# SDR 97ZZZX1153

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 28, 1997
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: [N303DC](https://openairdocs.org/aircraft/N303DC), registered now
- Make and model: Cessna 402B
- Registry model: [Cessna 402B](https://openairdocs.org/model/cessna-402b) (OpenAirDocs)
- Aircraft serial: 402B0303
- Engine: Cont TSIO520E
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Cylinder
- Part number: 653446A11
- Condition: Cracked
- Location: Nr 1-4-5 Cyls
- 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/97ZZZX1153

## Discrepancy

WHILE TROUBLESHOOTING A LEAKING INTAKE VALVE GUIDE SEAL, FOUND A CRACK IN THE NR 1 CYL EXHAUST PORT.  FOUND SAME CRACKS IN NR 4 AND NR 5  CYLINDERS.  YOU CANNOT SEE THEM WITHOUT DROPPING THE EXHAUST STACKS OFF THE ENGINE.  THESE CYLINDERS HAD APPROX 850 HOURS SMOH, BUT HAVE BEEN O.H. 2 PREVIOUS TIMES SO THEY MAY HAVE HAD AS MUCH AS 3650 HOURS SINCE NEW.  SUGGEST A 500 HOUR INSPECTION ON O.H. CYLINDERS ON TURBOCHARGED 520 ENGINES.

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