STC ST11267DS

Number: ST11267DS

This certificate issued to: American Airlines, Inc., M&E Engineering 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: A321-253NY

Description of Type Design Change: Installation of a flight crew rest and cabin crew rests in accordance with Master Data List, 104641-MDL, Revision A, dated November 08, 2025 or later FAA approved revision and Serial Number Effectivity Report 104641-SNER, Revision New, dated January 13, 2025 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: January 22, 2025 Date Reissued:

Date of Issuance: November 8, 2025 Date Amended:

Signature Mandy K. Lucke

Title: ODA-700094-SW Administrator

Number: ST11267DS

Transfer the ownership of Supplemental Type Certificate Number: ST11267DS

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: ST11267DS

The Airplane Flight Manual Supplement, 104641-AFMS, Revision NEW, dated November 07, 2025 or later FAA approved revision shall be made available to the operator at the time of installation.

The Instructions for Continued Airworthiness, document number 104641-ICA, Revision B, dated October 6, 2025 or later FAA 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 A321-253NY aircraft for the change is as follows:

a. The Type Certification basis for Airbus Model A321-253NY airplanes 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, January 22, 2025 is based upon Part 25, as amended by Amendment 25-153. 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 the latest amendment 25-0 through 25-153:

25.21(a)(1), 25.29, 25.301, 25.303, 25.601, 25.603, 25.605, 25.609, 25.611(a), 25.789(a), 25.812(e)(1), 25.815,

25.853(a)(d)(e), 25.981(a)(3)(d), 25.1421, 25.1423(c), 25.1529, 25.1541, 25.1557(a)(c), 25.1585(a)(1)

Regulations at an intermediate amendment level:

25.613 Amendment 25-72, 25.791(a)(b)(e) Amendment 25-72

Regulations at the amendment level in TCDS A28NM:

25.305(a)(b), 25.307(a), 25.561, 25.619, 25.625, 25.787(a), 25.803(a), 25.811(b), 25.1301(a)(b)(c), 25.1309(a),

25.1411(a)(b)(c)(d)(e)(f)(g), 25.1447(a)(c)(1)

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 :

26.11(c) Amendment 26-7

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