# STC SA2833WE-D - Type: Supplemental type certificate - Status: Current, Reissued - Holder: United Airlines Inc, United States - Description: Installs two HF communications systems per United Air Lines drawing COA 4-1723. The system design is as much like Boeing installation on W. A. L. airplanes as possible but using Aeronautical Engineers Inc. design dual wire antenna systems per drawings AE2257 and AE2264 and South Eastern Region STC No. ST564SO. (720-022) - Applied: March 12, 1975 - Status date: November 30, 2011 - Product: Aircraft, Large Multi-Engine - Certification basis: Part 21 - Data sheets: [TCDS 4A28](https://openairdocs.org/tcds/4A28) - Certificate PDF: https://openairdocs.org/files/sha256/87/00/87009ee11d9cff1ee3ebe4e03803174c7c493673343fd4c7a04e6f33dde64fbc - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ED32E51A8FBC357E862579970055EAF5.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA2833WE-D ## ADs that name it (0) None. ## Approved models (1) - The Boeing Company 720 Series ([TCDS 4A28](https://openairdocs.org/tcds/4A28)) ## 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. 600 Jefferson Street Houston, Texas 77002 Part 4b of the Civil Air Regulations 4A28, Rev. A Boeing 720-022 Description of Type Design Change: Installs two HF communications systems per United Air Lines drawing COA 4-1723. The system design is as much like Boeing installation on W. A. L. airplanes as possible but using Aeronautical Engineers Inc. design dual wire antenna systems per drawings AE2257 and AE2264 and South Eastern Region STC No. ST564SO. Limitations and Conditions: This approval should not be extended to other specific airplanes of this model on which other previously approved modifications are incorporated, unless it is determined that the interrelationship between this cha nge and any of those other previously approved modifications will introduce no adverse effect upon the airworthiness of that airplane. 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. This certificate and the supporting data, which is the basis for approval, shall remain in effect until surrendered, suspended, revoked or a termination date is otherwise established by the Administrator of the Federal Aviation Administration. Date of application: March 12, 1975 Date of issuance: March 27, 1975 Date reissued: November 30, 2011 ( Signature) Haifa Haj-Eid Supervisor, Technical & Administrative Support Staff, Los Angeles Aircraft Certification Office ( Title) NOTE: **DO NOT DELETE THIS PAGE.** **DO NOT ADD ANY DATA TO THIS PAGE.** **THIS PAGE IS FOR PAGE NUMBERING PURPOSES, PLEASE DISCARD PRINTED COPY.** ## Every issue (1) - November 30, 2011: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/87/00/87009ee11d9cff1ee3ebe4e03803174c7c493673343fd4c7a04e6f33dde64fbc) --- 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.