# STC SA09140AC-D

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC System 55 Two Axis automatic flight guidance system, Model ST-621, with Optional Autotrim System.
- Applied: February 7, 1996
- Status date: May 3, 1996
- Product: Aircraft, Single-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A21](https://openairdocs.org/tcds/3A21)
- Certificate PDF: https://openairdocs.org/files/sha256/c6/cc/c6cc8782cf4745965694861f23fad3fd9aab96ad50ac72ae236a2c5c7c6f1dba
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4F9D95B13DFCC27B85256CC1007F39DD.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA09140AC-D

## ADs that name it (0)

None.

## Approved models (4)

- Cessna Aircraft Company 210 ([TCDS 3A21](https://openairdocs.org/tcds/3A21))
- Cessna Aircraft Company 210A ([TCDS 3A21](https://openairdocs.org/tcds/3A21))
- Cessna Aircraft Company 210B ([TCDS 3A21](https://openairdocs.org/tcds/3A21))
- Cessna Aircraft Company 210C ([TCDS 3A21](https://openairdocs.org/tcds/3A21))

## What the certificate says

This is OCR from the scanned FAA certificate. OCR can misread letters and numbers.

Enitri States a Baerica Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA09140AC-D This certificate issued to: S-TEC Corporation 946 Pegram Mineral Wells, Texas 76067 Certifies that the change in the type design for the following product with the limilations and conditions shorefer as specified hereon meels the sinvorthiness requirments of Port 3 of the CIVIl Air Regulations.

Original Product -Type Contificate Number: 3A21 Make: Cessna Model: 210, 210A, 210B, and 210C Description of Type Design Change:

Installation of S-TEC System 55 Two Axis Automatic Flight Guidance System, Model SI-621, with Optional Autotrim System, according to Bulletin No. 721, Revision 1, dated 3-13-96 and Master Drawing List No. 92899, Revision A, dated 3-13-96 with Optional Flight Director/Steering Horizon or later FAA Approved revisions of the above data (14 Volt System).

1. FAA/DAS Approved Supplemental Flight Manual, P/N 891233, dated 2-12-96 is required for Cessna Models 210, 210B, and 210C or later FAA Approved revisions of the above supplement.

(See Continuation Sheet, Page 2, a part of this STC.)

Thomas DAS Staff Coordinator, DAS 5 SW (Title)

47.

FAA FOss 8110-2 (10-68)

2. FAA/DAS Approved Supplemental Flight Manual, P/N 891234, dated 2-12-96 is required for Cessna Model 210A or later FAA Approved revisions of the above supplement.

3. FAA/DAS Approved Supplemental Flight Manual, P/N 891234-1, dated 5-03-96 1s required for Cessna Models 210 and 210A or later FAA Approved revisions of the above supplement.

4. FAA/DAS Approved Supplemental Flight Manual, P/N 891254, dated 5-03-96 is required for Cessna Models 210B and 210C or later FAA Approved revisions of the above supplement.

5. Compatibility of this modification with other previously approved modifications must be determined by the installer.

**47 PAGE 2 OF 2 PAGES**

## Every issue (1)

- May 3, 1996: Amended, Current. [certificate](https://openairdocs.org/files/sha256/c6/cc/c6cc8782cf4745965694861f23fad3fd9aab96ad50ac72ae236a2c5c7c6f1dba)

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