Cessna 177 N3416T accident near Thermal, California

Probable cause

A fire in the engine compartment due to the pilot overpriming the hot engine.

NTSB analysis

The pilot reported that, after flying several legs of a cross-country flight, he landed the airplane to purchase fuel. After shutting down the engine and then topping off the wing tanks with fuel, the pilot attempted to start the engine; however, it would not turn over. He pumped the primer and then continued to crank the starter. He then observed a fire in the muffler area and continued to crank the starter in an attempt to suck the fire through the muffler. The engine never started, and the propeller did not turn. A postaccident examination revealed no catastrophic failures with the engine. However, white discoloration and excessive heat damage to the lower right firewall were found, indicating that the fire likely originated in this area. The fire was likely due to the pilot overpriming the induction system, which would have filled the carburetor air box with fuel and resulted in a fire starting in the lower firewall area.

Text from the NTSB. Open the NTSB docket for WPR15LA267 for the full record.