# Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) Models 250-C30R/3, -C30R/3M, -C47B, and -C47M Turboshaft Engines
> **Rule** · Final rule; request for comments. · Published 2003-06-30 · Effective 2003-07-15 · 68 FR 38590
## Document
- **Document number:** 03-15993
- **Category:** airworthiness
- **Manufacturer:** Rolls-Royce Corporation (Formerly Allison
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 68 FR 38590
- **Publication date:** 2003-06-30
- **Effective date:** 2003-07-15
- **FAA docket:** Docket No. 2003-NE-23-AD
## Abstract

The FAA is adopting a new airworthiness directive (AD) for Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) models 250-C30R/3, -C30R/ 3M, -C47B, and -C47M turboshaft engines. This AD requires initial and repetitive electrical signal inspections of the hydromechanical unit (HMU) Power Lever Angle (PLA) potentiometer. This AD is prompted by an investigation by the National Transportation Safety Board (NTSB), which revealed that a potential undetected failure of the PLA potentiometer electrical signal could cause uncommanded and sudden changes in engine power. The actions specified in this AD are intended to prevent uncommanded and sudden changes in engine power.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2003/06/30/03-15993/airworthiness-directives-rolls-royce-corporation-formerly-allison-engine-company-allison-gas-turbine)
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