# SDR QR9R2026042000001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 20, 2026
- Submitted: April 20, 2026
- 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: 9758
- Aircraft time: 4,845 hours
- System (JASC): [6240 · Main Rotor Indicating System](https://openairdocs.org/jasc/6240)
- Part: Sensor
- Part number: 430106202
- Part serial: 2116917337663
- Condition: Faulty
- Location: Rotor Tach
- Stage of operation: TX
- How discovered: V
- Nature of condition: F
- Precautionary procedure: C
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/QR9R2026042000001

## Discrepancy

AFTER STARTING ENGINE #2, INITIALLY NR APPEARED ON THE TRIPLE TACH AND MATCHED #2 N2, BUT THEN RETURNED TO 0.  A BATTERY DISCONNECT/RESET DID NOT RESOLVE THE PROBLEM. REMOVED AND REPLACED SPEED PICK-UP SENSOR.

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