# STC SE12225AC

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: High Cotton Aircraft Conversions, LLC, United States
- Description: This STC will incorporate P&W 1700 rpm propeller reduction gearbox on P&WC engines to allow 1700 rpm propeller installation
- Applied: December 6, 2023
- Status date: September 14, 2026
- Product: Engine
- Data sheets: [TCDS E4EA](https://openairdocs.org/tcds/E4EA)
- Certificate PDF: https://openairdocs.org/files/sha256/e5/b5/e5b5abd1c5fbaff1a76966fe8d19e417ad09cf78c8882593937ffdce5adba060
- Approved model list and other attachments: [SE12225AC_AML.pdf](https://openairdocs.org/files/sha256/09/16/0916f46990052d8d26ae27abddeb6436fb820e9206c790b1d076423facdd5067)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID164948627420260924201451.0001
- DRS record last changed: September 24, 2026
- Page: https://openairdocs.org/stc/SE12225AC

## ADs that name it (0)

None.

## Approved models (3)

- Pratt & Whitney Canada Corp. PT6A-41 ([TCDS E4EA](https://openairdocs.org/tcds/E4EA))
- Pratt & Whitney Canada Corp. PT6A-41AG ([TCDS E4EA](https://openairdocs.org/tcds/E4EA))
- Pratt & Whitney Canada Corp. PT6A-42 ([TCDS E4EA](https://openairdocs.org/tcds/E4EA))

## 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.

SE12225AC High Cotton Aircraft Conversions, LLC 6776 E Highland Dr.

Jonesboro, AR 72401 * * * See AML SE12225AC See AML SE12225AC See AML SE12225AC

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

(See Continuation Sheet 3 of 3) 12/06/2023 09/14/2026 11/25/2025 for Jason Deutschman Manager, Central Certification Branch Compliance & Airworthiness Division Aircraft Certification Service 3 This STC will incorporate P&W 1700 rpm propeller reduction gearbox on P&WC engines to allow 1700 rpm propeller installation per FAA Approved Model List (AML) No. SE12225A dated November 11, 2025, or later FAA approved revision.

FAA 8110-2 ( 10/24) Page 2 of __

SE12225AC 09/14/2026 3

SE12225AC 09/14/2026 Limitations and Conditions (continued):

2. The following Assembly, Installation and Maintenance Data is required:

a) Applicable Document: 6400002 Rev 5 dated Sept 22, 2025, Engine Kit Design Data, Assembly, PT6A-41, -41AG, -42, -43 MAX, or later accepted revisions.

b) Applicable Document: 6500001 Rev 4 dated Jul 5, 2025, Installation and Maintenance Instructions ENGINE, PT6A-41, -41AG, -42, -43 MAX, or later accepted revisions.

c) Applicable Document: 6500005 Rev IR dated Sept 2, 2025, Instructions for Continued Airworthiness, ICA ENGINE, PT6A-41 MAX, -41AG MAX, -42 MAX, -43 MAX, or later accepted revisions.

-END- 3 3

### SE12225AC_AML.pdf

**FAA APPROVED MODEL LIST (AML) NO. SE12225AC**

HIGH COTTON AIRCRAFT CONVERSIONS, LLC 6776 E HIGHLAND DR. JONESBORO, AR 72401 Date: See Digital Signature

Page 1 of 1

Approved Model List, PT6A-4X MAX Engine Item Make Model Cert Basis / Amend TCDS MDL / Assy DWG FMS ICA MFG P/N Model specific notes Initial Approval Date Amended Date 1 P&WC PT6A-41, PT6A-41AG CAR 13 Amend

13.6 E4EA 6400002 Rev 5 dated Sept 22, 2025

- 6500005 Rev IR dated Sept 2, 2025 6400002-41 MAX,

6400002- 41AG MAX 850 hp MC 12/9/25 - 2 P&WC PT6A-42 CAR 13 Amend

13.6 E4EA 6400002 Rev 5 dated Sept 22, 2025

- 6500005 Rev IR dated Sept 2, 2025 6400002-42 MAX

850 hp MC 12/9/25 - 3 P&WC PT6A-41, - 41AG, -42 CAR 13 Amend

13.6 E4EA 6400002 Rev 5 dated Sept 22, 2025

- 6500005 Rev IR dated Sept 2, 2025 6400002-43 MAX 950 hp MC, 1000 hp TO 12/9/25 -

FAA Approved _________________________________ for Paul Nguyen Manager, Central Certification Branch Compliance & Airworthiness Division Aircraft Certification Service

## Every issue (1)

- September 14, 2026: Reissued, Current. [certificate](https://openairdocs.org/files/sha256/e5/b5/e5b5abd1c5fbaff1a76966fe8d19e417ad09cf78c8882593937ffdce5adba060), [SE12225AC_AML.pdf](https://openairdocs.org/files/sha256/09/16/0916f46990052d8d26ae27abddeb6436fb820e9206c790b1d076423facdd5067)

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