Cessna 172H N8056L accident near Los Angeles, California

Probable cause

The pilot’s inadequate preflight inspection during which he failed to remove all water contamination in the fuel system, which resulted in a total loss of engine power on takeoff. Contributing to the accident was the condition of the fuel caps, which allowed the water to enter the fuel system.

NTSB analysis

The pilot reported that the airplane was stored outdoors for several weeks before the accident flight. The pilot observed water in the left fuel tank during the preflight inspection and he extracted about 1 ounce of water before he derived that there wasn’t much water in the fuel system. He started the engine, taxied onto the runway, and took off to the southeast. During the initial climb, the engine lost power about 200 ft above ground level. The pilot declared an emergency to the tower controller and initiated a descending right turn. The airplane impacted the ground and came to rest on an active railroad crossing. The pilot was extracted from the accident airplane moments before it was struck by a passenger train.

During the weeks prior to the accident, it had rained for 18 days. Postaccident examination of the airframe revealed that the right and left wing tank fuel cap gaskets were deteriorated and were not intact. Excessive quantities of corrosion and rust were observed throughout the gascolator and the carburetor.

Postaccident examination of the airplane’s engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have prevented normal operation. It is likely that the deteriorated fuel caps allowed water to enter the fuel tanks when rain was present and that water remained in the airplane's fuel system after the pilot’s preflight inspection and engine runup. A total loss of power during the initial climbout likely occurred when the contaminated fuel reached the engine.

Text from the NTSB. Open the NTSB docket for WPR22LA076 for the full record.