# STC SA7137SW-D

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC yaw damper system Model ST-404.
- Applied: January 14, 1987
- Status date: September 9, 1991
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 3A20](https://openairdocs.org/tcds/3A20)
- Certificate PDF: https://openairdocs.org/files/sha256/52/07/520777cb9e28e06dbba0931da5c6dbd5e2512c095296867e2bd57ff5f9eac6fa
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3DE45707AFD3430A85256CC20056A19D.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA7137SW-D

## ADs that name it (0)

None.

## Approved models (5)

- Raytheon Aircraft Company 65-90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Raytheon Aircraft Company 65-A90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Raytheon Aircraft Company B90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Raytheon Aircraft Company C90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))
- Raytheon Aircraft Company E90 ([TCDS 3A20](https://openairdocs.org/tcds/3A20))

## What the certificate says

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

Ban 500 & 9 dia Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number 5A713754-0 This contificato, issuas lo S-TEC Corporation Rt. 4, Bldg. 946 Wolters Industrial Complex Mineral Wells, Texas 76067 solifes that the shange in the lyps design for the following product with the limitations and conditions thomfor as specified horeon meets the sirworthiness requiremont of Port 3 of the CiVil Air Regulations Original Product -Typo Cortificala Numbos: 3A20 Make: Beech Model: 65-90, 65-490, B90, C90, and £90 Description of Type Design Change:

Installation of S-TEC Yaw Damper System, Model ST-404, according to Bulletin No.

504, Revision 2, dated 8-09-91 and Master Drawing List No. 92417, Revision B, dated 8-09-91 and/or later FAA Approved revisions of the above data (28 Volt System).

1. FAA Approved Supplement to Pilot's Operating Handbook and/or FAA Approved Airplane Flight Manual, P/N 89729, dated 2-04-87 is required for Beech Models B90 and C90 and/or later FAA Approved revisions of the above supplement.

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

2. FAA Approved Supplement to Pilot's Operating Handbook and/or FAA Approved Airplane Flight Manual, P/N 89729-1, dated 6-09-8/ is required for Beech Models 65-90, 65-A90, B90, and C90 and/or later FAA Approved revisions of the above supplement.

3. FAA Approved Supplement to Pilot's Operating Handbook and/or FAA Approved Airplane Flight Manual, P/N 89946, dated 9-09-91 is required for Beech Model E90 and/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.

**17 PAGE 2 OF 2 PAGES**

## Every issue (1)

- September 9, 1991: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/52/07/520777cb9e28e06dbba0931da5c6dbd5e2512c095296867e2bd57ff5f9eac6fa)

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