# Proposed AD 2003-NE-23-AD: Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) Models 250-C30R/3, -C30R/3M, -C47B, and--C47M Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2003-13-10
- Products: Rolls-Royce
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 9, 2004, 69 FR 32287
- Comments due: August 9, 2004
- Became: [AD 2003-13-10](https://openairdocs.org/ad/2003-13-10)
- Docket: 2003-NE-23-AD
- FR document: 04-13010
- Official PDF: https://openairdocs.org/files/sha256/c3/2f/c32f91df961147f727fb3d647557373261e1697ed4761a07ed4be55250f0c09b (from https://www.govinfo.gov/content/pkg/FR-2004-06-09/pdf/04-13010.pdf)
- Federal Register: https://www.federalregister.gov/documents/2004/06/09/04-13010/airworthiness-directives-rolls-royce-corporation-formerly-allison-engine-company-allison-gas-turbine
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DA21EDE797A3446086256EAE004D26BC.0001
- Page: https://openairdocs.org/proposed/2003-NE-23-AD

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) for RRC models 250-C30R/3, -C30R/3M, -C47B, and -C47M turboshaft engines. That AD currently requires initial and repetitive electrical signal inspections of the hydromechanical unit (HMU) Power Lever Angle (PLA) potentiometer. This proposed AD would continue to require those inspections and would add replacement of the existing HMU with a new design HMU as a mandatory terminating action to the repetitive inspection requirements. This proposed AD results from the manufacturer releasing a redesigned HMU that has a dual-element potentiometer. We are proposing this AD to prevent uncommanded and sudden changes in engine power.

## Notices in this docket

- Jun 9, 2004: Notice of proposed rulemaking (NPRM). (first notice), FR document 04-13010, comments due Aug 9, 2004 (https://www.federalregister.gov/documents/2004/06/09/04-13010/airworthiness-directives-rolls-royce-corporation-formerly-allison-engine-company-allison-gas-turbine)

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