Incident Overview
A dual student pilot reported an engine failure while holding at 4,000 feet mean sea level in instrument meteorological conditions. The Minneapolis Air Route Traffic Control Center had cleared the aircraft for an approach, instructing the crew to overfly the airport at 4,000 feet on the localizer back course and then intercept the ILS. As the aircraft left the holding pattern, the engine shook violently for 2 to 3 seconds, followed by complete engine failure.
Pilot Actions
The pilot established a glide and declared an emergency with ARTCC. Attempts to restart the engine were unsuccessful. The aircraft broke out of clouds at approximately 500 feet above ground level over a forest. The dual student pilot reported looking for the least dense area and headed toward that site. The aircraft began encountering trees just as the pilot was attempting to stall the airplane. The aircraft came to rest in a wooded, swampy area.
Examination and Conditions
Examination of the wreckage revealed no anomalies. According to Department of Transportation/FAA/CT-82/44 Publication: Light Aircraft Piston Engine Carburetor Ice Detector/Warning Device Sensitivity/Effectiveness, June 1982, Carburetor Icing Probability Chart, the temperature (21 degrees Fahrenheit) and dew point (16 degrees Fahrenheit) at the time the airplane lost power places the probability for carburetor icing in the 'icing - glide and cruise power' area of the chart.