# SDR 96ZZZX4345

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: June 24, 1996
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: [N11HW](https://openairdocs.org/aircraft/N11HW), registered now
- Make and model: Beech 58
- Registry model: [Beech 58](https://openairdocs.org/model/beech-58) (OpenAirDocs)
- Aircraft serial: TH271
- System (JASC): [7714 · Engine RPM Indicating System](https://openairdocs.org/jasc/7714)
- Part: Tach Generator
- Part number: H60050
- Condition: Shaft Sheared
- Location: Tach Drive
- Stage of operation: IN
- Nature of condition: W
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/96ZZZX4345

## Discrepancy

THE TACHOMETER GENERATOR FAILED UNDER NORMAL OPERATING CONDITIONS.  THE SUSPECT CAUSE IS A SMALL O-RING FITTED ON THE DRIVESHAFT AND INSIDE THE ROTOR SHAFT IS AN UNSPECIFIED PART.  (DOES NOT APPEAR IN PARTS BREAKDOWN.)  THIS O-RING RESTRICTED THE SELF-CENTERING ACTION OF THE DRIVESHAFT WITH MATING DRIVE ON THE AIRCRAFT.  THIS CAUSED THE DRIVESHAFT TO FAIL.

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