Piper PA-22 N669A accident near Enderlin, North Dakota

Probable cause

The pilot’s failure to properly inspect and sump the fuel system before the flight and the maintenance personnel’s inadequate maintenance of the fuel system which resulted in fuel starvation and the subsequent loss of engine power due to the contamination of the right tank fuel gascolator and fuel lines.

NTSB analysis

According to the pilot, shortly after takeoff about 200 ft above ground level (agl), the engine started to run rough. The pilot turned on the carburetor heat and there was a slight improvement in engine performance, but then the engine lost all power. The pilot made an off-airport landing. Upon touchdown, the nosewheel dug into the ground and the airplane flipped inverted. The airplane sustained substantial damage to the left wing, rudder, and engine mount.

A postaccident examination of the engine revealed no anomalies that would have precluded normal operation. Examination of the fuel system revealed that the gascolator and bowl for the right tank rear fuel line were full of sediment and debris. Additionally, the fuel lines going to and coming out of the gascolator contained the same deposits that were found in the fuel bowl. The airplane owner said that he assumed the strainer that was under the right front seat was part of the brake system. He was unaware that it was a quick drain gascolator for the right fuel tank and he never sumped that drain. It could not be determined when maintenance personnel last inspected the gascolator.

The pilot reported that she flew a total of about 1 hour before the loss of power occurred and had been operating solely on the right fuel tank. Each fuel tank held 18 gallons of fuel and operated independently of each other depending on fuel selector valve selection. Fuel consumption was between 4.5 to 11 gallons per hour, so it is possible there was only about 7 gallons of fuel remaining in the right fuel tank. Although the owner’s handbook cautioned that operating solely on the right fuel tank should only be done if operating in straight and level flight and when the right fuel tank is at 1/3 capacity or lower, the right fuel tank likely contained more than 1/3 its capacity.

The sediment and debris clogging the gascolator filter bowl and fuel lines for the right tank’s rear fuel line likely prevented fuel from flowing freely to the engine, which resulted in a loss of engine power due to fuel starvation.

Text from the NTSB. Open the NTSB docket for CEN24LA184 for the full record.