Primary finding
Probable cause
the pilot's improper use of carburetor heat, which resulted in carburetor ice and loss of engine power. Factors relating to the accident were: carburetor icing conditions, and the crop (corn) in the emergency landing area.
Investigator assessment
Analysis narrative
The pilot said that when he was turning final for landing, a complete power loss occurred. Also, he said that trees on the approach prevented him from landing on the runway. Subsequently, the airplane was substantially damaged during a forced landing in a corn field. At the time of the accident, visibility was restricted by fog. About thirty minutes after the accident, at an airport 20 miles to the west-southwest of the accident site, the temperature/dew point spread was one degree (62F/61F). According to an icing 'probability' chart, conditions were conducive for carburetor ice. The pilot said he thought he had used the carburetor heat during the flight, but was unable to recall the position of the carburetor heat at the time the engine suffered the loss of power. An examination of the airplane after the accident failed to reveal any preexisting anomalies.
Source record
Factual narrative
On August 31, 1997, at 0815 eastern daylight time, a Cessna 150J, N60200, was substantially damaged during a forced landing in a corn field near Romeo, Michigan. The pilot said that when he was turning final for landing to the south at the Romeo Airport, the engine suffered a complete power loss and that trees on the approach prevented landing on the runway. The pilot and one passenger reported no injuries. Visibility was restricted in the area due to fog; however, exact conditions at the accident site were not reported. The personal 14 CFR Part 91 flight departed a private airport in Shelby Township, Michigan, about 0800. The nearest weather reporting station was 20 miles to the west-southwest. Thirty minutes prior to the accident that reporting station was reporting visibility restricted to two and one half miles in fog. The temperature/dew point spread was one degree (62F/61F). An icing "probability" chart is attached as an addendum to this report. The temperature and dew point calculations fall within the potential icing range for the float type carburetor on the accident airplane. The pilot said that he thought that he had used the carburetor heat during the flight, but was unable to recall the position of the carburetor heat at the time the engine suffered the loss of power. An inspection of the airplane and engine after the accident failed to reveal any preexisting mechanical anomalies. -