Piper PA-28-140 N32435 accident near East Troy, Wisconsin

Probable cause

The pilot/mechanic’s improper torquing of the fuel hose fitting while replacing the fuel pump, which allowed air to enter the fuel system and resulted in a loss of engine power during initial climb. Contributing to the accident was the pilot/mechanic’s failure to detect and rectify the loose fuel hose during a subsequent annual inspection.

NTSB analysis

The pilot had flown the airplane for about an hour to practice maneuvers and then returned to the airport where he made an uneventful landing. He then taxied back to the runway for another takeoff. During the initial climb, the pilot noticed that the fuel pressure reading was dropping, but there was insufficient runway remaining to abort the takeoff. As the climb continued, the fuel pressure varied between 0 and 4 pounds per square inch (psi) and the engine surged. The pilot leveled the airplane and verified that the auxiliary electric fuel pump was on. Unable to maintain altitude, he performed a forced landing in a cornfield. The airplane incurred substantial damage to both wings, the fuselage, and the engine mount.

Postaccident examination revealed that the fuel hose fitting to the suction side of the mechanical fuel pump was loose and falling off. After tightening the fitting, an engine test run was performed. (No test run was performed with the fuel hose loose.) A full-throttle engine run could not be performed due to impact-related damage to the propeller blades. However, no anomalies were detected in the engine speed range that could be achieved.

The pilot, who was also a mechanic with an inspection authorization, had replaced a leaking mechanical fuel pump 16 days before the accident and had performed an annual inspection of the airplane 9 days before the accident.

It is likely that the pilot/mechanic improperly torqued the fuel hose fitting during installation of the replacement fuel pump, which allowed air to enter the fuel system and resulted in a loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN24LA337 for the full record.