ATL94LA018

While returning from a supervised solo training flight, the aircraft engine lost power. After an unsuccessful restart attempt, including application of carburetor heat, the student pilot elected to continue the approach to the destination airport, which was approximately 3 miles ahead. The airplane landed in a grassy area adjacent to the runway and nosed over. Post accident examination of the engine failed to reveal any evidence of mechanical malfunction or fuel starvation. During the engine examination, the tops of the pistons appeared to have been steam cleaned during combustion. The engine was run on the airframe and operated normally. Weather conditions at the time of the accident were favorable for the formation of carburetor ice. At no time during the flight did the pilot report using the carburetor heat before the engine quit.

On November 12, 1993, at 1630 eastern standard time, a Cessna 150, N6461G, nosed over while attempting an emergency landing at Mathis Airport in Cumming, Georgia. The instructional flight operated under 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The airplane sustained substantial damage, and the student pilot was not injured. The training flight departed Cumming, at approximately 1400 hours.

The student pilot had completed some upper air maneuvers which included turns, altitude changes and various power applications. According to the student pilot, while enroute to Cumming, the engine quit about 3 miles northeast of the airport at 3000 feet. Attempts by the student pilot to restart the engine, including the application of carburetor heat, failed. Since the position of the aircraft was within gliding range of the airport, the pilot elected to continue the approach to Mathis Airport and established an approach to the northwest runway. The airplane touched down in a grassy area beside the runway. As the airplane rolled out from the landing, it collided with a soft spot on the end of the runway and nosed over.

Examination of the airplane disclosed that there were about eight to 10 gallons of aviation fuel in the fuel tanks. The examination further determined that the fuel filtration system was free of contaminants. After restoring the airplane to the normal upright position and cleaning the spark plugs of engine oil, a functional check of the engine was conducted. Before the engine was started, an examination of the cylinders through the spark plug holes was accomplished. This inspection discovered that the tops of the pistons appeared to have been "bead blasted"; except for the previous stated oil, the spark plugs were also clean. According to a mechanic witnessing the aircraft examination, the engine started within seven blades, and operated normally (see attached mechanic's statement).

Finally, according to the icing probability curves, weather conditions at the time of the accident were favorable for the formation of carburetor icing (see attached icing probability curves). At no time during the maneuvering phase of the flight, did the pilot report using the carburetor heat.