# STC ST04605CH

- Type: Supplemental type certificate
- Status: Current, Amended
- Holder: Preferred Improvements LLC, United States
- Description: Installation of a Garmin GTS 8000 Traffic Alert and Collision Avoidance System (TCAS) II
- Applied: March 30, 2022
- Status date: May 22, 2024
- Product: Aircraft, Large Airplane
- Certification basis: Part 25
- Data sheets: [TCDS A-669](https://openairdocs.org/tcds/A-669)
- Certificate PDF: https://openairdocs.org/files/sha256/2a/43/2a43cd7b1b157458e5bace5976edee21e93508a820cde6c5b85d8f1dd660c52b
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID107761200420240605182132.0001
- DRS record last changed: December 5, 2025
- Page: https://openairdocs.org/stc/ST04605CH

## 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.

ST04605CH Preferred Improvements, LLC 11234 Hackett Rd.

Apple Creek, OH 44606 Part 25 the Code of Federal Regulations A-669 The Boeing Company DC3C-SC3G; DC3C-S1C3G;

DC3C-S4C4G; DC3C-R-1830-90C Installation of a Garmin GTS 8000 Traffic Alert and Collision Avoidance System (TCAS) II in accordance with Preferred Improvements, LLC Master Data List, Doc. No. DC3-108-001, Revision C, dated January 31, 2024, or later FAA approved revision.

(See continuation sheet 3 of 4 for complete Description of Type Design Change.)

1) The installer must determine whether this design change is compatible with previously approved modifications.

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

(See continuation sheet 3 of 4 for complete Limitations and Conditions.)

March 30, 2022 March 21, 2023 May 22, 2024 Paul (Vu) Nguyen Manager, Central Certification Branch Compliance & Airworthiness Division Aircraft Certification Services 4 FOR:

ST04605CH 4

ST04605CH Date of Issuance: March 21, 2023 Date Amended: May 22, 2024

Description of Type Design Change (continued):

Preferred Improvements, LLC Airplane Flight Manual Supplement (DC3-108-202, Revision A, approved April 11, 2024, or later FAA approved revision) is required with this installation.

The aircraft must be maintained in accordance with the FAA-accepted Instructions for Continued Airworthiness (DC3-108-203, Revision C, dated October 19, 2023, or later FAA approved revision).

3) The aircraft must be modified by the following STCs:SA3820SW, ST11178SC and ST04530AT

4) The aircraft must have FAA approved installation of the following avionics: Dual Garmin GTX 3000 Mode-S Transponders with ADS-B Out and Dual Garmin GTN 750 Series GPS/WAAS Navigators

5) Skin thickness in areas of antenna installations must be confirmed prior to alteration.

6) 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.

(See continuation sheet 4 of 4 for complete Certification Basis.)

ST04605CH Date of Issuance: March 21, 2023 Date Amended: May 22, 2024

Certification Basis (continued)

b. The certification basis for parts changed or affected by this change since the reference date of application, March 30, 2022, is shown on TCDS A-669, plus the following:

FAR Part 4b, Sections:

Structures 4b.200(a)(b)(c)Orig.; 4b.201(a)(b)(c)Orig.;4b.202(a)(b)Amdt.4b-3; 4b.260(a)(c)Orig.;

4b.261Orig.;

4b.270(a)Amdt.4b-12.

Design and Construction 4b.300Orig.; 4b.301Orig.; 4b.302Orig.; 4b.303Orig.; 4b.304(a)(b)Orig.; 4b.305Orig.;

4b.306(a)(b)(d)Orig.; 4b.307(c)Orig.

14 CFR Part 25, Sections:

25.1302, 25.1309(a)(b)(c), 25.1317, 25.1351(a)(1), 25.1541, 25.1585(a) - - Original Amendment.

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

25.1307 (c), 25.1581(a)(1-3) - - Amendment 72

25.1303 - - Amendment 90

25.1431 (a)(c)(d) - - Amendment 113

25.1301 (a)(1,2,3,4), 25.1310, 25.1353(a)(b), 25.1357(a)(c)(e)(f) - - Amendment 123

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## Every issue (2)

- May 22, 2024: Amended, Current. [certificate](https://openairdocs.org/files/sha256/2a/43/2a43cd7b1b157458e5bace5976edee21e93508a820cde6c5b85d8f1dd660c52b)
- March 21, 2023: Issued, Current. [certificate](https://openairdocs.org/files/sha256/bb/3f/bb3fc6ca9f52279fe263663ac2586c6bc0c1047e64e3c10ab0830e65347616dc)

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