Piper PA-18-150 accident near Joliet, Illinois, August 14, 2025
On August 14, 2025 at about 10:14 pm local time, a 1975 Piper PA-18-150, registered N476SM, was substantially damaged in an accident during maneuvering near Joliet, Illinois. It was a banner-towing flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the No. 2 cylinder exhaust valve, which resulted in a total loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 14, 2025 · about 10:14 pm local time
- Place
- Joliet, Illinois · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150, built 1975 · all PA-18-150s on the register
- Registration
- N476SM · registry record · serial 18-7509080
- Damage
- Substantial damage
- Flight
- Banner-towing flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that he fueled the airplane and departed for a planned 3-hour banner tow flight. About two hours into the flight, he heard a “loud bang” from the engine, which resulted in strong vibrations and a gradual loss of engine power. Shortly after, the engine lost total power, and the pilot executed a forced landing to a field. During the landing roll, the airplane ground looped and impacted a fence, which resulted in substantial damage to the left elevator. Postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve failed. Most of the valve stem remained inside the valve guide while the valve head was destroyed inside the cylinder. There were no other engine mechanical malfunctions or anomalies that would have precluded normal operation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of engine power (total) during maneuvering defining event
- Collision during takeoff/land during landing (landing roll)
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,088.9 hours in all; 384.2 in this make and model; 352.6 in the last 90 days; 98.6 in the last 30 days; 986.3 as pilot in command
- Last flight review: August 26, 2024
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 12,252 hours
- Last inspection: annual inspection, January 3, 2025; 440 hours since
- Maximum gross weight: 1,750 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360-C4P (piston); 8,518 hours total
- Operator: Drake Aerial Enterprises LLC
The flight
- Departed from: KJOT Joliet IL at 8:15 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 84°F (29°C), dew point 61°F (16°C)
- Altimeter: 30.02 inHg
- Observation at 5:15 pm from KJOT, 1 miles away
Weather report (METAR): KJOT 142215Z AUTO 00000KT 10SM CLR 29/16 A3002 RMK AO2 T02890159
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Photographs from the investigation 10 pictures from the NTSB's docket, as the NTSB released them
Photograph 1 – Accident site
Photograph 2 – Oil under fuselage
Photograph 3 – Engine left side
Photograph 4 – No. 2 piston
Photograph 5 - No. 2 piston
Photograph 6 - No. 2 cylinder
Photograph 7 - No. 2 cylinder
Photograph 8 - No. 2 exhaust valve stem
Photograph 9 - No. 2 exhaust valve stem
Photograph 10 – No. 2 exhaust valve springs and push rodsThe NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on August 19, 2026. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 10 pages | View Download |
| 2 | FAA Engine Examination Summary | PDF, 3 pages | View Download |
| 3 | Engine Examination Summary | PDF, 2 pages | View Download |
| 4 | Photos | PDF, 11 pages · our copy | View Download |
| 5 | Maintenance Records (Engine) | PDF, 15 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.