# STC SA231CE

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Ontic Engineering and Manufacturing Inc., United States
- Description: Twin engine synchronizer.
- Applied: March 6, 1964
- Status date: April 30, 2007
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 3, Part 21
- Data sheets: [TCDS 2A4](https://openairdocs.org/tcds/2A4)
- Certificate PDF: https://openairdocs.org/files/sha256/a7/f2/a7f2a78853de379277ae0f71192151fdf2b7ccb2a5f33b0d7cfee6f3c8e48185
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A316E6F6F3649CD1862572D4004C075C.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA231CE

## ADs that name it (0)

None.

## Approved models (3)

- Twin Commander Aircraft Corporation 560-F ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft Corporation 680-F ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft Corporation 680-FL ([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.

Part 3 of the Civil Air Regulations. (See Type Certificate Data Sheet No. 2A4 for Complete certification basis)

Original Product--Type Certificate Number: 2A4 Make: Twin Commander Aircraft Corporation Model: 560-F, 680F and 680FL

Install twin-engine synchronizer in accordance with Installation Manual Woodward Electronic Synchronizer Kit for Aero Commander Models 560F and 680F, 680FL, dated February 26, 1964 and drawing 213187 dated February 17, 1964 or later FAA approved revision.

1. Woodward Airplane Flight Manual Supplement dated April 29, 1964, or later FAA approved revision is required.

2. Compatibility of this design change with previous modifications must be determined by the installer.

3. 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.

Ontic Engineering and Manufacturing Inc.

20400 Plummer Street Chatsworth, CA 91311 Date of application : March 6, 1964

Date of issuance : April 29, 1964

Date reissued : September 30, 2005, April 30, 2007

( Signature) Thomas A. Enyart Manager, Propulsion Branch Los Angeles Aircraft Certification Office

( Title)

## Every issue (1)

- April 30, 2007: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/a7/f2/a7f2a78853de379277ae0f71192151fdf2b7ccb2a5f33b0d7cfee6f3c8e48185)

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