CHI02LA180

After takeoff, the airplane experienced a gradual loss of engine power and was substantially damaged during the resulting forced landing. The climb rate decayed until the pilot was unable to maintain a positive rate of climb. The airplane impacted a roof top antenna and landed in a residential area approximately one mile south of the airport. Temperature and dew point at the departure airport were reported as 32 degrees Celsius and 19 degrees Celsius, respectively. The post-accident engine examination revealed black, sooty deposits on all spark plugs and a black, sooty residue in the exhaust system. No other anomolies were noted. The pilot reported checking carburetor heat on run-up, however he did not apply carburetor heat prior to takeoff. In addition, the pilot reported that carburetor heat was not applied in response to the engine power loss. Based on statements from the pilot, two to four minutes elapsed between the time the run-up was completed and the takeoff was initiated. Other pilots operating on the day of the accident reported experiencing problems with carburetor ice. These pilots noted that carburetor heat was necessary during takeoff and climb. Data published by Transport Canada indicated a probability of light carburetor icing in these conditions.

On June 29, 2002, at 1453 central daylight time, an amateur-built Aune Glastar GS-1, N699S, piloted by a private pilot, was substantially damaged when it impacted an antenna and the terrain following a loss of engine power on initial climb after takeoff. The airplane had departed runway 16 (4,001 feet by 100 feet, asphalt), at the South St. Paul Municipal-Richard E Fleming Field Airport (SGS), South St. Paul, Minnesota. Visual meteorological conditions prevailed. The flight was being conducted under the provisions of 14 CFR Part 91 and was not on a flight plan. The pilot and his one passenger sustained serious injuries. The flight was originating at the time of the accident and was bound for the Faribault Municipal Airport (FBL), Faribault, Minnesota.

In his written statement, the pilot noted that immediately after takeoff "the climb rate was slightly less than normal, but all gauges checked OK. I continued to climb ..., but as I got to the tree line and houses, my climb rate seemed to be decreasing. As I got farther over the houses, my climb rate had turned to a descent and my RPMs had reduced to 2580." The pilot attempted to reach the river approximately one-half mile east of the airport, but was unable due to deteriorating climb performance. The pilot stated, "Before I could make it to the river, I had to land in a residential backyard." The aircraft clipped a roof top antenna and came to rest in the back yard of a single-family residence.

A post-accident engine examination by the FAA revealed black, sooty deposits on all spark plugs. The exhaust system was also found to contain a black, sooty residue. No other anomolies were noted. In addition, no anomolies were found with the fuel, ignition or air induction systems.

The pilot reported checking the carburetor heat during the run-up. He also stated that he did not apply carburetor heat in response to the loss of engine power after takeoff. The FAA inspector estimated the elapsed time between when the carb heat was applied during the run-up, and the time the takeoff was initiated as 2~4 minutes. The inspector went on to note that conversations with other pilots operating in the area on the day of the accident indicated that they experienced problems with carburetor ice, and that carburetor heat was necessary during takeoff and climb.

Weather conditions reported by the SGS AWOS, at 1458 cdt, included a temperature of 32 degrees Celsius, dew point 19 degrees Celsius, and altimeter 29.88 in. Density altitude was calculated at 3,080 feet.

Carburetor icing data published by Transport Canada indicates the probability of light carburetor icing at cruise or descent power with the reported temperature/dew point conditions.