# SDR 2003FA0000991

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 18, 2003
- Submitted: October 1, 2003
- Operation: General aviation
- Aircraft: N155WH
- Make and model: Urocop EC 155B
- Registry model: [Urocop EC 155B](https://openairdocs.org/model/eurocopter-ec-155b) (OpenAirDocs)
- Aircraft serial: 6563
- Engine: Tmeca ARRIEL1
- System (JASC): [8012 · Engine Start Valves/Controls](https://openairdocs.org/jasc/8012)
- Part: Switch
- Part number: 945UN01Q4AF8A
- Condition: Failed
- Location: Start
- Part time: 513 hours
- Stage of operation: NR
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2003FA0000991

## Discrepancy

DURING A TEST RUN FOLLOWING AN ENGINE CHANGE OF THE NR 1 ENGINE, THE NR 1 ENGINE FAILED TO RETURN TO IDLE WHEN THE NR 1 START SWITCH WAS BROUGHT FROM FLIGHT TO IDLE POSITION.  SUBSEQUENT TROUBLE-SHOOTING FOUND THAT THE SWITCH WOULD ALSO FAIL FROM IDLE TO FLIGHT POSITIONS. THIS CONDITION,  IF NOT REALIZED BY THE FLIGHT CREW, COULD RESULT IN AN UNDERPOWERED SINGLE ENGINE TAKE-OFF.  THIS IS NOT THE FIRST FAILURE OF THIS TYPE WITH THIS SWITCH.

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