# STC SA09213AC-D

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC System 30 ALT Altitude Hold System, Model ST-673.
- Applied: May 12, 1997
- Status date: May 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/ce/ba/ceba9413c5642547830f36372632620c312ee148b26c8a3d1f2d185ffda71452
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C8AB82853E9835C585256CC1007F3A1A.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA09213AC-D

## ADs that name it (0)

None.

## Approved models (4)

- Cessna Aircraft Company 172M ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Cessna Aircraft Company 172N ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Cessna Aircraft Company 172P ([TCDS 3A12](https://openairdocs.org/tcds/3A12))
- Cessna Aircraft Company 172Q ([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: SA09213 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 following product with the limitations and conditions thorofor as specifed heroon meets the anorthiness reguremonts of Part 3 of the bivil dir Regulations.

Original Product I ype Certificate Number: 3A12 Make: Cesssna Model: 172M, 172N, 172P AND 172Q Description of Type Design Change: ;

Installation of S-TEC System 30 ALT Altitude Hold System, Model ST-673, according to Bulletin No. 773, dated 5-09-97 and Master Drawing List No. 92991, dated 5-09-97 or later FAA Approved revisions of the above data (28 Volt System).

Also eligible on Cessna Models 172M, 172N, and 172P When Modified By 180 H.P. Engine Conversion.

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

Date of Application: 5-12-97 Date voisued:

Date of Issuance: 5-16-97 Date Amended:

EDERAL AVIATION By Direction of the Administrator LL Signatu TOMINISTRATO William J. Thomas DAS Staff Coordinator, DAS 5 SW (Title)

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA09213 AC-D Limitations and Conditions: (con't.)

2. FAA/DAS Approved Supplemental Flight Manual, P/N 891374, dated 5-16-97 is required for Cessna Models 172M; and 172N, S/N 17271034 And Below; and Cessna Models 172M; and 172N, S/N 17271034 and Below When Modified By 180 H.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 891375, dated 5-16-97 is required for Cessna Models 172N, S/N 17271035 And On; 172P and 172Q;

and Cessna Models 172N, S/N 17271035 And On and 172P When Modified By 180 H.P. Engine Conversion or later FAA Approved revisions of the above supplement.

4. 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

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)

- May 16, 1997: Issued, Current. [certificate](https://openairdocs.org/files/sha256/ce/ba/ceba9413c5642547830f36372632620c312ee148b26c8a3d1f2d185ffda71452)

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