ERA24LA257 · Piper PA28 235

The purpose of the flight was for the pilot receiving instruction to practice instrument approaches. The preflight, taxi, and runup were all normal with no anomalies found. During the takeoff, shortly after rotation, the engine began to lose power. The pilot performed a forced landing in the grass just past the runway. During the forced landing, the airplane impacted a fence, resulting in substantial damage to the fuselage and the wings. A postaccident test run of the engine revealed that the engine and the airframe fuel system was capable of normal operation at multiple power settings, including full power. However, after the engine test run, the carburetor was disassembled and was found to be severely corroded and contaminated with corrosion debris. The corrosion debris was found in the carburetor bowl, mixture sleeve, and main metering jet. Disassembly of the carburetor also revealed that the check valve for the carburetor accelerator pump was missing; however, since the loss of engine power was well after the pilot moved the throttle to full, it is unlikely that this condition would have resulted in the loss of engine power. Other components within the carburetor and the fuel pump showed signs of corrosion. The corrosion evidence was consistent with the fuel system having been previously contaminated with water or another corrosive contaminant, such that multiple components within the fuel system corroded. It is likely that, during the accident flight, loose corrosion debris entered the carburetor main jet, which restricted fuel flow and resulted in a partial loss of engine power. While the airplane’s service manual instructed draining the carburetor bowl during a 100-hour inspection, it is unknown whether the debris would have been detected as the investigators performed the same action prior to the engine test run, and no contamination was found from the sample.

Verbatim NTSB analysis and probable cause from the NTSB dataset