Champion AERONCA 7HC N8919R accident near Louisville, Kentucky

Probable cause

A loss of engine power due to fuel system contamination resulting in damage to the carburetor float.

NTSB analysis

During the initial takeoff, with the airplane about 800 feet above the ground, the engine experienced a loss of power. The certificated flight instructor (CFI) took authority of the controls and elected to land in an open field within a residential area. During the forced landing, the airplane impacted a street stop sign and separated both main landing gears, resulting in substantial damage. A postaccident engine examination revealed that the carburetor's brass float had a perforation located at its lowest point in the bowl. The perforation exhibited surface features such as pits and roughening consistent with a chemical etching reaction, similar to corrosion. The affected areas on the float were consistent with a small quantity of corrosive liquid having been retained in the bottom of the carburetor bowl for a sufficient time. The perforation in the float most likely adversely affected the carburetor’s performance and led to the loss of engine power. The carburetor had been restored and it is likely that the fuel system was not properly flushed after the restoration process to remove any possible foreign object/liquid contamination.

Text from the NTSB. Open the NTSB docket for ERA10LA449 for the full record.