# STC SE4-864

- Type: Supplemental type certificate
- Status: Current, Reissued
- Holder: Covington Aircraft Engines, Inc., United States
- Description: Increase in impeller drive ratio from 10:1 to 12:1.
- Status date: December 28, 2001
- Product: Engine
- Certification basis: Part 21
- Data sheets: TCDS 5E-1, [TCDS E-123](https://openairdocs.org/tcds/E-123)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/345BFAB9069543CD85256CC2005A755B.0001
- DRS record last changed: December 6, 2025
- Page: https://openairdocs.org/stc/SE4-864

## ADs that name it (0)

None.

## Approved models (2)

- Pratt & Whitney Division R-985 Series (TCDS 5E-1)
- Pratt & Whitney Division Wasp Jr. Series ([TCDS E-123](https://openairdocs.org/tcds/E-123))

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