Witness Account
A witness near the accident site heard a 'sputtering' engine noise. He went outside and observed the airplane about 50 to 100 feet above his barn, flying straight and level. The witness described the engine noise as 'missing, like the engine would stop and start.'
Accident Sequence
The pilot/owner of the airplane and a flight instructor had departed on a training flight. According to the witness, the airplane made a left turn towards a tree line, a second left turn that paralleled the tree line, and a third left turn towards a field. The airplane descended towards the field 'like it was trying to land.' It touched down towards the end of a 7.3-acre rectangular field and struck a fence located about 83 feet beyond the initial touchdown point.
Post-Crash Fire
A post-crash fire ensued following the fence strike.
Examination
Examination of the wreckage, which included an engine teardown, did not reveal any pre-impact mechanical malfunctions.
Carburetor Icing
Review of an FAA Carburetor Icing Probability Chart placed the temperature and dewpoint reported in the vicinity of the accident site in the 'serious icing at glide power' area of the chart.