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 the ADDRESSES section. Include “Docket No. FAA-2025-0334; Project Identifier AD-2024-00108-T” 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 Kuri DeLuna, Aviation Safety Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: 817-222-5350; email: wichita-cos@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 has received reports indicating mis-wired fire extinguishing bottles, which could be due to the lack of design features that would inherently preclude inadvertent mis-wiring during installation and connection of subject fire extinguisher bottles. This condition, if not addressed, could result in fire extinguisher bottles that might not activate in the event of an engine or APU fire and consequently, an unextinguished fire in the engine nacelle or APU.

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.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024; and Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024. This material specifies procedures for an engine fire extinguisher system functional test, inspection of the fire extinguisher bottle cartridge wire numbers and yellow ID sleeves for proper identification and legibility and applicable corrective actions. Corrective actions include installing new yellow ID sleeves and new ring terminals. These documents are distinct since they apply to different airplane models.

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.

Proposed AD Requirements in This NPRM

This proposed AD would require revising the existing inspection program to incorporate new airworthiness limitations for repetitive inspections of the engine fire extinguisher wiring and, as applicable, APU fire extinguisher wiring. This proposed AD would also require accomplishing the actions specified in the material already described except for any differences identified as exceptions in the regulatory text of this proposed AD.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 1,245 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA estimates the following costs to do any necessary corrective actions that would be required based on the results of the proposed inspection. The agency has no way of determining the number of aircraft that might need these corrective actions: ( printed page 11497)

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators.

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.

The Proposed Amendment

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

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

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

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

Textron Aviation, Inc. (Type Certificate Previously Held by Cessna Aircraft Company): Docket No. FAA-2025-0334; Project Identifier AD-2024-00108-T.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by April 21, 2025.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Textron Aviation, Inc. (Type Certificate previously held by Cessna Aircraft Company) airplanes, certificated in any category, specified in paragraphs (c)(1) and (2) of this AD.

(1) Model 560 airplanes, having serial numbers (S/Ns) 560-0001 through 560-0707 inclusive, and 560-0751 through 560-0815 inclusive.

(2) Model 560XL airplanes, having S/Ns 560-5001 through 560-5372 inclusive, 560-5501 through 560-5677 inclusive, 560-5679 through 560-5830 inclusive, 560-6001 through 560-6294 inclusive, and 560-6296 through 560-6360 inclusive.

(d) Subject

Air Transport Association (ATA) of America Code 26; Fire Protection.

(e) Unsafe Condition

This AD was prompted by reports of mis-wired fire extinguishing bottles. The FAA is issuing this AD to address mis-wired fire extinguishing bottles, which might not activate in the event of an engine or auxiliary power unit (APU) fire. The unsafe condition, if not addressed, could result in an unextinguished fire in the engine nacelle or APU.

(f) Compliance

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

(g) Fire Bottle Wire Test and Inspection

For all airplanes except for serial numbers 560-6307 through 560-6360 inclusive; Within 100 flight hours or 60 days after the effective date of this AD, whichever occurs first, do the actions specified in paragraph (g)(1) and (2) of this AD.

(1) Perform an engine fire extinguisher system functional test in accordance with step 4. of the Accomplishment Instructions of Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024, or Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024, as applicable.

(2) Perform an inspection of the fire extinguisher bottle cartridge wire numbers and yellow ID sleeves for proper identification and legibility in accordance with step 6. of the Accomplishment Instructions of Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024; or Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024; as applicable. If the proper identification is not found or any yellow ID sleeve is not legible, within 100 flight hours or 60 days after the effective date of this AD, whichever occurs first do all applicable corrective actions, in accordance with step 6. of the Accomplishment Instructions of Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024; or Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024; as applicable.

(h) No Report

Although Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024; and Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024, specify to report inspection findings, this AD does not require any report.

(i) Inspection Program Revision

No later than 24 months after accomplishing paragraph (g) of this AD, do the revision specified in paragraph (i)(1) or (2) of this AD, as applicable.

(1) For Model 560 airplanes, revise the existing inspection program to include the information identified in table 1 to paragraph (i)(1) of this AD. The initial compliance time for the task is at the later of the times specified in paragraphs (i)(1)(i) and (ii) of this AD.

(i) Within 100 flight hours or 60 days after the effective date of this AD, whichever occurs first.

(ii) Within 24 months after accomplishing paragraph (g) of this AD. ( printed page 11498)

(2) For Model 560XL airplanes, revise the existing inspection program to include the information identified in table 2 to paragraph (i)(2) of this AD. The initial compliance time for the tasks is at the later of the times specified in paragraphs (i)(2)(i) and (ii) of this AD.

(i) Within 100 flight hours or 60 days after the effective date of this AD, whichever occurs first.

(ii) Within 24 months after accomplishing paragraph (g) of this AD.

(j) No Alternative Actions or Intervals

After the existing inspection program has been revised as required by paragraph (i) of this AD, no alternative actions ( e.g., inspections) or intervals, may be used unless the actions and intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (k) of this AD.

(k) 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 responsible Flight Standards Office, as appropriate. If sending information directly to the manager of the certification office, send it to the attention of the person identified in paragraph (l) of this AD. Information may be emailed to: AMOC@faa.gov.

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.

(l) Related Information

For more information about this AD, contact Kuri DeLuna, Aviation Safety Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: 817-222-5350; email: wichita-cos@faa.gov.

(m) 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) Textron Aviation Citation Service Letter SL560-26-02, Revision 1, dated July 31, 2024.

(ii) Textron Aviation Citation Service Letter SL560XL-26-02, Revision 1, dated July 31, 2024.

(3) For Textron Aviation material identified in this AD, contact Textron Aviation, Inc., P.O. Box 7706, Wichita, KS 67277; telephone 316-517-6215; fax 316-517-5802; email citationpubs@txtav.com; website support.cessna.com/custsupt/csupport/newlogin.jsp.

(4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.

(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.