Cessna 172K accident near Wilmot, Wisconsin, October 4, 2016
On October 4, 2016 at about 8:11 pm local time, a 1968 Cessna 172K, registered N46377, was substantially damaged in an accident during maneuvering near Wilmot, Wisconsin. 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
A failure of the No. 1 piston pin plug due to corrosion in the cylinder barrel, which resulted in oil contamination, oil starvation to the crankshaft connecting rod bearings, and a subsequent partial 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
- October 4, 2016 · about 8:11 pm local time
- Place
- Wilmot, Wisconsin · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172K, built 1968 · all 172Ks on the register
- Registration
- N46377 · no longer on the register · serial 17257226
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The private pilot stated that the engine experienced a partial loss of power shortly after takeoff on the local flight. In an effort to regain power, the pilot switched fuel tanks, applied carburetor heat, and richened the fuel mixture, but the engine continued to operate at reduced power. The pilot attempted to land at a nearby airport; however, he overshot the runway and decided to perform a forced landing to an adjacent cornfield. During the landing, the right wing impacted the corn, and the airplane came to rest upright. Partial disassembly of the engine revealed a failure of the No. 1 piston pin plug due to corrosion in the No. 1 cylinder barrel. The plug failure resulted in significant oil contamination and subsequent oil starvation and damage to the crankshaft connecting rod bearings. The damage to the bearings resulted in the partial 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
- Loss of engine power (partial) during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during emergency descent
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Fatigue/wear/corrosion
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,042 hours in all; 900 in this make and model; 1 in the last 90 days; 1 in the last 30 days; 1,042 as pilot in command
- Last flight review: May 1, 2015
- Medical certificate: Class 3
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 3,194 hours
- Last inspection: annual inspection, October 1, 2015; 34 hours since
- Maximum gross weight: 2,299 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-E2D (piston); 3,194 hours total
The flight
- Departed from: BUU Burlington WI at 7:45 pm
- Destination: PWK Wheeling IL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 140° at 6 knots, gusting 14
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 70°F (21°C), dew point 52°F (11°C)
- Altimeter: 30.02 inHg
- Observation at 8:15 pm from BUU, 11 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on November 9, 2016. 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, 9 pages | View Download |
| 2 | Excerpt of Engine Records | PDF, 1 page | View Download |
| 3 | Photo Array | PDF, 5 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.