STC ST00142NY

Number: ST00142NY

This certificate issued to: American Airlines, Inc., Maintenance and Engineering (M&E) Division, 3900 North Mingo Road, MD 537/TUL, Tulsa, Oklahoma 74116

Part 25 of the Code of Federal Regulations.

Original Product Make: Airbus Type Certificate Number: A28NM Model: A321-211/-231/-253N/-253NX

Description of Type Design Change: Cargo Floor Panel Material Substitution Installation of Cargo Floorboards in accordance with Master Data List, ST00142NY-MDL, Revision A, dated March 4, 2026 and serial number effectivity report ST00142NY-SNER, Revision B, dated January 20, 2026 or later FAA approved revision.

This approval should not be incorporated in any aircraft of this specific model until compatibility of this modification with previously approved modifications has been determined by the installer. If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

(Limitations and Conditions continued on page 3 of 3)

Date of Application: October 03, 2005 Date Reissued: October 30, 2015 Date of Issuance: November 18, 2005 Date Amended: August 21, 2015, August 16, 2021, March 4, 2026 By direction of the Administrator

Signature Cheryl L. Hurst

Title: ODA-700094-SW Administrator

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: ST00142NY

Transfer the ownership of Supplemental Type Certificate Number: ST00142NY

To (Name and address of transferee)

From (Name and address of grantor)

FAA Form 8110-2 (3/21) Page 2 of 3

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: ST00142NY

The Instructions for Continued Airworthiness, Document Number ST00142NY-ICA, Revision B, dated March 3, 2026, or later FAA/ODA accepted revision shall be made available to the operator at the time of installation. The aircraft shall be maintained in accordance with the applicable Instructions for Continued Airworthiness. A revised EWIS ICA is not required for this STC.

Certification Basis:

Based on 14 CFR 21.115 and 21.101, and the FAA policy for non-significant changes in FAA Order 8110.48, the certification basis for the Airbus Model A319 Series aircraft for the change is as follows:

a. The Type Certification basis is shown on TCDS A28NM for parts not changed or not affected by the change.

b. The certification basis for parts changed or affected by the change since the reference date of application, October 03, 2005 is based upon Part 25, as amended by Amendment 25-117 and Part 26 as amended by Amendment 26-6 or later amendment (see below). Based on 14 CFR 21.115 and 21.101, and the FAA policy for non-significant changes in FAA Order 8110.48, the certification basis for this modification was determined to be:

Regulations at amendment 25-0 through 25-115

25.29, 25.301, 25.303, 25.305(a)(b), 25.307(a) , 25.365, 25.561, 25.601, 25.603, 25.605 (a), 25.607, 25.609, 25.613,

25.625(a), 25.793, 25.856, 25.1529

Regulations at amendment 25-116 through 25-146

25.21(a)(1), 25.787, 25.855(c)(d), 25.1301(a)

Special Conditions:

None

14 CFR Part 26 Regulations Based on 14 CFR §21.101(g), applicable provisions of 14 CFR part 26 are included in the certification basis. For any future 14 CFR part 26 amendments, the holder of this STC must demonstrate compliance with the applicable sections. As of the issuance of this STC, compliance has been found for the following regulations 14 CFR §

26.11(c)(d)(5) (Amendment 26-0). For A321-253N/-253NX only, compliance has been found for the following regulations 14 CFR § 26.11(c) (Amendment 26-7).

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FAA Form 8110-2 (3/21) Page 3 of 3