STC ST04671CH

Number: ST04671CH

Part 25 of the Federal Aviation Regulations.

Original Product Type Certificate Number: A16WE Make: Boeing Model: 737-700 Series

Date of Application: May 6, 2025 Date Reissued:

Date of Issuance: July 31, 2025 Date Amended: July 23, 2026 By Direction of the Administrator Signature:

Brenda L. Litchfield ODA Administrator Title: Envoy Aerospace, LLC ODA-831240-CE Astronics Connectivity Systems and Certification Corp.

804 S. Northpoint Blvd Waukegan, IL 60085 Installation of Southwest Airlines Interior Reconfiguration for Extended Leg Room (ELR) Cabin in accordance with Astronics Connectivity Systems and Certification Corp. Master Data List, Doc. No. DC104-142007C-00, Revision G, dated July 21, 2026, or later FAA-approved revisions.

1) This STC is applicable to all serial numbers for this Make-Model-Series.

2) The installer must determine whether this design change is compatible with previously approved modifications.

3) FAA Approved Airplane Flight Manual Supplement, Astronics Connectivity Systems and Certification Corp.

Doc. No. AFMS-142153-00, Revision -, approved July 23, 2026, or later FAA approved revision, is required on board the modified aircraft for the applicable configurations as defined in the Master Data List.

4) FAA Approved Airplane Flight Manual Supplement, Astronics Connectivity Systems and Certification Corp.

Doc. No. AFMS-142153-01, Revision -, approved July 23, 2026, or later FAA approved revision, is required on board the modified aircraft for the applicable configurations as defined in the Master Data List.

5) If the holder agrees to permit another person to use this certificate to alter a product, the holder must give the other person written evidence of that permission.

Number: ST04671CH

(Continuation Sheet) Number: ST04671CH Date Amended: July 23, 2026 Certification Basis:

Based on 14 CFR §§ 21.115 and 21.101, and the FAA policy for design changes that are identified as not significant in FAA Order 8110.48A, the certification basis for the Boeing 737-700 Series aircraft is as follows:

a. The type certification basis for the Boeing 737-700 Series aircraft is shown on TCDS A16WE for parts not changed or affected by the change.

b. This certification basis for parts changed or affected by the change since the reference date of application is based upon 14 CFR Part 25 as amended by Amendment 25-77 as follows:

Applicable to MDL Group 1:

Applicable regulations at the latest amendment 25-0 through 25-77 § 25.29(a)(b) § 25.301(a)(b) § 25.303 § 25.305(a)(b)(c) § 25.307(a) § 25.561(a)(b)(c) § 25.562(a)(b)(c) § 25.601 § 25.603(a)(b)(c) § 25.605(a) § 25.609(a) § 25.611 § 25.613(a)(b) § 25.619(a)(b)(c) § 25.625(a)(d) § 25.785(a)(b)(c)(d)(2)(f)(1)(3) § 25.785(i)(j)(k) § 25.787(a)(b) § 25.789(a) § 25.791(a)(b)(e) § 25.813(a)(b)(c)(d) § 25.815 § 25.817 § 25.1301(a)(b)(c)(d) § 25.1309(a)(b) § 25.1447(a)(c)(1) § 25.1529 § 25.1541(a)(b)

Applicable 14 CFR Part 25 regulations at other amendment levels § 25.853(a)(c) [Amdt 25-116].

Applicable 14 CFR Part 26 regulations at the latest amendment 26-0 through 26-7 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 latest amendment date of this STC, compliance has been found for the following regulations:

14 CFR § 26.11(c) [Amdt. No. 26-7]; § 26.47(c) [Amdt. No. 26-7]. This modification does not affect or create fatigue critical baseline structure.

Equivalent Level of Safety Findings ELOS Memorandum # TD8301SE-T-C-1; 14 CFR Part 25 25.813(c)(1)(i), 25.813(c)(2)(i) [Amdt 25-76];

Equivalent Level of Safety (ELOS) Finding for the Passageway to and Opening of Overwing Exits for Boeing 737-600, -700, -700C, -800, -900 Series Aircraft.

Special Conditions 25-358-SC, Special Conditions: Boeing Model 737 Series Airplanes; Seats with Non-Traditional, Large, Non- Metallic Panels [Docket No. NM359].

(Continuation Sheet) Number: ST04671CH Date Amended: July 23, 2026 Certification Basis: (continued) Applicable to MDL Groups 2-3:

Applicable regulations at the latest amendment 25-0 through 25-77 § 25.29(a)(b) § 25.301(a)(b) § 25.303 § 25.305(a)(b)(c) § 25.307(a) § 25.561(a)(b)(c) § 25.562(a)(b)(c)(1)-(4)(7)(8) § 25.601 § 25.603(a)(b)(c) § 25.605(a) § 25.609(a) § 25.611 § 25.613(a)(b) § 25.619(a)(b)(c) § 25.625(a)(d) § 25.785(a)(b)(c)(d)(2)(f)(1)(3) § 25.785(i)(j)(k) § 25.787(a)(b) § 25.789(a) § 25.791(a)(b)(e) § 25.813(a)(b)(c)(d) § 25.815 § 25.817 § 25.1301(a)(b)(c)(d) § 25.1309(a)(b) § 25.1447(a)(c)(1) § 25.1529 § 25.1541(a)(b)

Applicable 14 CFR Part 25 regulations at other amendment levels § 25.853(a)(c) [Amdt 25-116].

Applicable 14 CFR Part 26 regulations at the latest amendment 26 -0 through 26-7 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 latest amendment date of this STC, compliance has been found for the following regulations:

14 CFR § 26.11(c) [Amdt. No. 26-7]; § 26.47(c) [Amdt. No. 26-7]. This modification does not affect or create fatigue critical baseline structure.

Equivalent Level of Safety Findings ELOS Memorandum # TD8301SE-T-C-1; 14 CFR Part 25 25.813(c)(1)(i), 25.813(c)(2)(i) [Amdt 25-76];

Equivalent Level of Safety (ELOS) Finding for the Passageway to and Opening of Overwing Exits for Boeing 737-600, -700, -700C, -800, -900 Series Aircraft.

Special Conditions 25-358-SC, Special Conditions: Boeing Model 737 Series Airplanes; Seats with Non-Traditional, Large, Non- Metallic Panels [Docket No. NM359].

(Continuation Sheet) Number: ST04671CH Date Amended: July 23, 2026 Certification Basis: (continued) Applicable to MDL Groups 4-5:

Applicable regulations at the latest amendment 25-0 through 25-77 § 25.29(a)(b) § 25.301(a)(b) § 25.303 § 25.305(a)(b)(c) § 25.307(a) § 25.561(a)(b)(c) § 25.562(a)(b)(c) § 25.571(a)(b) § 25.601 § 25.603(a)(b)(c) § 25.605(a) § 25.607(a)(b)(c) § 25.609(a) § 25.611 § 25.613(a)(b) § 25.619(a)(b)(c) § 25.625(a)(d) § 25.785(a)(b)(c)(d)(2)(f)(1)(3) § 25.785(i)(j)(k) § 25.787(a)(b) § 25.789(a) § 25.791(a)(b)(e) § 25.813(a)(b)(c)(d) § 25.815 § 25.817 § 25.1301(a)(b)(c)(d) § 25.1307(c) § 25.1309(a)(b)(d)(g) § 25.1351(a)(1) § 25.1353(a)(b) § 25.1357(a)(c) § 25.1415(b)(1) § 25.1431(a)(b)(c) § 25.1447(a)(c)(1) § 25.1501(a)(b) § 25.1529 § 25.1541(a)(b) § 25.1581(a)(b)(d)

Applicable 14 CFR Part 25 regulations at other amendment levels § 25.853(a)(c) [Amdt 25-116], § 25.869(a)(4) [Amdt 25-113], § 25.981(a)(3) [Amdt 25-102].

Applicable 14 CFR Part 26 regulations at the latest amendment 26 -0 through 26-7 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 latest amendment date of this STC, compliance has been found for the following regulations:

14 CFR § 26.11(c) [Amdt. No. 26-7]; § 26.47(c) [Amdt. No. 26-7].

Equivalent Level of Safety Findings ELOS Memorandum # TD8301SE-T-C-1; 14 CFR Part 25 25.813(c)(1)(i), 25.813(c)(2)(i) [Amdt 25-76];

Equivalent Level of Safety (ELOS) Finding for the Passageway to and Opening of Overwing Exits for Boeing 737-600, -700, -700C, -800, -900 Series Aircraft.

Special Conditions 25-358-SC, Special Conditions: Boeing Model 737 Series Airplanes; Seats with Non-Traditional, Large, Non- Metallic Panels [Docket No. NM359].

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