Preflight and Takeoff
Before takeoff, the pilot conducted an engine run-up. After removing carburetor heat, the pilot noted that the carburetor heat handle was 'loose.'
Loss of Power and Stall
During the initial climb, the engine experienced a partial loss of power, and black smoke was observed coming from the exhaust. While maneuvering to return to the departure point, the airplane stalled and subsequently crashed into water.
Post-Accident Examination
Examination of the engine revealed no mechanical failure or malfunction. The carburetor heat control cable was found to be separated from the carburetor heat control arm assembly.
Disassembly of the carburetor showed evidence of previous fuel leakage from the carburetor bowl vent, which would introduce extra fuel into the air induction system. Additionally, the adjustment tab of the metal float and the head of the float needle valve were determined to be worn.
The carburetor had been installed on the engine on June 3, 1996, and had accumulated 1,246 hours since installation at the time of the accident.
Pilot Information
According to the pilot, the worn condition of the carburetor had been known for the past seven years.
Accepted Procedures
The accepted procedure after removing carburetor heat is to note that the engine rpm increases either to the setting before the heat was applied, or to a greater rpm if carburetor ice was present.