Accident
During the initial climb after takeoff, the aircraft ascended normally to an estimated height of 100 to 150 feet when the engine suddenly lost all power without warning. The pilot switched fuel tanks and attempted to restart the engine but was unsuccessful. The pilot then executed a forced landing in a river short of an open field. The aircraft subsequently sank.
Investigation
Upon recovery from the water, the mixture control was found approximately 1-1/8 inches from the full rich position. No preimpact part failure or malfunction was discovered. The engine was dried out and serviced with new oil. A subsequent engine run was conducted, but power was limited to about 1500 RPM due to vibration from a bent propeller.
Findings
The pilot reported that during takeoff he had leaned the mixture because of the ambient temperature. The temperature recorded at Knoxville at 1452 hours was 88 degrees Fahrenheit.