# SDR 2001F00611

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 22, 2001
- Submitted: November 5, 2001
- Operation: Air carrier
- Aircraft: [N437AL](https://openairdocs.org/aircraft/N437AL), registered now
- Make and model: Bell 407
- Registry model: [Bell 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (OpenAirDocs)
- Aircraft serial: 53141
- System (JASC): [6510 · Tail Rotor Drive Shaft](https://openairdocs.org/jasc/6510)
- Part: Disc Pack
- Part number: 407340340103
- Condition: Cracked
- Location: Tail Rotor
- Stage of operation: IN
- 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/2001F00611

## Discrepancy

DAILY INSPECTION OF TAILROTOR DRIVESHAFT BEARINGS AND FOUND CRACKED DISC PACK.  THE COUPLING IS CRACKED, PROBABLE CAUSE IS EXCESSIVE RIGIDITY IN THE BEARING MOUNT SYSTEM.  ALLOW TAILROTOR DRIVESHAFT TO FLOAT SO DISC PACKS DO NOT FLEX AS MUCH OR AS OFTEN.  (M)

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