# SDR 8PCR20171031001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 31, 2017
- Submitted: October 31, 2017
- Operation: Air carrier
- Aircraft: [N258PB](https://openairdocs.org/aircraft/N258PB), registered now
- Make and model: Cessna 402C
- Registry model: [Cessna 402C](https://openairdocs.org/model/cessna-402c) (OpenAirDocs)
- Engine: Cont TSIO520VB
- Engine time: 1,943 hours
- System (JASC): [8520 · Reciprocating Engine Power Section](https://openairdocs.org/jasc/8520)
- Part: Bolt
- Part number: 656990
- Condition: Sheared
- Location: Engine
- Part time: 1,943 hours
- Stage of operation: TX
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/8PCR20171031001

## Discrepancy

ENGINE DISASSEMBLED FOR OVERHAUL.  CRANKSHAFT CLUSTER GEAR BOLTS (6 EACH) SHEARED.  NEW PART NUMBER LARGE GEAR (P/N 656991) AND BOLTS (P/N 656990) WERE IN PLACE IAW LATEST SERVICE BULLETINS.  LACK OF FRETTING SIGNATURES ON CRANKSHAFT GEARS AND ATTACHING BOLTS INDICATE THAT THIS WAS A SINGLE OVERLOAD EVENT; LIKELY KICK-BACK DURING STARTING.  NOTIFIED OPERATOR TO INSPECT SHOWER OF SPARKS STARTING SYSTEM.

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