# SDR QR9R2026073000001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 30, 2026
- Submitted: July 30, 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: 9702
- Aircraft time: 4,508 hours
- System (JASC): [7714 · Engine RPM Indicating System](https://openairdocs.org/jasc/7714)
- Part: Sensor
- Part number: 430106202
- Part serial: 2416917343450
- Condition: Faulty
- Location: Rotor Tach
- Stage of operation: TO
- 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/QR9R2026073000001

## Discrepancy

ON TAKEOFF, ROTOR RPM WARNING LIGHT AND NRO NEEDLE ON TRIPLE TACH WENT TO ZERO. REMOVED AND REPLACED ROTOR RPM SENSOR IAW AMM 63-21-00, 5-1.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.