Incident Overview
The pilot reported that during a landing approach, the engine lost power after he activated the carburetor heat. The aircraft subsequently landed off the runway and struck a drainage ditch during the landing rollout. The pilot was able to perform an immediate turn toward the runway and land on the grass after determining the airplane would not reach the runway surface.
Pilot Actions
According to the pilot, he had reduced power to 20 inches of manifold pressure for approximately two minutes to slow the aircraft for lowering the landing gear. When the airplane was abeam the runway numbers, he pulled the carburetor heat on. Shortly thereafter, the engine coughed and lost power. The pilot then made an immediate turn to the runway. He checked that the fuel pump was on and attempted to pump the throttle, but it had no effect. He landed on the grass to the left of the runway when it became apparent the airplane was going to land short.
Environmental Conditions
The reported temperature and dew point were 80 and 70 degrees Fahrenheit, respectively. According to the Aviation Safety Bureau Transport Canada guide for favorable icing conditions, this temperature and dew point spread placed the airplane in the 'moderate icing-glide power' range.
Post-Accident Inspection
Following the accident, the engine was inspected and started. It was run and no anomalies were noted.