# SDR 20000403SH002

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: March 6, 2000
- Submitted: April 3, 2000
- Operation: General aviation
- Aircraft: [N421LH](https://openairdocs.org/aircraft/N421LH), registered now
- Make and model: Cessna 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (OpenAirDocs)
- Aircraft serial: 421C1207
- Engine: Cont GTSIO520N
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Stud
- Condition: Failed
- Location: Engine
- Part time: 128 hours
- Component: Engine
- Stage of operation: NR
- How discovered: V
- Nature of condition: K
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/20000403SH002

## Discrepancy

DURING NORMAL ENGINE OPERATION, NOTICED OIL LEAK ON FRONT OF ENGINE.  AFTER CLEANING AND INSPECTION, FOUND THE FRONT THROUGH-STUD BROKEN.  POSSIBLE CAUSE COULD BE IMPROPER HARDENING OF THE BOLT.  (X)

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