Accident Details
Probable Cause and Findings
An engine fire that resulted from a fuel leak into the carburetor air box due to the electric fuel pump over-pressurizing the carburetor needle/seat assembly. Contributing to the severity of the fire was the flight instructor’s failure to turn off the electric fuel pump before exiting the airplane.
Aircraft Information
Registered Owner (Historical)
Analysis
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.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN21LA211