Proposed Rule2025-21416
Airworthiness Directives; Textron Aviation, Inc. (Type Certificate Previously Held by Cessna Aircraft Company) Airplanes
Primary source
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Published
November 28, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all Textron Aviation, Inc., Model 525B airplanes. This proposed AD was prompted by the manufacturer's revision of the aircraft maintenance manual (AMM) to introduce more restrictive inspection intervals. This proposed AD would require revising the Airworthiness Limitations Section (ALS) of the existing AMM or instructions for continued airworthiness (ICA) and the existing approved maintenance or inspection program, as applicable. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 90 Issue 227 (Friday, November 28, 2025)</title>
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[Federal Register Volume 90, Number 227 (Friday, November 28, 2025)]
[Proposed Rules]
[Pages 54599-54601]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-21416]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-5037; Project Identifier AD-2025-00212-A]
RIN 2120-AA64
Airworthiness Directives; Textron Aviation, Inc. (Type
Certificate Previously Held by Cessna Aircraft Company) Airplanes
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 all Textron Aviation, Inc., Model 525B airplanes. This proposed AD
was prompted by the manufacturer's revision of the aircraft maintenance
manual (AMM) to introduce more restrictive inspection intervals. This
proposed AD would require revising the Airworthiness Limitations
Section (ALS) of the existing AMM or instructions for continued
airworthiness (ICA) and the existing approved maintenance or inspection
program, as applicable. 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 January 12,
2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5037; 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.
FOR FURTHER INFORMATION CONTACT: Soban Saeed, Aviation Safety Engineer,
FAA, 1801 South Airport Road, Wichita, KS 67209; phone: (316) 946-4123;
email: <a href="/cdn-cgi/l/email-protection#3576767718767a66755354541b525a43"><span class="__cf_email__" data-cfemail="f5b6b6b7d8b6baa6b5939494db929a83">[email protected]</span></a>.
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 the ADDRESSES section. Include ``Docket No. FAA-2025-5037;
Project Identifier AD-2025-00212-A'' 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 revise 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
<a href="http://regulations.gov">regulations.gov</a>, 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 Soban
Saeed, Aviation Safety Engineer, FAA, 1801 South Airport Road, Wichita,
KS 67209. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.
Background
The FAA was notified by Textron Aviation that the existing Model
525B AMM contained incorrect inspection intervals for airworthiness
limitation tasks for Chapter 54--Nacelle/Pylons and Chapter 55--
Stabilizers. The incorrect inspection intervals were introduced during
a technical manual update. The FAA is issuing this AD to prevent
undetected cracks in the engine mount and vertical stabilizer front and
rear spar caps. The unsafe conditions, if not addressed, could result
in reduced structural integrity and consequent reduced controllability
of the airplane.
FAA's Determination
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 revising the ALS of the existing AMM
or ICA and the existing approved maintenance or inspection program, as
applicable, by incorporating the actions and associated thresholds and
intervals specified in table 1 to paragraph (g) of this proposed AD.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 601 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
[[Page 54600]]
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Revise the ALS..................... 1 work-hour x $85 per hour $0 $85 $51,085
= $85.
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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
0
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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
Textron Aviation Inc.: Docket No. FAA-2025-5037; Project
Identifier AD-2025-00212-A.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by January 12, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Textron Aviation, Inc. (Type Certificate
previously held by Cessna Aircraft Company) Model 525B airplanes,
certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 5530, Vertical
Stabilizer Structure; 5415, Nacelle/Pylon, Attach Fittings.
(e) Unsafe Condition
This AD was prompted by the manufacturer's revision of the
aircraft maintenance manual (AMM) to introduce more restrictive
inspection intervals. The FAA is issuing this AD to prevent
undetected cracks in the engine mount and vertical stabilizer front
and rear spar caps. The unsafe conditions, if not addressed, could
result in reduced structural integrity and consequent reduced
controllability of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Revision of the (ALS) or ICA
Within 150 hours time-in-service (TIS) or 12 months after the
effective date of this AD, whichever occurs first: Revise the
Airworthiness Limitations Section (ALS) of the existing AMM or
instructions for continued airworthiness (ICA) and the existing
approved maintenance or inspection program, as applicable, by
incorporating the revised tasks and associated thresholds and
intervals identified in table 1 to paragraph (g) of this AD.
Table 1 To Paragraph (g)--Revised Model 525B Airworthiness Limitation Tasks
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Existing task Revised task Inspection
Task No. Task title interval interval document Zone
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54-50-00-250......... Forward Engine Mount 6,000 hours TIS. 6,100 hours TIS, 4-12-NA......... 411, 412
Channel Flange (Eddy then 4,100
Current) Special hours TIS
Detailed Inspection. thereafter.
54-50-00-252......... Aft Engine Beam Aft 11,500 hours TIS 14,100 hours 4-12-MR......... 311, 312
Upper Angle Common TIS, then every
to Aft Web, BL 24.50 2,700 hours TIS
(Eddy Current) thereafter.
Special Detailed
Inspection.
54-50-00-254......... Forward Engine Mount 12,000 hours TIS 16,300 hours 4-12-MS......... 410, 420
Aft Channel Web TIS, then every
(Eddy Current) 11,600 hours
Special Detailed TIS thereafter.
Inspection.
54-50-00-255......... Forward Engine Mount 12,000 hours TIS 15,600 hours 4-12-NB......... 410, 420
Forward Channel Web TIS, then every
(Eddy Current) 11,100 hours
Special Detailed TIS thereafter.
Inspection.
55-40-00-250......... Vertical Fin Left and 9,000 hours TIS, 9,000 hours TIS, 4-12-ML......... 340
Right Front Spar Cap then every then every
at Attachment Hole 7,500 hours TIS 7,000 hours TIS
#2 (Eddy Current) thereafter. thereafter.
Special Detailed
Inspection.
55-40-00-251......... Vertical Fin Left and 15,000 hours TIS 17,700 hours 4-12-MO......... 340
Right Front Spar Cap TIS, then every
at Attachment Hole 14,900 hours
#1 (Eddy Current) TIS thereafter.
Special Detailed
Inspection.
[[Page 54601]]
55-40-00-252......... Vertical Fin Left and 15,000 hours 23,600 hours 4-12-MQ......... 340
Right Rear Spar Cap TIS, then every TIS, then every
at Attachment Hole 14,500 hours 12,100 hours
#1 (Eddy Current) TIS thereafter. TIS thereafter.
Special Detailed
Inspection.
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Note 1 to paragraph (g): Additional guidance for accomplishing
the actions required by this AD can be found in Textron Aviation
Service Letter SL525B-05-04, Revision 1, dated January 7, 2025.
(h) Provisions for Alternative Actions and Intervals
After the action required by paragraph (g) of this AD has been
done, no alternative actions and associated thresholds and intervals
are allowed unless they are approved as specified in the provisions
of paragraph (i) of this AD.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Central Certification 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 Central Certification Branch, send it
to the attention of the person identified in paragraph (j)(1) of
this AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#83c2ceccc0c3e5e2e2ade4ecf5"><span class="__cf_email__" data-cfemail="b1f0fcfef2f1d7d0d09fd6dec7">[email protected]</span></a>.
(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.
(j) Additional Information
(1) For more information about this AD, contact Soban Saeed,
Aviation Safety Engineer, FAA, 1801 South Airport Road, Wichita, KS
67209; phone: (316) 946-4123; email: <a href="/cdn-cgi/l/email-protection#84c7c7c6a9c7cbd7c4e2e5e5aae3ebf2"><span class="__cf_email__" data-cfemail="4a090908670905190a2c2b2b642d253c">[email protected]</span></a>.
(2) For Textron Aviation material identified in this AD that is
not incorporated by reference, contact Textron Aviation, Inc., P.O.
Box 7706, Wichita, KS 67277; phone: (316) 517-6215; email:
<a href="/cdn-cgi/l/email-protection#a4c7cdd0c5d0cdcbcad4d1c6d7e4d0dcd0c5d28ac7cbc9"><span class="__cf_email__" data-cfemail="a9cac0ddc8ddc0c6c7d9dccbdae9ddd1ddc8df87cac6c4">[email protected]</span></a>; website: <a href="http://ww2.txtav.com/technicalpublications/">ww2.txtav.com/technicalpublications/</a>.
(k) Material Incorporated by Reference
None.
Issued on November 24, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-21416 Filed 11-26-25; 8:45 am]
BILLING CODE 4910-13-P
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