# STC SA09355AC-D - Type: Supplemental type certificate - Status: Current, Issued - Holder: S-TEC Corporation, United States - Description: Installation of S-TEC system 20/30 single and two axis automatic flight guidance system Model ST-812-20/30 - Applied: April 10, 1998 - Status date: April 14, 1998 - Product: Aircraft, Small Multi-Engine - Certification basis: Part 21 - Data sheets: [TCDS 3A25](https://openairdocs.org/tcds/3A25) - Certificate PDF: https://openairdocs.org/files/sha256/d4/17/d417aebd50321c8bfe7bbcd716444933b59a4801b10b04f5311238ef00ae8669 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4AA3E5D8130212CF85256CC1007F3AAE.0001 - DRS record last changed: December 6, 2025 - Page: https://openairdocs.org/stc/SA09355AC-D ## ADs that name it (0) None. ## Approved models (5) - Cessna Aircraft Company 320B ([TCDS 3A25](https://openairdocs.org/tcds/3A25)) - Cessna Aircraft Company 320C ([TCDS 3A25](https://openairdocs.org/tcds/3A25)) - Cessna Aircraft Company 320D ([TCDS 3A25](https://openairdocs.org/tcds/3A25)) - Cessna Aircraft Company 320E ([TCDS 3A25](https://openairdocs.org/tcds/3A25)) - Cessna Aircraft Company 320F ([TCDS 3A25](https://openairdocs.org/tcds/3A25)) ## What the certificate says This is OCR from the scanned FAA certificate. OCR can misread letters and numbers. United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA09355 AC-D This certificate issued to: S-TEC Corporation One S-TEC Way Mineral Wells Municipal Airport Mineral Wells, TX 76067-9236 Certifies that the change in the type design for the felowing product with the limitations and conditions therefor as specifed hereen meets the aimorthiness requiements of I art 3 of the Crit i Kegulations. Original Product I ype Certifcato A umber: 3A25 Make: Cessna Al edel: 320B, 320C, 320D, 320E, and 320F Description of Type Design Change: Installation of S-TEC System 20/30 Single and Two Axis Automatic Flight Guidance System, Model ST-812-20/30. according to Bulletin No. 912, dated 4-08-98 and Master Drawing List No. 921087, dated 4-08-98 or later FAA Approved revisions of the above data (28 Volt System). FAA/DAS Approved Supplemental Flight Manual, P/N 891706, dated 4-14-98 is required for Cessna Models 320B, 320C, 320D, 320E, and 320F for S-TEC System 20 or later FAA Approved revisions of the above supplement. (See Continuation Sheet, Page 2, a part of this STC.) 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. Date of Application: 4-10-98 Date Reissued: Date of Issuance: 4-14-98 Date Amended: By Direction of the Administrator FEDERAL AVIATION Win Shames (Signature) TOMINSTRATON William J. Thomas DAS Staff Coordinator, DAS 5 SW (Title) f not exceeding $1,000, or Impri. ding 3 years, or both tificate may be t te with FAR 21.47. United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA09355 AC-D Limitations and Conditions: (con't.) 2 FAA/DAS Approved Supplemental Flight Manual, P/N 891710, dated 4-14-98 is required for Cessna Models 320B, 320C, 320D, 320E, and 320F for S-TEC System 30 or later FAA Approved revisions of the above supplement. Compatibility of this modification with other previously approved modifications must be determined by the installer. 000, or Imprlsonment not excreding 3 yeatse or bath- FAA Form 8110-2-1(10-69) Fage 2 of 2 This certificate may be transferred In accordance with FAR 21.49. TRANSFER ENDORSEMENT Transfer the ownership of Supplemental Type Certificate Number to (Name of transferee) - (Address of transferee) _ (Number and street) (City, State, and ZIP code) from (Name of grantor) (Print or type) (Address of grantor) (Number & street) (City, State, and ZIP code) Extent of Authority (if licensing agreement): Signature of grantor (In ink): ## Every issue (1) - April 14, 1998: Issued, Current. [certificate](https://openairdocs.org/files/sha256/d4/17/d417aebd50321c8bfe7bbcd716444933b59a4801b10b04f5311238ef00ae8669) --- 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.