# STC SA09209AC-D

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC System 20/30 single and two axis automatic flight guidance systems, Model ST-671-20/30.
- Status date: August 27, 1999
- Product: Aircraft, Single-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A17](https://openairdocs.org/tcds/3A17)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2931A06D843CAB5585256CC1007F3A16.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA09209AC-D

## ADs that name it (0)

None.

## Approved models (8)

- The Cessna Aircraft Company R172E (USAF T-41B) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172E (USAF T-41C) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172E (USAF T-41D) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172F (USAF T-41D) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172G (USAF T-41C) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172G (USAF T-41D) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172H (USAF T-41D) ([TCDS 3A17](https://openairdocs.org/tcds/3A17))
- The Cessna Aircraft Company R172K ([TCDS 3A17](https://openairdocs.org/tcds/3A17))

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