# STC SA2206WE - Type: Supplemental type certificate - Status: Current, Reissued - Holder: United Airlines Inc, United States - Description: Installation of Bendix Third Attitude Indicator to meet the requirements of 14 CFR § 121.305(j) - Applied: March 30, 1970 - Status date: November 30, 2011 - Product: Aircraft, Large Multi-Engine - Certification basis: Part 21, Part 121 - Data sheets: [TCDS 4A28](https://openairdocs.org/tcds/4A28) - Certificate PDF: https://openairdocs.org/files/sha256/59/d1/59d11362b67ae9799c56807f7eac893feb53cf4baed0fe6968df9ce68732b2d3 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C484976D1738F2A48625799700575D31.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA2206WE ## 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. This Certificate issued to United Air Lines, Inc. 600 Jefferson Street Houston, Texas 77002 Part 4b of the Civil Air Regulations dated December 31, 1953; Amendments 4b-1 thru 4b-6 thereto; Item 2 of Special Civil Regulations No. SR-422B; Special Conditions and provisions of Amendments listed in Attachment A of FAA letter to Boeing dated October 12, 1959 Original Product Type Certificate Number : 4A28 Boeing 720-022 Description of Type Design Change: Installation of Bendix Third Attitude Indicator to meet the requirements of 14 CFR § 121.305(j) in accordance with FAA Approved United Air Lines Engineering and Maintenance Report F-1454 Appendix “A”, or later FAA approved revisions Limitations and Conditions: This approval of this change in ty pe design applies basically to Boeing Model 720-022 only. This approval s hould not be extended to other specific aircraft of this model on which other previously approved modifications ar e incorporated unless it is determined that the interrelationship between this cha nge and any of those other previ ously approved modifications will introduce no adverse effect upon the airworthiness of th at aircraft. This determination should include consideration of significant changes in weight distri bution such as an increased in the fixed disposable weight in the fuselage. If the holder agrees to perm it 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 30, 1970 Date of issuance: July 20, 1970 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 (2) - November 30, 2011: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/59/d1/59d11362b67ae9799c56807f7eac893feb53cf4baed0fe6968df9ce68732b2d3) - July 20, 1970: Issued, Historical. [certificate](https://openairdocs.org/files/sha256/ec/e9/ece9c7e7a11dbd35eba11f0441163f23b717d9d8eef88f3ad6bb76b6f1f7f63a) --- 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.