CEN21LA211

The flight instructor and student pilot were landing the airplane during an instructional flight when they noticed a loss of engine power during landing rollout. After exiting the runway, the flight instructor was able to restart the engine on the second attempt. The pilots subsequently noticed that an engine fire had developed, shut down the engine, and exited the airplane. The fire substantially damaged the engine mount and firewall before it could be extinguished. The flight crew turned the electric fuel pump on before landing in accordance with normal operating procedure, and the flight instructor did not turn it off before exiting the airplane [as called for by the emergency procedure for an engine fire]. Postaccident examination revealed that with the electric fuel pump turned on, fuel leaked from the carburetor into the air box. The carburetor was disassembled with no anomalies observed. The fuel leaking from the carburetor was likely due to the electric fuel pump over-pressurizing the carburetor needle/seat assembly, which allowed the carburetor bowl to overfill. The leaking fuel likely came in contact with hot exhaust pipes and ignited, which resulted in the engine fire.

On May 6, 2021, about 1707 central daylight time, a Piper PA-28 airplane, N54MC, was substantially damaged when it was involved in an accident at David Wayne Hooks Memorial Airport (DWH), Spring, Texas. The flight instructor and student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. During landing rollout, the flight instructor noticed a loss of engine power. After exiting the runway, the flight instructor was able to restart the engine on the second attempt. The flight instructor and student pilot subsequently noticed a fire that produced smoke and extreme heat in the cabin compartment. The flight crew shut the engine off and egressed the airplane. The electric fuel pump was turned on before landing, which is normal operating procedure, and remained on after the fire was observed and when the flight crew egressed the airplane. Per the emergency procedures checklist, it should have been turned off. The fire substantially damaged the engine mount and firewall before airport fire department personnel were able to extinguish it. Postaccident examination revealed that fuel leaked from the carburetor into the air box when the electric fuel pump was turned on. Carburetor disassembly by a carburetor repair station revealed no anomalies with the needle/seat assembly, mixture control shaft, nozzle, idle tube, accelerator pump, or throttle lever. Repair station personnel noted that if the electric fuel pump pressure is greater than 6 pounds per square inch, the carburetor needle/seat assembly will allow fuel to enter the carburetor bowl and overflow into the air box.