviation authority (CAA) of
another country and are approved for operation in the United States. Pursuant to the
FAA’s bilateral agreement with this State of Design Authority, that authority has notified
the FAA of the unsafe condition described in the MCAI referenced above. The FAA is
issuing this NPRM after determining that the unsafe condition described previously is
likely to exist or develop on other products of the same type design.
Proposed AD Requirements in this NPRM
This proposed AD would require accomplishing the actions specified in EASA
AD 2026-0132, described previously, as incorporated by reference, except for any
differences identified as exceptions in the regulatory text of this AD. See “Differences
Between this Proposed AD and the MCAI” for a discussion of the general differences
included in this proposed AD.
Differences Between this Proposed AD and the MCAI
Where the MCAI specifies contacting Airbus Helicopters if an unacceptable value
of the nut tightening torque is found, this proposed AD would require performing
corrective actions in accordance with a method approved by the Manager, International
Validation Branch, FAA; or EASA; or Airbus Helicopters’ Design Organization
Approval (DOA). If approved by the DOA, the approval must include the DOAauthorized signature.
Interim Action
The FAA considers that this proposed AD would be an interim action. If final
actions are later identified, the FAA might consider further rulemaking.
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 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, the FAA proposes
to incorporate EASA AD 2026-0132 by reference in the FAA final rule. This proposed
AD would, therefore, require compliance with EASA AD 2026-0132 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 EASA AD 2026-0132 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 AD
2026-0132. Material required by EASA AD 2026-0132 for compliance will be available
at regulations.gov under Docket No. FAA-2026-11814 after the FAA final rule is
published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 980
helicopters of U.S. registry.
The FAA estimates the following costs to comply with this proposed AD:
Estimated costs
Action

Labor Cost

Parts Cost

Cost per
product

Cost on U.S.
operators

Inspect the nut
tightening
torque of the
upper ball
bearing end

1 work-hour x
$85 per hour =
$85

$190

$275

$269,500

Report
inspection
results

1 work-hour x
$85 per hour =
$85

$0

$85

$83,300

The FAA estimates the following costs to do any replacements that would be

required based on the results of the proposed inspection. The agency has no way of
determining the number of helicopters that might need these replacements:
On-condition costs
Action

Labor Cost

Parts Cost

Cost per product

Inspect ball bearing
end threads

1 work-hour x $85
per hour = $85

$0

$85

Inspect the MR
servo-control
threads

1 work-hour x $85
per hour = $85

$0

$85

Clean MR servocontrol threads

1 work-hour x $85
per hour = $85

$0

$85

Replace one ball
bearing end

1 work-hour x $85
per hour = $85

Up to $530

Up to $615

Replace one MR
servo-control

4 work-hours x $85
per hour = $340

Up to $54,300

Up to $54,640

The FAA has included all known costs in its cost estimate. According to the
manufacturer, however, some of the costs of this proposed AD may be covered under
warranty, thereby reducing the cost impact on affected operators.
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 a 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
OMB Control Number for this information collection is 2120-0056. Public reporting for
this collection of information is estimated to take approximately 1 hour per response,
including the time for reviewing instructions, searching existing data sources, gathering
and maintaining the data needed, and completing and reviewing the collection of
information. All responses to this collection of information are mandatory. Send
comments regarding this burden estimate or any other aspect of this collection of
information, including suggestions for reducing this burden, 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) Would not affect intrastate aviation in Alaska, and
(3) Would 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.
§ 39.13 [Amended]
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
Airbus Helicopters: Docket No. FAA-2026-11814; Project Identifier MCAI-202600715-R.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by
[INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL
REGISTER].
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus Helicopters Model AS350B3, AS355F, AS355F1,
AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters, certificated in any
category.
(d) Subject
Joint Aircraft System Component (JASC) Code 6710, Main rotor control.
(e) Unsafe Condition
This AD was prompted by a report of the loss of the tightening torque between

the upper ball bearing end and a main rotor (MR) servo-control. The FAA is issuing this
AD to inspect the nut tightening torque of the upper ball bearing end of all the MR servocontrols and, if necessary, accomplish corrective actions. The unsafe condition, if not
addressed, could result in the disconnection of the upper ball bearing end from the MR
servo-control and loss of control of a helicopter.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Required Actions
Except as specified in paragraph (h) of this AD: Comply with all required actions
and compliance times specified in, and in accordance with European Union Aviation
Safety Agency (EASA) AD 2026-0132, dated July 8, 2026 (EASA AD 2026-0132).
(h) Exceptions to EASA AD 2026-0132
(1) Where EASA AD 2026-0132 refers to its effective date, this AD requires
using the effective date of this AD.
(2) Where EASA AD 2026-0132 refers to flight hours, this AD requires using
hours time-in-service.
(3) Where paragraph (5) of EASA AD 2026-0132 and the material referenced in
EASA AD 2026-0132 specify to contact AH [Airbus Helicopters] for corrective actions
and instructions, this AD requires accomplishing corrective actions in accordance with a
method approved by the Manager, International Validation Branch, FAA; or EASA; or
Airbus Helicopters’ Design Organization Approval (DOA). If approved by the DOA, the
approval must include the DOA-authorized signature.
(4) Where the material referenced in EASA AD 2026-0132 specifies discarding
certain parts, this AD requires removing those parts from service.
(5) Where the material referenced in EASA AD 2026-0132 specifies “check”, this
AD requires replacing that text with “inspection”.

(6) This AD does not adopt the “Remarks” section of EASA AD 2026-0132.
(i) Credit for Previous Actions
This paragraph provides credit for the actions required by paragraph (g) of this
AD, if those actions were performed before the effective date of this AD using the
following:
(1) Airbus Service Bulletin AS350-67-30-0002, dated 01 April 2026.
(2) Airbus Service Bulletin AS355-67-30-0001, dated 01 April 2026.
(3) Airbus Service Bulletin EC130-67-30-0001, dated 01 April 2026.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation Branch, FAA, has the authority to
approve 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 and email to: AMOC@faa.gov.
(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) Additional Information
For more information about this AD, contact Aryanna Sanchez, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (520)
990-9321; email: aryanna.t.sanchez@faa.gov.
(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 2026-0132, dated July
8, 2026.
(ii) [Reserved]
(3) For EASA material identified in this AD, contact EASA, Konrad-AdenauerUfer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email:
ADs@easa.europa.eu; website: easa.europa.eu.
(4) You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 10101 Hillwood Parkway, 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
fr.inspection@nara.gov.
Issued on October 15, 2026.

Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division,
Aircraft Certification Service.
[FR Doc. 2026-21387 Filed: 10/16/2026 8:45 am; Publication Date: 10/19/2026]