STC ST12456IB

FAA 8110-2 (10/24) Page 1 of ___ IMPORT ST12456IB EAD Aerospace Airworthiness T/A Eclipse Technics 1 Rue De Chancarelle 84240 La Bastide Des Jourdans France Part 25 Title 14, Code of Federal Regulations T00001SE The Boeing Company 777-300 and 777-300ER Series

1. This STC is applicable to all serial numbers for the applicable Make and Model.

2. The installer must determine whether this design change is compatible with previously approved modifications. (See Limitations and Conditions on page 3 of 3) 12/22/2025 08/13/2026 John Yoo Manager, International Validation Branch Compliance & Airworthiness Division Aircraft Certification Service 3

1. Thinkom Satcom Antenna Installation on Boeing 777 in accordance with EAD Aerospace Master Document List 02009-EAS-C-MDL-01,Version A, Initial Release, dated April 10, 2026, or later EASA approved revisions.

(See Description of Type Design Change Continued on Page 3 of 3)

2. Maintenance in accordance with EAD Aerospace Instructions for Continued Airworthiness Supplement 02009-EAS-C-ICA-01, Version A, Initial Release, dated October 23, 2025, or later EASA accepted revisions.

3. Operation in accordance with EAD Aerospace Airplane Flight Manual Supplement 02009-EAS-C-AFM-01, Version A, Initial Release, dated April 10, 2026, or later EASA approved revisions.

3. Maintenance must be done in accordance with the Airworthiness Limitation (AWL) documents listed in the Instructions for Continued Airworthiness referenced in the Description section.

4. If the holder agrees to permit another person to use the certificate to alter the product, the holder shall give the other person written evidence of that permission.

Certification Basis:

The certification basis for this modification is based upon Part 25 as specified in Type Certificate Data Sheet (TCDS) T00001SE, except for areas changed or affected by the design change, for which the certification basis is the TCDS plus:

1. 14 CFR Part 25 regulations at Amendment 25-128: 25.23; 25.29; 25.101; 25.111; 25.113;

25.115; 25.117; 25.119; 25.121; 25.123 25.125; 25.145; 25.147; 25.149; 25.175;25.177;

25.251; 25.301; 25.303; 25.305; 25.307; 25.321; 25.333; 25.337; 25.341; 25.351; 25.365

25.367; 25.561; 25.571(a)(3)(b)(e); 25.581;25.601; 25.603; 25.605; 25.607; 25.609; 25.611;

25.613; 25.619; 25.623; 25.625; 25.629; 25.631; 25.777(a)(c);25.841; 25.869; 25.899;

25.901 (c); 25.1302; 25.1360; 25.1401; 25.1419; 25.1431(a)(c)(d); 25.1501; 25.1519;

25.1529; 25.1541; 25.1581; 25.1583; 25.1585; 25.1587.

2. Equivalent Level of Safety (ELOS) finding for 14 CFR 21.21(b)(1), 25.251(b) and (d):

FAA ELOS Memo ST20891IB-T -25.251, "Vibration/buffeting compliance criteria for large external antenna installation".

This modification has been substantiated to be a no acoustic change in accordance with 14 CFR 21.93(b).

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