# STC SA8386SW-D

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC yaw damper system, Model ST-529.
- Applied: April 12, 1994
- Status date: September 18, 1996
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 2A4](https://openairdocs.org/tcds/2A4)
- Certificate PDF: https://openairdocs.org/files/sha256/52/ef/52ef9fa40ebcedcbdf5393c015f405b3ffa283ab5a3228baf44add769d9cefb8
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/AA062D3486DA015A85256CC20058E76F.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA8386SW-D

## ADs that name it (0)

None.

## Approved models (1)

- Twin Commander Aircraft Corporation 680-E ([TCDS 2A4](https://openairdocs.org/tcds/2A4))

## What the certificate says

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

Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number 5A833654-0 This coolificate, issuad lo S-TEC Corporation 946 Pegram Mineral Wells, TX 76067 Port 3 of the CIVIl Air Rogulations Original Product -Typobontificato Numbon: 2A4 Make: Twin Commander Model: 680-E Description of Type Design Change:

installation ot S-ltc Yaw Damper System, Model Si-529, according to Bulletin No.

629, Revision 1, dated 9-11-96 and Master Drawing List No. 92677, Revision A, datec 9-11-96 or later FAA Approved revisions of the above data (28 Volt System).

1. FAA/DAS Approved Airplane Flight Manual Supplement, P/N 891057, dated 4-29-94 is required for Twin Commander Models 680-E and 720 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)

This certificate may be transferred in accordance with FAR 21.17.

FAN FoR 8110-2 (10-681

Hred Saces of Amera Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA838654-D, Revision 1 Limitations and Conditions: (con't.)

2. FAA/DAS Approved Airplane Manual Supplement, P/N 891057, Revision 1, dated 9-18-96 is required for Twin Commander Model 680-E or later FAA Approved revisions of the above supplement.

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

or hith FAN FORM 911ULZ-1 (10-68) This certificate may be transferred in accordance with I'll .I.t?

TRANSFER ENDORSEMENT Transfer the ownership of Supplemental Type Certificate Number — to (Name of transferee) (Address of transferee) (Number and street) (City, Stale, and ZIP code) from (Name of grantor) (Print or type) _ (Address of grantor) (Number and street) (City, Stale, and ZIP code) Extent of Authority (if licensing agreement): - Date of Transfer:

Signature of grantor (In ink): _

## Every issue (1)

- September 18, 1996: Amended, Current. [certificate](https://openairdocs.org/files/sha256/52/ef/52ef9fa40ebcedcbdf5393c015f405b3ffa283ab5a3228baf44add769d9cefb8)

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