Incident Overview
A pilot conducting a banner towing operation experienced a loss of engine power shortly after takeoff. The pilot had just completed refueling and departed to continue the banner tow mission. During the climbout phase, the engine ceased producing power, and the pilot's attempts to restore normal engine operation were unsuccessful.
Emergency Descent and Forced Landing
Faced with a complete loss of engine power, the pilot initiated an emergency descent toward a soybean field to perform a forced landing. The airplane touched down in the field, but during the landing rollout, the aircraft nosed over.
Post-Accident Examination
Following the accident, an examination of the airplane was conducted. The engine was tested and found to operate normally across its entire power range, from idle to maximum RPM. However, inspection of the carburetor revealed that the float valve could stick in the closed position, which would cut off the fuel supply to the engine.
Fuel and Refueling Policy
The operator's refueling policy involved using a blend of 100 low-lead aviation fuel and automotive gasoline for airplanes that held a supplemental type certificate (STC) authorizing the use of automotive fuel. The accident airplane, registered as N9128D, was equipped with an STC permitting the use of automotive fuel.