# STC SA3-139

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Preferred Improvements LLC, United States
- Description: Installation of standard C-47 cargo door.
- Applied: November 11, 1957
- Status date: December 13, 2017
- Product: Aircraft, Large Airplane
- Certification basis: Part 21
- Data sheets: [TCDS A-669](https://openairdocs.org/tcds/A-669)
- Certificate PDF: https://openairdocs.org/files/sha256/f1/71/f171532c1ac13a022a7cdc980fd361642aa4dbc5e9eca361d893f6f9ce43b6f7
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9FAADC5C5062FE0286258211005E3775.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SA3-139

## ADs that name it (0)

None.

## Approved models (4)

- The Boeing Company DC3C-R-1830-90C ([TCDS A-669](https://openairdocs.org/tcds/A-669))
- The Boeing Company DC3C-S1C3G ([TCDS A-669](https://openairdocs.org/tcds/A-669))
- The Boeing Company DC3C-S4C4G ([TCDS A-669](https://openairdocs.org/tcds/A-669))
- The Boeing Company DC3C-SC3G ([TCDS A-669](https://openairdocs.org/tcds/A-669))

## 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.

FAA Form 8110-2 (5/14) Page 1 of

Part of the

Signature

Title SA3-139 Preferred Improvements, LLC 11234 Hackett Road Apple Creek, OH 44606 4a 2 Civil Air Regulations A-669 DC-3C Installation of Standard C-47 Cargo Door. Data required: Remmert-Werner Drawings No's. SK-10322, SK-10323 ( 2 sheets), SK-10325, SK-10180, or later FAA Approved revision.

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

Douglas 10/1/70; 3/25/81; 3/7/14; 12/5/17; 12/13/17 July 14, 1960 November 11, 1957 December 4, 1957 Grant E. Youngdahl Program Manager Wichita ACO Branch

FAA Form 8110-2 (5/14) Page 2 of

To (Name and address of transferee)

From (Name and address of grantor)

2 SA3-139

## Every issue (2)

- December 13, 2017: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/f1/71/f171532c1ac13a022a7cdc980fd361642aa4dbc5e9eca361d893f6f9ce43b6f7)
- March 7, 2014: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/0d/23/0d2396685306b129ccaef73883cbeaf34ba0ad3de93f36dddd21645810cdf91c)

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