Flight Preparations
A layer of fog prevented the pilot from taking off as initially planned. After the fog condition improved, the pilot refueled the airplane with 11 gallons of aviation fuel and completed a preflight inspection. A runup was then conducted, and the pilot attempted a takeoff.
First Aborted Takeoff
As the airplane accelerated down the runway, the pilot aborted the takeoff due to engine problems. He returned and attempted to correct the rough engine condition by completing another runup procedure. That runup included the carburetor heat system.
Second Takeoff and Engine Failure
Immediately after the normal runup procedure was completed, the pilot attempted another takeoff. As the airplane climbed through 200 feet above ground level, the engine developed a rough condition again. The pilot attempted to restore full power, which included the application of carburetor heat. He then made an emergency landing in a nearby river.
Post-Accident Examination
Examination of the aircraft and the engine assembly failed to disclose a mechanical problem or a subsystem malfunction. The pilot reported no previous engine problems. Weather conditions at the nearest reporting site were favorable for the formation of carburetor ice. The pilot had received a weather briefing before the flight.