# SDR QR9R2025040900001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 9, 2025
- Submitted: April 9, 2025
- Operation: General aviation
- Filed by: [M1 Support Services, repair station QR9R369D](https://openairdocs.org/faa-repair-station/QR9R369D/m1-support-services.md) (OpenAirDocs)
- Make and model: Bolkms BK117C2
- Aircraft serial: 9155
- Aircraft time: 4,864 hours
- System (JASC): [6240 · Main Rotor Indicating System](https://openairdocs.org/jasc/6240)
- Part: Sensor
- Part number: 430106202
- Condition: Faulty
- Location: Rotor Speed
- Stage of operation: CR
- How discovered: V
- Nature of condition: F
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QR9R2025040900001

## Discrepancy

LOW ROTOR RPM LIGHT ON THE WU WITH ASSOCIATED TONE CAME ON INADVERTANTLY 6 TIMES DURING A 30 MINUTE FLIGHT. DURING TROUBLESHOOTING OF MAIN ROTOR RPM SYSTEM, FOUND RPM MONITORING SYSTEM TO BE WORKING. RPM SENSOR IS AT FAULT. REMOVED AND REPLACED SPEED PICK-UP (NR SENSOR) IAW AMM 62-41-00, 4-1. MOC SUCCESSFULLY C/W IAW AMM 05-60-00,6-1.

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