# STC SA09548AC-D

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: S-TEC Corporation, United States
- Description: Installation of S-TEC/Chelton CA370S Air Data Attitude Heading Reference System (ADAHRS)
- Applied: June 23, 2008
- Status date: August 25, 2008
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21, Part 23
- Data sheets: [TCDS 2A4](https://openairdocs.org/tcds/2A4)
- Certificate PDF: https://openairdocs.org/files/sha256/96/f9/96f95103567af625bd269bd5512714e35b5ce87c432596523350bd08877f5a82
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3F933ECEBB624D33862574CE007D3F7B.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA09548AC-D

## ADs that name it (0)

None.

## Approved models (4)

- Twin Commander Aircraft Corporation 690C ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft Corporation 690D ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft Corporation 695 ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft Corporation 695A ([TCDS 2A4](https://openairdocs.org/tcds/2A4))

## What the certificate says

Read from the PDF's text layer, without the form's printed wording; the layout is lost and the order can differ. The PDF is the record.

This Certificate issued to

Part 23 of the Federal Aviation Regulations Original Product Type Certificate Number :

1. Installation of S-TEC/Chelton CA370S Air Data Attitude Heading Reference System (ADAHRS) Installation in accordance with Master Data Li st ST-930-L-0001 dated 8-18-08 or later FAA Approved revisions of the above data.

1. Prior installation of a Meggitt MA370S Air Data Attitude Heading Reference System (ADAHRS) is a prerequisite for the application of this STC

2. Compatibility of this modification with other previ ously approved modifications must be determined by the installer.

S-TEC Corporation One S-TEC Way Mineral Wells Municipal Airport Mineral Wells, TX 76067-9236 } Refer to TCDS, Make, Model on Page 4

Date of application : June 23, 2008 Date of issuance : August 25, 2008 Date reissued :

(Signature)

James W. Smisek DAS Administrator, DAS700096SW (Title)

FAA Form 8110-2-1(10-69) Page 2 of 4

Number SA09548AC-D

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)

Signature of grantor (In ink):

FAA Form 8110-2-1(10-69) Page 3 of 4

Number SA09548AC-D

Limitations and Conditions (con’t.)

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

Certification Basis: Compliance determination used for this STC FAR 23.301(a)(b)(c)--Loads FAR 23.1309--Equipment, systems, and installations FAR 23.303--Factor of Safety FAR 23.1323--Airspeed indicating system FAR 23.305--Strength and Deformation FAR 23.1325--Static pressure system FAR 23.307(a) - Proof of Structure FAR 23.1327--Magnetic direction indicator FAR 23.365(a)(b)(c)(d) FAR 23.1331--Instruments using a power source FAR 23.561(e)--Emergency Landing Conditions FAR 23.1351--Electrical Sy stems and Equipment - General FAR 23.571(a)--Metallic pressurized cabin structures FAR 23.1357--Electrical Systems and Equipment - Circuit protective devices FAR 23.575--Inspection and other procedures FAR 23.1359--Electrical system fire protection FAR 23.603-Materials and Workmanship FAR 23.1365--Electric cables and equipment FAR 23.605-(a)--Fabrication methods FAR 23.1431--Electronic Equipment FAR 23.607--Fasteners FAR 23.1501--General FAR 23.609--Protection of Structure FAR 23.1525--Kinds of operation FAR 23.611--Accessibility Provisions FA R 23.1527--Maximum operating altitude FAR 23.613--Material Strength properties FAR 23.1529--In structions for Continued Airworthiness (ICA FAR 23.615(a)(c) FAR 23.1559--Operating limitations placard FAR 23.619--Special Factors FAR 23.1581--Airplane Flight Manual and Approved Manual Material - General FAR 23.625--Fitting factors FAR 23.1583--Airpl ane Flight Manual and Approved Manual Material - Operating limitations FAR 23.627--Fatigue strength FAR 23.1585--Air plane Flight Manual and Approved Manual Material - Operating procedures FAR 23.867--Electrical bonding and protection against lightning and static electricity

FAR 23.1301--Function and installation FAR 23.1308--High-intensity Radiated Fields (HIRF) Protection

FAA Form 8110-2-1(10-69) Page 4 of 4

Number SA09548AC-D

**APPLICABLE MODEL LISTING**

**TCD S**

**MAKE AND MODEL 2A4 TWIN COMMANDER 690C, 690D, 695, 695A**

------------------------------------------------------------END ---------------------------------------------------------------- --

## Every issue (1)

- August 25, 2008: Issued, Current. [certificate](https://openairdocs.org/files/sha256/96/f9/96f95103567af625bd269bd5512714e35b5ce87c432596523350bd08877f5a82)

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