# STC ST04530AT

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Preferred Improvements LLC, United States
- Description: Installation of a wingtip modification on DC3C aircraft (specific models listed)
- Applied: May 7, 2019
- Status date: December 12, 2021
- Product: Aircraft, Large Airplane
- Certification basis: Part 21, Part 21, Part 21, Part 21, Part 21, Part 21, Part 21, Part 21, Part 21, Part 25
- Data sheets: [TCDS A-669](https://openairdocs.org/tcds/A-669)
- Certificate PDF: https://openairdocs.org/files/sha256/c5/d4/c5d4df5c0f9d1ccb79de037e490b36efcb0c2d866e1f5b26e1562d617fb163e3
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID174936231020221130142549.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/ST04530AT

## ADs that name it (0)

None.

## Approved models (4)

- The Boeing Company DC3A-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))
- The Boeing Company DC3D-R-1830-90C ([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.

FFAA Form 8110-2 (03/21) Page 1 of ___ ST04530AT Preferred Improvements LLC 11234 Hackett Road Apple Creek, OH 44606 Part 25 the Federal Aviation Regulations A-669 The Boeing Company DC3C-SC3G, -S1C3G, -S4C4G, -R-1830-90C Installation of a wingtip modification on DC3C aircraft (specific models listed) in accordance with Master Drawing List 1806-1001, Revision A, dated October 27, 2021, or later FAA approved revision. Maintenance procedures are to be conducted in accordance with Instructions for Continued Airworthiness 1806-6101, Revision B, dated March 12, 2021, or later FAA approved revision.

(Limitations and Conditions are listed on page 3 of 3) May 7, 2019 December 13, 2021 November 17, 2021 (for) Christina M. Underwood, Manager Atlanta Aircraft Certification Office 3

1. Compatibility of the design change with previously approved modifications must be determined by the installer.

2. The aircraft must be modified by STCs SA3820SW and ST11178SC prior to installation of this modification.

3. A copy of this STC must be included in the permanent record of the modified aircraft.

4. If the holder agrees to permit another person to use this certificate to alter a product, the holder must give the other person written evidence of that permission.

Certification Basis:

Based on 14 CFR §§ 21.115 and 21.101, and the FAA policy for significant changes in FAA Order 8110.48, the certification basis for this change is as follows:

a. The certification basis for parts not changed or not affected by this change is shown on TCDS A-669.

b. The certification basis for parts changed or affected by this change since the reference date of application, May 7, 2019, is shown on TCDS A-669, plus the following:

FAR Part 4b, Sections: 100(a)(b)(c)(g), 101(a)(2)(3)(c)(2)(3), 102, 104, 200, 201, 202, 210, 211, 213, 214, 270, 300, 301, 302, 303, 304(a)(b), 305, 306, 307, 308.

CFR Part 25, Sections:

25.251, 25.1301(d), 25.1353(a)(b), 25.1385(a)(b), 25.1387(a)(b)(c), 25.1389, 25.1391,

25.1393, 25.1395 -- Original Amendment.

25.581(a)(b), 25.1309(a)(b)(d), 25.1419(a)(b) -- Amendment 23.

25.1529, H25.1, H25.2, H25.3, H25.4 -- Amendment 54.

25.1317 -- Amendment 122.

25.899 -- Amendment 123.

25.1316 -- Amendment 134.

----------------------------------------END---------------------------------------- 3 3

## Every issue (3)

- December 12, 2021: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/c5/d4/c5d4df5c0f9d1ccb79de037e490b36efcb0c2d866e1f5b26e1562d617fb163e3)
- December 12, 2021: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/8c/a6/8ca650189a84bbd797bdb4ef992a25db44c5c6bb5b6bb549dfc13d98e47d2dff)
- December 12, 2021: Reissued, Historical. [certificate](https://openairdocs.org/files/sha256/c5/d4/c5d4df5c0f9d1ccb79de037e490b36efcb0c2d866e1f5b26e1562d617fb163e3)

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