# STC SA09237AC-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 Systems, Model ST-674-20/30.
- Applied: June 12, 1997
- Status date: June 16, 1997
- Product: Aircraft, Single-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A12](https://openairdocs.org/tcds/3A12)
- Certificate PDF: https://openairdocs.org/files/sha256/b8/d9/b8d9ffceaad66bff4c6fe92e579cadc2057b55884167d66167ded243eb3eb467
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D18FB65E22D58D8585256CC1007F3A35.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA09237AC-D

## ADs that name it (0)

None.

## Approved models (2)

- Cessna Aircraft Company 172M ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Cessna Aircraft Company 172N ([TCDS 3A12](https://openairdocs.org/tcds/3A12))

## 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: SA09237AC-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 following product with the limitations and conditions therefor as specifed hereon meets the aiworthiness regurements of Fart 3 of the Cird Air Regulations.

Original Product I ype Certifcate Number: 3A12 Make: Cessna Model: 172M AND 172N Description of Type Design Change:

Installation of S-TEC System 20/30 Single And Two Axis Automatic Flight Guidance Systems, Model ST-674-20/30, according to Bulletin No. 774, dated 6-11-97 and Master Drawing List No. 921007, dated 6-11-97 or later FAA Approved revisions of the above data (14 Volt System).

1. Also eligible on The Above Models When Modified By 180 H.P. Engine Conversion.

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

Date of Application: 6-12-97 Date Reissued:

Date of Issuance: 6-16-97 Date Amended:

By Direction of the Administrator FEDERAL AVIATION (Signature TOMINISTRATOR William J. Thomas DAS Staff Coordinator, DAS 5 SW (Title)

PAA Form 6110-2(10-68) Page 1 of 2

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA09237 AC-D Limitations and Conditions: (con't.)

2. FAA/DAS Approved Supplemental Flight Manual, P/N 891423, dated 6-16-97 is required for S-TEC System 20 for Cessna Model 172M And The Above Model When Modified By 180H.P. Engine Conversion or later FAA Approved revisions of the above supplement.

FAA/DAS Approved Pilot's Operating Handbook and/or Airplane Flight Manual Supplement, P/N 891424, dated 6-16-97 is required for S-TEC System 20 for Cesssna Model 172N And The Above Model When Modified By 180 H.P. Engine Conversion or later FAA Approved revisions of the above supplement.

4. FAA/DAS Approved Supplemental Flight Manual, P/N 891429, dated 6-16-97 is required for S-TEC System 30 for Cessna Model 172M And The Above Model When Modified By 180 H.P. Engine Conversion or later FAA Approved revisions of the above supplement.

5. FAA/DAS Approved Pilot's Operating Handbook and/or Airplane Flight Manual Supplement, P/N 891430, dated 6-16-97 is required for S-TEC System 30 for Cesssna Model 172N And The Above Model When Modified By 180 H.P. Engine Conversion or later FAA Approved revisions of the above supplement.

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

FAA Form 8110-2-1 (10-69) Page 2 of 2 This certificate may be transferred in accordance with FAR 21-47-

The EAA will reissue the certificate in the name of the transferee and forward it

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)

- June 16, 1997: Issued, Current. [certificate](https://openairdocs.org/files/sha256/b8/d9/b8d9ffceaad66bff4c6fe92e579cadc2057b55884167d66167ded243eb3eb467)

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