# STC SA09530AC-D

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC System 55X Two-Axis Automatic Flight Guidance System, Model ST-904.
- Applied: September 18, 2002
- Status date: September 20, 2002
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 6A1](https://openairdocs.org/tcds/6A1)
- Certificate PDF: https://openairdocs.org/files/sha256/90/ed/90ed0689809e74c5528cbf0e9ba9db8c483d91d531075946a56d0df6a677b7c6
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CB421985DD39B25685256CC1007F3B48.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA09530AC-D

## ADs that name it (0)

None.

## Approved models (1)

- Twin Commander Aircraft LLC 500-S ([TCDS 6A1](https://openairdocs.org/tcds/6A1))

## What the certificate says

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

1117-200208 United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA09530AC-D This certificate issued to: S-TEC Corporation One S-TEC Way Mineral Wells Municipal Airport Mineral Wells, TX 76067-9236 I art 3 of the Civit stir Kegulations.

Original Product I ype Certificate Number: 6A1 Make: Twin Commander Model: 500-S Description of Type Design Change:

Installation of S-TEC System 55X Two Axis Automatic Flight Guidance System, Model ST-904, according to Bulletin No. 1004, dated 9-17-02 and Master Drawing List No. 921221, dated 9-17-02 or later FAA Approved revisions of the above data (28 Volt System).

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

If the holder agrees to permit another person to use this certificate to alter the product, the holder shall give the other person written evidence of that permission.

Date of Application: 9-18-02 Date Reissued:

Date of Issuance: 9-20-02 Date Amended:

By Direction of the Administrator FEDERAL AVIATION (Signature) TOMINSTRATO Michael Keirnan DAS Staff Coordinator, DAS 5 SW (Title)

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Number: SA09530ACD Limitations and Conditions: (con't.)

Eligibility limited to model 500-S, S/N 01755 through S/N 03305.

Also eligible on the above model when modified per STC SA585SW (extended nose).

FAA/DAS Approved Pilot's Operating Handbook and/or Airplane Flight Manual Supplement, P/N 892128, dated 9-20-02 is required for Twin Commander model 500-S, S/N 01755 through S/N 03305 and the above model when modified per STC SA585SW (extended nose) 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

INSTRUCTIONS: The transfer endorsemeat below may be used to notify the appropriate FAA Pegional Office of the transfer of this Supplemental Type Certificate.

The FAA will reissue the certificate in the name of the transferee and forward it to him.

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 and street) (City, State, and ZIP code) Extent of Authority (if licensing agreement):

Signature of grantor (In ink):

## Every issue (1)

- September 20, 2002: Issued, Current. [certificate](https://openairdocs.org/files/sha256/90/ed/90ed0689809e74c5528cbf0e9ba9db8c483d91d531075946a56d0df6a677b7c6)

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