# SDR 97ZZZX4430

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 18, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N501AL](https://openairdocs.org/aircraft/N501AL), registered now
- Make and model: Bolkms BO105C
- Aircraft serial: S58
- System (JASC): [6230 · Main Rotor Mast/Swashplate](https://openairdocs.org/jasc/6230)
- Part: Rotor Mast
- Part number: 4619305032
- Condition: Flange Cracked
- Location: Transmission
- Part time: 7,071 hours
- Component: 4638001004
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/97ZZZX4430

## Discrepancy

DURING MAIN ROTOR HUB REMOVAL NOTED THE MAIN ROTOR MAST FLANGE WAS FOUND CRACKED.  THE MAST FLANGE WAS FOUND CRACKED APPROXIMATELY THREE-FOURTHS AROUND.  THE CRACK WAS NEAR THE RADIUS OF THE FLANGE AND THE STUD HOLES.

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