# STC SA8391SW-D

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC System 65 two axis automatic flight guidance system, Model ST-533.
- Applied: May 11, 1994
- Status date: May 13, 1994
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 1A10](https://openairdocs.org/tcds/1A10)
- Certificate PDF: https://openairdocs.org/files/sha256/9d/22/9d222a413260d0109065409c3e814a795f3b3f3c1f16ae8155a8e5609f7ccd9a
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E72F24893827CCD985256CC20058E778.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA8391SW-D

## ADs that name it (0)

None.

## Approved models (2)

- The New Piper Aircraft Inc. PA-23-235 ([TCDS 1A10](https://openairdocs.org/tcds/1A10))
- The New Piper Aircraft Inc. PA-23-250 ([TCDS 1A10](https://openairdocs.org/tcds/1A10))

## 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: SA839154-0 This certificate issued to: S-TEC Corporation 946 Pegram Mineral Wells, Texas 76067 Certifies that the change in the type design for the following product with the limilations and conditions shamefor as specified heron meets the sinvonhiness requisoments of Port 3 of the CiVIl Air Regulations Original Product -Type Contificate Numbon: 1A10 Make: Piper Model: PA-23-235 and PA-23-250 Dissoviption of Typo Desigo Change:

Installation of S-TEC System 65 Two Axis Automatic Flight Guidance System, Model ST-533, according to Bulletin No. 633, dated 5-10-94 and Master Drawing List No.

92682, dated 5-10-94 with Optional Flight Director/Steering Horizon or later FAA Approved revisions of the above data (14 Volt System).

1. Only eligible on Model PA-23-250, S/N 27-1 through S/N 27-504.

2. FAA/DAS Approved Airplane Flight Manual Supplement, P/N 891096, dated 9-10-94 is required for Piper Models PA-23-235; and PA-23-250, S/N 27-1 Through S/N 27-504 or later FAA Approved revisions of the above supplement.

(See Continuation Sheet, Page 2, a part ot this SiC.)

Thomas DAS Staff Coordinator, DAS 5 SW (Title)

This certificate may be transferred in accordance with FAR 21.17 FAX FOR 81 10-2 (10-68)

niced Stores of merica Department of Transportation Federal Aviation Administration Supplemental Type Certificate (Continuation Sheet) Numbex 5A8391 5W-D Limitations and Conditions: (con't.)

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

or hoth FAR FORM 911UZ-1 (1068) This certificate may be transferred in accordance with fill i1.t7.

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): - Date of Transfer:

Signature of grantor (In ink): - U.S. GOVERNMENT PRINTING OFFICE: 1966 OF-205-579

## Every issue (1)

- May 13, 1994: Issued, Current. [certificate](https://openairdocs.org/files/sha256/9d/22/9d222a413260d0109065409c3e814a795f3b3f3c1f16ae8155a8e5609f7ccd9a)

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