WPR11LA210

The pilot reported that, while on final approach, the engine rpm dropped and that the engine then lost power. He advanced the throttle, pushed in the carburetor heat control, and attempted to restart the engine, but engine power was not restored. He subsequently performed a forced landing to a road. During the landing, the airplane's right wing tip struck a sign and a mailbox, which resulted in substantial damage to the right wing spar. After the forced landing, the pilot was able to restart the engine, and he then taxied the airplane back to the airport. The pilot reported no known mechanical failures or malfunctions with the airplane, and a postaccident examination of the carburetor found no preaccident mechanical malfunctions or failures that would have precluded normal operation. Atmospheric conditions at the time of the accident were conducive to the formation of serious carburetor icing at glide power. It is likely that the pilot's delayed use of carburetor heat resulted in the total loss of engine power due to the accumulation of carburetor icing.

On April 24, 2011, at 0945 Pacific daylight time, a Cessna 150H, N23295, experienced a loss of engine power on final approach for the Martin Field Airport (S95), College Place, Washington. The airplane landed short of the runway on an adjacent road and collided with obstacles. The pilot/owner operated the airplane under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. The pilot, the sole occupant, was not injured. The airplane's right wing struck a sign, which resulted in substantial damage. Visual meteorological conditions prevailed for the local area flight that departed at 0930, and no flight plan had been filed.According to the pilot, he was doing touch-and-go takeoffs and landings. On the accident flight as he turned the airplane onto the base leg of the approach, the rpm's dropped. He pushed in the carburetor heat and checked the fuel selector. The pilot then attempted to restart the engine. The pilot turned the airplane toward the runway and tried to restart the engine again. He knew he was not going to make the runway, and an adjacent road seemed the best place to land instead of the soft, recently plowed field that was also nearby. He landed the airplane and on the rollout, the right wing struck the top of "watch for low-flying aircraft" sign. The pilot stated that after the airplane came to a stop, he attempted to restart the engine. On the second attempt, he first primed the engine, and was then able to start it. He then taxied the airplane back to his tie down spot at the airport. A weather reporting station about 6 nautical miles from the accident site reported a temperature of 48 degrees F and dew point of 30 degrees F at the time of the accident. These weather conditions were conducive to the formation of serious carburetor icing at glide power. A post accident examination and flow bench test of the airplane's carburetor revealed no anomalies that would have precluded normal operation.