# STC SA5740NM

- Type: Supplemental type certificate
- Status: Current, Issued
- Holder: Aviadesign Inc, United States
- Description: Installation of front wing spar reinforcement assembly.
- Applied: January 14, 1992
- Status date: July 16, 1992
- Product: Aircraft, Small Multi-Engine
- Certification basis: Part 21
- Data sheets: [TCDS 2A4](https://openairdocs.org/tcds/2A4)
- Certificate PDF: https://openairdocs.org/files/sha256/ce/fe/cefe2ef9a22d5d63ad82645721bdd70fcb6df18053a28e57bd19fd5c25c254b7
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FEC5B7544E15F14C85256CC200122B19.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/SA5740NM

## ADs that name it (4)

- [AD 2013-09-05](https://openairdocs.org/ad/2013-09-05): Fuselage · Twin Commander 690, 690A and 690B. Effective May 29, 2013. Named in the applicability
- [AD 94-04-12](https://openairdocs.org/ad/94-04-12): Wing Structure · Twin Commander 685, 690, 690A and 1 more. Effective Apr 12, 1994. Cited in the text
- [AD 94-04-14](https://openairdocs.org/ad/94-04-14): Spar Cap · Twin Commander 500-S, 500-U, 680-FL(P) and 6 more. Effective Apr 12, 1994. Cited in the text
- [AD 94-04-11](https://openairdocs.org/ad/94-04-11): Spar Cap · Twin Commander 500-S and 690B. Effective Apr 11, 1994. Cited in the text

## Approved models (3)

- Twin Commander Aircraft LLC 690 ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft LLC 690A ([TCDS 2A4](https://openairdocs.org/tcds/2A4))
- Twin Commander Aircraft LLC 690B ([TCDS 2A4](https://openairdocs.org/tcds/2A4))

## What the certificate says

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

United States of America Department of Transportation Federal Aviation Administration Supplemental Type Certificate Number: SA5740NM This certificate issued to: Aviadesign, Inc.

Suite 940, 300 Esplanade Drive Oxnard, CA 93030 Part 3 of the Civil Air Regulations.

Original Product -Type Certificate Number: 2A4 Make: Twin Commander Model: 685, 690, 690A, and 690B Description of Type Design Change: Installation of front wing spar reinforcement assembly in accordance with Aviadesign, Inc. Master Drawing List No. AD-AC-0192, Issue C, dated July 13, 1992, or later FAA approved revision.

Limitations and Conditions: . Approval of this change in type design applies to the above model aircraft only.

This approval should not be extended to other aircraft on which other previously approved modifications are incorporated unless it is determined that the relationship between this change and any of those previously approved modifications, including changes in type design, will introduce no adverse effect upon the airworthiness of that aircraft. A copy of this Certificate must be maintained as part of the permanent records for the modified aircraft.

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: January 14, 1992 Date Reissued:

Date of Issuance: July 16, 1992 Date Amended: Jenuary 6, 1999 AVIATION By direction of the oldi Ilman (Signature) COMINISTR Acting Manager, Seattle Aircraft Certification Office (Title)

## Every issue (1)

- July 16, 1992: Issued, Current. [certificate](https://openairdocs.org/files/sha256/ce/fe/cefe2ef9a22d5d63ad82645721bdd70fcb6df18053a28e57bd19fd5c25c254b7)

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