# SDR AU001151

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 5, 2000
- Submitted: January 4, 2001
- Operation: General aviation
- Make and model: Hiller UH-12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (OpenAirDocs)
- Engine: Lyc VO540C2A
- System (JASC): [6220 · Main Rotor Head](https://openairdocs.org/jasc/6220)
- Part: Hub
- Part number: 5143711
- Condition: Cracked
- Location: Main Rotor
- Part time: 687 cycles
- Stage of operation: TO
- How discovered: O
- Nature of condition: F
- Precautionary procedure: C
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AU001151

## Discrepancy

(AUS) MAIN ROTOR HUB SEVERELY CRACKED IN AN AREA NOT KNOWN FOR CRACKING. FOLLOWING TAKEOFF CONTROL WAS ALMOST IMPOSSIBLE AND THE MASSIVE VIBRATION CAUSED THE FORE/AFT ENGINE MOUNT TO BE TORN FROM ITS HOUSING AND THE SHAFT TO CRACK. THE CRACK WAS OPENINGUP UNDER LOAD AND CAUSING A MASSIVE OUT OF BALANCE VIBRATION. THE  SEPARATION OF THE MAIN ROTOR BLADE WAS CONSIDERED IMMINENT.

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