# SDR 2NVA2025042401

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 23, 2025
- Submitted: April 24, 2025
- Operation: Air carrier
- Aircraft: [N74808](https://openairdocs.org/aircraft/N74808), registered now
- Make and model: Robsin R44RAVENII
- Aircraft serial: 10974
- Aircraft time: 1,699 hours
- System (JASC): [6220 · Main Rotor Head](https://openairdocs.org/jasc/6220)
- Part: Yoke
- Part number: C9081
- Condition: Failed Insp
- Location: Main Rotor
- Part time: 500 hours
- Stage of operation: TX
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2NVA2025042401

## Discrepancy

LOSS OF MR RPM INDICATION DURING RUN UP. SUBSEQUENT VISUAL INSPECTION OF HALL EFFECT SENDERS REVEALED NON CONFORMITY OF C908-1 REV K YOKE. DISASSEMBLY REVEALED FULL TORQUE ON ALL FASTENERS, BUT WEAR ON SPLINES OF YOKE AND PINION. ALL INFO SENT TO ROBINSON HELICOPTER COMPANY TECHNICAL SUPPORT FOR EVALUATION. ASSEMBLY HAD 500 HOURS IN SERVICE.

---
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.