Cessna 172I accident near Ettrick, Wisconsin, April 18, 1993
On April 18, 1993 at about 2:30 pm local time, a Cessna 172I, registered N8337L, was destroyed in an accident near Ettrick, Wisconsin. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AN INFLIGHT EXPLOSION OF A TOLUENE-BASED FLUID INSIDE THE AIRPLANE'S COCKPIT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 18, 1993 · about 2:30 pm local time
- Place
- Ettrick, Wisconsin · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172I · all 172Is on the register
- Registration
- N8337L · no longer on the register · serial 17256537
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
WITNESSES REPORTED THAT THE AIRPLANE FIRST SOUNDED NORMAL, AND THEN ITS ENGINE RPM INCREASED, FOLLOWED BY AN EXPLOSION & SMOKE. THREE WITNESSES OBSERVED THE AIRPLANE DURING AN UNCONTROLLED VERTICAL DESCENT. ONE STATED THE AIRPLANE EXPLODED APPROX 100 FT ABOVE THE GROUND. ANOTHER STATED HE OBSERVED THE AIRPLANE DESCENDING VERTICALLY, LOSING SIGHT OF IT JUST PRIOR TO OBSERVING FIRE AND SMOKE. THE THIRD STATED HE OBSERVED THE AIRPLANE FLYING STRAIGHT AND LEVEL, THEN SUDDENLY PITCH DOWN. DURING THE DESCENT, HE OBSERVED GREY SMOKE COMING FROM THE AIRPLANE. A CAN OF TCP FUEL TREATMENT WAS FOUND IN THE BURNT WRECKAGE. THE FILLER NECK AND CAP HAD DISTORTIONS WHICH DID NOT MATCH. TCP IS COMPRISED MAINLY OF TOLUENE, A HIGHLY VOLATILE SUBSTANCE. FUMES FROM A TOLUENE-BASED FLUID SUCH AS TCP COULD EXPLODE DURING THE LIGHTING OF A CIGARETTE. THE CAN WAS KEPT IN THE BAGGAGE COMPARTMENT BY THE OWNER. EIGHT PIECES OF WINDSHIELD PLEXIGLASS WERE FOUND AROUND THE IMPACT CRATER; THE REMAINDER OF THE WINDSHIELD WAS NOT FOUND.
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
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 155 hours in all; 104 in this make and model; 11 in the last 90 days; 3 in the last 30 days; 118 as pilot in command
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: annual inspection, January 6, 1993
- Maximum gross weight: 2,300 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-E2D (piston); 0 hours total
The flight
- Departed from: 20Y Monticello MN at 1:30 pm
- Destination: UGN Waukegan IL
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 180° at 13 knots
- Visibility: 8 statute miles
- Sky: overcast at 1,000 ft; not recorded at 1,000 ft
- Temperature: 52°F (11°C), dew point 45°F (7°C)
- Altimeter: 29.00 inHg
- Observation at 2:45 pm from LSE, 21 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.