Taylorcraft BL-65 N29886 accident near Wasilla, Alaska

Probable cause

The pilot's failure to remove all water from the fuel tank, which resulted in fuel contamination and a subsequent partial loss of engine power.

NTSB analysis

Before the day of the accident, the nose fuel tank cap had been dislodged during a snowstorm, which allowed snow to enter the fuel tank. During preflight inspection, the pilot drained fuel from the fuel tank and discovered water in the fuel. He continued to drain the fuel until no water was visible. The pilot took off and during cruise flight the engine began to run rough so he performed a precautionary landing on a road. He drained fuel from the fuel tank again and once again found water in the fuel. He continued to drain fuel until there was no more sign of water. The pilot’s mechanic responded to the site to assist the pilot. The mechanic drained all of the fuel from the carburetor to ensure there was no water.

They started the engine, and it ran normally again so the pilot decided to take off. Shortly after departure from the road, the engine began to run rough again. The pilot landed back on the road. During the landing roll, the right wing impacted a street sign, and the airplane came to rest in a ditch. Postaccident examination of the engine revealed water in fuel samples drained from the gascolator and carburetor. Other than the presence of water, no anomalies were noted with the engine that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ANC23LA013 for the full record.