# SDR CA150602015

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: May 13, 2015
- Submitted: August 5, 2015
- Operation: General aviation
- Engine: Pwa PW123
- System (JASC): [7320 · Fuel Controlling System](https://openairdocs.org/jasc/7320)
- Part: Hmu
- Condition: Malfunctioned
- Location: Nr 2 Engine
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA150602015

## Discrepancy

(CAN) THE NR 2 ENGINE IS ACCELERATING UNCOMMANDED WHEN THE TORQUE IS GREATER THAN 50 PERCENT.  THE ACFT RECENTLY DID AN AIR RETURN DUE TO A SLOW TORQUE FLUCTUATION ON NR 2 ENGINE.  THIS FAULT APPEARS TO HAVE BEEN RECTIFIED BY REPLACEMENT OF THE HMU.  THE SUBSEQUENT GROUND RUNS APPEARED NORMAL UNTIL THE POWER LEVERS ARE PUSHED ABOVE 50-60 PERCENT TORQUE AND AT THIS TIME THE NR 2 ENGINE STARTS AN UNCOMMANDED ACCELERATION THAT REQUIRES THE POWER LEVER TO BE RETARDED.  TROUBLESHOOTING IS ON GOING.

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