# Accident 20250814021609A: Piper PA-18-150, Joliet, IL, August 14, 2025

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: August 14, 2025, 17:10 local time
- Place: Joliet, IL
- Airport: Joliet Regional
- Damage: Substantial damage
- Phase of flight: Cruise/Level Flight
- Operating rules: General operating rules (Part 91)
- Location: 41.5150° N, 88.1521° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=41.5150&lon=-88.1521&mi=10
- Aircraft: N476SM, registered now (https://openairdocs.org/aircraft/N476SM) (OpenAirDocs)
- Registry model: Piper PA-18-150 (registry code 7101828, https://openairdocs.org/model/piper-pa-18-150) (OpenAirDocs)
- Registry engine: Lycoming 0-320 series (registry code 41508, https://openairdocs.org/engine/lycoming-0-320-series) (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Reported engine: LYCOMING O-360-C4P
- People aboard: 1
- Fatal injuries: 0
- Other injuries: 0
- Pilot certificates: Commercial pilot
- Pilot flight hours: 1,088 total
- NTSB investigation: [NTSB CEN25LA322](https://openairdocs.org/ntsb/CEN25LA322) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20250814021609A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

ON AUGUST 14, 2025, AT APPROXIMATELY 1710 CENTRAL DAYLIGHT TIME, A PIPER PA-18-150, ^PRIVACY DATA OMITTED^, WAS SUBSTANTIALLY DAMAGED WHEN IT WAS INVOLVED IN AN ACCIDENT NEAR JOLIET, IL. THE PILOT WAS UNINJURED AND THERE WERE NO PASSENGERS ON BOARD. THE AIRCRAFT WAS OPERATED UNDER PART 91 BANNER TOW FLIGHT.

THE PILOT IN COMMAND (PIC) REPORTED AT APROXIMATELY 1710 LOCAL TIME, 2-HOURS INTO A PLANNED 3-HOUR FLIGHT, WHILE CRUSING AT AN ALTITUDE OF 1100 FEET ABOVE GROUND LEVEL (AGL), THE PIC HEARD A “LOUD BANG,” FELT A STRONG VIBRATION, AND THE AIRCRAFT EXPERIENCED A PARTIAL LOSS OF ENGINE POWER, WHICH ESCALATED TO A TOTAL LOSS OF ENGINE POWER. THE PIC ATTEMPTED TO RETURN TO KJOT, BUT DUE TO INSUFFECIENT ALTITUDE AND THRUST, DETERMINED A FORCED LANDING WAS IMMINENT. THE BANNER WAS JETTISONED AT 300 FT AGL OVER AN APARTMENT COMPLEX AND THE PIC EXECUTED A FORCED LANDING IN A SOCCER FIELD. UPON LANDING THE AIRCRAFT IMPACTED A CHAINLINK FENCE, GROUND LOOPED AND CAME TO REST ON THE SOUTHWEST CORNER OF THE SOCCER FIELD. THE AIRCRAFT SUSTAINED SUBSTANTIAL DAMAGE TO THE LEFT ELEVATOR, LEFT FORWARD AND AFT WING STRUT, WITH ADDITIONAL DAMAGE TO THE LEFT WING TIP AND PROPELLER.

DURING THE POST ACCIDENT INVESTIGATION OIL WAS FOUND IN THE EXHAUST PIPE AND ALONG THE BELLY OF THE AIRCRAFT. DURING THE ENGINE TEARDOWN EXAMINATION IT WAS REVEALED THAT THE #2 ENGINE CYLINDER EXHAUST VALVE HEAD WAS BROKEN OF THE EXHAUST VALVE STEM. MOST OF THE VALVE STEM REMAINED INSIDE THE VALVE GUIDE WHILE THE VALVE HEAD WAS DESTROYED INSIDE THE CYLINDER.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CEN25LA322](https://openairdocs.org/ntsb/CEN25LA322), Aug 14, 2025: Piper PA-18-150 (N476SM), Joliet, IL, substantial damage. Probable cause: The failure of the No. 2 cylinder exhaust valve, which resulted in a total loss of engine power.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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