# SDR CA101027007

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 4, 2010
- Submitted: January 4, 2011
- Operation: General aviation
- Make and model: Robsin R44RAVENII
- Aircraft time: 1,640 hours
- Engine: Lyc IO540AE1A5
- System (JASC): [6310 · Engine/Transmission Coupling](https://openairdocs.org/jasc/6310)
- Part: Sprag Assy
- Part number: C1883
- Condition: Cracked
- Location: Main Rotor
- Part time: 1,523 hours
- Stage of operation: TO
- How discovered: O
- Nature of condition: E, F
- Precautionary procedure: C
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA101027007

## Discrepancy

DURING T/O, BANG HEARD BY PILOT, ABORTED T/O.  CONFIRMED SUSPECTED SPRAG FAILURE DIAGNOSIS WITH HELICOPTERS AND PILOTS REPORTED SYMPTOMS. CLUTCH ASSY REPLACED IN FIELD. DIAGNOSIS FURTHER CONFIRMED BY DIASSASEMBLY OF RETURNED SPRAG UNIT BY MFG.

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