# SDR 2025FA0000589

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 14, 2025
- Submitted: August 29, 2025
- Operation: General aviation
- Aircraft: [N476SM](https://openairdocs.org/aircraft/N476SM), registered now
- Make and model: Piper PA-18-180
- Registry model: [Piper PA-18-180](https://openairdocs.org/model/piper-pa-18-180) (OpenAirDocs)
- Aircraft serial: 187509080
- Aircraft time: 12,666 hours
- Engine: Lyc O360C4P
- Engine time: 8,518 hours
- Propeller: Mcauly 1A200FA
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Exhaust Valve
- Part number: 74541SL19001A
- Part serial: NA
- Condition: Departed
- Location: Engine
- Part time: 436 hours
- Stage of operation: CR
- How discovered: O
- Nature of condition: R, Y
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2025FA0000589

## Discrepancy

AIRCRAFT WAS IN CRUISE FLIGHT IN BANNER TOW CONFIGURATION.  A LOUD AUDITABLE BANG WAS HEARD.  ENGINE EXPERIENCED EXTREME VIBRATION FOLLOWED BY TOTAL LOSS OF POWER.  PILOT CONDUCTED A FORCED LANDING IN A SOCCER FIELD.  UPON ENGINE INSPECTION, #2 CYL. EXPERIENCED EXHAUST VALVE HEAD FAILURE FROM VALVE STEM.  THE VALVE HEAD IN TURN PUNCHED A HOLE THRU THE PISTON HEAD.  ALUMINUM FLAKES FOUND THROUGH OUT ENGINE, PRESUMABLY FROM PISTON DAMAGE.  ENGINE REMOVED FOR REBUILD.

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