# SDR M7K2008F00109

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 5, 2007
- Submitted: August 5, 2008
- Operation: Air carrier
- Aircraft: [N815MH](https://openairdocs.org/aircraft/N815MH), registered now
- Make and model: Urocop EC 130 B4
- Registry model: [Urocop EC 130 B4](https://openairdocs.org/model/eurocopter-ec-130-b4) (OpenAirDocs)
- Aircraft serial: 4022
- Engine: Tmeca ARRIEL2B1
- System (JASC): [6700 · Rotorcraft Flight Control](https://openairdocs.org/jasc/6700)
- Part: Potentiometer
- Part number: 116SF2C502W253
- Condition: Defective
- Location: Collective
- Part time: 930 hours
- Stage of operation: NR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/M7K2008F00109

## Discrepancy

AC HAD SOME SUDDEN YAWING WHEN PASSING THROUGH A SPECIFIC COLLECTIVE POWER SETTING THAT WAS REPEATABLE AND INDICATED A SUDDEN CHANGE OF ENGINE TORQUE SUCH AS ONE MAY EXPERIENCE WITH COMPRESSOR STALLS.  NO FAULT CODES WERE GENERATED AD THE ENGINE HAD NO OBSERVABLE DEFECT WHEN EXAMINED.  APPARENT THAT A DEAD SPOT HAD DEVELOPED IN THE POTENTIOMETER SIGNAL CONTROLLING ENGINE ANTICIPATION. NEW POTENTIOMETER WAS INSTALLED WITH NO FURTHER DEFECT.  (K)

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