What happened
The aircraft was operating at an altitude between 500 and 1,200 feet above ground level when the engine began exhibiting rough running characteristics. In response to the irregular operation, the pilot adjusted the fuel mixture control. Approximately ten minutes later, the engine experienced a recurrence of rough running, prompting the pilot to apply carburetor heat.
Despite these corrective actions, the engine subsequently lost all power. The pilot initiated a forced landing procedure and successfully touched down in a snow-covered field. A post-accident examination of the aircraft revealed the presence of ice inside the airbox, indicating that the power loss was caused by carburetor icing.
The investigation
A physical inspection of the aircraft following the accident was conducted to determine the mechanical status of the engine and associated components. The investigation focused on the intake system where the power loss originated.
The examination confirmed that significant ice accumulation had occurred within the airbox. This finding provided direct evidence of the mechanism that led to the engine failure during flight.