Cessna 172 accident near Wonewoc, Wisconsin, April 1, 2013
On April 1, 2013 at about 5:20 pm local time, a Cessna 172, registered N8033B, was substantially damaged in an accident during initial climb near Wonewoc, Wisconsin (Three Castles Airpark airport). It was a personal 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 restricted vented fuel cap and obstructed fuel vent lines, which resulted in a total loss of engine power due to fuel starvation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 1, 2013 · about 5:20 pm local time
- Place
- Wonewoc, Wisconsin · Three Castles Airpark · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172 · all 172s on the register
- Registration
- N8033B · no longer on the register · serial 29833
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, during the flight before the accident flight, the engine began running roughly during cruise flight with the right wing fuel tank selected. After attempting to resolve the issue by applying carburetor heat, he made a precautionary landing at a nearby grass airstrip. After landing, the pilot loosened the right fuel tank cap and heard a "whoosh" sound and the metal fuel tank "crinkle." The pilot stated that he thought he had resolved the fuel tank venting issue when he removed the right fuel tank cap. After spending 30 minutes on the ground, the pilot restarted the engine with both fuel tanks selected and performed an uneventful engine run-up before departing. Shortly after takeoff, the engine experienced a total loss of power, and the pilot executed a forced landing into a marsh. A postaccident examination revealed that the external and cross-tank vent lines were obstructed by foreign material likely deposited by insects. In this condition, the engine responded to cockpit controls during an operational test run. Following the engine test run, the right fuel tank cap was loosened, and a "whoosh" sound was heard. Testing of the right fuel cap revealed a restriction to the flapper-valve assembly, which prevented air from passing freely through the vented cap as designed. The combination of a restricted vented fuel cap and the obstructed vent lines likely prevented the fuel from flowing to the engine and resulted in fuel starvation and the total loss of engine power.
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
- Fuel related during initial climb
- Fuel starvation during initial climb
- Loss of engine power (total) during initial climb defining event
- Off-field or emergency landing during landing
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Aircraft › Aircraft systems › Fuel system › (general) › Inoperative
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 325 hours in all; 194 in this make and model; 15 in the last 90 days; 9 in the last 30 days; 197 as pilot in command; 0 on instruments
- Last flight review: September 7, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,488 hours
- Last inspection: annual inspection, September 21, 2012
- Maximum gross weight: 2,200 lb
- Seats: 4
- Landing gear: fixed
- Engine: Continental O-300-A (piston); 0 hours total
The flight
- Departed from: PKF Park Falls WI at 3:30 pm
- Destination: 3K6 St Jacob IL
- Flight plan: none
- Runway 28, 2,740 ft by 90 ft
Weather at the time
- Light: daylight
- Wind: from 270° at 18 knots, gusting 23
- Visibility: 10 statute miles
- Sky: a few clouds at 4,300 ft
- Temperature: 30°F (-1°C), dew point 12°F (-11°C)
- Altimeter: 30.13 inHg
- Observation at 4:55 pm from VOK, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.