# STC ST11391DS - Type: Supplemental type certificate - Status: Current, Reissued - Holder: Aircraft Systems and Manufacturing, Inc., United States - Description: 5G Tolerant Radio Altimeter System Upgrade - Applied: August 20, 2024 - Status date: March 3, 2026 - Product: Aircraft, Large Airplane - Certification basis: Part 25 - Data sheets: [TCDS A16WE](https://openairdocs.org/tcds/A16WE) - Certificate PDF: https://openairdocs.org/files/sha256/1b/0f/1b0fc092accbe13eb70eb215efb617f55aadb6b5cf1bb3e06d434eb9a7ffafc9 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID179590097320260401163143.0001 - DRS record last changed: April 1, 2026 - Page: https://openairdocs.org/stc/ST11391DS ## ADs that name it (0) None. ## Approved models (3) - The Boeing Company 737-300 Series ([TCDS A16WE](https://openairdocs.org/tcds/A16WE)) - The Boeing Company 737-400 Series ([TCDS A16WE](https://openairdocs.org/tcds/A16WE)) - The Boeing Company 737-500 Series ([TCDS A16WE](https://openairdocs.org/tcds/A16WE)) ## What the certificate says Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record. ST11391DS Aircraft Systems and Manufacturing, Inc. 1717 Universal City Boulevard Universal City, Texas 78148 Part 25 Title 14 of the Code of Federal Regulations A16WE The Boeing Company 737-300/737-400/737-500 Series This STC is applicable to all serial numbers of the above-listed make-model-series aircraft. The installer must determine whether this design change is compatible with previously approved modifications. If the holder agrees to permit another person to use this certificate to alter the product, the holder must give the other person written evidence of that permission. See continuation on Page 3 of 3. 20-Aug-2024 11-Mar-2026 07-Dec-2025 Robert H. Wilcox ODA Administrator, ODA-834704-SW 3 5G Tolerant Radio Altimeter System Upgrade in accordance with Master Data List, Document Number 5806-0000-00, Revision IR, dated December 6, 2025, or later approved revision. ST11391DS 11-Mar-2026 3 ST11391DS 11-Mar-2026 Limitations and Conditions (continued): In addition to the basic aircraft maintenance manuals, the aircraft must be maintained in accordance with the Instructions for Continued Airworthiness (ICA) Document No. 5806-2170-00, Revision A, dated July 17, 2025, or later FAA accepted revision. Airworthiness Limitations inspections per 14 CFR Part 25, Appendix H are contained in Chapter 5 of the ICA. The FAA has reviewed the applicant's assessment showing that this modification does not impact the existing electrical wiring interconnection system instructions for continued airworthiness (EWIS ICA) and found that no additional EWIS ICA tasks are required. Certification Basis: The type certification basis for the Boeing 737-300/-400/-500 series aircraft for parts not changed or not affected by this change is shown on TCDS A16WE, Revision 79 dated August 19, 2025. The certification basis for parts changed or affected by this change is based upon Part 25 as amended through Amendment 25‐151 and Part 26 as amended through Amendment 26‐7. Regulations at the latest amendment 25-0 through 25-151 used for this modification: 14 CFR § 25.29(b), 25.301(a)(b), 25.303, 25.305(a)(b), 25.307(a), 25.603, 25.607, 25.609(a), 25.611(a), 25.613(a) (b)(c), 25.625(a)(b)(c), 25.1301(a), 25.1309(a)(b)(c)(d)(e), 25.1353(a), 25.1360(a)(b), 25.1363(b), 25.1431(a)(b)(c) (d), 25.1529, 25.1541. Regulations at the latest amendment 26‐0 through 26‐7 used for this modification: 14 CFR § 26.1, Amdt. 26-0; § 26.11(c), Amdt. 26-7 Regulations at an intermediate amendment: 25.869(a)(1)(4) Amdt. 113 Issue Paper: Project: ASM-24-10-ODA, Item: SA-1, Stage: 4, Date: December 6, 2024, Subject: Radio Altimeter Bandpass Filter Installation. -END- ## Every issue (1) - March 3, 2026: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/1b/0f/1b0fc092accbe13eb70eb215efb617f55aadb6b5cf1bb3e06d434eb9a7ffafc9) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.